Vol. 67; No. 6
423
Application of Immunological Principles in Dermatology* WiLLIAM A. ANDERSON, M.D., Clinical Associate Professor of Medicine, New1 York Hospital-Cornell Medical Cen.ter, New York Citv
THE fast moving developments in immunology are having a profound effect on both the diagnostic and therapeutic aspects of dermatology and other clinical disciplines. They have also helped clarify the pathogenesis of some previously poorly understood diseases. Immunological responses may be through cellular or humoral pathways. The small lymphocytes of the immune system are derived from bone marrow precursuis. Those involved in cellular immunity, the T-lymphocytes, are thymus dependent and are characterized by the capacity to bind sheep red blood cells, thus forming rosettes. The lymphocyte essential for humoral immune response is the B-lymphocyte. This term is derived from their production in the bursa of Fabricius in the chicken. Their source in humans is unknown, but bone marrow and Peyer patches of the lower gut have been suggested. 1 Delayed hypersensitivity, a synonym for cell mediated sensitivity, begins with processing of antigen by either tissue or wandering macrophages.2 After ingesting antigen, macrophage RNA is specifically programmed to stimulate the small lymphocyte, the next link in the immune response.3 It seems that only certain clones of B or T cells can respond to a given antigen. If a T-cell is stimulated, it enlarges and proceeds to divide yielding progeny specifically programmed against the stimulating antigen. These cells release a soluble migration inhibition factor, causing wandering macrophages to collect at the reaction site. They also produce transfer factor, which specifically sensitizes other T-lymphocytes, dramatically increasing the *Read at the 80th Annual Convention of the National Medical Association, Hotel Fontainbleau, Miami Beach, Florida, August 10-15, 1975.
reaction. Other soluble factors released at the site of interaction have cytotoxic activity, increase vascular permeability and promote chemotaxis of mononuclear cells. Delayed hypersensitivity is demonstrable in four to five days after exposure to antigen. In a sensitized individual, the characteristic delayed type skin reaction appears in five to six hours and reaches a maximum in 18 to 48 hours. The delayed or cell mediated response is active in such infections as candidiasis, tuberculosis, late syphilis and leprosy. It is also seen in immune response to malignancy and contact dermatitis. A distinctly different small lymphocyte, the B-lymphocyte, is active in humoral or immediate sensitivity.4 After a four to 24hour latent period, the cells are transformed into plasmacytes by antigen-altered macrophage RNA and proceed to divide and produce specific antibody. This antibody is active in removing or neutralizing bacterial toxins, fungi or immune complexes. The active agents in humoral sensitivity are the immunoglobulins, products of plasma cells. Here again, only certain cell clones seem able to produce a given immunoglobulin. These immunoglobulins are divisible by antigenic specificity and electrophoresis into five classes: IgG, IgM, IgA, IgD and IgE. IgG makes up about 85% of total humoral immunoglobulin, has a molecular weight of 140,000 - 150,000 and is identical to a structural unit of Bence-Jones protein. It is active in responses to both intrinsic and extrinsic allergens and binds complement. IgM constitutes 5-10% of total immunoglobulins and has a high M.W., about 900,000. It is present in large amounts at the early stages of antigenic challenge. It binds complement and exerts protective activity against microbes and other large immuno-
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gens. IgM is 100 times as potent as IgG in killing certain gram negative bacilli. A single IgM molecule can activate complement and lyse a gram negative bacillus.3 IgA has a M.W. of 170,000 - 500,000 and comprises about 10% of human immunoglobulin. It is found in relatively large quantities in saliva, colostrum and tears, and in smaller amounts in intestinal secretions and prostatic fluid. These antibodies seem to play a protective role at mucous surfaces and resist digestion by proteolytic enzymes. Antibody activity against certain bacilli and ragweed has been demonstrated for IgA. IgA deficiency is associated with increased episodes of respiratory infections and an increased incidence of autoimmune disease. Thus it both protects against local infection and prevents development of autoimmune processes by interfering with antigen absorption from mucous surfaces. It does not bind complement. IgD is present in small amounts in normal human plasma and activity has been demonstrated against penicillin, milk protein and nuclear and thyroid antigens. Its M.W. is about 200,000. IgE, usually present in trace amounts in serum, is responsible for anaphylactic sensitivity and is the antibody of reagin activity. It attaches firmly to most cells and does not bind complement. IgE levels are elevated in patients with atopic eczema, pollen allergies and helminth infections. In atopic reactions, IgE adheres to mast cells and leucocytes. Then if the sensitized cell contacts a specific antigen, harmful mediators, including histamine, serotonin and slow reacting substances are released. This mechanism is active in anaphylaxis and certain forms of urticaria. Reactions involving complement are of increasing importance to the dermatologist. The direct complement pathway is activated by an antigen-antibody reaction involving IgG and IgM molecules. By this pathway Cl, the first component of complement is activated. This Cl activates C4 and C2, cleaving them to particles which have virus neutralization and other activity and which participate in activating C3. The reaction products of Cl, 4, 2 and 3 activate CS and
NOVEMBER, 1975
C6 and so on to C9, producing progressive activation of complement components and substances with anaphylotoxic, kinin, chemotactic, bacteriolytic and other biological activity. It has been shown that bacterial lipopolysaccaride (LPS) and certain antigen-antibody reactions can lead to utilization of C3-C9 without significant participation of Cl, C4 or C2.3 Factors of the properdin enzyme system are successively activated by LPS or antigenantibody reaction, and in turn activate components C3-C9. The immune cytotoxic mechanism involves binding antibody to tissue cells at sites of specific antigen. Such antigen may be intrinsic as in pemphigus or an extrinsic antigen intimately associated with tissue as in certain drug reactions. The antibody involved is almost always IgG. Antibody coated cells are then susceptible to destruction by complement components or by phagocytosis. Precipitated antigen-antibody complexes are active in the Arthus phenomenon, activating complement and leading to inflammation and vasculitis. Similar immune complex mechanisms are involved in systemic lupus erythematosus and in serum sickness. Increased understanding of immunologic phenomena helps explain many previously baffling dermatologic conditions. These include immunodeficiency states, both primary and secondary. Immunodeficiency can result from any one or a combination of causes.5 These can be primary T-cell or B-cell deficiencies or combined primary deficiency states. Acquired deficiency states may be secondary to infection, sarcoidosis, lymphomas or immunosuppressive therapy. Burton's X-linked agammaglobulinemia, a primary B-cell deficiency, is characterized by increased immunoglobulin production and is usually manifest in the second six months of life (Table 1). Lymphocyte counts are normal, as are the Schick test, DNCB sensitization ane other measures of cellular immunity. Lymph node biopsy reveals no plasma cells after antigen stimulation. The delay in onset of this disorder results from passive protection by maternal antibody. These infants are infected by pyogenic organisms such as
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Immunological Principles in Dermatology
pneumococci, meninogococci, streptococci and pseudomonas. Skin abscesses, cellulitis and furunculosis are common. These infections can be readily controlled by antibiotic or gammaglobulin therapy. The patients handle exanthems and other viral infections in a normal fashion. A dermatomyositis-like disease and other collagen diseases have been reported in these children. Table 1. SOME PRIMARY IMMUNODEFICIENCIES
Cellular Defect Bruton's Sex-Linked B Agammaglobulinemia Selective IgA Deficiency
B
Thymic Hypoplasia (DiGeorge)
T
Combined Immunodeficiency
B,T, S
Wiskott-Aldrich Syndrome
B,T
Clinical
Genetics
4lmmunoglobulins
X-Linked Cellulitis, Furunculosis Recessive No TFungal or Viral Infections JIgA Unknown tlncidence of Collagen Dis. TResp. Infection Normal Circulating None Antibody TViral & Fungal Infections Mucocut. Candidiasis Vacc. Gangrenosum, Gen. Vacc. Fatal BCG Infections Hypocalcemia lIg a) Autosomal Lymphopenia Recessive Viral, Fungal Infections b) X-Linked Vaccinia, BCG c) Sporadic Complications Thrombocytopenia X-Linked Recessive Atopic Dennatitis
JIgM, TIgA Ataxia Telang.
B,T
G.I. Bleeding TViral, Fungal & Bacterial Infect. Ataxia Telangiectases 4IgA & IgE Lymphoma, Leukemia Respiratory Infection, Lymphopenia
Recessive
Primary immunoglobulin-A deficiency may be asymptomatic, but some individuals experience an increase in respiratory infections. There is also an increase in autoimmune disease, including systemic lupus erythematosus. It is suggested that the absence of IgA permits entrance of dietary protein and altered epithelial tissues through the gut and these antigens stimulate production of auto-antibodies. The DiGeorge syndrome or thymic hypoplasia results from failure in embryogenesis of the entodermal derivatives of the third and
425
fourth pharyngeal pouches. There is resultant aplasia of the thymus and parathyroid glands, manifest by absence of cell mediated immunity and neonatal tetany. Physical features include hypertelorism, low set ears and shortened lip philtrum. Due to T-cell deficiency, these infants are usually susceptible to overwhelming viral, fungal and bacterial infections. Serum immunoglobulin levels are normal, but delayed sensitivity is weak-toabsent. Thus DNCB sensitization is weak or unsuccessful and there is no reaction to candida antigen. Thymus transplantation has been found successful and beneficial in these patients. In combined immune deficiency, there is defective cell mediated and humoral immunity. The immunoglobulins are low and lymphopenia may be profound. The bone marrow is deficient in plasma cells, lymphocytes and lymphoblasts. No germinal centers develop in the lymph nodes. These patients do not respond to DNCB or candida antigen. A rapid succession of infections begins early in life and demise is to be expected before age two. Gram negative infections, candidiasis and benign viral infections are poorly handled. Vaccinia can become generalized and varicella may be fatal. This disorder may be an autosomal recessive, X-linked or sporadic in inheritance pattern. The Wiskott-Aldrich syndrome is characterized by eczema, thrombocytopenia and recurrent infection. Inheritance is X-linked and death in the first 10 years of life is to be expected due to infection, hemorrhage or malignancy of the lymphoid tissue. There are serious bacterial, fungal and viral infections and IgM levels are low. IgA and IgG are normal. There is a specific inability to respond to polysaccharide antigen. Children affected by hereditary ataxia telangiectasia develop ataxia and choreoathetoid movements in infancy. The telangiectases appear at about age five or six and involve the conjuctiva, face, ears and antecubital and popliteal spaces. Progressive recurrent respiratory infection may appear early or late and lead to death in the second or third decade. Malignancy of lymphoid tissue is common. These patients lack IgA, and an
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IgE deficiency has been noted. There is also defective cellular immunity. Atopic-like dermatitis may be associated with several immunodeficiency states, suggesting a role for immunologic impairment in its pathogenesis. These patients are hyperresponsive to antigenic stimuli, resulting in overproduction of immunoglobulin, especially IgE. Cell mediated responses are often depressed. It has been suggested that a chronic T-cell deficiency exists in atopics leading to overproduction of circulating antibody. However, alternate explanations have been proposed. A local functional decrease in cell mediated immunity, due to development of humoral antibody, has been suggested to explain the prevalence of chronic dermatophytosis in the atopic patient.6 Many atopic infants have IgA deficiency, which can result in excessive allergen entry and overproduction of IgE. Hereditary angioedema is characterized by attacks of non-pruritic angioedema induced by stress or tissue injury. There is a deficiency of Cl inhibitor leading to activation of C2 and C4 and increased vascular permeability. This is a dominantly inherited defect. Defective phagocytosis, due to abnormal C5 function, is seen in infants with a Leiner disease picture. It is characterized by generalized seborrheic dermatitis, diarrhea and increased susceptibility to gram negative infections. Chronic granulomatous disease of childhood is characterized by lymphadenopathy, hepatosplenomegaly and granuloma formation in the skin, lymphnodes and bone. The neutrophils are unable to lyse microorganisms after phagocytosis, leading to lowered resistance to catalase positive organisms such as candida, E. coli and staphylococci. These ingested micro-organisms are actually protected from antibodies. Catalase negative organisms such as streptococci and pneumococci are handled competently. Bacterial hydrogen peroxide accumulates after phagocytosis, leading to death of these latter organisms. This disorder is usually inherited as an X-linked recessive. Onset occurs in early infancy leading to a chronic course and death from infection after an average life
NOVEMBER, 1975
span of seven years. Secondary immunodeficiency may develop in lymphomas, after certain viral and parasitic infections, or may be associated with malnutrition. latrogenic immunodeficiency occurs after treatment with x-rays, corticosteroids, methotrexate, cyclophosphamide and other immunosuppressants. Overwhelming viral, bacterial or fungal infections may develop and malignant neoplasms have been reported, probably due to decreased immune surveillance. Immunologic reactions are widely used in diagnosis of diseases important to the dermatologist. The Wassermann, Kahn and VDRL tests for syphilis depend on complement fixation, and does the more specific Reiter protein complement fixation test. The TPI test demonstrates specific antitreponemal activity of serum. In the FTA-ABS test, labelled anti-human gammaglobulin is demonstrated to be bound by treponemal antigen. Several skin tests for cell mediated immunity have application in clinical dermatology. These include tests for candida, trichophyton, lepromin and tuberculin. Complement fixation reactions are useful in diagnosis and prognosis of coccidioidomycosis and histoplasmosis. In recent years immunofluorescent procedures have contributed greatly to advances in diagnosis of collagen-vascular diseases and bullous dermatoses.7 In the direct immunofluorescent test, a section of patient's tissue is treated with anti-human globulin produced in goat or other species. This globulin has been labelled with a fluorescent marker, such as fluorescein or anthracene. It may be specific for various complement components or for an individual immunoglobulin. After this reaction, the slide is examined under the fluorescent microscope to identify its immunologic components. The indirect test for immunofluorescence seeks to demonstrate circulating antibody in the patient's serum. First, a substrate tissue such as monkey or guinea pig esophagus or rat liver is treated with the test serum and then fluorescent labelled antihuman antibody is added in sandwich fashion. Examination with a fluorescent microscope will demon-
strate antinuclear, intercellular or basement membrane antibody attachment. In discoid lupus erythematosus (D.L.E.), the direct test shows basement membrane granular fluorescence (Table 2). Both the lesion and normal skin are positive in systemic lupus erythematosus (S. L. E.). Thus in suspected systemic lupus erythematosus without skin lesions, a biopsy from normal skin can be helpful in diagnosis. Also the indirect test shows antinuclear fluorescence in S.L.E. but not in D.L.E. A peripheral nuclear pattern is characteristic, whereas speckled or nucleolar patterns are seen with other collagen vascular diseases. A shrunken peripheral pattern indicates severe systemic lupus erythematosus.8 Table 2. IMMUNOFLUORESCENT TESTS Dermatitis
Herpetiformis DIRECT
B.M.-Fibrils IgA
INDIRECT Neg.
DIRECT
L. E. B. M.-Granular
DiscoidLesion only S.L.E.Lesion & Normal INDIRECT A.N.A. Fluorescence PeripheralL. E. Shrunken PeripheralSevere L. E.
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Pemphigus Bullous Vulgaris Pemphigoid Intercellular Epidermis Intercellular
B. M. B. M.
SCLERODERMA Neg.
A. N. A. Speckled & Nucleolar
No direct fluorescence is seen in scleroderma but positive speckled or nucleolar fluorescence is seen in serum antinuclear antibody tests. Both direct and indirect findings are negative in morphea, but up to 25% of linear scleroderma cases have positive antinuclear antibody tests. The ANA test is rarely positive in dermatomyositis. Since non-specific basement membrane fluorescence can be seen in areas of telangiectasia from various causes, specimens from telangiectatic skin can be misleading. Almost all pemphigus cases of the various types show direct epidermal intercellular fluorescence of the biopsy specimen in normal skin or mucous membrane adjacent to
a lesion and indirect immunofluorescence can also be demonstrated. Intercellular immunofluorescence is pathognomonic for pemphigus, and is useful in differential diagnosis from pyoderma vegetans, subcorneal pustular dermatosis, Hailey- Hailey disease and Darier's disease. Fluorescence of dermal papillae and sometimes basement membrane fluorescence is seen in direct studies of dermatitis herpetiformis lesions. The granular papillary fluorescence is diagnostic for dermatitis herpetiformis, and has been shown to be due to IgA deposits. The biopsy site is of utmost importance, and examination of an early urticarial lesion, erythematous skin near the lesion or buttock skin is desirable. No indirect immunoflurescence is seen in dermatitis herpetiformis. In bullous pemphigoid, over 80% of cases have demonstrable circulating antibody to basement membrane antigen. Cicatricial pemphigoid cases rarely demonstrate circulating epithelial antibody. On direct testing, linear basement membrane fluorescence can be demonstrated in normal skin adjacent to the lesion in bullous pemphigoid and most cicatricial pemphigoid cases. The section should be taken adjacent to a bulla and from a fresh lesion. In older lesions, the basement membrane may have been destroyed, resulting in a negative finding. The direct immunofluorescence of bullous and cicatricial pemphigoid has been shown due to deposits of IgG and complement. Direct basement membrane fluorescence has been reported in herpes gestationis, and detailed studies show deposits of IgG, C3, C4 and properdin.9 Scans using radio labelled antibody have been helpful in pinpointing lymphoid malignancy. 10 Immunology principles are widely applied in treatment of several dermatologic disorders, and progress is being reported in experimental treatment for other skin conditions. Immunologic suppression is used in treating pemphigus, lupus erythematosus and other collagen vascular disorders. Some agents successfully used are corticosteroids, (concluded on page 454.)
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JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION
cell anemia or other pathologic hemoglobin abnormalities. Clinically significant maternal sickle cell disease will also be detected through this route (Fig. 3). 3. Screening for iron deficiency anemia, G-6-PD deficiency, and lead poisoning among infants and children. 4. Decreased emphasis on screening solely for detecting trait conditions since no significant direct benefits can be offered to the participant and since there is a possibility that the screening results will place the participant at risk to adverse economic and psychologic consequences. 5. An increased emphasis upon educating and assisting the medical profession to screen during the perinatal period, infants and young children, and in preoperative preparation.
3. 4. 5.
6.
7.
8.
LITERATURE CITED
9.
1. WILKINSON, D. Y. For Whose Benefit'? Politics and Sickle Cell. The Black Scholar, 5:26-3 1, 1974. 2. WHITTEN, C. F. Sickle Cell Programming-An
10.
NOVEMBER, 1975
Imperiled Promise. N. Eng. J. Med., 288:318-19, 1973. Screening in Medical Care: Reviewing the Evidence. Nuffield Provincial Hospitals Trust. Oxford Univ. Press, London, 1968. BEMIS, E. L. Sickle Cell Safari. Blood, 42:14749, 1973. MOTULSKY, A. G. Frequency of Sickling Disorders in U.S. Blacks. N. Eng. J. Med., 288:3133, 1973. PETRAKIS, N. L. and S. L. WEISENFELD, F. J. SAMS, J. F. COLLEN, J. L. CUTLER and A. B. SIEGELAUB. Prevalence of Sickle Cell Trait and Glucose-6- Phosphate Dehydrogenase Deficiency. N. Eng. J. Med., 282:767-70, 1970. PIOMELLI, S. and C. A. REINDORF, M. T. ARZANIAN and L. M. CORASH. Clinical and Biochemical Interactions of Glucose-6- Phosphate Dehydrogenase Deficiency and Sickle Cell Anemia. N. Eng. J. Med., 287:213-217, 1972. GIMA, A. S. and J. C. LEE. Prevalence of Sickle Cell Anemia: An Improved Outlook. JNMA, 67:259-63, 1975. HERRELL, W. E. Screening For Sickle-Cell Trait. Clin. Med., 79:10-12, 1972. HOWELLS, T. H. and R. G. HUNTSMAN, J. E. BOYS and A. MAHMOOD. Anaesthesia and Sickle-Cell Hemoglobin. Brit. J. Anaesth., 44:975-87, 1972.
(Anderson, ftron page 42 7) 3. PARK, B. H. and R. A. GOOD. Principles of Modern Immunobiology. Lea and Febiger, Phila., 1974, p. 51. 4. FREEDMAN, S. O., Clinical Immunology, lowering of corticosteroid dosage in these Harper and Row, N.Y., 1971, p. 22. disorders. I I 5. WALZER, R. A. Cutaneous Manifestations of Immunodeficiency. Dermatology Digest, 37:14, Transfer factor is reported helpful in pa1975. tients with Wiscott-Aldrich syndrome, mu6. JONES, H. E. Immunologic Susceptibility to cocutaneous candidiasis, aphthous stomatitis, Chronic Dermatophytosis. Arch. Derm., 110:213verruca vulgaris and malignant melanoma. 220, 1974. Immuran and prednisone produced continu7. Cooperative Study. Uses for Immunofluorescent Test of Skin and Sera. Arch. Derm., 111:371ing remission in five of seven patients with 381, 1975. severe bullous pemphigoid.12 An anti-T-cell 8. BURNHAM, T. K. Antinuclear Antibodies. antiserum has been proposed for treatment of Arch. Derm., 111:203-207, 1975. mycosis fungoides.13 Enhancement of cell 9. GILLIAM, J. N. Am. Acad. Derm., Chicago, mediated immunity by using BCG, levamiDec., 1974. 10. Med. World News, June 1975. sole (an antihelminthic drug) or DNCB have 11. MICHEL, B. Symposium on Immunofluorescent been found effective in treatment of melaTests. A.M.A. Convention, Atlantic City, June noma, herpes simplex and warts.14-16 17, 1975. 12. SPITZLER, L. E. Transfer Factor. Cutis, 15:420-423, 1975. LITERATURE CITED 13. EDELSON, R. L. Dermatol. News, 8:1, 1975. 1. GOOD, R. A. and D. W. FISHER. Immunobi14. Schoch Letter, 22: 1, June 1975. 15. Contemp. Rev., Winter 1975, p. 14-15. ology, Sinauer Associates, Stamford, Conn., 16. HOLMES, E. C. et al. Immunotherapy of Ma1973, p. 10. 2. FREEDMAN, S. 0. Clinical Immunology, lignancy in Humans. J.A.M.A., 232:1052-1055, Harper and Row, N.Y., 1971, p. 18-20, p. 122. 1975.
azothiopnine, cyclophosphamide and methotrexate. Use of cyclophosphamide and azothioprine is reported to allow significant
423
Application of Immunological Principles in Dermatology* WiLLIAM A. ANDERSON, M.D., Clinical Associate Professor of Medicine, New1 York Hospital-Cornell Medical Cen.ter, New York Citv
THE fast moving developments in immunology are having a profound effect on both the diagnostic and therapeutic aspects of dermatology and other clinical disciplines. They have also helped clarify the pathogenesis of some previously poorly understood diseases. Immunological responses may be through cellular or humoral pathways. The small lymphocytes of the immune system are derived from bone marrow precursuis. Those involved in cellular immunity, the T-lymphocytes, are thymus dependent and are characterized by the capacity to bind sheep red blood cells, thus forming rosettes. The lymphocyte essential for humoral immune response is the B-lymphocyte. This term is derived from their production in the bursa of Fabricius in the chicken. Their source in humans is unknown, but bone marrow and Peyer patches of the lower gut have been suggested. 1 Delayed hypersensitivity, a synonym for cell mediated sensitivity, begins with processing of antigen by either tissue or wandering macrophages.2 After ingesting antigen, macrophage RNA is specifically programmed to stimulate the small lymphocyte, the next link in the immune response.3 It seems that only certain clones of B or T cells can respond to a given antigen. If a T-cell is stimulated, it enlarges and proceeds to divide yielding progeny specifically programmed against the stimulating antigen. These cells release a soluble migration inhibition factor, causing wandering macrophages to collect at the reaction site. They also produce transfer factor, which specifically sensitizes other T-lymphocytes, dramatically increasing the *Read at the 80th Annual Convention of the National Medical Association, Hotel Fontainbleau, Miami Beach, Florida, August 10-15, 1975.
reaction. Other soluble factors released at the site of interaction have cytotoxic activity, increase vascular permeability and promote chemotaxis of mononuclear cells. Delayed hypersensitivity is demonstrable in four to five days after exposure to antigen. In a sensitized individual, the characteristic delayed type skin reaction appears in five to six hours and reaches a maximum in 18 to 48 hours. The delayed or cell mediated response is active in such infections as candidiasis, tuberculosis, late syphilis and leprosy. It is also seen in immune response to malignancy and contact dermatitis. A distinctly different small lymphocyte, the B-lymphocyte, is active in humoral or immediate sensitivity.4 After a four to 24hour latent period, the cells are transformed into plasmacytes by antigen-altered macrophage RNA and proceed to divide and produce specific antibody. This antibody is active in removing or neutralizing bacterial toxins, fungi or immune complexes. The active agents in humoral sensitivity are the immunoglobulins, products of plasma cells. Here again, only certain cell clones seem able to produce a given immunoglobulin. These immunoglobulins are divisible by antigenic specificity and electrophoresis into five classes: IgG, IgM, IgA, IgD and IgE. IgG makes up about 85% of total humoral immunoglobulin, has a molecular weight of 140,000 - 150,000 and is identical to a structural unit of Bence-Jones protein. It is active in responses to both intrinsic and extrinsic allergens and binds complement. IgM constitutes 5-10% of total immunoglobulins and has a high M.W., about 900,000. It is present in large amounts at the early stages of antigenic challenge. It binds complement and exerts protective activity against microbes and other large immuno-
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JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION
gens. IgM is 100 times as potent as IgG in killing certain gram negative bacilli. A single IgM molecule can activate complement and lyse a gram negative bacillus.3 IgA has a M.W. of 170,000 - 500,000 and comprises about 10% of human immunoglobulin. It is found in relatively large quantities in saliva, colostrum and tears, and in smaller amounts in intestinal secretions and prostatic fluid. These antibodies seem to play a protective role at mucous surfaces and resist digestion by proteolytic enzymes. Antibody activity against certain bacilli and ragweed has been demonstrated for IgA. IgA deficiency is associated with increased episodes of respiratory infections and an increased incidence of autoimmune disease. Thus it both protects against local infection and prevents development of autoimmune processes by interfering with antigen absorption from mucous surfaces. It does not bind complement. IgD is present in small amounts in normal human plasma and activity has been demonstrated against penicillin, milk protein and nuclear and thyroid antigens. Its M.W. is about 200,000. IgE, usually present in trace amounts in serum, is responsible for anaphylactic sensitivity and is the antibody of reagin activity. It attaches firmly to most cells and does not bind complement. IgE levels are elevated in patients with atopic eczema, pollen allergies and helminth infections. In atopic reactions, IgE adheres to mast cells and leucocytes. Then if the sensitized cell contacts a specific antigen, harmful mediators, including histamine, serotonin and slow reacting substances are released. This mechanism is active in anaphylaxis and certain forms of urticaria. Reactions involving complement are of increasing importance to the dermatologist. The direct complement pathway is activated by an antigen-antibody reaction involving IgG and IgM molecules. By this pathway Cl, the first component of complement is activated. This Cl activates C4 and C2, cleaving them to particles which have virus neutralization and other activity and which participate in activating C3. The reaction products of Cl, 4, 2 and 3 activate CS and
NOVEMBER, 1975
C6 and so on to C9, producing progressive activation of complement components and substances with anaphylotoxic, kinin, chemotactic, bacteriolytic and other biological activity. It has been shown that bacterial lipopolysaccaride (LPS) and certain antigen-antibody reactions can lead to utilization of C3-C9 without significant participation of Cl, C4 or C2.3 Factors of the properdin enzyme system are successively activated by LPS or antigenantibody reaction, and in turn activate components C3-C9. The immune cytotoxic mechanism involves binding antibody to tissue cells at sites of specific antigen. Such antigen may be intrinsic as in pemphigus or an extrinsic antigen intimately associated with tissue as in certain drug reactions. The antibody involved is almost always IgG. Antibody coated cells are then susceptible to destruction by complement components or by phagocytosis. Precipitated antigen-antibody complexes are active in the Arthus phenomenon, activating complement and leading to inflammation and vasculitis. Similar immune complex mechanisms are involved in systemic lupus erythematosus and in serum sickness. Increased understanding of immunologic phenomena helps explain many previously baffling dermatologic conditions. These include immunodeficiency states, both primary and secondary. Immunodeficiency can result from any one or a combination of causes.5 These can be primary T-cell or B-cell deficiencies or combined primary deficiency states. Acquired deficiency states may be secondary to infection, sarcoidosis, lymphomas or immunosuppressive therapy. Burton's X-linked agammaglobulinemia, a primary B-cell deficiency, is characterized by increased immunoglobulin production and is usually manifest in the second six months of life (Table 1). Lymphocyte counts are normal, as are the Schick test, DNCB sensitization ane other measures of cellular immunity. Lymph node biopsy reveals no plasma cells after antigen stimulation. The delay in onset of this disorder results from passive protection by maternal antibody. These infants are infected by pyogenic organisms such as
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Immunological Principles in Dermatology
pneumococci, meninogococci, streptococci and pseudomonas. Skin abscesses, cellulitis and furunculosis are common. These infections can be readily controlled by antibiotic or gammaglobulin therapy. The patients handle exanthems and other viral infections in a normal fashion. A dermatomyositis-like disease and other collagen diseases have been reported in these children. Table 1. SOME PRIMARY IMMUNODEFICIENCIES
Cellular Defect Bruton's Sex-Linked B Agammaglobulinemia Selective IgA Deficiency
B
Thymic Hypoplasia (DiGeorge)
T
Combined Immunodeficiency
B,T, S
Wiskott-Aldrich Syndrome
B,T
Clinical
Genetics
4lmmunoglobulins
X-Linked Cellulitis, Furunculosis Recessive No TFungal or Viral Infections JIgA Unknown tlncidence of Collagen Dis. TResp. Infection Normal Circulating None Antibody TViral & Fungal Infections Mucocut. Candidiasis Vacc. Gangrenosum, Gen. Vacc. Fatal BCG Infections Hypocalcemia lIg a) Autosomal Lymphopenia Recessive Viral, Fungal Infections b) X-Linked Vaccinia, BCG c) Sporadic Complications Thrombocytopenia X-Linked Recessive Atopic Dennatitis
JIgM, TIgA Ataxia Telang.
B,T
G.I. Bleeding TViral, Fungal & Bacterial Infect. Ataxia Telangiectases 4IgA & IgE Lymphoma, Leukemia Respiratory Infection, Lymphopenia
Recessive
Primary immunoglobulin-A deficiency may be asymptomatic, but some individuals experience an increase in respiratory infections. There is also an increase in autoimmune disease, including systemic lupus erythematosus. It is suggested that the absence of IgA permits entrance of dietary protein and altered epithelial tissues through the gut and these antigens stimulate production of auto-antibodies. The DiGeorge syndrome or thymic hypoplasia results from failure in embryogenesis of the entodermal derivatives of the third and
425
fourth pharyngeal pouches. There is resultant aplasia of the thymus and parathyroid glands, manifest by absence of cell mediated immunity and neonatal tetany. Physical features include hypertelorism, low set ears and shortened lip philtrum. Due to T-cell deficiency, these infants are usually susceptible to overwhelming viral, fungal and bacterial infections. Serum immunoglobulin levels are normal, but delayed sensitivity is weak-toabsent. Thus DNCB sensitization is weak or unsuccessful and there is no reaction to candida antigen. Thymus transplantation has been found successful and beneficial in these patients. In combined immune deficiency, there is defective cell mediated and humoral immunity. The immunoglobulins are low and lymphopenia may be profound. The bone marrow is deficient in plasma cells, lymphocytes and lymphoblasts. No germinal centers develop in the lymph nodes. These patients do not respond to DNCB or candida antigen. A rapid succession of infections begins early in life and demise is to be expected before age two. Gram negative infections, candidiasis and benign viral infections are poorly handled. Vaccinia can become generalized and varicella may be fatal. This disorder may be an autosomal recessive, X-linked or sporadic in inheritance pattern. The Wiskott-Aldrich syndrome is characterized by eczema, thrombocytopenia and recurrent infection. Inheritance is X-linked and death in the first 10 years of life is to be expected due to infection, hemorrhage or malignancy of the lymphoid tissue. There are serious bacterial, fungal and viral infections and IgM levels are low. IgA and IgG are normal. There is a specific inability to respond to polysaccharide antigen. Children affected by hereditary ataxia telangiectasia develop ataxia and choreoathetoid movements in infancy. The telangiectases appear at about age five or six and involve the conjuctiva, face, ears and antecubital and popliteal spaces. Progressive recurrent respiratory infection may appear early or late and lead to death in the second or third decade. Malignancy of lymphoid tissue is common. These patients lack IgA, and an
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IgE deficiency has been noted. There is also defective cellular immunity. Atopic-like dermatitis may be associated with several immunodeficiency states, suggesting a role for immunologic impairment in its pathogenesis. These patients are hyperresponsive to antigenic stimuli, resulting in overproduction of immunoglobulin, especially IgE. Cell mediated responses are often depressed. It has been suggested that a chronic T-cell deficiency exists in atopics leading to overproduction of circulating antibody. However, alternate explanations have been proposed. A local functional decrease in cell mediated immunity, due to development of humoral antibody, has been suggested to explain the prevalence of chronic dermatophytosis in the atopic patient.6 Many atopic infants have IgA deficiency, which can result in excessive allergen entry and overproduction of IgE. Hereditary angioedema is characterized by attacks of non-pruritic angioedema induced by stress or tissue injury. There is a deficiency of Cl inhibitor leading to activation of C2 and C4 and increased vascular permeability. This is a dominantly inherited defect. Defective phagocytosis, due to abnormal C5 function, is seen in infants with a Leiner disease picture. It is characterized by generalized seborrheic dermatitis, diarrhea and increased susceptibility to gram negative infections. Chronic granulomatous disease of childhood is characterized by lymphadenopathy, hepatosplenomegaly and granuloma formation in the skin, lymphnodes and bone. The neutrophils are unable to lyse microorganisms after phagocytosis, leading to lowered resistance to catalase positive organisms such as candida, E. coli and staphylococci. These ingested micro-organisms are actually protected from antibodies. Catalase negative organisms such as streptococci and pneumococci are handled competently. Bacterial hydrogen peroxide accumulates after phagocytosis, leading to death of these latter organisms. This disorder is usually inherited as an X-linked recessive. Onset occurs in early infancy leading to a chronic course and death from infection after an average life
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span of seven years. Secondary immunodeficiency may develop in lymphomas, after certain viral and parasitic infections, or may be associated with malnutrition. latrogenic immunodeficiency occurs after treatment with x-rays, corticosteroids, methotrexate, cyclophosphamide and other immunosuppressants. Overwhelming viral, bacterial or fungal infections may develop and malignant neoplasms have been reported, probably due to decreased immune surveillance. Immunologic reactions are widely used in diagnosis of diseases important to the dermatologist. The Wassermann, Kahn and VDRL tests for syphilis depend on complement fixation, and does the more specific Reiter protein complement fixation test. The TPI test demonstrates specific antitreponemal activity of serum. In the FTA-ABS test, labelled anti-human gammaglobulin is demonstrated to be bound by treponemal antigen. Several skin tests for cell mediated immunity have application in clinical dermatology. These include tests for candida, trichophyton, lepromin and tuberculin. Complement fixation reactions are useful in diagnosis and prognosis of coccidioidomycosis and histoplasmosis. In recent years immunofluorescent procedures have contributed greatly to advances in diagnosis of collagen-vascular diseases and bullous dermatoses.7 In the direct immunofluorescent test, a section of patient's tissue is treated with anti-human globulin produced in goat or other species. This globulin has been labelled with a fluorescent marker, such as fluorescein or anthracene. It may be specific for various complement components or for an individual immunoglobulin. After this reaction, the slide is examined under the fluorescent microscope to identify its immunologic components. The indirect test for immunofluorescence seeks to demonstrate circulating antibody in the patient's serum. First, a substrate tissue such as monkey or guinea pig esophagus or rat liver is treated with the test serum and then fluorescent labelled antihuman antibody is added in sandwich fashion. Examination with a fluorescent microscope will demon-
strate antinuclear, intercellular or basement membrane antibody attachment. In discoid lupus erythematosus (D.L.E.), the direct test shows basement membrane granular fluorescence (Table 2). Both the lesion and normal skin are positive in systemic lupus erythematosus (S. L. E.). Thus in suspected systemic lupus erythematosus without skin lesions, a biopsy from normal skin can be helpful in diagnosis. Also the indirect test shows antinuclear fluorescence in S.L.E. but not in D.L.E. A peripheral nuclear pattern is characteristic, whereas speckled or nucleolar patterns are seen with other collagen vascular diseases. A shrunken peripheral pattern indicates severe systemic lupus erythematosus.8 Table 2. IMMUNOFLUORESCENT TESTS Dermatitis
Herpetiformis DIRECT
B.M.-Fibrils IgA
INDIRECT Neg.
DIRECT
L. E. B. M.-Granular
DiscoidLesion only S.L.E.Lesion & Normal INDIRECT A.N.A. Fluorescence PeripheralL. E. Shrunken PeripheralSevere L. E.
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Pemphigus Bullous Vulgaris Pemphigoid Intercellular Epidermis Intercellular
B. M. B. M.
SCLERODERMA Neg.
A. N. A. Speckled & Nucleolar
No direct fluorescence is seen in scleroderma but positive speckled or nucleolar fluorescence is seen in serum antinuclear antibody tests. Both direct and indirect findings are negative in morphea, but up to 25% of linear scleroderma cases have positive antinuclear antibody tests. The ANA test is rarely positive in dermatomyositis. Since non-specific basement membrane fluorescence can be seen in areas of telangiectasia from various causes, specimens from telangiectatic skin can be misleading. Almost all pemphigus cases of the various types show direct epidermal intercellular fluorescence of the biopsy specimen in normal skin or mucous membrane adjacent to
a lesion and indirect immunofluorescence can also be demonstrated. Intercellular immunofluorescence is pathognomonic for pemphigus, and is useful in differential diagnosis from pyoderma vegetans, subcorneal pustular dermatosis, Hailey- Hailey disease and Darier's disease. Fluorescence of dermal papillae and sometimes basement membrane fluorescence is seen in direct studies of dermatitis herpetiformis lesions. The granular papillary fluorescence is diagnostic for dermatitis herpetiformis, and has been shown to be due to IgA deposits. The biopsy site is of utmost importance, and examination of an early urticarial lesion, erythematous skin near the lesion or buttock skin is desirable. No indirect immunoflurescence is seen in dermatitis herpetiformis. In bullous pemphigoid, over 80% of cases have demonstrable circulating antibody to basement membrane antigen. Cicatricial pemphigoid cases rarely demonstrate circulating epithelial antibody. On direct testing, linear basement membrane fluorescence can be demonstrated in normal skin adjacent to the lesion in bullous pemphigoid and most cicatricial pemphigoid cases. The section should be taken adjacent to a bulla and from a fresh lesion. In older lesions, the basement membrane may have been destroyed, resulting in a negative finding. The direct immunofluorescence of bullous and cicatricial pemphigoid has been shown due to deposits of IgG and complement. Direct basement membrane fluorescence has been reported in herpes gestationis, and detailed studies show deposits of IgG, C3, C4 and properdin.9 Scans using radio labelled antibody have been helpful in pinpointing lymphoid malignancy. 10 Immunology principles are widely applied in treatment of several dermatologic disorders, and progress is being reported in experimental treatment for other skin conditions. Immunologic suppression is used in treating pemphigus, lupus erythematosus and other collagen vascular disorders. Some agents successfully used are corticosteroids, (concluded on page 454.)
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cell anemia or other pathologic hemoglobin abnormalities. Clinically significant maternal sickle cell disease will also be detected through this route (Fig. 3). 3. Screening for iron deficiency anemia, G-6-PD deficiency, and lead poisoning among infants and children. 4. Decreased emphasis on screening solely for detecting trait conditions since no significant direct benefits can be offered to the participant and since there is a possibility that the screening results will place the participant at risk to adverse economic and psychologic consequences. 5. An increased emphasis upon educating and assisting the medical profession to screen during the perinatal period, infants and young children, and in preoperative preparation.
3. 4. 5.
6.
7.
8.
LITERATURE CITED
9.
1. WILKINSON, D. Y. For Whose Benefit'? Politics and Sickle Cell. The Black Scholar, 5:26-3 1, 1974. 2. WHITTEN, C. F. Sickle Cell Programming-An
10.
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Imperiled Promise. N. Eng. J. Med., 288:318-19, 1973. Screening in Medical Care: Reviewing the Evidence. Nuffield Provincial Hospitals Trust. Oxford Univ. Press, London, 1968. BEMIS, E. L. Sickle Cell Safari. Blood, 42:14749, 1973. MOTULSKY, A. G. Frequency of Sickling Disorders in U.S. Blacks. N. Eng. J. Med., 288:3133, 1973. PETRAKIS, N. L. and S. L. WEISENFELD, F. J. SAMS, J. F. COLLEN, J. L. CUTLER and A. B. SIEGELAUB. Prevalence of Sickle Cell Trait and Glucose-6- Phosphate Dehydrogenase Deficiency. N. Eng. J. Med., 282:767-70, 1970. PIOMELLI, S. and C. A. REINDORF, M. T. ARZANIAN and L. M. CORASH. Clinical and Biochemical Interactions of Glucose-6- Phosphate Dehydrogenase Deficiency and Sickle Cell Anemia. N. Eng. J. Med., 287:213-217, 1972. GIMA, A. S. and J. C. LEE. Prevalence of Sickle Cell Anemia: An Improved Outlook. JNMA, 67:259-63, 1975. HERRELL, W. E. Screening For Sickle-Cell Trait. Clin. Med., 79:10-12, 1972. HOWELLS, T. H. and R. G. HUNTSMAN, J. E. BOYS and A. MAHMOOD. Anaesthesia and Sickle-Cell Hemoglobin. Brit. J. Anaesth., 44:975-87, 1972.
(Anderson, ftron page 42 7) 3. PARK, B. H. and R. A. GOOD. Principles of Modern Immunobiology. Lea and Febiger, Phila., 1974, p. 51. 4. FREEDMAN, S. O., Clinical Immunology, lowering of corticosteroid dosage in these Harper and Row, N.Y., 1971, p. 22. disorders. I I 5. WALZER, R. A. Cutaneous Manifestations of Immunodeficiency. Dermatology Digest, 37:14, Transfer factor is reported helpful in pa1975. tients with Wiscott-Aldrich syndrome, mu6. JONES, H. E. Immunologic Susceptibility to cocutaneous candidiasis, aphthous stomatitis, Chronic Dermatophytosis. Arch. Derm., 110:213verruca vulgaris and malignant melanoma. 220, 1974. Immuran and prednisone produced continu7. Cooperative Study. Uses for Immunofluorescent Test of Skin and Sera. Arch. Derm., 111:371ing remission in five of seven patients with 381, 1975. severe bullous pemphigoid.12 An anti-T-cell 8. BURNHAM, T. K. Antinuclear Antibodies. antiserum has been proposed for treatment of Arch. Derm., 111:203-207, 1975. mycosis fungoides.13 Enhancement of cell 9. GILLIAM, J. N. Am. Acad. Derm., Chicago, mediated immunity by using BCG, levamiDec., 1974. 10. Med. World News, June 1975. sole (an antihelminthic drug) or DNCB have 11. MICHEL, B. Symposium on Immunofluorescent been found effective in treatment of melaTests. A.M.A. Convention, Atlantic City, June noma, herpes simplex and warts.14-16 17, 1975. 12. SPITZLER, L. E. Transfer Factor. Cutis, 15:420-423, 1975. LITERATURE CITED 13. EDELSON, R. L. Dermatol. News, 8:1, 1975. 1. GOOD, R. A. and D. W. FISHER. Immunobi14. Schoch Letter, 22: 1, June 1975. 15. Contemp. Rev., Winter 1975, p. 14-15. ology, Sinauer Associates, Stamford, Conn., 16. HOLMES, E. C. et al. Immunotherapy of Ma1973, p. 10. 2. FREEDMAN, S. 0. Clinical Immunology, lignancy in Humans. J.A.M.A., 232:1052-1055, Harper and Row, N.Y., 1971, p. 18-20, p. 122. 1975.
azothiopnine, cyclophosphamide and methotrexate. Use of cyclophosphamide and azothioprine is reported to allow significant
