820
LEVAMISOLE, RHEUMATOID ARTHRITIS, AND COLD LYMPHOCYTOTOXIC ANTIBODIES
SIR,--Cold-reactive lymphocytotoxic antibodies are well recognised in connective-tissue disorders in man. Many reports have appeared of their occurrence in systemic lupus erythematosus (s.L.E.).’ and their presence in some patients with other connective-tissue disorders, including rheumatoid arthritis (R.A.) has also been noted.2 Levamisole, a drug first used as an antihelminthic, has an as yet undefined ability to stimulate the immune response,3 and it is undergoing clinical evaluation in conditions where stimulation of the immune response might be useful. Levamisole has had varying effects in R.A.4,5 We feel that the use of an immunostimulatory drug in a condition which often shows many autoimmune phenomena, although potentially useful, is also potentially harmful and requires close scrutiny. We have been looking at, among other variables, the incidence of cold lymphocytotoxic antibodies in sera of patients with R.A., comparing those on levamisole with those on standard anti-rheumatic therapy. Sera from 84 patients with R.A. and 26 controls were examined for cold lymphocytotoxic antibodies. All patients had "classical" or "definite" R.A.,6 and none were receiving gold, chloroquine, cytotoxic drugs, or corticosteroids. Each had
LYMPHOCYTOTOXIC ANTIBODIES IN RHEUMATOID ARTHRITIS
"antibodies with weak cytotoxic activity against lymphocytes" in seronegative spondylarthritis after treatment with levamisole. No details of the method or temperature used for detection of these antibodies was given, so no comparison can be made. The specificity and significance of cold lymphocytotoxic antibodies in S.L.E. and R.A. has not been elucidated, though it is widely accepted that the activity is probably due to the presence in each serum of a number of different cold lymphocytotoxic antibodies of differing specificities. The finding, however, of such a striking increase in these antibodies during levamisole therapy suggests that the drug may interfere with suppressor lymphocyte activity, thus allowing production of antibodies that are normally suppressed. Whatever the mechanism implications of such an increase in lymphocytotoxic antibodies suggest that considerable caution must be exercised if patients with well-established autoimmune disorders are to be given levamisole. Further work is now urgently required to establish the effect, if any, of these antibodies and their nature, specificity, and permanence. Glasgow and West Scotland Blood Transfusion Service, Law Hospital, Carluke, Lanarkshire
J. D. BROWNING
Tissue Typing/Clinical Immunology Laboratory, Department of Bacteriology,
Royal Infirmary, Glasgow G4 0SF
H. M. DICK
Centre for Rheumatic Diseases,
A. EL-GHOBAREY W. C. DICK
Glasgow
DETECTION OF OCCULT BLOOD IN FÆCES
SiR,—The detection of occult blood in faeces depends on the
pseudoperoxidase activity in which *r
LEVAMISOLE, RHEUMATOID ARTHRITIS, AND COLD LYMPHOCYTOTOXIC ANTIBODIES
SIR,--Cold-reactive lymphocytotoxic antibodies are well recognised in connective-tissue disorders in man. Many reports have appeared of their occurrence in systemic lupus erythematosus (s.L.E.).’ and their presence in some patients with other connective-tissue disorders, including rheumatoid arthritis (R.A.) has also been noted.2 Levamisole, a drug first used as an antihelminthic, has an as yet undefined ability to stimulate the immune response,3 and it is undergoing clinical evaluation in conditions where stimulation of the immune response might be useful. Levamisole has had varying effects in R.A.4,5 We feel that the use of an immunostimulatory drug in a condition which often shows many autoimmune phenomena, although potentially useful, is also potentially harmful and requires close scrutiny. We have been looking at, among other variables, the incidence of cold lymphocytotoxic antibodies in sera of patients with R.A., comparing those on levamisole with those on standard anti-rheumatic therapy. Sera from 84 patients with R.A. and 26 controls were examined for cold lymphocytotoxic antibodies. All patients had "classical" or "definite" R.A.,6 and none were receiving gold, chloroquine, cytotoxic drugs, or corticosteroids. Each had
LYMPHOCYTOTOXIC ANTIBODIES IN RHEUMATOID ARTHRITIS
"antibodies with weak cytotoxic activity against lymphocytes" in seronegative spondylarthritis after treatment with levamisole. No details of the method or temperature used for detection of these antibodies was given, so no comparison can be made. The specificity and significance of cold lymphocytotoxic antibodies in S.L.E. and R.A. has not been elucidated, though it is widely accepted that the activity is probably due to the presence in each serum of a number of different cold lymphocytotoxic antibodies of differing specificities. The finding, however, of such a striking increase in these antibodies during levamisole therapy suggests that the drug may interfere with suppressor lymphocyte activity, thus allowing production of antibodies that are normally suppressed. Whatever the mechanism implications of such an increase in lymphocytotoxic antibodies suggest that considerable caution must be exercised if patients with well-established autoimmune disorders are to be given levamisole. Further work is now urgently required to establish the effect, if any, of these antibodies and their nature, specificity, and permanence. Glasgow and West Scotland Blood Transfusion Service, Law Hospital, Carluke, Lanarkshire
J. D. BROWNING
Tissue Typing/Clinical Immunology Laboratory, Department of Bacteriology,
Royal Infirmary, Glasgow G4 0SF
H. M. DICK
Centre for Rheumatic Diseases,
A. EL-GHOBAREY W. C. DICK
Glasgow
DETECTION OF OCCULT BLOOD IN FÆCES
SiR,—The detection of occult blood in faeces depends on the
pseudoperoxidase activity in which *r
