874 ELEMENTAL DIETS

COMPLEMENT IN BRONCHIAL ASTHMA

SIR,-Encouraged by Kay et al./ who found analysis of complement C4 useful in the classification of asthma in childhood, we have measured C4 levels in 47 asthmatic children 2-16 years of age.

comprised all children who had been admitted to during 1974 with a diagnosis of asthma. Bloodsamples were taken on an outpatient basis at least a fortnight after admission. Plasma was kept deep-frozen at -70° C until all samples were analysed by single radial immunodiffusion2 using commercial kits (Behringwerke), serum-IgE and radioallergosorbence (R.A.S.T.) were investigated with ’Phadebas Kits’ (Pharmacia, Uppsala). The children were classified clinically and immunochemically: children without evidence of allergic causes of asthma in the case-history or in the prick test-and bronchial provocation were classified as clinically non-allergic. Children with IgE levels below the geometric mean +2 S.D. in healthy nonatopic children3 or R.A.s.T.-negative (= below 2 +) against all investigated pollens, animal danders, dust components, and food were classified as immunochemically non-allergic.

These 47 the hospital

°

SIR,-Dr Allison and Dr Woolfson (Sept. 13, p. 507) criticised the cost of commercially prepared elemental diets, and insist they can be made up easily and more cheaply. They may be right in a specialised unit, but the average hospital has perhaps one dietitian, who certainly could not cope with the work involved. It is thus clear that permanent skilled personnel would be required to prepare the diets, and these would have to be available every day, including weekends and holidays, Preparation could not be left to nursing staff, who may change daily, and any attempt to compare costs must make allowance for the factor of preparation. Also, Dr Allison and Dr Woolfson blurred the distinction between elemental and liquid diets. They state: "... we have found a ’Caloreen’/’Complan’ mixture both simple and effective". In such cases elemental diets are clearly unnecessary, and putting a normal meal through a liquidiser would be a better and cheaper alternative! Peterborough

District

Hospital

J. THORNTON HOLMES

The C4 levels showed a scatter from 60 to 247% (mean 132-5%). As the accompanying table shows, we found no FAILURE TO DETECT ENDOTOXIN IN SERUM OF CHILDREN WITH MALARIA C4

LEVELS IN CHILDHOOD ASTHMA CLASSIFIED INTO ALLERGIC AND NON-ALLERGIC

it

significant difference between the allergic and non-allergic Sixteen groups using either classification (t test). children belonged to disparate groups according to the two classifications: fifteen were allergic by the immunochemical classification and non-allergic clinically; the opposite result was obtained for one child. This difference was significant using the sign test (r < 0-01). C4 takes part in the classic pathway of the complement system and is an indicator of activity in, for example, infections. Complement activation in asthma, if it takes part in the asthma syndrome, is believed to use the alternative pathway.5An elevated level of C4 in a child is difficult to interpret in view of the wide normal ranges) and the frequency of respiratory infections in childhood. Low values may depend on the rapid destruction of C4 during storage. We were thus unable to confirm the findings of Kay et al.1 but found the combination of IgE and R.A.S.T. analyses most useful in the classification of asthma in childhood. Department of Clinical Chemistry, Department of Paediatrics, University Hospital, Linköping, Sweden.

LARS OLOF HANSSON.

N.-I. MAX KJELLMAN INGEMAR LEIJON.

Kay, A. B., Bacon, G. D., Merger, B. A. Lancet, 1974, ii, 916. Mancini, A., Carbonara, O., Heremans, J. F. Immunochemistry, 1965, 2, 235. 3. Kjellman, N.-I. M., Johansson, S. G. O., Roth, A. Clin. Allergy (in the press). 4. Alper, C. A. in Metabolic, Endocrine and Genetic Disorders of Children (edited by V. Kelley); p. 1205. Hagerstown, Maryland, 1. 2.

1974. 5. 6.

Pepys, J. in Disodium Cromoglycate in Allergic Airways Disease, symposium, London, March 5, 1969, p. 5. Sjöholm, A. G. Scand. J. Immun. 1975, 4, 25.

SIR,-Bacterial endotoxins are potent substances that can initiate a number of important biological reactions, including activation of the complement, kinin, and coagulation systems.’I They can produce fever and can stimulate B lymphocytes to produce immunoglobulin. Fever and production of large amounts of apparently non-specific immunoglobulin are characteristic features of malaria. Furthermore, activation of the complement,2 kinin,3 and coagulationpathways has been demonstrated in malaria, and these reactions are thought to contribute to the pathogenesis of the clinical features of the infection. These observations suggest that an endotoxin-like substance might have an important role in the production of the clinical features of acute malaria. Although it is unlikely that malaria parasites have a structural component chemically similar to bacterial endotoxin, the experiments of Loose et al.5 suggest another way in which endotoxin might be playing a part in the pathogenesis of human malaria. These experiments showed that mice infected with Plasmodium berghei were extremely sensitive to injections of endotoxin, probably as a result of faulty detoxification of endotoxin by the Kupffer cells of the liver. It thus seemed possible that in acute human malaria an endotoxin released by the gut flora might be able to reach the systemic circulation without being detoxified in the liver. We have therefore looked for circulating endotoxin in children with acute P. falciparum malaria. 12 children aged 2-10 yr (mean 5 yr) with clinical features of acute malaria were studied; 2 had signs of cerebral malaria. All had a heavv parasitxmia with a range of 1-42% parasited erythrocytes (mean 7%). Blood was collected before the start of treatment. Endotoxm-free glassware was used during separation of the serum and throughout the test. Sera were extracted with chloroform to remove endotoxin inhibitors and then tested for the presence of endotoxin using a Llmulus lysate preparation (Marine Biologicals).6 The sensitivity of the assay using Escherichia coli 055 B5 endotoxin (Difco) was 0.1ng/m[. None of the 12 sera gave a positive test.

We have thus been unable to detect circulating endotoxin in children with severe acute P. falciparum malaria. This confirms the report of Glew and Levin,’ who were unable to detect 1. Bacterial

Lipopolysaccharides: Chemistry, Biology and Clinical Significance of Endotoxins. J. infect. Dis. 1973, 128, suppl. 144.

2. Greenwood, B. M., Brueton, M. J. Clin. exp. Immun. 1974, 18, 267 3. Maegraith, B., Fletcher, A. in Advances in Parasitology (edited by B Dawes); vol. 10, p. 49. London, 1972. 4. Reid, H. A., Nkrumah, F. K. Lancet. 1972, i, 218. 5. Loose, L. D., Trejo, R., Di Luzio, N. R. Proc Soc. exp Biol Med 1971.

137, 794. J., Poore, T. E., Zauber, N. P., Oser, R. S. New EnglJ Med 283, 1313. 7. Glew, R. H., Levin, J. Proc. Soc exp. Biol. Med 1975, 148, 508.

6. Levin,

1970,

Letter: Complement in bronchial asthma.

874 ELEMENTAL DIETS COMPLEMENT IN BRONCHIAL ASTHMA SIR,-Encouraged by Kay et al./ who found analysis of complement C4 useful in the classification o...
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