THE ASSAY OF INTERLEUKIN-4 IN THE SERUM OF NORMAL SUBJECTS AND ATOPICPATIENTS USING A NOVEL IMMUNOASSAY

Interleukin 4 (IL-4) was measured in the serum of normals and mild ato pic patients using a high sensitivity ELISA system involving an amplif ication stage, The method was found to have a limit of detection of 0. 02 pg/ml after a square root transformation of the concentration data and to show good reproducibility with coefficients of variation betwee n 11 and 14%. Recoveries of standard IL-4 from serum was greater than 90%. Markedly elevated levels of IL-4 were seen in the atopic groups c ompared with the normals, No association was found between total white cell counts, lymphocyte or eosinophil counts and serum IL-4 levels. T his study demonstrates that serum IL-4 levels can distinguish between atopic subjects and normals, even in mild or symptomless disease, This may prove valuable in the management of atopic disorders. (C) 1997 Ac ademic Press Limited.