IGE SYNTHESIS-ENHANCING FACTOR - MODIFICATION OF ITS PRODUCTION IN THE COURSE OF LONG-TERM IMMUNOTHERAPY

The isotype-specific mechanisms involved in IgE synthesis are a sophis ticated system about which very little is known. Several research grou ps have demonstrated that there is an enhancing factor (EF) in lymphoc yte supernatants which is related to the regulation of the synthesis o f IgE, and the influence medium-long-term immunotherapy (IT) exerts on it. Following this line of research, we studied the influence of long -term IT (> 3 years) and the presence of interleukin-4 (IL-4), not onl y in the different fractions where EF is contained, but also in lympho cyte supernatants after stimulation. Bidirectional mixed lymphocyte cu ltures were performed between lymphocytes from healthy controls (n=62) and allergic patients (n=98) after different periods of IT. The super natants obtained were submitted to affinity chromatography and the sec ond fractions, containing EF, were added to healthy control lymphocyte s (n=11) in order to test their enhancing effect on IgE synthesis. Mod ifications in EF production were observed, depending on the duration o f IT. There were no detectable levels of IL-4 either in EF fractions o r supernatants from stimulated lymphocytes.