In vitro synthesis of IgE by human peripheral blood leucocytes: relationship to serum titre of leucocyte donor.

A microculture system was developed for in vitro IgE synthesis employing human peripheral blood leucocytes (PBL), comprising 1.0 x 10(6) cells in 1.0 ml serum-supplemented medium, in round-bottomed tubes. Examination of the kinetics of IgE synthesis indicated that production was relatively linear during culture for up to 12 days, and was not susceptible to stimulation with polyclonal B cell mitogen. Employing a standardized 7-day culture period, PBL IgE synthesis was compared within a group of 50 volunteers, comprising normal non-atopic individuals exhibiting serum IgE titres less than 50 units/ml, and moderate atopics with serum titres up to approximately 400 units/ml. PBL IgE synthesis was found to reflect closely the serum IgE status of the cell donor, a feature thus far unique to this culture system, and indicative of the preservation of normal in vivo regulatory mechanisms in the in vitro cultures.