In vitro IgE formation by peripheral blood lymphocytes from normal individuals and patients with allergic...

Peripheral blood lymphocytes from five normal donors and five individuals with allergic bronchopulmonary aspergillosis (ABPA) were used for measurement of in vitro IgE formation in tissue culture preparations. IgE was measured by a sensitive radioimmunoassay using concentrated tissue culture medium (TCM) and expressed as ng IgE/ml of TCM. The results demonstrated that IgE was formed by unstimulated lymphocytes from one of five normal donors (range 1.5-2.4 ng/ml) and in two of five ABPA donors (range 2-4 ng/ml). However, when different dilutions of pokeweed mitogen were added to the tissue culture, three of five normal donors and three of five ABPA donors in remission showed enhanced IgE formation. At the time of an ABPA exacerbation in one individual, there was a definite increse in IgE synthesis up to 40 ng/ml which was suppressed by pokeweed mitogen to 17.3 ng/ml. Clear differences between normals and ABPA patients in remission are not apparent.