Circulating immune complexes may be associated with increased suppressor T-cell activity in atopic allergy

Using two groups of atopics, one with abnormally elevated serum IC levels (IC+) the other with normal IC values (IC−) we have investigated the generation of suppressor cells after Con A stimulation in three different in vitro assays: PHA-induced lymphocyte transformation, one-way MLC cultures, and IgG synthesis after PWM stimulation of B cells. In all cases, lymphocytes derived from IC+ patients, after Con A pretreatment in vitro, exhibited enhanced suppressor activity compared to IC− and normals. Furthermore, lymphocytes from IC+ individuals tended to respond poorly to specific antigen stimulation. Both groups of atopics were closely matched for clinical and familial parameters as well as for treatment modalities and therapeutic results. HLA and B-cell alloantigen studies did not reveal any group segregation. These results show that an increased T-suppressor cell activity may be found together with abnormally elevated circulating immune complexes in nonvasculitic, atopic patients.