Previous investigations of patients with Hodgkins disease have primarily concentrated on the role of the thymus-dependent lymphoid system. Preliminary studies in our laboratory showing increased cell-associated Ig and accelerated Ig synthesis with specificity towards homologous lymphoid cells suggest active participation of the humoral immune system in the pathogenesis of Hodgkins disease. The present proposal describes a comprehensive approach to the study of the role of the bone marrow-derived lymphocyte in Hodgkins disease. Cell-associated Ig, relative B and T lymphocyte numbers and in vitro Ig synthesis will be measured using lymphocytes from the spleen, lymph nodes, bone marrow and blood of Hodgkins patients. Specificity of the culture-produced Ig, Ig eluted from Hodgkins tumor tissue and serum Ig will be interacted with autologous and homologous lymphocytes. The ability of the putative antibody to react with the target lymphocytes will be determined using Ig absorption to lymphocytes and lymphocytotoxicity. Further delineation of the preferred lymphoid target cells will be evaluated by sheep red cell rosette inhibition and by the increase in surface Ig containing cells after incubation with test materials. The results will be correlated with the clinical stage, histologic type and therapeutic status of the study patients.