A micro-method for PHA-induced stimulation of human lymphocytes. II. communication: effect of splenectomy on the inhibitory activity of serum in patients with Hodgkin's disease.

Lymphocytes of 19 unselected patients with Hodgkin's disease were stimulated with PHA in vitro using a microculture system. The sera of these donors were simultaneously tested for their ability to support PHA-induced stimulation of normal lymphocytes as compared to sera drawn from healthy volumteers. Wheras DNA synthesis in Hodgkin's disease using normal sera was almost uniformly decreased, transformation of normal lymphocytes was suppressed in 9 of 11 sera from patients with Hodgkin's disease without splenectomy, but only in 1 of 8 sera from patients tested after removal of the spleen. 3 donors could be tested both before and after splenectomy, 2 showed a complete disappearance of inhibiting substances in their sera. These findings are discussed as to the immunological significance of inhibiting factors and splenectomy in Hodgkin's disease.