T and B‐RFC inhibiting factor in plasma from patients with active Hodgkin's disease

We report the presence of a rosette inhibiting factor (RIF) in the plasma of patients with active Hodgkin's disease. This factor suppresses the rosette forming ability of autologous Active T, Total T, and B lymphocytes with sheep red blood cells, and tends to disappear when clinical remission is achieved. To a lesser extent, the RIF also lowers the Active T, Total T and B‐RFC percentages of lymphocytes obtained from normal donors. Although carcinoma and non‐Hodgkin's lymphoma patients, as a group, did not exhibit rosette inhibitive properties, certain individuals with these diagnoses did show isolated RIF activity. The RIF could be adsorbed out of plasma using peripheral blood lymphocytes (PBL) from normal controls and appears to be a large heat stable molecule which does not affect PBL viability.