Characterization of lymphocyte E rosette inhibitory factor in sera from tuberculous patients.

Rosette inhibitory factor (RIF) in serum of patients suffering from active pulmonary tuberculosis, after in vitro contact with lymphocytes from healthy subjects, inhibits spontaneous rosette formation of these lymphocytes with sheep red blood cells (SRBC). RIF is not a C-reactive protein. By the use of chromatography on Sephadex G-200 and single analytic flotation, RIF was found to be contained in the beta-lipoprotein fraction. The presumable mechanism of formation of this factor and suggestions concerning its action on T cells are discussed.