PHA-induced soluble factors(s) can activate B-cells from patients with chronic lymphatic leukaemia.

Blood lymphocytes from eight patients with chronic lymphatic leukaemia (CLL) were stimulated by phytohaemagglutinin (PHA). The effect was defined as a pronounced increase of ³H-thymidine incorporation, and a concomitant blast transformation of a large portion of surface Ig-positive, E-rosette-forming (E-RFC) negative cells. E-RFC depletion reduced these effects to nearly background levels, and the pooled data strongly suggest that malignant R-lymphocytes in CLL are capable of responding to a PHA-induced T cell factor. A possible use for this factor in characterizing different subpopulations of CLL cells is discussed. [ABSTRACT FROM AUTHOR]