Hairy cell leukemia: functional, immunologic, kinetic, and ultrastructural characterization.

A diagnosis of hairy cell leukemia was made by optic microscopy, phase-contrast microscopy, electron microscopy, scanning microscopy, and histochemistry of the abnormal blood cells. In vivo these cells were found to have a half-time in the blood of approximately 150 hr. In vitro they had the capacity to adhere firmly to plastic, making it possible to obtain a pure population of hairy cells. Neither T-rosette formation nor phytohemagglutinin (PHA) transformation could be demonstrated in these cells. On the other hand, the presence of immunoglobulins on the surface of the hairy cells (HC) by immunofluorescence, and the synthesis and secretion by these cells of IgM type lambda-chains shown by radioimmunodiffusion, were in favor of their B-type lymphocyte origin. Similarities to chronic lymphocytic leukemia were apparent.