Expression of Receptors for IgA in Hairy‐Cell and Other B‐Cell Leukaemias

In six cases of both hairy-cell leukaemia (HCL) and chronic lymphocytic leukaemia (CLL) it was shown that the pathological cells express receptors for the Fc portion of IgA (RFc alpha). Many of the cells simultaneously expressed receptors for IgA, IgM and IgG, and blocking studies showed that these are distinct receptors. In contrast, the malignant cell of most of the various other B-cell leukaemias studied showed low levels of RFc alpha expression. The significance of the results is briefly discussed and it is suggested that receptor expression may be a marker of certain stages of B-cell development.