Serum erythropoietin in chronic lymphocytic leukaemia.

Anaemia is a frequent complication of advanced chronic lymphocytic leukaemia (CLL) and several cytokines known to inhibit erythropoietin (Epo) formation are produced by CLL B cells. Therefore we measured serum Epo levels in 47 CLL patients to determine whether Epo was a significant factor in the development of their anaemia. Epo levels were increased compared to normal individuals and this elevation appeared adequate for the degree of anaemia. The slope of the regression of Epo versus haemoglobin (Hb) was similar to that of a reference group. Serum transferrin receptor (sTfR) levels were also appropriately elevated for the degree of anaemia and correlated with serum Epo. Advanced stage was not associated with reduction of Epo production but diminished erythropoietic activity was observed in several patients. The results indicate that anaemia in CLL is not characterized by inadequate Epo production.