The secretory erythropoietin response in patients with multiple myeloma and Waldenström's macroglobulinaemia.

Immunoreactive levels of serum erythropoietin (EPO) have been measured in 95 patients with multiple myeloma (MM) and 12 patients with Waldenström's macroglobulinaemia (MW). Of the MM patients 23% were uraemic (mostly light and moderate renal failure) and 61.7% were anaemic. In the anaemic nonuraemic MM patients the mean serum EPO titre was 106.8 +/- 30.4 mU/ml which, when related to the extent of anaemia, was found to be appropriately elevated for the degree of anaemia (the mean haemoglobin (B-HGB) concentration was 6.66 +/- 1.31 mmol/l). The mean serum EPO concentration in uraemic and anaemic MM patients was 39.2 +/- 9.2 mU/ml, which was markedly lower than serum EPO levels in the non-uraemic MM patients, but still higher than in nonanaemic control subjects (22.5 +/- 8.5 mU/ml). The mean B-HGB concentration in uraemic MM patients was 6.04 mmol/l. In the anaemic MM patients with severe renal failure (S-creatinine levels greater than 400 mumol/l) the compensatory secretion of EPO was inadequate in relation to the degree of anaemia. The data indicate that unless the hypoproliferative anaemia of MM is accompanied by considerable renal failure the anaemia does not appear to be associated with a deficient biogenesis of EPO. Likewise the anaemia found in patients with MW also seems, generally, to elicit an appropriate increase in EPO secretion. Reasonably clinically stable MM patients with anaemia and uraemia may be candidates for replacement therapy with recombinant human erythropoietin (rhEPO).