Impaired erythropoietin responsiveness to the anaemia in rheumatoid arthritis. A possible inverse relationship with iron stores and effects of the oral iron chelator 1,2-dimethyl-3-hydroxypyrid-4-one.

We investigated the serum erythropoietin (Epo) response in 11 rheumatoid arthritis (RA) patients without anaemia, 7 with RA and iron deficiency (ID) and 12 with RA and anaemia of chronic disease (ACD). In all patients the serum Epo was higher than in healthy subjects. Apparently this increase was insufficient to prevent anaemia in ID and ACD. Serum Epo correlated negatively with serum ferritin. Ten RA patients with ACD were treated with the oral iron chelator 1,2-dimethyl-3-hydroxypyrid-4-one (L1). No obvious toxicity signs occurred after one week of treatment. It effectively released iron from iron stores. The Hb rise (in 70% of the patients) was correlated positively with an Epo increase and negatively with a serum ferritin decrease. We conclude that a serum Epo increase does not overcome ACD. Epo response might correlate inversely with iron stores. L1 treatment effectively chelates iron from iron stores. The effects of L1 on erythropoiesis and serum Epo and its safety need further substantiation after prolonged treatment in more RA patients.