The role of erythropoietin in the anaemia of chronic disease in rheumatoid arthritis.

We reviewed studies on the role of erythropoietin (Epo) in the anaemia of chronic disease (ACD) in rheumatoid arthritis (RA). A relatively impaired Epo response to the anaemia was found in a number of studies although in others serum Epo level was the same as in other types of anaemia. Some arguments are found in favor of a reduced bone marrow-Epo sensitivity although these reflect results mainly from in vitro experiments. It is not yet established whether bone marrow macrophage Epo production is impaired in ACD. In two cases Epo administration to RA patients resulted in increased erythropoiesis. It was concluded that impaired Epo production or reduced bone marrow Epo sensitivity might be associated with ACD but it is not certain whether these factors are causally linked with ACD or side phenomena of RA disease activity. Future Epo treatment in RA and ACD will possibly solve this question.