Erythropoiesis and mean red-cell lifespan in normal subjects and in patients with the anaemia of active rheumatoid arthritis.

Recently developed ferrokinetic methods offer a tool to measure effective and ineffective erythropoiesis and mean red-cell lifespan (Ricketts et al, 1975). We have used this tool to investigate erythropoiesis in normal subjects and in patients with the anaemia of active rheumatoid arthritis. In normal subjects the results are comparable with the results published by Cavill et al (1977). In patients with the anemia of active rheumatoid arthritis there appears to be a total and an effective red-cell production as in the normal subjects. The ineffective erythropoiesis in the patients is increased and the produced red cells have a shortened mean lifespan in the circulation. The increased ineffective erythropoiesis is probably due to inadequate supply of iron to the marrow and the shortened mean red-cell lifespan to an extra-corpuscular haemolytic factor. The impaired marrow response to the anaemia of active rheumatoid arthritis has been confirmed.