Basic red cell ferritin (RCF) content reflects the rate of iron uptake by marrow erythroid cells in patients with anaemia due to chronic inflammation which are sometimes also associated with metabolic disorders of the erythrocytes. For 29 patients with active inflammatic states of chronic rheumatoid arthritis (RA) and microcytic (mean corpuscular volume up to 80fl) or normocytic (MCV 80-95fl) anaemia respectively, the mean RCF content, irrespective of plasma ferritin levels, was determined using a recently established ELISA test. Red cell intermediates (ATP, GSH, 2.3 DP.G) were measured using conventional methods. The results revealed decreased RCF levels (2.8 +/- 1.5 ag/RBC) in 12 patients with RA and normal values (8.8 +/- 4.7 ag/RBC) in 17 patients which obviously did not correlate with the degree of the anaemia. The extent and pattern of the intermediates of RBC did not significantly vary from normal values. Thus, ATP, GSH and 2.3 DPT levels of RBC were only slightly increased up to 10%, especially in those patients with higher anaemic degrees. The findings of our study suggest that conventional indices for iron metabolic disorder in anaemic patients with chronic inflammatic disease should include peripheral microcytosis, transferrin saturation, and RCF content but could neglect plasma ferritin concentrations. Concerning the RBC metabolism this study did not disclose any further influences on iron metabolism parameters due to changes of mean cell age in patients with RA. Specific alterations which might hence produce additional functional disturbances of the erythrocytes in the peripheral microcirculation thus leading further to tissue cell damages in RA could be excluded as well.