ASSESSMENT OF ERYTHROPOIESIS FOLLOWING RENAL-TRANSPLANTATION

Ten patients, who received cadaveric kidneys, were followed for 24 wk with serial measurements of serum erythropoietin (S-Epo), transferrin receptor (S-TfR) and iron variables. The mean pretransplant creatinine clearance was 8.2 (range 0-22) ml/min and the mean haemoglobin (Hb) l evel was 99+/-18.6 (range 66-124) g/l. Nine patients demonstrated a gr adual increase in S-Epo levels, which reached a peak, and was accompan ied by a parallel increase in S-TfR levels with a median lag period of 3 wk between both peaks. Hb correction followed the S-TfR peak after a second lag period (median 7 wk). Elevated S-Epo and S-TfR did not re sult in correction of anaemia in 1 patient due to impaired graft funct ion. Within 4 months, S-Epo levels reached the normal range while TfR levels were higher than normal. Follow-up of iron status demonstrated the development of iron deficiency in 5 patients, which was corrected spontaneously. Improvement in erythropoiesis after renal transplantati on seems to occur by means of expansion of the erythroid marrow, as de tected by increasing S-TfR levels, subsequent to a S-Epo peak. This ex pansion precedes Hb normalization. A nonuraemic environment is probabl y a prerequisite for the correction of anaemia but not for the increas e in S-Epo or S-TfR levels. Iron deficiency may occur after transplant ation due to an increase in iron utilization.