Anemia in Kidney Transplants Without Erythropoietic Agents: Levels of Erythropoietin and Iron Parameters

Abstract Aim To study the association between hemoglobin, endogenous erythropoietin (EPO) levels and ferric parameters in kidney recipients not treated with EPO-stimulating agents. Materials and methods Transverse study of 219 kidney transplant outpatients. The median time after transplantation was 54 months (P 25–75 , 23–107). We assessed blood counts, ferric parameters, EPO levels, renal function (MDRD-4), and adjuvant treatment. We performed a linear regression analysis to predict hemoglobin. Results Median EPO values were 14.05 mUI/mL (P 25–75 = 10.2–19.7). Applying the formulas described by Beguin, kidney transplant recipients showed a low observed/expected ratio of erythropoietin and of transferrin. Considering anemia to be an hemoglobin of n = 53), including 2.3% with hemoglobin 2 in nonanemic; P = .021). There were no differences in C-reactive protein. The patients receiving a combination of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) showed the highest prevalence of anemia compared with other groups (42.9%, P = .027). EPO levels were significantly lower among patients treated with these drugs ( P = .041), without differences in transferrin and ferritin. The percentage of anemic patients treated with mammalian target of rapamycin inhibitors (mTORi) was 31% versus 22.2% among those not receiving these immunosuppressants ( P = .23). Although there were no differences in hemoglobin levels, patients treated with mTORi, showed higher EPO levels ( P = .005) and lower mean corpuscular volume ( P P = .021). The formula obtained by multiple linear regression to calculate hemoglobin was: hemoglobin = 11829–0909 * log (EPG level) − 0455 (if female) + 0.010 * 0.013 * transferrin + 0.013 * creatinine clearance (r = .424, P Conclusions Treatment with ACEI and/or ARBs seemed to produce a defect in the synthesis of EPO, while those treated with mTORi, a hyporesponsive state.