Study Zeroes In On Post-Transplant Anemia
Anemia that occurs after renal transplantation is due to more than just impaired allograft function. Gender, creatinine clearance, and age also contribute to development of the condition.
Steven J. Chadban, MD, PhD, of the Royal Prince Alfred Hospital in Camperdown, New South Wales, and his colleagues compared the prevalence of anemia in 851 kidney transplant recipients and 732 non-transplant CKD patients. At the time data was gathered for the study, the transplant group had a mean age of 48 years compared with 64 years for the CKD group.
Although the groups were matched for creatinine clearance (mean 65 and 68 mL/min per 1.73 m2, respectively), the prevalence of anemia was 30.8% in the transplant recipients compared with 3.4% in the CKD patients, according to a report in the American Journal of Kidney Diseases (2007;49:301-309).
Dr. Chadban's group calculated that transplant status, creatinine clearance, gender, and age taken together are responsible for 56% of the variability in hemoglobin concentration between the groups.In both groups, anemia occurred more frequently in women than men. In the transplant group, 35.9% of women had anemia compared with 26.6% of men; the proportions in the CKD group were 6.0% and 1.3%, respectively.
The investigators defined anemia as a hemoglobin concentration less than 120 g/L in women and less than 125 g/L in men. In each group, hemoglobin concentration was related to creatinine clearance, but the magnitude of the relationship was different in the groups.
At a creatinine clearance of 120 mL/min per 1.73 m2, the hemoglobin concentration in transplant recipients was only 6 g/L lower than in subjects with CKD; but at a creatinine clearance of 40 mL/min per 1.73 m2, the hemoglobin concentration in transplant recipients was 14 g/L lower. Each decrease in creatinine clearance of 10 mL/min per 1.73 m2 was associated with a reduction in hemoglobin concentration of 2.3 g/L in men and 2.0 g/L in women. Hemoglobin concentration was not related to either the time from transplantation or a diagnosis of diabetes.The researchers concluded that renal transplantation is associated with a “dramatic excess” in anemia compared with non-transplant patients with CKD.
Transplant-related drug therapy could explain some of the excess anemia, according to the investigators. Use of some immunosuppressive medications was associated with lower hemoglobin concentrations.
For example, men and women who treated with cyclosporin had a mean hemoglobin level of 129 g/L compared with 136 g/L in patients who did not receive the drug. In male transplant patients only, tacrolimus use was associated with a lower mean hemoglobin level compared with no use of the drug (134 vs. 141 g/L).