POSTTRANSPLANTATION ANEMIA IN ADULT RENAL ALLOGRAFT RECIPIENTS: PREVALENCE AND PREDICTORS

Transplantation, April 27, 2006; 81(8): 1112-8.

BACKGROUND: Management of anemia is an important factor in the care of patients with chronic kidney disease as the anemic state can confer significant morbidity and mortality. Posttransplantation anemia (PTA) has received comparatively less attention in the literature, and the prevalence and predictors of PTA vary between different studies. The purpose of this study was to investigate a large posttransplant population from 3 centres in the UK to elucidate the point prevalence of PTA, its determinants and the use of erythropoiesis stimulating agents (ESA) in these patients.

METHODS: All adult patients with functioning renal transplants and attending renal transplant outpatients at Guy's, King's College, or St. Helier Hospitals, London, as of 31/12/2004 who had a valid hemoglobin in the previous 3 months, and who were more than 3 months postengraftment, were identified. Patients' notes and electronic patient records were obtained and a detailed cross-sectional clinical and biochemical database was constructed. The data were analyzed for the point prevalence of PTA, the prevalence of ESA use and for determinants of hemoglobin. The WHO criteria were used to define anemia and all patients on treatment with an ESA was classified as anemic irrespective of hemoglobin.

RESULTS: A total of 1,511 (947 male) patients were studied. Mean age was 48.1+/-13.7 years with no difference between the sexes. Mean time posttransplantation was 8.5+/-7.2 years and mean estimated MDRD GFR was 47.6+/-18.9 ml/min with a higher GFR in males (49.9+/-19.0 v 43.8+/-18.0 mL/min, P<0.0001). Mean hemoglobin in the studied population was 12.9+/-1.6 g/dl with a significantly higher level among males than females (mean 13.3+/-1.6 v 12.3+/-1.4 g/dl, P<0.0001). The prevalence of anemia was 45.6% with a prevalence of 44.1% among males and 48.1% amongst females. Severe anemia was present in 50 subjects (3.3% of the total cohort). One hundred and forty-five patients (9.6% of the entire cohort) were being treated with an ESA. Of these subjects, 41 did not meet WHO criteria for the definition of anemia. After multiple regression analyses, age, female sex, renal function and to a lesser extent serum ferritin and therapy with angiotensin converting enzyme inhibitors/angiotensin II receptor blockers (both negatively associated) were predictive of hemoglobin.

CONCLUSIONS: The prevalence of anemia posttransplantation was high while comparatively few patients were being treated with erythropoiesis stimulating agents. The strongest predictors of hemoglobin in this cohort of patients were age, female sex and allograft function. Medical therapy with MMF and sirolimus was associated with a high prevalence of anemia but this was likely to be the result of poorer graft function in these subjects who mostly had chronic allograft nephropathy. A large interventional prospective study with valid control groups is now needed to assess the long-term contributions of clinical and biochemical factors of renal function and to elucidate the effects of therapy on outcome.