Prediction of Resistance to Erythropoiesis Stimulating Agent Therapy in Hemodialysis Patients
Background and objective: The present standard of treatment of renal anemia is erythropoiesis stimulating agents (ESA) and intravenous (IV) iron preparations. Although the majority of hemodialysis (HD) patients have a good response to treatment with ESA, up to 25% of patients can be resistant to treatment with ESA, which has an important clinical and economic meaning: the studies indicate the relation between the resistance to ESA and worse clinical outcomes, increased cardiovascular morbidity and general mortality. Besides, ESA therapy is expensive and leads to enormous costs for health care systems. Therefore, methods on how to reduce the resistance to ESA and avoid unnecessary ESA consumption in the clinical practice are very necessary. The aim of this work was to provide prognostic factors for ESA resistance based on easily obtainable clinical parameters and routine laboratory markers, which allows accurate identification of HD patients at risk of ESA resistance.
Materials and methods: The prospective study was conducted in all Kaunas city outpatient HD centers from January 1, 2010, to December 31, 2015. The study group consisted of 301 patients ill with the final stage of chronic kidney disease (CKD) who underwent outpatient HD procedures at least for 6 months before the inclusion into the study. Aiming to evaluate the demand for ESA depending on the degree of anemia, we calculated the erythropoietin resistance index (ERI) defined as a weekly dose of ESA for a kilogram of body weight (IU/kg/week) divided by Hb concentration (g/dL).
Results: During multivariate binary logistic regression analysis the most significant factors predicting resistance to ESA were female sex, BMI < 20 kg/m2, cumulative iron dose > 3450 mg/year, TSAT < 22.5%, ferritin < 402.3 μg/L, phosphorus > 1.78 mmol/L, albumin < 39.6 g/L, CRP > 4.8 mg/L and the number of hospital days due to infection per year > 13.5. Diagnosis of diabetes mellitus was associated with a better response to ESA.
Conclusions: We suggest that routinely obtained data can be used in clinical practice to stratify patients according to the risk of ESA resistance, which may help to assign appropriate treatment strategies.