Diagnostic accuracy and clinical usefulness of erythrocyte creatine content to predict the improvement of anaemia in patients receiving maintenance haemodialysis

Abstract

Background The improvement of anaemia over time by eythropoiesis stimulating agent (ESA) is associated with better survival in haemodialysis patients. We previously reported that erythrocyte creatine, a marker of erythropoietic capacity, was a reliable marker to estimate the effectiveness of ESA. The aim of this study was to examine the accuracy and clinical usefulness of erythrocyte creatine content to predict the improvement of anaemia in haemodialysis patients. Methods ESA dose was fixed 3 months prior to the enrollment and was maintained throughout the study period. Erythrocyte creatine and haematologic indices were measured at baseline in 92 patients receiving maintenance haemodialysis. Haemoglobin was also measured 3 months after. Improvement of anaemia was defined as ≥ 0.8 g/dL change in haemoglobin from baseline to 3 months. Results Erythrocyte creatine was significantly higher in 32 patients with improvement of anaemia compared to 60 patients with no improvement of anaemia (2.47 ± 0.74 vs. 1.57 ± 0.49 µmol/gHb, P = 0.0001). When 10 variables (anaemia at baseline, iron deficiency at baseline, erythrocyte creatine, ESA dose, reticulocyte, haptoglobin, C-reactive protein, intact PTH, serum calcium and albumin) were used in the multivariate logistic analysis, erythrocyte creatine emerged as the most important variable associated with the improvement of anaemia (P = 0.0001). The optimal cut-off point of erythrocyte creatine to detect the improvement of anaemia was 1.78 µmol/gHb (Area under the curve: 0.86). Sensitivity and specificity of erythrocyte creatine to detect the improvement of anaemia were 83.3% and 90.6%. Conclusion Erythrocyte creatine content is a reliable marker to predict the improvement of anaemia 3 months ahead in patients receiving maintenance haemodialysis.