Endogenous Erythropoietin and Hepatic Dysfunction in Acute Kidney Injury Requiring Renal Replacement Therapy

Backgrounds/Objectives: Elevated erythropoietin (EPO) is observed in human acute kidney injury (AKI). Whether blood EPO level is associated with mortality or other organ dysfunction in critically ill patients is unknown. Methods: A prospective observational cohort study of 162 AKI patients requiring renal replacement therapy (RRT) was conducted in our intensive care unit (ICU) during October 2013 through October 2016. We evaluated the relation with plasma EPO at RRT initiation and 90-day mortality, hemoglobin, urine output, and sequential organ failure assessment (SOFA) score until day 7 or discharge from the ICU. Results: The analysis revealed that EPO was significantly associated with 90-day mortality with an adjusted hazard ratio of 2.13 (95% CI 1.11–5.78). Hemoglobin levels, RRT dependence, and daily urine output on days 1 through 7 did not differ between the high EPO group (≥56.2 mIU/mL) and low EPO groups (< 56.2 mIU/mL). As for organ dysfunction, hyperbilirubinemia patients (≥2.0 mg/dL; hepatic SOFA ≥2) were more frequent in the high EPO group (62.1 vs. 37.9%; p < 0.05), while other SOFA scores did not differ between both groups. Exacerbation of hepatic dysfunction was observed more frequently in the high EPO than the low EPO group (49.3 vs. 27.2%; p < 0.05). Conclusion: Elevated EPO was not associated with anemia or RRT dependence. However, higher rates of mortality and hepatic dysfunction were observed in high EPO patients than in low EPO patients.