Imperfect Maturation of Erythroid Progenitors in Patients with Cirrhosis-Associated Anemia

Background and Aims: Anemia is seen in nearly >70% of patients with cirrhosis and is often non-responsive to nutritional supplements; therefore, we assessed the erythropoiesis and associated alteration in bone marrow (BM). Methods: It is a cross-sectional study. Flow cytometry was performed to assess the hematopoietic stem cells (HSCs) and erythroid population of 60 patients with cirrhosis compared with patients with 7 non-cirrhotic portal fibrosis (NCPF) and 3 controls. Proteomics were performed of the pure CD71 erythroid population taken from patients with cirrhosis to decipher the internal abnormalities supported by validation experiments. Real Time PCR, colony assay and heme quantification, cytokine array, and ELISA were performed to assess erythropoietic stimulating agents (ESA), inflammatory cytokines, and growth factors as an external factor affecting erythropoiesis. Results: We found a decrease in intermediate erythroid progenitors [IEPs; CD71+ CD235a+], conversely early erythroid precursors [EEP; CD71+ CD235a-] and late erythroid progenitors [LEP; CD71- CD235a+] were increased (p < 0.05) in cirrhotic and NCPF as compared to control. However, unlike NCPF, cirrhosis exhibited decreased CD71+ transferrin receptor (TfR1) expression over erythroid cells and increased immature erythrocytes (p < 0.05) in peripheral circulation. In vitro culture of erythroid precursors showed impaired differentiation and maturation that was confirmed by the reduced (p < 0.05) number of erythroid colonies (BFU-E). Proteomics analysis showed downregulated proteins associated with hemoglobin synthesis, ROS detoxification, translation, and mitochondrial activity. Furthermore, we found an altered expression of genes related to erythropoiesis and hemoglobin synthesis and increase (p < 0.05) in inflammatory cytokines such as IL-5, TRAIL-R2, TGF-α, and TGF-β in BM. Conclusions: This study suggests that the dysregulated erythropoiesis observed in patients with cirrhosis having anemia is maintained despite adequate nutrition.