Ineffective Erythropoiesis Markers in β-Thalassemia: A Systematic Review

<b>Background/Objectives</b>: Ineffective erythropoiesis (IE) is a hallmark of β-thalassemia and contributes to major clinical complications, including severe anemia, extramedullary hematopoiesis, and progressive iron overload. Despite its central role in disease pathophysiology, there is no established biomarker for the reliable identification and monitoring of IE. This systematic review was conducted to evaluate potential serum markers that reflect IE in β-thalassemia. <b>Methods</b>: Across seven databases (PubMed, ScienceDirect, Web of Science, SpringerLink, Taylor & Francis, ProQuest, and SAGE), thirteen studies met the eligibility criteria and were analyzed to identify circulating biomarkers associated with IE in β-thalassemia. <b>Results</b>: The most consistently reported markers were growth differentiation factor-15 (GDF-15), soluble transferrin receptor (sTfR), erythropoietin (EPO), and erythroferrone (ERFE), all of which demonstrated strong correlations with the degree of IE and erythroid expansion. Additional markers, including circulating cell-free DNA (cfDNA), CA15.3, hepcidin, ferritin, and phosphatidylserine (PS)-exposed red blood cells, were also found to be elevated, reflecting increased erythroid turnover, apoptosis, and secondary iron dysregulation. These findings suggest that while individual markers capture different aspects of IE, their combined evaluation may provide a more comprehensive picture of disease burden. <b>Conclusions</b>: IE represents the central pathophysiological driver of β-thalassemia and is closely linked to disease complications. Early detection through circulating biomarkers offers the potential for timely identification of high-risk patients, monitoring of therapeutic responses, and prognostication. Although current evidence highlights GDF-15, sTfR, ERFE, and EPO as the most promising candidates, further validation in larger, longitudinal cohorts is required before clinical implementation.