Role of Absolute Reticulocyte Count in Evaluation of Pancytopenia in Patients Undergoing Bone Marrow Biopsy

Abstract

Background: Pancytopenia is a hematological condition characterized by a simultaneous decrease in red blood cells, white blood cells, and platelets, reflecting a wide spectrum of underlying bone marrow pathologies. Bone marrow biopsy remains the gold standard for diagnosis; however, in this context, the absolute reticulocyte count (ARC) serves as a potentially valuable, non-invasive biomarker reflecting marrow activity and erythropoietic function. Aims & Objectives: The primary objectives of this study were to assess the diagnostic utility of ARC in patients undergoing bone marrow biopsy for pancytopenia, to determine whether ARC can accurately predict the underlying etiology, to achieve at least an 80% diagnostic concordance between ARC and bone marrow biopsy results, and to evaluate the feasibility of implementing ARC as a first-line, non-invasive diagnostic approach prior to bone marrow examination. Methodology: This comparative cross-sectional study was conducted at the Central Diagnostic Laboratory, Mayo Hospital/King Edward Medical University, Lahore, over a period of 15–30 days following ethical approval. Non-probability convenience sampling was employed to recruit patients fulfilling the diagnostic criteria for pancytopenia. Two milliliters of EDTA-anticoagulated blood were collected from each patient after obtaining informed consent. Samples that were clotted, hemolyzed, lipemic, or insufficient were excluded. The ARC was calculated using the reticulocyte percentage and red blood cell (RBC) count. Data were analyzed using SPSS version 23, with quantitative variables expressed as mean ± standard deviation (SD) and qualitative variables presented as frequencies and percentages. Results and Findings: A total of 147 pancytopenic cases were analyzed. The most prevalent underlying cause was aplastic anemia (n=61; 41.4%), followed by leukemia (n=40; 27.2%), myelodysplastic syndrome (MDS) (n=17; 11.6%), infections (n=14; 9.5%), megaloblastic anemia (n=11; 7.5%), and bone marrow necrosis (n=4; 2.7%). The mean ARC was lowest in aplastic anemia and necrosis (11.7×10⁹/L and 3.9×10⁹/L, respectively), indicating markedly reduced marrow activity. Megaloblastic anemia (18.36×10⁹/L) and MDS (26.1×10⁹/L) demonstrated moderately low values, while infections (105.9×10⁹/L) and leukemia (81.06×10⁹/L) showed significantly elevated ARC levels, suggesting hyperactive marrow response. A strong correlation was observed between ARC levels and bone marrow biopsy findings, supporting ARC’s role as a predictive diagnostic parameter. Conclusion: The study demonstrates that the absolute reticulocyte count is a reliable, non-invasive, and rapid indicator of bone marrow activity, showing a strong diagnostic correlation with bone marrow biopsy findings in pancytopenia. ARC can serve as an effective preliminary tool for differentiating hypo-productive and hyper-productive marrow conditions such as aplastic anemia, megaloblastic anemia, leukemia, and infections. While bone marrow biopsy remains indispensable for definitive diagnosis and prognosis, incorporating ARC as an initial diagnostic measure could enhance clinical decision-making and reduce unnecessary invasive procedures.