Utility of reticulocyte indices in the diagnosis of pancytopenia

INTRODUCTION: Pancytopenia is a hematological condition in which there is a reduction in all three cell lines of blood. This study aims to evaluate the utility of reticulocyte indices such as reticulocyte % (retic %), immature reticulocyte fraction (IRF), and mean reticulocyte volume (MRV) in identifying the cause of pancytopenia. MATERIALS AND METHODS: Reticulocyte indices were measured by an automated coulter. These values were then correlated with relevant biochemical and bone marrow results and cases were stratified into different etiological groups. Receiver operator curve (ROC) analysis was performed and various cut-off values were derived based on the reticulocyte indices. ROC was repeated to further classify cut-off values at every level to help formulate a diagnostic algorithm. RESULTS: A total of 154 cases of pancytopenia were obtained. Ages ranged from 7 months to 87 years with a mean of 42, the male:female ratio was 1.08:1. The majority of the cases were megaloblastic anemias in which the cut-off values for retic % was <0.91 with a sensitivity of 78.1% and specificity of 70%, IRF was 0.45 with a sensitivity of 76.7% and specificity of 64%, and MRV was >121.8 fl with a sensitivity of 83.6% and specificity of 80%. The values on ROC could segregate nutritional from nonnutritional causes. The IRF and MRV also helped to differentiate megaloblastic anemia from dual deficiency anemia. CONCLUSION: Reticulocyte indices help identify the cause of pancytopenia. They can segregate nutritional anemia from other causes of pancytopenia allowing presumptive treatment to be initiated and may obviate invasive procedures such as bone marrow examination.