Red blood cell morphology in patients with β-thalassemia minor

Background: A systematic analysis of the occurrence of red blood cell (RBC) abnormalities in beta-thalassemia minor has not been performed to date. This study aimed to identify and quantify the frequency of RBC abnormalities in patients with beta-thalassemia minor. Methods: We examined blood smears of 33 patients with beta-thalassemia minor by light microscopy for the occurrence of 15 defined RBC abnormalities. In the case of positivity, the abnormal cells/20 high power fields (HPF) at 1000-fold magnification were counted. Results: Anisocytosis, poikilocytosis and target cells (median 42/20 HPF) were observed in all, and ovalocytes in 32 (96.9%, median 10/20 HPF) subjects. Dacryocytes (81.8%), stomatocytes (81.8%, median 10/20 HPF), elliptocytes (75.8%), cells with basophilic stippling (72.7%) and irregularly contracted cells (63.6%) were frequently, and schistocytes (15.2%), bite cells (6%) and pincer cells (3%) were occasionally found. Conclusions: Morphological abnormalities of erythrocytes are common in peripheral blood (PB) smears of patients with beta-thalassemia minor. In this study, anisocytosis, poikilocytosis and target cells were apparent in all, and ovalocytes, elliptocytes, cells with basophilic stippling, dacryocytes, stomatocytes and irregularly contracted cells were observed in the majority of the analyzed slides. Our observations may be useful to improve the differential diagnosis of anemia in clinical laboratory routine.