Comparative analysis of four methods for enumeration of platelet counts in thrombocytopenic patients

Background: Even with the most reliable automated blood cell analyzers, obtaining an accurate platelet count in patients with thrombocytopenia is still challenging especially when making decisions for platelet transfusions. The Cell-Dyn Sapphire offers three methods for platelet counting including the optical, impedance, and immunological techniques. Aim: A comparative analysis evaluating the performance of these three methods, along with the manual technique, was performed in thrombocytopenic patients. Materials and Methods: A total of 32 blood samples from patients without a history of chemotherapy and a platelet count <50 ×- 109/l were tested in parallel by four different methods. Results: Compared to other techniques, impedance method provided an overestimation of platelet count (P = 0.0008) and failed to show a result in 15% of cases with low platelet counts (