Evaluation of Red Blood Cell Indices and Reticulocyte Parameters for Thalassemia Carrier Screening Using the Dymind Automated Hematology Analyzer

Objective: The Dymind automated hematology analyzers, comprising the DF55, DH76, and DH615, were recently released. The appropriate cutoffs of the mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) for hemoglobinopathy screening are related to the study population and automated analyzers. This study aimed to evaluate the Dymind automated hematology analyzers for screening thalassemia and common abnormal hemoglobin (Hb).Material and Methods: Blood samples of known α0-thalassemia and β-thalassemia carriers were analyzed to establish the suitable cutoffs for each analyzer, derived from the receiver operating characteristic curve. These selected cutoffs were used for prospective validation for screening α0-thalassemia and β-thalassaemia, in combination with the dichlorophenolindophenol (DCIP) test for Hb E screening. Thalassemia genotypes were determined using Hb typing and Deoxyribonucleic acid (DNA) analyses.Results: MCV 80 fL and MCH 27 pg, analyzed using the DF55, DH76, and DH615 analyzers, were the appropriate cutoffs. Using these cutoffs in combination with the DCIP test for screening α0-thalassaemia, β-thalassaemia, and Hb E revealed 100% sensitivity and 100% negative predictive value. Our study showed that a reticulocyte hemoglobin equivalent (Ret-He) less than 26 pg could be indicative of both the thalassemia trait and iron deficiency. Interestingly, the cutoff below 23.7 pg is more indicative of the α0-thalassemia trait. For the sample stability study, the MCV and MCH remained stable at 4 °C. Additionally, the MCH remained stable at room temperature.Conclusion: Therefore, the combined MCV and MCH analyzed using the Dymind automated hematology analyzers with the DCIP test, together with Ret-He parameters from the DH615, are effective for screening thalassemia and common abnormal Hb in the Thai population.