Detection of β-Thalassemia Carriers by Red Cell Parameters Obtained from Automatic Counters using Mathematical Formulas

Background: beta-thalassemia major is a severe disease with high morbidity. The world prevalence of carriers is around 1.5-7%. The present study aimed to find a reliable formula for detecting beta-thalassemia carriers using an extensive database of more than 22,000 samples obtained from a homogeneous population of childbearing age women with 3161 (13.6%) of beta-thalassemia carriers and to check previously published formulas. Methods: We applied a mathematical method based on the support vector machine (SVM) algorithm in the search for a reliable formula that can differentiate between thalassemia carriers and non-carriers, including normal counts or counts suspected to belong to iron-deficient women. Results: Shine's formula and our SVM formula showed > 98% sensitivity and >99.77% negative predictive value (NPV). All other published formulas gave inferior results. Conclusions: We found a reliable formula that can be incorporated into any automatic blood counter to alert health providers to the possibility of a woman being a beta-thalassemia carrier. A further simple hemoglobin characterization by HPLC analysis should be performed to confirm the diagnosis, and subsequent family studies should be carried out. Our SVM formula is currently limited to women of fertility age until further analysis in other groups can be performed.