Evaluation of reticulocyte indices and mathematical formulas for beta-thalassemia carriers screening among Egyptian beta-thalassemia patients’ families

Background Egypt lies within the global thalassemia belt, where beta-thalassemia presents a notable socioeconomic burden. Patients and methods One hundred fifty-seven relatives of beta-thalassemia patients were included in this cross-sectional study. It aimed to ascertain a cost-efficient and accurate screening approach for identifying beta-thalassemia carriers (BTC) by evaluating some erythrocyte and reticulocyte parameters measured on Advia 2120 analyzer (Siemens) and assessing four mathematical Formulas (Metzner index, Green and King et al. , Roth et al. , and Vicinanza et al. formulas). Results Participants were stratified into distinct categories: BTC (42%), normal (24.2%), mild iron-deficiency anemia (IDA) (17.2%), severe IDA (3.8%), and a subset with both IDA and BTC (mix group) accounting for 12.7%. Receiver operating characteristic curve analysis identified absolute reticulocyte count as the optimal discriminator (area under a curve=0.837) between BTC and IDA. The Mentzer index and Green and King et al. formula demonstrated superior diagnostic utility among the evaluated formulas. However, none of the formulas effectively distinguished between BTC and the mix group, a frequently overlooked and challenging group for diagnosis. Interestingly, our data highlighted absolute reticulocyte count and percentage as the sole parameters capable of distinguishing BTC from the mix group. Consequently, two algorithms were developed. The first one had a good agreement (κ=0.62) with 77.3% concordance, while the second one demonstrated improved screening performance (κ=0.66) with 79.8% agreement. Conclusion The optimal screening strategy involves distinguishing between various categories of both IDA and BTC. Our algorithms, designed as a low-cost and user-friendly mass screening tool, may serve this purpose effectively.