Diagnosis of patients with hemoglobinopathies including α-thalassemia in a laboratory with limited resources

Abstract

BACKGROUND: Diagnosis of α-thalassemia can be challenging as it is clinically insignificant in the majority of patients who are presented with one or two α-gene deletion, it cannot be always suspected from the red cell indices, and the confirmatory tests of α-thalassemia are not readily available, applied, and/or provide conclusive results. The importance of diagnosis of α-thalassemia is mainly to identify the patients with α0-thalassemia, hemoglobin (Hb) H disease, Hb Bart's hydrops fetalis, and to identify the ameliorating effect that the coinheritance of α-thalassemia may have on the clinical phenotype of patients with HbS and other structural β-globin chain variants and/or patients with beta-thalassemia. The aim of this study is to evaluate the presentation and diagnosis of patients with α-thalassemia in a cohort of Iraqi patients with hemoglobinopathies.PATIENTS, MATERIALS, AND METHODS: This is a prospective cohort study that included 216 patients diagnosed with different types of hemoglobinopathies from June 2016 to October 2019. For each patient after reviewing the cause of presentation and family history of thalassemia, blood samples were sent for complete blood count, including calculated absolute reticulocyte count, peripheral blood smear, Hb H preparation, serum iron and total iron-binding capacity, sickling test, and if indicated Hb high-performance liquid chromatography (HPLC) (using BioRad D10). Family study was requested for several patients.RESULTS: Male:female for patients with α-thalassemia is 1:1.25. Consanguinity and family history of α-thalassemia are present in 85.2% and 51.9%, respectively. Out of 216 patients with different types of hemoglobinopathies, 25% are diagnosed with isolated or copresence of α-thalassemia. Low/lower normal HbA2% is the most sensitive parameter for the diagnosis of α-thalassemia.CONCLUSIONS: The most sensitive parameter for the diagnosis of α-thalassemia in this study is the low/lower normal HbA2% in patient with normal iron study. Other parameters such as the presence of golf-ball red cells in Hb H preparation and/or presence of HbH wave in Hb HPLC can be helpful but are only seen in smaller fraction of patients.