Thalassemia and COVID-19: Susceptibility and Severity

Context: COVID-19 results in an imbalance between procoagulant and anticoagulant homeostatic mechanisms that could be complicated with thrombotic events. In Betha-thalassemia patients, the presence of comorbidities, iron overload, adrenal hypofunction, splenectomy, and chronic hypercoagulable state might increase the susceptibility to COVID-19 and its severity. Evidence Acquisition: The search was conducted in PubMed, Web of Science, and Scopus databases for the key terms of Betha- thalassemia/thalassemia and COVID-19 until July 2021. Results: The survey of published observational studies (mostly multicenterandcase reports) indicated a lower prevalence of COVID- 19 in Betha-thalassemia patients compared with the general population, as well as mild to moderate COVID-19 in these patients, especially in those without comorbidity. Betha-Thalassemia children were susceptible to COVID-19 but with less severity compared to adults. There is no report of pulmonary embolism and thrombotic events in Betha-thalassemia patients with COVID-19; however, coagulation abnormality and pulmonary microembolism have been found in these patients. Conclusions: Findings could be interpreted by the presence of high hemoglobin F (HbF) levels, the advantage of hydroxyurea (HU) therapy, splenectomy, and iron chelation therapy in these patients. However, due to the low sample size and studying mainly young patients, the results should be interpreted with caution, and it still needs more studies with a larger sample size to confirm these findings.