COVID-19 in Patients with Transfusion Dependent Thalassemia (TDT) in Indonesia: Characteristics of the Disease and Patients, and Comparison between Epidemiological Data for COVID-19 and Thalassemia in Indonesia and Southeast Asia

Background: People living with transfusion dependent thalassemia have a high risk of becoming infected with COVID-19. This can be caused by both internal factors, namely the formation of alloantibodies and autoimmune disorder, and external factors such as routine visits for blood transfusions. Chronic complications of thalassemia also render them more vulnerable to infectious diseases, including COVID-19. However, anecdotal data shows that thalassemia patients experience less incidence of COVID-19 compared to the general population. Purpose: This study aims to find the correlation between COVID-19 in thalassemia-dependent transfusion patients in Indonesia and Southeast Asia. Patients and Methods: This study used a cross-sectional design. The study was conducted at the Division of Hematology and Medical Oncology of the Cipto Mangunkusumo Hospital in Jakarta from May 2020–August 2021. The total sampling method was used involving all thalassemia major patients who had been infected with COVID-19 (obtained directly from medical record and through the thalassemia patients-parents foundation). Results: From 10,397 patients with thalassemia, 67 (0.64%) people were infected by COVID-19 and 2 (2.9%) were deceased. Meanwhile, the incidence of COVID-19 in the general population of Indonesia was 0.87% (more than in the thalassemia population). This means that thalassemia might provide additional protection against COVID-19 due to several mechanisms. This phenomenon has also been seen in other countries with a high prevalence of thalassemia, wherein there are less COVID-19 cases despite the pandemic. On the contrary, countries with low rates of thalassemia had experienced deadly surges of the pandemic. Conclusion: Indonesia and other countries with a high prevalence of thalassemia have lower COVID-19 incidence than countries with low prevalence of thalassemia. Thalassemia might provide additional protection against COVID-19. Well-designed studies are needed to provide better evidence on the protective effect of thalassemia on COVID-19.