COVID-19 in patients with transfusion dependent thalassemia in Indonesia: characteristics of the disease and patients, and comparison between epidemiological data for COVID-19 and thalassemia in Indonesia and South-East Asia

People living with transfusion dependent thalassemia have a high risk of getting infected by COVID-19. This can be caused both by internal factors, namely the formation of alloantibodies and autoimmune disorders, and external factors such as routine visits for blood transfusions. Chronic complications of thalassemia also render the patients more vulnerable to infectious diseases, including COVID-19. However, anecdotal data shows that thalassemia patients have less incidence of COVID-19 if compared to the general population. This study aims to find the correlation between COVID-19 in thalassemia-dependent transfusion patients in Indonesia and South-East Asia. This research used a cross-sectional design. The study was conducted at the Division of Haematology and Medical Oncology of the Cipto Mangunkusumo Hospital in Jakarta, from May 2020 to August 2021. Total sampling method was used involving all thalassemia major patients who had been infected with COVID-19 obtained directly from medical records and through the thalassemia patients’ parents foundation. In 10,397 patients with thalassemia, 67 (0.64%) people were infected by COVID-19 and two (2.9%) died. 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 is also seen in other countries with a high prevalence of thalassemia, which show less COVID-19 cases despite the pandemic. On the contrary, countries with low rates of thalassemia carriers had experienced deadly surges of the pandemic. Indonesia and other countries with a high prevalence of thalassemia have lower COVID-19 incidence than countries with a 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 against COVID-19.