Inborn Errors of Immunity-the Sri Lankan Experience 2010-2022.

PURPOSE:Inborn errors of immunity (IEI) are typically monogenic. Data from the Indian subcontinent are relatively scarce. This paper evaluates IEI diagnosed in Sri Lanka. METHODS:Data of patients diagnosed with IEI from 2010 to 2022 at the Department of Immunology, Medical Research Institute, Colombo, Sri Lanka, were retrospectively analyzed. RESULTS:Two hundred and six patients were diagnosed with IEI, with a prevalence of 0.94 per 100,000. The onset of disease was below 12 years in 84.9%, whereas in 10.9%, it was after 18 years. The male: female ratio was 1.78:1. Consanguinity was identified in 26.6%. IEI were found in all but one (bone marrow failure) of the 10 IUIS categories. Predominantly antibody deficiencies were the most common category among the nine identified (30.1%), followed by combined immune deficiencies with syndromic features (21.3%), immunodeficiencies affecting cellular and humoral immunity (19.9%), congenital defects of phagocyte number or function (13.1%), and defects in intrinsic and innate immunity (8.2%). Severe combined immune deficiency (SCID) was the commonest disease (14.6%), followed by chronic granulomatous disease (CGD) (10.6%) and X linked agammaglobulinemia (8.7%). Of the patients with a known outcome (n = 184), 51 died (27.7%). Mortality rates were high in SCID (83.3%), Omenn syndrome (OS) (100%), and CGD (31.8%) patients. CONCLUSION:IEI in Sri Lanka are diagnosed mainly in childhood. The low diagnosis rates suggest a need for educating clinicians regarding IEI in adulthood. The high mortality rates associated with some IEI indicate the need of transplant services in the country.