Background. Inborn errors of immunity (IEIs) are a group of heterogeneous disorders with inherited faults in the immune system that increase susceptibility to infections, malignancies, lymphoproliferation, and autoimmune/autoinflammatory disorders. Methods. We retrospectively studied the demographic characteristics, clinical features, and immunological profiles of the 90 IEIs patients, who were diagnosed and classified according to the European Society for Immunodeficiencies (ESID) and International Union of Immunological Societies (IUIS) criteria from July 2010 to June 2021. The study was carried out in the Non-communicable Diseases Research Center, Imam Ali Hospital, Alborz, Iran. Results. Within a period of 11 years, 53 (58.9%) males and 37 (41.1%) females were diagnosed and followed up for 20 IEI disorders. The median (IQR) age of onset, age of clinical diagnosis and diagnostic delay was 0.7 (0.08-2.0), 3.18 (1.0-8.0) and 1.5 (0.17-5.0) years, respectively. Twelve patients (36.4%) had a positive family history of IEI, and the majority of patients (84.5%) had recurrent infections. Pneumonia (51.7%) was the most common clinical manifestation among IEI patients, followed by skin complications (46.2%). The most frequently diagnosed IEI was immunoglobulin A deficiency (IgAD) (14.4%) and severe combined immunodeficiency (SCID) (11.1%). Predominantly antibody deficiencies group (36.7%) was the most common category, followed by combined immunodeficiencies with associated or syndromic features group (27.8%). Conclusions. IEIs have different patterns within populations with high consanguinity. There is a need to search for underlying genetic and epigenetic factors in most common IEIs in Alborz.
Keywords: Clinical features; demographic characteristics; heterogeneous disorders; immune system; inborn errors of immunity.