Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 0 0 2026 04 29 1 9 EN Leila Ghasemi Hashtrodi Department of Pediatric Rheumatology, Shahid Beheshti University of Medical Sciences, Tehran, Iran Zahra Chavoshzadeh Department of Allergy and Clinical Immunology, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mehrnaz Mesdaghi Department of Allergy and Clinical Immunology, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Narges Eslami Department of Allergy and Clinical Immunology, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Golnaz Eslamian Department of Allergy and Clinical Immunology, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mehdi Alizadeh Children Growth Research Center, Research Institute for Prevention of Non-Communicable Diseases, Ghods Hospital, Qazvin University of Medical Sciences, Qazvin, Iran Leily Sokoty Department of Epidemiology, Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Alborz, Iran Shahrzad Fallah Department of Allergy and Clinical Immunology, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Maryam Asarehzadegan Dezfouli Department of Allergy and Clinical Immunology, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Maryam Heydarazad Zadeh Department of Allergy and Clinical Immunology, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Shabnam Hajiani Ghotbabadi Department of Rheumatology, Shiraz University of Medical Sciences, Shiraz, Iran Hedieh Haji Khodavardi Khani Department of Immunology, Faculty of Medical Science, Shahed University, Tehran, Iran Nima Parvaneh Division of Allergy and Clinical Immunology, Department of Pediatrics, Children's Medical Center Hospital, Tehran University of Medical Sciences, Tehran, Iran Reza Sinaee Department of Pediatrics, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran Azadeh Zeinab Mirzaee Pediatric Respiratory Disease Research Center (PRDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Masih Daneshvari Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Nima Rezaei Research Center for Immunodeficiencies, Children's Medical Center Hospital, Tehran University of Medical Sciences, Tehran, Iran AND Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran Samin Sharafian Department of Allergy and Clinical Immunology, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran Reza Shiari Department of Pediatric Rheumatology, Mofid Children’s Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2025 04 04 2025 11 14 Combined immunodeficiencies (CIDs) represent a rare group of inherited immune disorders in which defects in T- and B-lymphocyte function lead to recurrent infections, immune dysregulation, and an increased tendency toward autoimmune and rheumatologic complications. A retrospective cross-sectional analysis was performed on 150 patients with CID, diagnosed according to the European Society for Immunodeficiencies (ESID) criteria and followed at the Children’s Medical Center and Mofid Children’s Hospital (Tehran, Iran) between 2009 and 2020. Clinical records, immunologic evaluations, and rheumatologic findings were reviewed, with particular attention to autoantibody detection and disease frequency. Among 150 patients, 42 (28%) exhibited rheumatologic manifestations, with a higher frequency in females. Undifferentiated rheumatoid arthritis, undifferentiated juvenile idiopathic arthritis, and Kawasaki disease were the predominant conditions. Although lower lymphocyte counts and immunoglobulin levels were observed among non-rheumatologic patients, the differences were not statistically significant. Impairments in T-cell–mediated immunity and antibody synthesis among individuals with CID hinder the recognition of autoantibody-associated rheumatologic disorders and delay diagnosis. Moreover, these conditions often present atypically in immunocompromised hosts; therefore, a vigilant clinical approach is essential for early identification and management. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/4405 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/4405/2332