Tehran University of Medical Sciences Immunology and Genetics Journal 2645-4831 2 3 2019 09 01 135 146 Salar Pashangzadeh Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Science, Tehran, Iran AND Department of immunology, Faculty of medicine, Iran University of medical sciences, Tehran, Iran Mahsa Sohani Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Science, Tehran, Iran AND Department of Hematology and Blood Transfusion, Students Research Center, School of Allied Medicine, Tehra 2019 07 19 Background/objectives: Among primary immunodeficiency (PID), selective immunoglobulin A deficiency (SIgAD) is the most prevalent type. SIgAD patients can be either asymptomatic or symptomatic. Symptomatic patients suffer from a wide range of manifestations including infections, allergy, autoimmunity, and malignancy. SIgAD patients are more susceptible to some autoimmune diseases, while the exact mechanisms behind this association are not found yet. Therefore, this study was conducted in order to evaluate the possible association between autoimmune disease and specific clinical records or immunological data in SIgAD patients. Methods: The present cohort included 166 SIgAD patients who were diagnosed at the Research Centre for Immunodeficiencies at the children’s medical Centre. A comprehensive history, demographic information, clinical manifestations, laboratory data were obtained from all patients to assess the autoimmune complications. Results: Autoimmunity was seen in 16 patients (9.6%, 10 males and 6 females). The most common autoimmunity types were juvenile idiopathic arthritis, vitiligo and alopecia (18.8%). 9 patients (6.5%) had a PID family history. Significant data that were higher in patients with autoimmunity were the mean age at the study time (p=0.019), rheumatoid problem (p=0.043), liver problem (p=0.031), IgG level (p=0.006) and IgE level (p=0.004). Conclusion: The association between SIgA deficiency and autoimmunity could lead to severe clinical complications. So, it is better for immunologists to aware of these problems. https://igj.tums.ac.ir/index.php/igj/article/view/33 https://igj.tums.ac.ir/index.php/igj/article/download/33/23