Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 40 3 2002 09 15 165 170 "Aghamohammadi A Moin M Farhoudi A Pourpak Z Rezaei N Abolmaali K Movahedi M Gharagozlou M Mir Saeid Ghazi B Atarod L Hojati Ashrafi T Mahmoudi M Isaeian A Mansouri D Arshi S " 2015 09 28 Epidemiological studies have shown wide geographical and racial variation in the prevalence and patterns of immunodeficiency disorders. To determine the frequency of primary immunodeficiencies (PID) in Iran, the Iranian primary Immunodeficiencies Registry (IPIDR) was organized in 1999. the diagnosis of immunodeficiency in our patients was based on standard criteria. The patient’s data were extracted, by using a uniform questionnaire from their hospital records. Three hundred and twenty eight patients with PID have been registered in our registry till 2000. Among these patients, the following frequencies were found: predominantly antibody deficiency in 48.48% of patients (n=159), T-cell disorders in 25.91% (n=85), phagocytic disorders in 24.7% (n=81), and complement deficiencies in 0.91% (n=3). Common variable immunodeficiency was the most frequent disorder (n=73), followe by chronic granulomatous disease (n=55), ataxia telangiectasia (n=39), x-linked agammaglobulinemia (n=35), selective IgA deficiency (n=34). This study reveals that antibody deficiencies are the most frequent diagnosed primary immunodeficiency disorder in our patients, which is similar to that observed in other registries. A comparative study shows some differences between our results and other registries https://acta.tums.ac.ir/index.php/acta/article/view/2603 https://acta.tums.ac.ir/index.php/acta/article/download/2603/2585