The prevalences [correction] and patient characteristics of primary immunodeficiency diseases in Turkey--two centers study.

Purpose: Primary immunodeficiency diseases (PIDs) are inherited disorders of the immune system resulting in increased susceptibility to unusual infections and predisposition to autoimmunity and malignancies. The European Society for Immunodeficiencies (ESID) has developed an internet-based database for clinical and research data on patients with PID. This study aimed to provide a minimum estimate of the prevalence of each disorder and to determine the clinical characteristics and outcomes of patients with PID in Turkey.

Methods: Clinical features of 1435 patients with primary immunodeficiency disorders are registered in ESID Online Patient Registry by the Pediatric Immunology Departments of the Medical Faculties of Uludag University and Ege University Between 2004 and 2010. These two centers are the major contributors reporting PID patients to ESID database from Turkey.

Results: Predominantly antibody immunodeficiency (73.5 %) was the most common category followed by autoinflammatory disorders (13.3 %), other well defined immunodeficiencies (5.5 %), congenital defects of phagocyte number, function or both 3.5 %), combined T and B cell immunodeficiencies (2 %), defects in innate immunity (1 %), and diseases of immune dysregulation (0.7 %). Patients between 0 and 18 years of age constitued 94 % of total and the mean age was 9.2 ± 6 years. The consanguinity rate within the registered patients was 14.3 % (188 of 1130 patients). The prevalance of all PID cases ascertained from the registry was 30.5/100.000. The major cause of the mortality was severe infection which was seen in forty-two of seventy five deceased patients. The highest mortality was observed in patients with severe combined immunodeficiencies and ataxia-telangiectasia.

Conclusion: Promoting the awareness of PID among the medical professionals and the general public is required if premature death and serious morbidity occurs due to late diagnosis of the wider spectrum of PID are to be avoided.