Objective: Common Variable Immune Deficiency (CVID) is a heterogeneous immune disorder characterized by impaired and/or inadequate B cell differentiation with hypogammaglobulinemia. It is characterized by frequent and recurrent respiratory infections, autoimmune disorders, chronic lung diseases, granulomatous diseases, and increased risk for lymphoid malignancies.

Materials and Methods: The medical records of 47 patients (22 females, 25 males) who had been followed up at our clinic and had sufficient data in their files were retrospectively reviewed. Patients were diagnosed with CVID according to the ESID (European Society for Immunodeficiency) criteria.

Results: The median age of the patients was 32 (19-65) years. The most frequent clinical presentation of the patients was with recurrent upper respiratory infections (46%), pneumonia (29.8%), otitis media (23.4%) and chronic sinusitis (17%). During the follow-up period, 17 patients (36.8%) developed autoimmune complications, 14 (29.8%) of whom had autoimmune cytopenia. A total of 26 patients (55.3%) had bronchiectasis confirmed with computed tomography of the thorax. Lymphopenia was detected in 13 patients (27.7%). The median immunoglobulin level at the time of diagnosis was IgG 2.77 (0.33-6.90) g/L, IgM 0.31 (0.06-5.99) g/L, and IgA 0.25 (0.01- 5.02) g/L.

Conclusion: CVID is very heterogeneous in terms of both clinical and laboratory features. Moreover, it is more common than expected, particularly in adulthood. The centers dealing with CVID should share their experiences in order to increase awareness among physicians.