Vitamin D deficiency in the absence of enteropathy in three cases with common variable immunodeficiency

Background: Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia and a defect in antibody production. Herein we describe 3 patients diagnosed with CVID in whom vitamin D deficiency was detected in the absence of enteropathy. Methods: Biochemical and immunological analysis, serum osteocalcin, parathyroid hormone, 25-OH vitamin D, 1,25(OH) 2 vitamin D, vitamin A, vitamin E, urinary calcium, and deoxypyridinoline measurements were carried out. Vitamin D receptor (VDR) expression was examined in the peripheral blood mononuclear cells and hair follicles by reverse transcriptase polymerase chain reaction. VDR gene polymorphism was evaluated by high-performance liquid chromatography. Results: None of the patients presented nutrient deficiencies other than vitamin D. Two of them were free of osteomalacia-related symptoms. VDR expression was found to be lower in the peripheral blood mononuclear cells and hair follicles when compared to the control group. Conclusions: Patients with CVID may present asymptomatic vitamin D deficiency. Vitamin D and VDRs play an important role in the innate immune system and modulate Toll-like receptor-related responses. Delay in diagnosis may predispose these patients not only to irreparable bone loss but also to infections, and autoimmune and malignant disorders, thus emphasizing the importance of prompt intervention. Copyright (C) 2008 S. Karger AG, Basel.