Bone Metabolism Alterations in Patients with Common Variable Immune Deficiency: A Retrospective Cohort Study

Objective: Common variable immunodeficiency (CVID) is a relatively frequent primary immunodeficiency disorder characterized by impaired B cell differentiation with hypogammaglobulinemia in the European Society for Immunodeficiencies (ESID) registry system. Increased inflammatory cytokines, prolonged and/or recurrent infections, gastrointestinal complications, and anti-inflammatory medications are risk factors for diminished bone mineral density (BMD) in CVID patients. Materials and Methods: The study group included 32 patients with CVID (19 males and 13 females; mean age: 37.33 ± 13.70 years, 40.6% female), who had been followed up on a regular basis for a period of four years. The patients were categorized into two groups according to their BMD: low BMD and normal BMD. Results: Seventeen patients (8 females and 9 males) had normal BMD (mean age 34.94 ± 11.41 years, 47.1% female) and fifteen patients (5 females and 10 males) had low BMD (mean age 40.03 ± 15.87 years, 33.3% female). In the low BMD group, three patients had osteoporosis and 12 patients had osteopenia. Univariate regression analysis revealed that lymphopenia (odds ratio, OR:6.562, 95% confidence interval, CI: 1.095-39.324, p=0.039) was significantly associated with low BMD. Multivariate regression analysis showed that higher alkaline phosphatase (ALP) levels (OR:1.017, 95% CI 1.001-1.033, p=0.041), lymphopenia (OR:11.028, 95% CI 1.326-91.709, p=0.026), and lower folic acid levels (OR:1.284, 95% CI 1.007-1.637, p=0.043) were also independent predictors for low BMD. Conclusion: Even with some limitations such as the small number for the study population, a single center experience, and a crosssectional design, we recommend that clinical immunologists should be alert for diminished BMD in CVID patients, especially those with low folic acid and high ALP levels and lymphopenia.