PURPOSE: Mycobacterium tuberculosis (MTb) infection remains a serious global lung health problem where morbidity and mortality associated with MTb is especially high in persons co-infected with HIV. Alveolar macrophages (AMs) are primary effector cells of lung innate immunity and critical cells in the host response to MTb. Recent study has revealed that vitamin D plays an important role in AM clearance of MTb. We proposed in this study that altered vitamin D levels may play a role in increasing susceptibility to MTb with HIV+ and HIV (-) individuals.
METHODS: We obtained discarded clinical samples from bronchoscopies performed on the HIV+ and HIV (-) individuals with and without MTb disease. We also obtained concurrent serum samples of these individuals. The levels of 25-OH Vitamin D was measured in serum and bronchoalveolar lavage fluid (BAL) according to manufacturer's protocol with a standard ELISA kit (IDS Ltd., Fountain Hills, AZ). Ratio of urea concentration of BAL fluid to serum urea concentration was used as the BAL dilution factor.
RESULTS: We have enrolled 12 patients in each group. The serum levels of 25-OH Vitamin D in HIV (-) individuals with MTb disease was low (37.18 nmol/L) as compared to HIV (-) individuals without MTb disease (54.95 nmol/L). Similarly the BAL fluid levels of 25-OH Vitamin D in HIV (-) individuals with MTb disease was low (12.15 nmol/L) as compared to HIV (-) individuals without MTb disease (14.0 nmol/L).
CONCLUSION: This initial pilot study will allow us to determine if there is a possible relation to vitamin D levels and the presence of MTb disease.
CLINICAL IMPLICATIONS: This work will lead to important findings in the pathogenesis of MTb infection and may also reveal specific targets (use of Vitamin D supplementation) that can be used in the future as the basis for treatment and prevention of disease.
DISCLOSURE: Sanjeev Sinha, No Financial Disclosure Information; No Product/Research Disclosure Information