학술논문

A Single Dose of Vitamin D Enhances Immunity to Mycobacteria
Document Type
Academic Journal
Source
American Journal of Respiratory and Critical Care Medicine. Jul 15, 2007 176(2):208-213
Subject
Language
English
ISSN
1073-449X
Abstract
RATIONALE:: Vitamin D was used to treat tuberculosis (TB) in the preantibiotic era. Prospective studies to evaluate the effect of vitamin D supplementation on antimycobacterial immunity have not previously been performed. OBJECTIVES:: To determine the effect of vitamin D supplementation on antimycobacterial immunity and vitamin D status. METHODS:: A double-blind randomized controlled trial was conducted in 192 healthy adult TB contacts in London, United Kingdom. Participants were randomized to receive a single oral dose of 2.5 mg vitamin D or placebo and followed up at 6 weeks. MEASUREMENTS AND MAIN RESULTS:: The primary outcome measure was assessed with a functional whole blood assay (BCG-lux assay), which measures the ability of whole blood to restrict luminescence, and thus growth, of recombinant reporter mycobacteria in vitro; the readout is expressed as a luminescence ratio (luminescence postinfection/baseline luminescence). IFN-γ responses to the Mycobacterium tuberculosis antigens early secretory antigenic target-6 and culture filtrate protein 10 were determined with a second whole blood assay. Vitamin D supplementation significantly enhanced the ability of participantsʼ whole blood to restrict BCG-lux luminescence in vitro compared with placebo (mean luminescence ratio at follow-up, 0.57, vs. 0.71, respectively; 95% confidence interval for difference, 0.01-0.25; p = 0.03) but did not affect antigen-stimulated IFN-γ secretion. CONCLUSIONS:: A single oral dose of 2.5 mg vitamin D significantly enhanced the ability of participantsʼ whole blood to restrict BCG-lux luminescence in vitro without affecting antigen-stimulated IFN-γ responses. Clinical trials should be performed to determine whether vitamin D supplementation prevents reactivation of latent TB infection. Clinical trial registered with www.clinicaltrials.gov (NCT 00157066).