Elevated serum 25-hydroxy (OH) vitamin D levels are associated with risk of TB progression in Gambian adults. (May 2016)

• Record Type: Journal Article
• Authors: Owolabi, Olumuyiwa; Agbla, Schadrac; Owiafe, Patrick; Donkor, Simon; Togun, Toyin; Sillah, Abdou K.; Ota, Martin O.C.; Sutherland, Jayne S.
• Is Part Of: Tuberculosis. Volume 98(2016)
• Page Start: 86
• Page End: 91
• Publication Date: 2016-05
• Subjects: Tuberculosis -- Incident cases -- 25(OH) D -- Vitamin D binding protein -- Latent TB infection; 616.995
• DOI: 10.1016/j.tube.2016.02.007
• Languages: English
• ISSNs: 1472-9792

Abstract

Summary: Background: Vitamin D is essential in the host defence against tuberculosis (TB) as an immune modulator. The aim of this study was to determine the level of 25-hydroxyvitamin D (25 (OH) D) from adult TB index cases before and after treatment and their exposed household contacts (HHC) in The Gambia. Methods: Serum from adult index TB cases and their TB-exposed household contacts (HHC) was analysed for 25(OH) D and Vitamin D binding protein (VDBP) concentrations. Tuberculin skin test (TST) status was used as a measure of Mycobacterium tuberculosis (Mtb) infectivity in the HHC. In addition, HHC who later progressed to active TB (incident cases) were assessed alongside non-progressors to determine the influence of 25 (OH) D levels on TB risk. Results: Eighty-three TB cases, 46 TST+ and 52 TST− HHC were analysed. Generally levels of 25(OH) D were considered insufficient in all subjects. However, median levels of 25(OH) D and VDBP were significantly higher in TB cases compared to both TST+ and TST− HHC at recruitment and were significantly reduced after TB therapy (p < 0.0001 for all). In addition, levels of serum 25(OH) D at recruitment were significantly higher in TB progressors compared to non-progressors (median (IQR): 25.0(20.8–29.2) in progressors and 20.3 (16.3–24.6) ng/ml in non-progressors; p = 0.007). Conclusion: In The Gambia, an equatorial country, 25(OH) D levels are higher in serum of TB progressors and those with active disease compared to latently infected and uninfected subjects. These results contrast to findings in non-equatorial countries.