Vitamin D status and antimicrobial peptide cathelicidin (LL-37) concentrations in patients with active pulmonary tuberculosis.
Am J Clin Nutr. 2010 Sep;92(3):603-11. Epub 2010 Jul 7.
Yamshchikov AV, Kurbatova EV, Kumari M, Blumberg HM, Ziegler TR, Ray SM, Tangpricha V.
Department of Medicine, Emory University, Atlanta, GA, USA. ayamshchikov at gmail.com
BACKGROUND: Vitamin D insufficiency is common in industrialized and developing nations. Recent studies have shown that vitamin D insufficiency is associated with a higher risk of active tuberculosis. Laboratory studies provided a mechanism for this link on the basis of findings that vitamin D metabolites regulate the expression of cathelicidin (LL-37), which is an endogenous antimicrobial peptide with activity against Mycobacterium tuberculosis. Little information is available on the clinical relation between vitamin D, LL-37 concentrations, and disease severity in patients with tuberculosis.
OBJECTIVE: The primary objective of the study was to evaluate the relation between vitamin D nutriture, serum LL-37 concentrations, and tuberculosis by using samples stored in the Tuberculosis Trials Consortium serum repository.
DESIGN: We measured 25-hydroxyvitamin D 25(OH)D and LL-37 concentrations in 95 serum specimens from patients with culture-confirmed pulmonary tuberculosis and correlated these concentrations to clinical and demographic variables.
RESULTS: The prevalence of vitamin D insufficiency serum 25(OH)D concentration lt 30 ng/mL in patients with active tuberculosis was 86% (n = 95) with a mean baseline serum 25(OH)D concentration of 20.4 ng/mL. Factors associated with vitamin D insufficiency were black race and indoor lifestyle. The mean ( plusmn SD) baseline LL-37 concentration was 49.5 plusmn 23.8 ng/mL. Higher LL-37 concentrations correlated with acid fast bacilli sputum smear positivity and weight gt 10% below ideal body weight. Serum vitamin D status of the study subjects did not correlate with serum LL-37 concentrations.
CONCLUSION: More prospectively designed studies are needed to evaluate the clinical implications of vitamin D insufficiency in patients with tuberculosis and the utility of circulating LL-37 as a potential biomarker in patients with active tuberculosis disease. The parent trial was registered at clinicaltrials.gov as NCT00023335. PMCID: PMC2921537 Available on 2011/9/1, PMID: 20610636