title: The Effects of First-Line Anti-Tuberculosis Drugs on the Actions of Vitamin D in Human Macrophages.
abstract: Tuberculosis (TB) is a major global health problem. Patients with TB have a high rate of vitamin D deficiency, both at diagnosis and during the course of treatment with anti-tuberculosis drugs. Although data on the efficacy of vitamin D supplementation onMycobacterium tuberculosis (Mtb)clearance is uncertain from randomized controlled trials (RCTs), vitamin D enhances the expression of the anti-microbial peptide human cathelicidin (hCAP18) in cultured macrophagesin vitro.One possible explanation for the mixed (primarily negative) results of RCTs examining vitamin D treatment in TB infection is that anti-TB drugs given to enrolled subjects may impact actions of vitamin D to enhance cathelicidin in macrophages. To address this hypothesis, human macrophage-like monocytic (THP-1) cells were treated with varying doses of first-line anti-tuberculosis drugs in the presence of the active form of vitamin D, 1N1,25-dihydroxyvitamin D3(1,25(OH)2D3). The expression of hCAP18 was determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). 1,25(OH)2D3strongly induced expression of hCAP18 mRNA in THP-1 cells (fold-change from control). The combination of the standard 4-drug TB therapy (isoniazid, rifampicin, pyrazinamide and ethambutol) in the cultured THP-1 cells demonstrated a significant decrease of hCAP18 mRNA at the dosage of 10 ug/mL. In 31 subjects with newly diagnosed drug-sensitive TB randomized to either high-dose vitamin D3(1.2 million IU over 8 weeks, n=13) versus placebo (n=18), there was no change from baseline to week 8 in hCAP18 mRNA levels in peripheral blood mononuclear cells or in plasma concentrations of LL-37, the protein product of hCAP18.These data suggest that first-line anti-TB drugs may alter the vitamin D-dependent increase in hCAP18 and LL-37 human macrophages.
authors.forename: Supavit
authors.initials: S
authors.lastname: Chesdachai
authors.forename: Susu M
authors.initials: SM
authors.lastname: Zughaier
authors.forename: Li
authors.initials: L
authors.lastname: Hao
authors.forename: Russell R
authors.initials: RR
authors.lastname: Kempker
authors.forename: Henry M
authors.initials: HM
authors.lastname: Blumberg
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Ziegler
authors.forename: Vin
authors.initials: V
authors.lastname: Tangpricha
keywords: antibiotics; cathelicidin; tuberculosis; vitamin D