Implication of vitamin D-associated factors in patients with non-tuberculous mycobacterial lung disease.

BACKGROUND: Little information is available regarding vitamin D-associated factors in patients with non-tuberculous mycobacteria (NTM) lung disease. OBJECTIVE: To determine the association between vitamin D-related factors and susceptibility to NTM lung disease. DESIGN: The relative gene expression levels of cathelicidin (CAMP), defensin (DEFB4), vitamin D receptor (VDR) and 1-hydroxylase (CYP27B1), as well as the serum levels of 25-hydroxyvitamin D (25[OH]D), cathelicidin (LL-37), defensin (hBD-2) and vitamin D-binding protein (DBP) from 82 patients with NTM lung disease and 28 control subjects were analysed. RESULTS: Gene expression of CAMP and DEFB4 was significantly higher, and gene expression of VDR and CYP27B1 was significantly lower, in NTM patients than controls. Serum LL-37 and hBD-2 levels were not significantly different between NTM patients and controls; however, the serum DBP level was higher in NTM patients than controls. The serum vitamin D status of patients did not correlate with serum LL-37, hBD-2, or DBP concentration or gene expression of CAMP, DEFB4, VDR or CYP27B1. CONCLUSION: A higher level of gene expression for antimicrobial peptide is more likely to be associated with NTM lung disease than serum vitamin D status.