Abstract:

Objective To evaluate the difference in expression levels of 25-(OH)D₃ and LL-37 in patients with different types of active pulmonary tuberculosis (PTB). Methods One hundred and seventy-eight PTB patients admitted to Chengdu Public Health Clinical Medical Center from June 2017 to December 2017 were enrolled as case group. One hundred and seventy-eight patients included 81 PTB cases (Group B), 57 PTB cases with extrapulmonary tuberculosis (Group C) and 40 PTB cases complicated with diabetes (Group D). According to the severity of the disease, the patients were divided into severe PTB (79 cases) and mild PTB (99 cases). One hundred medical workers who had physical examination in our hospital during the same period were selected as the healthy control group (Group A). The levels of 25-(OH)D₃ and LL-37 were measured by ELISA. The difference of 25-(OH)D₃ and LL-37 expression between the groups, and the correlation between the severity of PTB and levels of 25-(OH)D₃ and LL-37 were analyzed. Results The concentrations of 25-(OH)D₃ in peripheral blood in Group B, Group C and Group D were (31.58±11.89) nmol/L, (25.68±13.57) nmol/L and (26.39±10.01) nmol/L respectively, which were significantly lower than that in Group A ((40.57±14.32) nmol/L) (respectively t=4.61, P=0.000; t=6.48, P=0.000; t=5.72, P=0.000). The levels of LL-37 in Group B, Group C and Group D were (26.97±10.29) μg/L, (30.75±10.16) μg/L and (31.84±11.36) μg/L respectively, which were significantly higher than that in Group A ((24.38±4.57) μg/L), the differences were statistically significant (respectively t=2.26, P=0.025; t=4.48, P=0.000; t=4.03, P=0.000). Compared with Group B, the concentrations of 25-(OH) decreased and LL-37 increased in Group C and Group D, with statistically significant differences (respectively t=2.64, P=0.008; t=2.52, P=0.011 and t=2.14, P=0.032; t=2.29, P=0.022). In patients with severe PTB, the concentration of 25-(OH)D₃ was (24.59±12.36) nmol/L, and the level of LL-37 was (31.97±11.43) μg/L, which was statistically significant compared with those with mild PTB ((33.79±15.47) nmol/L and (27.32±10.69) μg/L; t=4.41, P=0.000; t=2.77, P=0.006). Conclusion The serum levels of vitamin D in patients with active PTB are significantly lower than that in normal adults, and the levels of LL-37 in active PTB cases are significantly higher than that in normal adults, and there are differences in the expression levels of vitamin D and LL-37 of patients with different types of active PTB in blood.

Key words: Tuberculosis,pulmonary, Vitamin D, Dermcidins, Controlled clinical trial