Vitamin D and LL-37 Levels In Childhood Tuberculosis Disease and Latent Tuberculosis Infection

<b>Background and Aim:</b> Vitamin D is an important prohormone in the immune system and there is strong evidence of its role in the development of tuberculosis(Tb) disease. Our aim is to determine the levels of vitamin D, cathelicidin B(LL-37) in patients with Tb disease, latent Tb infection(LTBI) and healthy children. Our second aim of this study is to determine the relationship between microbiological characteristics and the presence of vitamin D and/or LL-37 reduction in the development of the disease, prevalence and severity of the disease. <b>Methods:</b> Healthy controls(n=21), children with Tb(n=32) and LTBI(n=35) who were followed at Hacettepe University Department of Pediatric pulmonology were included and vitamin D, LL-37 levels were analyzed. Demographic characteristics, clinical, radiological, microbiological findings, TST results, treatment status were recorded. <b>Results:</b> In the Tb group, mean Vitamin D was found 18.2±7.9ng/ml to be significantly lower, 23.6±7.3ng/ml in LTBI group and 19.8± 5.76ng/ml in healthy controls(p = 0.018). When patients were divided into subgroups according to Tb types, in severe Tb(Miliary-Disseminated Tb); mean vitamin D level was found to be 15.8±5.6ng/ml and 18.7±8.36ng/ml in the other Tb group(p=0.31). Vitamin D insufficiency or deficiency was detected in 82.4% of patients with positive tuberculosis culture. Vitamin D insufficiency or deficiency was significantly higher in the tuberculosis culture positive group(p=0.04). <b>Conclusions:</b> Our study showed that vitamin D levels were significantly lower in patients with Tb disease; this is significantly more evident in the group where Tb was proven microbiologically. However the pathogenesis was not supported by LL-37 levels.