Interplay of Chemo Attractant Peptides (Cathelicidin and Chemerin) with Vitamin- D in Patients with Pulmonary Tuberculosis
Najeeha Talat Iqbal *
Departments of Paediatrics, Child Health, Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi, Pakistan.
Syeda Sadia Fatima
Department of Biological and Biomedical Sciences, Aga Khan University, Stadium Road, Karachi, Pakistan.
Rabia Hussain
Department of Pathology and Microbiology, Aga Khan University, Stadium Road, Karachi, Pakistan.
Nisar Ahmed Rao
Department of Pulmonology, Ojha Institute of Chest Diseases, Dow University of Health Sciences, University Road, Karachi, Pakistan.
Narius Virji
Jinnah Medical and Dental College, Karachi, Pakistan.
Bushra Jamil
Department of Medicine, Aga Khan University, Stadium Road, Karachi, Pakistan.
Muhammad Irfan
Department of Medicine, Aga Khan University, Stadium Road, Karachi, Pakistan.
*Author to whom correspondence should be addressed.
Abstract
Aim: Both Cathelicidin and Chemerin are chemo-attractant proteins and possess antimicrobial activity. Sufficient level of Vitamin D is important for optimum response of Cathelicidin for its anti-mycobacterial activity. Studies on the role of these antimicrobial peptides and their relationship with Vitamin D level are limited in tuberculosis. The aim of this study was to investigate an association of Vitamin D with antimicrobial peptide (Cathelicidin) and an adipokine (Chemerin) in patients with pulmonary tuberculosis (TB).
Methods: In a case control study we estimated level of Vitamin D, Chemerin, Cathelicidin and TNF α in pulmonary TB patients (n=22) and healthy endemic controls (n=17) using sandwich ELISA methodology. The study was conducted at Aga Khan University Karachi during 2011.
Results: TB group had higher proportion of subjects above median level of Cathelicidin (median test; p=0.034) and fewer number of subjects with Chemerin (median test; p=0.001). Pairwise comparison also showed significant differences between average ranks of Vitamin D vs. Cathelicidin (p<0.0001), Chemerin vs. Cathelicidin (p=0.04) and Vitamin D vs. TNFα (p<0.0001). Cathelicidin was identified as most discriminatory marker between TB disease and healthy group (ROC, AUC 0.780; p=0.007).
Conclusion: Our results highlight the role of Cathelicidin as a potential biomarker of active TB disease. The role of Cathelicidin and Chemerin as plausible biomarkers requires further studies in both inflammatory and non-inflammatory conditions.
Keywords: Tuberculosis, vitamin D, cathelicidin, chemerin