In tuberculosis patients, IL-1β is expressed in excess [15] at the site of the disease [16]. IL1 β +3954 C to T (rs1143634) has been associated with periodontitis [17] and tuberculosis [18]. IL-10 a Th2 cytokine gene mapped to chromosome 1 is a potent inhibitor of T cell function, major histocompatibility complex (MHC) class II expression, antigen specific proliferation and IFN-γ synthesis [19]. Interindividual variations in
IL-10 production are genetically contributed by polymorphisms within the IL-10 promoter (rs1800896) [20]. The polymorphism at position -1082 may affect the binding of this transcriptional factor and therefore alter transcriptional selleck chemical activation [21]. The aim of this study was to determine the association of IL-1β +3954 C/T and IL-10-1082 G/A gene polymorphisms susceptible to tuberculosis in patients and their household contacts. A total of 300 subjects were included in the study
which consists of tuberculosis patients, their household contacts learn more (HHC) and age–sex-matched healthy controls (HC) of 100 each group. Patients who attended free chest clinic at Mahavir Hospital (PPM-DOTS) were recruited based on radiographic examination, sputum culture for acid-fast bacilli (AFB) and histocytological examination. Tuberculin skin test (TST) positivity was assessed both in patients and household contacts by administering 5 tuberculin Cyclin-dependent kinase 3 units (TU) intradermally on the volar surface of the left arm. An induration of >10 mm within 48–72 h was considered positive (TST+). In healthy controls, TST was not performed. Body Mass Index (BMI) was calculated in all the subjects. The study was approved by the Institutional Ethics Committee, and written informed consent was obtained from each participant. Genomic DNA was extracted from venous
blood (1–2 ml) using DNA isolation kit (Flexi gene DNA isolation kit) according to the manufacturer’s protocol. Quantity and quality of DNA was confirmed by spectrophotometer (Thermo scientific), and DNA was stored at −20 °C. The IL-1β +3954 C/T was genotyped by restriction fragment length polymorphism (RFLP) where a 249-bp fragment of the IL-1β exon 5 was amplified using forward primer 5′-gtt gtc atc aga ctt tga cc-3′ and reverse primer 5′-ttc agt tca tat gga cca ga-3′ in a 20μl reaction. The mixture was amplified for three cycles of 95 °C for 4 min, then 30 cycles of 95 °C for 30 s, 59 °C for 30 s, 72 °C for 30 s and then a final 4 min at 72 °C. The products were digested overnight at 65 °C with 2.5 U Taq 1 and run on a 2% agarose gel, generating the following patterns: single band of 249 bp, TT homozygote; two bands at 135 and 114 bp, CC homozygote; all three bands, CT heterozygote (Fig. 1A). IL-10-1082 G/A polymorphism was genotyped by amplification refractory mutation system polymerase chain reaction (ARMS-PCR) method.