Association Analysis of Interleukin-17 Gene Polymorphisms with the Risk Susceptibility to Tuberculosis

Impact of IL-6 rs1800795 and IL-17A rs2275913 gene polymorphisms on the COVID-19 prognosis and susceptibility in a sample of Iranian patients

BACKGROUND

From asymptomatic to acute and life-threatening pulmonary infection, the clinical manifestations of COVID-19 are highly variable. Interleukin (IL)-6 and IL-17A are key drivers of hyper inflammation status in COVID-19, and their elevated levels are hallmarks of the infection progression. To explore whether prognosis and susceptibility to COVID-19 are linked to IL-6 rs1800795 and IL-17A rs2275913, these single-nucleotide polymorphisms (SNPs) were assessed in a sample of Iranian COVID-19 patients.

METHODS

This study enrolled two hundred and eighty COVID-19 patients (140 non-severe and 140 severe). Genotyping for IL-6 rs1800795 and IL-17A rs2275913 was performed using tetra primer-amplification refractory mutation system-polymerase chain reaction (tetra-ARMS-PCR). IL-6 and IL-17A circulating levels were measured using enzyme-linked immunosorbent assay (ELISA). Also, mortality predictors of COVID-19 were investigated.

RESULTS

The rs1800795 GG genotype (78/140 (55.7 %)) and G allele (205/280 (73.2 %)) were significantly associated with a positive risk of COVID-19 severe infection (OR = 2.19, 95 %CI: 1.35-3.54, P =.006 and OR = 1.79, 95 %CI: 1.25-2.56, P <.001, respectively). Also, rs1800795 GG genotype was significantly linked to disease mortality (OR = 1.95, 95 %CI: 1.06-3.61, P =.04). The rs2275913 GA genotype was protective against severe COVID-19 (OR = 0.5, 95 %CI: 0.31--0.80, P =.012). However, the present study did not reveal any significant link between rs2275913 genotypes with disease mortality. INR ≥ 1.2 (OR = 2.19, 95 %CI: 1.61-3.78, P =.007), D-dimer ≥ 565.5 ng/mL (OR = 3.12, 95 %CI: 1.27-5.68, P =.019), respiratory rate ≥ 29 (OR = 1.19, 95 %CI: 1.12-1.28, P =.001), IL-6 serum concentration ≥ 28.5 pg/mL (OR = 1.97, 95 %CI: 1.942-2.06, P =.013), and IL-6 rs1800795 GG genotype (OR = 1.95, 95 %CI: 1.06-3.61, P =.04) were predictive of COVID-19 mortality.

CONCLUSION

The rs1800795 GG genotype and G allele were associated with disease severity, and INR, D-dimer, respiratory rate, IL-6 serum concentration, and IL-6 rs1800795 GG genotype were predictive of COVID-19 mortality.

The association of IL-17A rs2275913 single nucleotide polymorphism with anti-tuberculous drug resistance in patients with pulmonary tuberculosis

BACKGROUND

Drug-resistant  Tuberculosis (DR-TB) is a global health burden with high morbidity and mortality in developing countries including Egypt. The susceptibility to infection with DR-TB strains may be genetically determined. Several interleukin gene polymorphisms were investigated as risk factors for tuberculosis infection but focusing on their association with DR-TB was limited. Therefore, the objective of this study is to assess the association of IL 17 - 197 G > A (rs2275913) single nucleotide polymorphism (SNP) with susceptibility to DR-TB strains in comparison to drug-sensitive tuberculosis (DS-TB) strains in Egyptian patients with pulmonary TB. This cross-sectional study was conducted on 80 patients with DR-TB strains and 80 with DS-TB strains as a control group. Both age and sex were comparable among the study's groups. IL-17 - 197 G > A (rs2275913) SNP was genotyped by real-time PCR, and IL-17 serum concentration was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The GA and AA genotype frequencies of IL 17 - 197 G > A (rs2275913) SNP were significantly higher in patients with DR-TB strains than those with DS-TB strains (p < 0.001). The frequency of the A allele was significantly (p < 0.001) higher in patients with DR-TB group (32.5%) compared to the control group (13.8%). Substantial higher serum levels of IL-17 were detected in the DR-TB group with significant association with AA and AG genotypes.

CONCLUSION

Polymorphism in IL-17 -197 G > A (rs2275913) resulted in higher serum levels of IL-17 and Egyptian patients with such polymorphism are three times at risk of infection with DR-TB strains than patients with wild type.

Polymorphisms in IL-17A Gene and Susceptibility of Colorectal Cancer in Bangladeshi Population: A Case-Control Analysis

OBJECTIVE

Interleukin-17A (IL-17A) genetic polymorphisms are associated with multiple cancer types, including colorectal cancer (CRC). However, no previous study was performed in the Bangladeshi population to evaluate the association. Our study aimed to find the association between two IL-17A variants (rs10484879 C/A and rs3748067 G/A) and susceptibility of CRC.

METHODS AND MATERIALS

This retrospective case-control study comprised 292 CRC patients and 288 age, sex, and BMI matched healthy volunteers. Genotyping of both variants was done by the tetra-primer ARMS-PCR method, and the results were analyzed by the SPSS software package (version-25.0).

RESULTS

Logistic regression analysis indicated that in case of IL-17A rs10484879 polymorphism, AC and AA genotype carriers showed 2.44- and 3.27-times significantly increased risk for CRC development (OR = 2.44, P = .0008 and OR = 3.27, P = .0133, individually). A significant association was also observed for AC + AA genotype (OR = 2.58, P = .0001). Again, over-dominant and allelic model revealed statistically significant link to CRC risk (OR = 2.13, P = .0035 and OR = 2.22, P = .001). For rs3748067 polymorphism, AG and AA genotype carriers showed 2.30- and 2.45-times enhanced risk for CRC (OR = 2.30, P = .005 and OR = 2.45, P = .031). A statistically significant association was also observed for AG + AA genotype (OR = 2.35, P = .001), over-dominant model (OR = 2.05, P = .014), and allelic model (OR = 2.11, P = .0004).

CONCLUSION

This study highlights that IL-17A rs10484879 and rs3748067 polymorphisms may be associated with CRC development. However, further functional research with larger samples may reveal more statistically significant outcomes.

Immune and inflammation-related gene polymorphisms and susceptibility to tuberculosis in Southern Xinjiang population: A case-control analysis

Genetic and immune factors play an important role in tuberculosis. Under different ethnicities and genetic backgrounds, different immune and inflammation-related gene polymorphisms may confer different susceptibility to tuberculosis. This study investigated the relationship between immune and inflammation-related gene polymorphism and susceptibility to tuberculosis in Xinjiang Uyghur population, China. In this case-control study, we enrolled 507 pulmonary tuberculosis patients and 454 healthy controls from Southern Xinjiang. single nucleotide polymorphism (SNP) genotyping was performed. The 12 SNPs of nine immune and inflammation-related genes (including TNF rs361525, IL6 rs2066992 and rs1524107, IL17A rs3748067, IL17F rs763780, VDR rs731236, rs2228570 and rs1544410, IFNGR1 rs1327474, P2RX7 rs3751143, CTAGE1 rs4331426 and Toll-like receptor 4 (TLR4) rs4986790) and their relationship with tuberculosis were evaluated. The T allele and TT genotype of IL-6 rs2066992 and rs1524107 increased the risk of active tuberculosis. The C allele of IFNGR1 rs1327474 was related to the reduced risk of tuberculosis in the Xinjiang Uyghur population. The G allele and AG/GG genotypes of TLR4 rs4986790 were associated with an increased risk of tuberculosis (p < .05). Furthermore, haplotype analysis found that the haplotype TT of interleukin (IL)-6 was a risk factor, whereas the CG type was a protective factor for active tuberculosis in the Xinjiang Uyghur population. There were three immune and inflammation-related genes (IL-6, IFNGR1 and TLR4) and a total of four SNPs (rs2066992, rs1524107, rs1327474 and rs4986790) related to the susceptibility of the Uyghur population to tuberculosis. Our findings may provide evidence for further understanding the mechanism of tuberculosis susceptibility in the Xinjiang Uyghur population.

Lung Neutrophilic Recruitment and IL-8/IL-17A Tissue Expression in COVID-19

The new SARS-CoV-2 virus differs from the pandemic Influenza A virus H1N1 subtype (H1N1pmd09) how it induces a pro-inflammatory response in infected patients. This study aims to evaluate the involvement of SNPs and tissue expression of IL-17A and the neutrophils recruitment in post-mortem lung samples from patients who died of severe forms of COVID-19 comparing to those who died by H1N1pdm09. Twenty lung samples from patients SARS-CoV-2 infected (COVID-19 group) and 10 lung samples from adults who died from a severe respiratory H1N1pdm09 infection (H1N1 group) were tested. The tissue expression of IL-8/IL-17A was identified by immunohistochemistry, and hematoxylin and eosin (H&E) stain slides were used for neutrophil scoring. DNA was extracted from paraffin blocks, and genotyping was done in real time-PCR for two IL17A target polymorphisms. Tissue expression increasing of IL-8/IL-17A and a higher number of neutrophils were identified in samples from the H1N1 group compared to the COVID-19 group. The distribution of genotype frequencies in the IL17A gene was not statistically significant between groups. However, the G allele (GG and GA) of rs3819025 was correlated with higher tissue expression of IL-17A in the COVID-19 group. SARS-CoV-2 virus evokes an exacerbated response of the host’s immune system but differs from that observed in the H1N1pdm09 infection since the IL-8/IL-17A tissue expression, and lung neutrophilic recruitment may be decreased. In SNP rs3819025 (G/A), the G allele may be considered a risk allele in the patients who died for COVID-19.

Interleukin 17F gene variations showed no association with BCG osteitis risk after newborn vaccination

AIM

Interleukin-17 (IL-17) family cytokines promote the host defence against mycobacterial infections. We have previously shown an association between IL17A variations and Bacillus Calmette-Guérin (BCG) osteitis. This paper evaluates the association of three IL17F polymorphisms with BCG osteitis after newborn vaccination.

METHODS

IL17F rs763780, rs11465553 and rs7741835 single nucleotide polymorphisms (SNPs) were studied in 132 adults, who presented with BCG osteitis in infancy. The genotypes and minor allele frequencies (MAFs) were compared between cases and Finnish population-based controls (N = 99) from the 1000 Genomes Project, and MAFs were compared between cases and allele data of Finnish subjects from the large Genome Aggregation Database.

RESULTS

There were no significant differences between former BCG osteitis patients and population-based controls in the IL17F rs763780 (wild 84.4% vs 84.8%), rs11465553 (86.4% vs 91.9%) or rs7741835 (65.7% vs 67.7%) genotypes. Homozygous variant genotypes were only present in 1.5%, 0.8% and 3.8% of cases, respectively. Likewise, MAFs of the three IL17F SNPs did not substantially differ from those of 11 252, 11 939 and 1371 Finnish subjects, respectively, from the available Genome Aggregation Database.

CONCLUSION

IL17F rs763780, rs11465553 and rs7741835 variations showed no association with the risk of BCG osteitis after newborn vaccination.

Protective efficacy of an attenuated Mtb ΔLprG vaccine in mice

Bacille Calmette-Guerin (BCG), an attenuated whole cell vaccine based on Mycobacterium bovis, is the only licensed vaccine against Mycobacterium tuberculosis (Mtb), but its efficacy is suboptimal and it fails to protect against pulmonary tuberculosis. We previously reported that Mtb lacking the virulence genes lprG and rv1410c (ΔLprG) was highly attenuated in immune deficient mice. In this study, we show that attenuated ΔLprG Mtb protects C57BL/6J, Balb/cJ, and C3HeB/FeJ mice against Mtb challenge and is as attenuated as BCG in SCID mice. In C3HeB/FeJ mice, ΔLprG vaccination resulted in innate peripheral cytokine production and induced high polyclonal PPD-specific cytokine-secreting CD4⁺ T lymphocytes in peripheral blood. The ΔLprG vaccine afforded protective efficacy in the lungs of C3H/FeJ mice following both H37Rv and Erdman aerosolized Mtb challenges. Vaccine efficacy correlated with antigen-specific PD-1-negative CD4⁺ T lymphocytes as well as with serum IL-17 levels after vaccination. We hypothesize that induction of Th17 cells in lung is critical for vaccine protection, and we show a serum cytokine biomarker for IL-17 shortly after vaccination may predict protective efficacy.

Many successful vaccines are based on attenuated human pathogens. The only licensed tuberculosis vaccine, BCG, is based on an attenuated version of live whole cell Mycobacterium bovis, the causative agent of tuberculosis (TB) in cattle. Advantages to using attenuated pathogens as vaccines include a broad antigen composition including proteins, lipids, carbohydrates and other molecules that can induce durable immune responses sometimes lasting decades. Here we test an attenuated Mycobacterium tuberculosis (Mtb), the causative agent of human TB, that lacks a key virulence factor as an alternative whole cell vaccine in mice. Attenuated Mtb lacking a key virulence protein, LprG, is immunogenic and protects mice against Mtb challenge. The LprG whole cell vaccine is protective in mice that develop lung pathology more similar to what is described in human TB and the LprG vaccine induces a key cytokine, IL-17, thought to be important for vaccine protection, in the peripheral blood early after vaccination. Together these data support the continued development of attenuated TB as a potential vaccine candidate. Furthermore our data suggests that serum IL-17 should be explored as a potential biomarker for vaccine efficacy in preclinical animal models.

Lack of Evidence for an Association between IL-17F Rs763780 Polymorphism and Pulmonary Tuberculosis

The relationship between the interleukin-17F (IL-17F) rs763780 polymorphism and tuberculosis (TB) has been a source of debate. The potential association between the IL-17F rs763780 polymorphism and TB was investigated using a meta-analysis of case-control studies, which were obtained using the EMBASE, PubMed, CNKI, Scopus, and Web of Science databases. Heterogeneity across studies was evaluated, and summary odds ratios and 95% confidence intervals were computed to estimate a summary effect size using either a fixed-effects or random-effects model. Eight eligible studies comprising nine comparisons for the IL-17F rs763780 polymorphism (3824 cases and 3787 controls) were obtained for this meta-analysis. Although a significant relationship between IL-17F rs763780 and TB susceptibility was observed using the allele genetic model (odds ratio = 1.34, 95% confidence interval = 1.04-1.74), there was high heterogeneity among the studies (I2 = 79%, P=0.0001). The stratified analyses by race, type of tuberculosis, and Hardy-Weinberg equilibrium suggested that the IL-17F rs763780 polymorphism was not associated with risk of pulmonary tuberculosis and the heterogeneity disappeared. Hardy-Weinberg equilibrium is the main cause of the heterogeneity. No evidence was found through this meta-analysis that suggested an association between the IL-17F rs763780 polymorphism and risk of pulmonary tuberculosis.

Gaps in Study Design for Immune Parameter Research for Latent Tuberculosis Infection: A Systematic Review

Background

Immune parameters (IP) have been extensively studied to distinguish between latent tuberculosis (LTBI) and active tuberculosis (TB).

Objective

To determine the IP associated with LTBI, compared to active TB and individuals not infected by M. tuberculosis published in literature.

Methods

We conducted a systematic search using Google Scholar and PubMed databases, combining the MeSH terms latent tuberculosis, Mycobacterium tuberculosis, cytokines, and biological markers, with the free terms, biomarkers and cytokines. Spanish, English, and Portuguese articles comparing the concentration of IP associated with LTBI, either in plasma/serum or in vitro, in adults and nonimmunocompromised versus individuals with TB or without M. tuberculosis infection between 2006 July and 2018 July were included. Two blinded reviewers carried out the searches, read the abstracts, and selected the articles for analysis. Participants' information, diagnostic criteria, IP, detection methods, and biases were collected.

Results

We analyzed 36 articles (of 637 abstracts) with 93 different biomarkers in different samples. We found 24 parameters that were increased only in active TB (TGF-α, CSF3, CSF2, CCL1 [I-309], IL-7, TGF-β1, CCL3 [MIP-1α], sIL-2R, TNF-β, CCL7 [MCP-3], IFN-α, fractalkine, I-TAG, CCL8 [MCP-2], CCL21 [6Ckine], PDGF, IL-22, VEGF-A, LXA4, PGE2, PGF2α, sCD163, sCD14, and 15-Epi-LXA4), five were elevated in LTBI (IL-5, IL-17F, IL-1, CCL20 [MIP-3α], and ICAM-1), and two substances were increased among uninfected individuals (IL-23 and basic FGF). We found high heterogeneity between studies including failure to account for the time/illness of the individuals studied; varied samples and protocols; different clinical classification of TB; different laboratory methods for IP detection, which in turn leads to variable units of measurement and assay sensitivities; and selection bias regarding TST and booster effect. None of the studies adjusted the analysis for the effect of ethnicity.

Conclusions

It is mandatory to harmonize the study of immune parameters for LTBI diagnosis. This systematic review is registered with PROSPERO CRD42017073289.

High levels of plasma interleukin-17A are associated with severe neurological sequelae in Langerhans cell histiocytosis

OBJECTIVE

Langerhans cell histiocytosis (LCH) is a granulomatous inflammatory myeloid neoplasia associated with a cytokine storm in both serum and lesions. Increased levels of plasma interleukin-17A (IL-17A) in LCH patients have been reported, but this finding was not confirmed in all studies. Neurodegeneration is a devastating complication of LCH (ND-LCH). We aimed to revisit the issue of plasma IL-17A levels in LCH, by using a larger number of patients, and also to investigate the relationship between IL-17A and LCH sequelae, especially ND-LCH.

METHODS

Plasma samples from 68 LCH patients and 127 controls were analyzed for IL-17A levels by two ELISAs with different anti-IL-17A capture antibodies: either polyclonal or neutralizing monoclonal antibodies in 17polyAb-ELISA or 17mAb-ELISA, respectively.

RESULTS

Both ELISAs had a similar capacity to specifically detect recombinant or native human IL-17A, as well as plasma IL-17A from LCH patients. We confirmed the finding of higher levels of plasma IL-17A in LCH patients compared to controls (p < 0.0001). The association of IL-17A with LCH was independent of the ELISA used, and of gender, age, disease class activity, and pattern of tissue-organ involvement (single-system versus multi-system). ROC analyses (p < 0.0001) allow to discriminate LCH patients from the control group, supporting the notion that IL-17A may be a potential biomarker for LCH. More interestingly, high IL-17A levels were significantly associated with LCH patients having sequelae, with the highest plasma levels in patients with ND-LCH (p < 0.0001).

CONCLUSION

The association between high levels of IL-17A and LCH was confirmed. IL-17A may be associated with ND-LCH development. This might have therapeutic implications, offering a novel target for precision therapy of ND-LCH.

Association of interleukin-17 gene polymorphisms and susceptibility to brucellosis in Hamadan, western Iran

IL-17is one of the most important inflammatory cytokines that stimulate immunity responses in humans infected with Brucella species, acting as a regulator that reduces release of γ-IFN, thus increasing resistance to brucellosis. Gene polymorphisms in the regulatory regions of cytokine-encoding genes affect the amountsof cytokines produced and play a fundamental role in infectious diseases. The aim of this study was to determine the association between IL-17 gene polymorphisms and susceptibility to brucellosis. In this case-control study, 86 patients with brucellosis and 86 healthy persons in Hamadan, western Iran, from September 2014 to September 2016, were included. IL-17 genetic variants at positions rs4711998 A/G, rs8193036 C/T, rs3819024 A/G, rs2275913 A/G, rs3819025 A/G, rs8193038 A/G, rs3804513 A/T, rs1974226 A/G and rs3748067 A/G were analyzed by restriction fragment length polymorphism-PCR. Serum IL-17 titers were measured by sandwich ELISA. GG genotypes at positions rs4711998 and rs3748067 were present significantly more frequently in patients with brucellosis than in controls (P < 0.05). The AA genotype at positions rs4711998, rs2275913 and rs3748067 and GG genotype at position rs19744226 were present significantly more frequently in controls than in the patient group. These results suggest that the AA genotype at positions rs3748067, rs3819025 and rs4711998 and GG genotype at position rs3819024 are likely protective factors against brucellosis, whereas the GG genotype at positions rs3748067, rs3819025 and rs4711998 and AA genotype at position rs3819024 may be risk factors against the disease. No significant relationships were found between serum IL-17 titers and genotypes of the single-nucleotide polymorphisms.

Bacterial pathogenesis and interleukin-17: interconnecting mechanisms of immune regulation, host genetics, and microbial virulence that influence severity of infection

Interleukin-17 (IL-17) is a pro-inflammatory cytokine involved in the control of many different disorders, including autoimmune, oncogenic, and diverse infectious diseases. In the context of infectious diseases, IL-17 protects the host against various classes of microorganisms but, intriguingly, can also exacerbate the severity of some infections. The regulation of IL-17 expression stems, in part, from the activity of Interleukin-23 (IL-23), which drives the maturation of different classes of IL-17-producing cells that can alter the course of infection. In this review, we analyze IL-17/IL-23 signalling in bacterial infection, and examine the interconnecting mechanisms that link immune regulation, host genetics, and microbial virulence in the context of bacterial pathogenesis. We consider the roles of IL-17 in both acute and chronic bacterial infections, with a focus on mouse models of human bacterial disease that involve infection of mucosal surfaces in the lungs, urogenital, and gastrointestinal tracts. Polymorphisms in IL-17-encoding genes in humans, which have been associated with heightened host susceptibility to some bacterial pathogens, are discussed. Finally, we examine the implications of IL-17 biology in infectious diseases for the development of novel therapeutic strategies targeted at preventing bacterial infection.

Th1 cytokines, true functional signatures for protective immunity against TB?

The lack of an effective preventative vaccine against tuberculosis (TB) presents a great challenge to TB control. Since it takes an extremely long time to accurately determine the protective efficacy of TB vaccines, there is a great need to identify the surrogate signatures of protection to facilitate vaccine development. Unfortunately, antigen-specific Th1 cytokines that are currently used to evaluate the protective efficacy of the TB vaccine, do not align with the protection and failure of TB vaccine candidates in clinical trials. In this review, we discuss the limitation of current Th1 cytokines as surrogates of protection and address the potential elements that should be considered to finalize the true functional signatures of protective immunity against TB.

Interleukin 17A gene polymorphism rs2275913 is associated with osteitis after the Bacillus Calmette-Guérin vaccination

AIM

Interleukin-17 (IL-17) appears to promote the host's defence against mycobacterial infections. This study evaluated the association between IL17A gene polymorphism and the risk of Bacillus Calmette-Guérin (BCG) osteitis after newborn vaccination and between IL17A gene polymorphism and IL-17A concentrations in serum.

METHODS

IL17A rs2275913 gene polymorphisms and serum IL-17A concentrations were studied in 132 adults aged 21-49 years from across Finland, who had BCG osteitis in infancy after a newborn BCG vaccination. The subjects were recruited in 2007-2008, and their whole-blood samples were sent to the National Institute for Health and Welfare, Turku, Finland. Their genotypes and minor allele frequencies were compared with 405 population-based unvaccinated controls aged two to three months from a prospective birth cohort study.

RESULTS

The genotypes and allele frequencies of IL17A rs2275913 differed significantly between the former BCG osteitis patients and controls. The genotype was variant in 75.8% of cases and 64.0% of controls (p = 0.012), and the minor allele frequency was 50.0% in the cases and 41.6% of the controls (p = 0.009). Serum IL-17 concentrations did not differ significantly between the cases with wild or variant genotypes.

CONCLUSION

IL17A rs2275913 gene polymorphism was associated with a risk of BCG osteitis after vaccination.

Interleukin-17 A and F gene polymorphisms affect the risk of tuberculosis: An updated meta-analysis

BACKGROUND

Cytokines are fundamental elements in mediating and stimulating the immune response against tuberculosis (TB). Growing evidence indicated that polymorphisms in the interleukin-17 (IL-17) A and F genes are implicated in TB.

OBJECTIVES

This meta-analysis was aimed to re-evaluate and update the relationship between IL-17A rs2275913 G/A and IL17F rs763780 T/C polymorphisms and TB risk.

METHODS

Using inclusive searches of the PubMed, MEDLINE, EMBASE, Web of Science and Elsevier Science Direct, we identified outcome data from all articles estimating the association between IL-17 A and F polymorphisms and TB risk.

RESULTS

A total of 15 studies comprising 7130 patients and 7540 controls were included. Our pooled analysis demonstrated that the IL-17A rs2275913 G/A SNP was not associated with the risk of TB in overall, or in Asians and Caucasians, but it conferred resistance to TB in Latin Americans using allele (OR=0.53), codominant (OR=0.53 and 0.38), dominant (OR=0.49) and recessive (OR=0.46) inheritance models. For IL-17F rs763780 T/C, the pooled evidence indicated that this variation was a risk factor for TB in allele (C vs T) and dominant (TC+CC vs TT) models in overall (OR of 1.35) and among Asians (OR=1.40), but not in Caucasians.

CONCLUSION

In summary, our meta-analysis suggested that the IL-17A rs2275913 was a protective factor against TB, but -17F rs763780 T/C was a risk factor for TB.

Haplotype of the Interleukin 17A gene is associated with osteitis after Bacillus Calmette-Guerin vaccination

Bacillus Calmette-Guerin (BCG) osteitis was more common in Finland than elsewhere at the time when universal BCG vaccinations were given to Finnish newborns. There is evidence that IL-17 plays a role in the defense against tuberculosis. The aim of this study was to evaluate the associations of IL17A rs4711998, IL17A rs8193036 and IL17A rs2275913 single-nucleotide polymorphisms (SNPs) with the risk of BCG osteitis after newborn vaccination. IL17A rs4711998, rs8193036 and rs2275913 SNPs were determined in 131 adults had presented with BCG osteitis after newborn BCG vaccination. We analyzed, using the HaploView and PLINK programs, whether allele or haplotype frequencies of these SNPs differ between the former BCG osteitis patients and Finnish population controls. Of the three IL17A SNPs studied, rs4711998 associated nominally with BCG osteitis; minor allele frequency was 0.215 in 130 BCG osteitis cases and 0.298 in 99 controls (p = 0.034). Frequency of the second common haplotype (GTA) differed significantly between BCG osteitis cases and controls (0.296 vs. 0.184, p = 0.040 after multi-testing correction). The GTA haplotype of the IL17A SNPs rs4711998, rs8193036 and rs2275913 was associated with osteitis after BCG vaccination.

Human genetic factors in tuberculosis: an update

Tuberculosis (TB) is a major threat to human health, especially in many developing countries. Human genetic variability has been recognised to be of great relevance in host responses to Mycobacterium tuberculosis infection and in regulating both the establishment and the progression of the disease. An increasing number of candidate gene and genome-wide association studies (GWAS) have focused on human genetic factors contributing to susceptibility or resistance to TB. To update previous reviews on human genetic factors in TB we searched the MEDLINE database and PubMed for articles from 1 January 2014 through 31 March 2017 and reviewed the role of human genetic variability in TB. Search terms applied in various combinations were 'tuberculosis', 'human genetics', 'candidate gene studies', 'genome-wide association studies' and 'Mycobacterium tuberculosis'. Articles in English retrieved and relevant references cited in these articles were reviewed. Abstracts and reports from meetings were also included. This review provides a recent summary of associations of polymorphisms of human genes with susceptibility/resistance to TB.