Human leucocyte antigen‐G 14‐bp InDel polymorphism and oral squamous cell carcinoma risk in Chinese Han population: A case–control study

Human leucocyte antigen‐G (HLA‐G) is a nonclassical HLA class I molecule involved in tumour immune escape. The purpose of this study was to investigate the association between the 14‐bp insertion/deletion (InDel) polymorphism in the 3′ untranslated region (3′‐UTR) of HLA‐G gene and oral squamous cell carcinoma (OSCC) risk in Chinese Han population (216 cases and 193 healthy controls), and furthermore, to evaluate serum soluble HLA‐G (sHLA‐G) levels in the OSCC patients. Our results demonstrated that the Ins allele was significantly less frequent in the OSCC patients than that in the healthy controls (odds ratio [OR] = 0.75; 95% confidence interval [CI]: 0.57–0.99; p = 0.040). Distribution of the 14‐bp genotypes in the OSCC patients and the healthy controls revealed that the Ins/Ins genotype was associated with decreased OSCC risk in both the codominant model (Ins/Ins versus Del/Del; OR = 0.57; 95% CI = 0.33–0.99; p = 0.044) and the log‐additive model (OR = 0.76; 95% CI: 0.58–0.99; p = 0.044). The serum sHLA‐G level was significantly higher in the OSCC patients than those in the healthy controls (p < 0.001). Receiver operating characteristic (ROC) curve revealed the valuable diagnostic value of sHLA‐G for OSCC detection, with an area under the ROC curve (AUC) of 0.891 (95% CI: 0.856–0.925, p < 0.001). The OSCC patients with Ins/Ins genotype had lower serum sHLA‐G levels than those with Ins/Del and Del/Del genotypes (p = 0.015). Furthermore, serum sHLA‐G levels were significantly increased with the increasing TNM stages of the OSCC patients (p = 0.017). Our findings revealed that the HLA‐G 14‐bp InDel polymorphism might be a genetic risk factor for OSCC susceptibility, and the serum sHLA‐G may act as a promising biomarker for noninvasive diagnosis of OSCC.     

The maternal 14 bp Ins/Del polymorphism in HLA‐G is not associated with preeclampsia risk

The effect of HLA‐G 14 bp Ins/Del polymorphism (rs371194629) on the risk of preeclampsia has been assessed in several populations, yet the results are still conflicting. Lack of power due to small sample sizes is a common cause of inconsistencies in genetic association studies. We aimed to test whether the maternal polymorphism is associated with preeclampsia, eclampsia or HELLP syndrome (acronym for Hemolysis, Elevation of Liver enzymes, Low Platelets). To achieve a statistical power greater than 0.90, a total of 741 women (332 controls, 246 preeclampsia, 57 eclampsia and 106 HELLP) were genotyped for the 14‐bp Ins/Del polymorphism. The genetic association with disease status was assessed by Fisher's exact test and odds ratio (OR) estimates using logistic regression model adjusted for maternal age and parity status. Allele and genotype distributions were the same between control and case groups (p > .05). The polymorphism was not associated with the risk of developing preeclampsia [OR = 0.93 (0.72–1.19); p = .541], or eclampsia [OR = 0.90 (0.60–1.38); p = .628] nor HELLP syndrome [OR = 0.92 (0.66–1.28); p = .628]. This well‐powered study clearly demonstrates that the maternal HLA‐G 14‐bp Ins/Del polymorphism is not associated with preeclampsia risk. However, as the offspring genotypes were not evaluated here, we could not rule out the effect of the foetal genotype on the preeclampsia pathogenesis.     

HLA‐G 14‐bp Ins/Ins Genotype in Patients Harbouring Helicobacter pylori Infection: A Potential Risk Factor?

H. pylori is a potent pathogen due to its capacity to successfully evade host defence mechanisms. Despite inducing immune responses in infected individuals, sometimes these responses fail to clear the infection and the bacterium establishes a persistent infection leading to chronic inflammation. In this context, we hypothesized that human leucocyte antigen G (HLA‐G), a non‐classical major histocompatibility complex molecule that has the ability to regulate immune responses both in physiological and in pathological conditions, may play an important role in promoting tolerance and helping H. pylori to subvert host defence and consequently establish a chronic infection. Therefore, we evaluated the expression of HLA‐G 14‐bp Ins/Del polymorphism in patients harbouring H. pylori infection, as well as their relationship with histological and demographic variables, to gain a better understanding of the actual role of HLA‐G and its genetic polymorphisms in bacterial infection. Sixty‐eight patients with clinical symptoms suggestive of H. pylori infection were enrolled to assess HLA‐G 14‐bp Ins/Del polymorphism allele and genotype frequencies. After adjustment for covariates (age and gender), the odds of having the genotype Ins/Ins, compared to Del/Del, were 3.77 times greater among HP+ cases than among controls. These findings suggest that the 14‐bp Ins/Ins genotype, already associated with inflammatory and autoimmune diseases as well as some viral and parasitic infections, could confer a greater risk of developing H. pylori infection.     

Associative role of HLA‐DRB1 SNP genotypes as risk factors for susceptibility and severity of rheumatoid arthritis: A North‐east Indian population‐based study

Rheumatoid arthritis (RA) is a complex, multifactorial, systemic autoimmune disease. Reports are suggestive of the role of HLA especially HLA‐DRB1 alterations in RA pathogenesis. Existing data involving different geographical populations on the role of alterations in specific locus of HLA‐DRB1 in RA susceptibility and severity are equivocal, with no data available from ethnically distinct North‐east Indian population, where RA cases are alarmingly increasing. This study aimed to evaluate the association of HLA‐DRB1 gene SNPs (rs13192471, rs660895 and rs6457617) with susceptibility and severity of RA in an ethnically distinct North‐east Indian population. Whole blood was collected from clinically characterized RA cases (satisfying the American College of Rheumatology 1987 criteria) (n = 123) and community‐based age and sex‐matched healthy controls (n = 156) with informed consent. The HLA‐DRB1 SNP analysis was performed for all the RA and control cases using ARMS‐PCR using case and control genomic DNA as template. Statistical analysis was performed by SPSSv13.0 software. The HLA‐DRB1 rs660895 showed both wild (AA) and heterozygote (AG) genotype but the heterozygote allele was found to be associated with reduced risk of RA compared to controls [OR = 0.531, p = .024]. The difference in distribution of rs6457617 polymorphism between RA and control cases was comparable [OR = 0.525, p = .079]. Significantly higher distribution of variant rs13192471 genotype was observed in RA cases (69.92%) compared to controls (46.75%) (p < .001) and was associated with increased risk of susceptibility to RA [OR = 2.576, p < .001] compared to controls, as well as progression to severity in RA cases [OR = 2.404, p = .048]. Combinatorially also, the presence of rs13192471 variant genotype was associated with increased risk of RA susceptibility [OR = 8.267, p = .026] and RA severity [OR = 3.647, p = .280]. Alterations in HLA‐DRB1 are associated with RA susceptibility. HLA‐DRB1 rs13192471 SNP plays a critical role in RA susceptibility and severity in North‐east Indian cases and has prognostic significance in RA.     

HLA‐G 14‐bp polymorphism affects the age of onset in Type I Diabetes Mellitus

Type I diabetes mellitus (T1DM) is an organ‐specific autoimmune disorder affecting the insulin‐producing pancreatic cells. T1DM genetic association studies have so far revealed the involvement of more than 40 loci, with particularly strong associations for the human leucocyte antigens (HLA). Further to the well‐established HLA class II associations, the immunomodulatory elements in the telomeric major histocompatibility complex locus, specifically nonclassical HLA class I, were also associated with T1DM, either in conferring susceptibility or by contributing to the overall pathogenesis. This study investigates the involvement of a 14‐bp deletion polymorphism (rs371194629) at the 3′ untranslated region of HLA‐G in the context of T1DM and age of onset. The frequency of the polymorphism was determined in unrelated T1DM Cypriot patients and findings that emerge from this study show a strong association between the HLA‐G 14‐bp polymorphism and T1DM with respect to the age of onset. Specifically, the deletion/deletion (DEL/DEL) genotype was found to be associated with an early age of onset (P = 0.001), while the presence of the insertion allele (INS) was associated to a later age of onset (P = 0.0001), portraying a possible dominant effect over the deletion allele, a role in delaying disease onset and an overall involvement of HLA‐G in the pathogenesis of type I diabetes mellitus.     

HLA-G 14-bp insertion/deletion polymorphism and risk of coronavirus disease 2019 (COVID-19) among Iraqi patients

Human leukocyte antigen (HLA)-G molecules are proposed to influence susceptibility to coronavirus disease 2019 (COVID-19). A case-control study was conducted on 209 patients with COVID-19 and198 controls to assess soluble HLA-G (sHLA-G) levels and HLA-G 14-bp insertion [Ins]/deletion [Del] polymorphism. Results revealed that median levels of sHLA-G were significantly higher in serum of COVID-19 patients than in controls (17.92 [interquartile range: 14.86–21.15] vs. 13.42 [9.95–17.38] ng/mL; probability <0.001). sHLA-G levels showed no significant differences between patients with moderate, severe or critical disease. Del allele was significantly associated with the risk of COVID-19 (odds ratio = 1.89; 95% confidence interval = 1.44–2.48; corrected probability = 0.001), while a higher risk was associated with Del/Del genotype (odds ratio = 2.39; 95% confidence interval = 1.25–4.58; corrected probability = 0.048). Allele and genotype frequencies of HLA-G 14-bp Ins/Del polymorphism stratified by gender or disease severity showed no significant differences in each stratum. Further, there was no significant impact of genotypes on sHLA-G levels. In conclusion, sHLA-G levels were up-regulated in COVID-19 patients regardless of disease severity. Further, it is suggested that HLA-G 14-bp Ins/Del polymorphism is associated with COVID-19 risk.     

IFN‐γ +874T/A polymorphism increases susceptibility to post‐traumatic osteomyelitis

Immunological inflammatory reaction is one of the key links in the occurrence and development of post‐traumatic osteomyelitis after microbial invasion. Growing evidence suggests complex interactions between IFN‐γ and bone remodelling cells. However, potential association of IFN‐γ gene polymorphism with susceptibility to post‐traumatic osteomyelitis remains unclear. This study aimed to investigate the potential link between IFN‐γ +874T/A polymorphism and risk of developing post‐traumatic osteomyelitis. A total of 189 patients with post‐traumatic osteomyelitis and 200 healthy controls were enrolled for genotyping using the SNaPshot genotyping method. Statistically significant associations were found between the gene polymorphism and the risk of post‐traumatic osteomyelitis by dominant model (AA + AT vs. TT, OR = 1.820, p = .017) and heterozygous model (AT vs. TT, OR = 1.781, p = .029). Moreover, the frequency of mutant allele A was significantly higher in the patients than that in the healthy controls (15.07% vs. 9.25%, OR = 1.742, p = .013). IFN‐γ +874T/A polymorphism may contribute to the increased susceptibility to post‐traumatic osteomyelitis.     

Interleukin 10 gene promoter polymorphisms (rs1800896, rs1800871 and rs1800872) and haplotypes are associated with the activity of systemic lupus erythematosus and IL10 levels in an Iranian population

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with unknown aetiology. According to the role of interleukin 10 (IL10) in SLE pathogenesis, the genetic alterations in its promoter region could be associated with elevated IL10 levels and exacerbated disease. Here, we investigated the association of genotype and haplotype frequencies of three IL10 gene promoter polymorphisms with susceptibility to SLE, IL10 plasma levels and disease activity of patients in an Iranian population. A total of 116 SLE patients and 131 healthy subjects were enrolled. The PCR‐RFLP technique was used to detect IL10 promoter genotypes at the positions of ?1082 (G/A), ?819 (C/T) and ?592 (C/A) in association with IL10 plasma levels and SLEDAI scores. The GG genotype of ?1082 polymorphism was associated with the increased risk of SLE [OR = 2.65, 95% CI (1.21–5.82), p‐value = 0.046]. The CC genotype in ?819 region was associated with SLE susceptibility [OR = 3.38, 95% CI (1.26–9.07), p‐value = 0.034] and C allele was introduced as risk allele [OR = 1.86, 95% CI (1.15–3.01), p‐value = 0.009] in this region. IL10 plasma levels were overexpressed in CC genotype carriers of ?592 SNP and decreased in AA genotype carriers of ?1082. IL10 was also increased in SLE patients with CGT (?592/?1082/?819) haplotype. The SLEDAI score was higher among CC genotype carriers at the position of ?592 and TT genotype carriers at the region of ?819. SLEDAI was also elevated among patients with CGC (?592/?1082/?819) and CAC (p = 0.011) haplotypes. The present study suggests that the IL10 –819(C/T), ?1082(G/A) and ?592(C/A) polymorphisms and the haplotypes are associated with SLE susceptibility, increased disease activity and elevated IL10 levels. While this is the first time to report such an association in an Iranian population, further studies are needed to confirm these findings.     

Association of HLA-G 3′UTR polymorphisms and haplotypes with colorectal cancer susceptibility and prognosis

Human leukocyte antigen (HLA)-G has been considered as an immune modulator in several types of cancers. Its genetic polymorphisms may potentially affect the risk of developing colorectal cancer (CRC). The overall purpose of this study was to analyze the implication of HLA-G 3′untranslated region (3′UTR) polymorphisms particularly 14 pb insertion/deletion (Ins/Del; rs371194629) and + 3142C/G (rs1063320) in CRC susceptibility and progression.A comparative analysis between patients (N = 233) and controls (N = 241) demonstrated that Del allele (Odds Ratios (OR) = 1.41, 95% CI = 1.091–1.819, p = 0.008), the homozygous Del/Del genotype (OR = 1.80, 95% CI = 1.205–2.664, p = 0.003) and the codominant C/G genotype (OR = 1.59, 95% CI = 1.106–2.272, p = 0.013) were associated to CRC risk. As expected, the DelG haplotype was associated with CRC susceptibility (OR = 1.47, 95% CI = 1.068–2.012, p = 0.018). Assessment of patients' survival by Kaplan-Meier analysis indicated that the Del allele and the homozygous Del/Del genotype were associated with reduced event free survival (EFS) (Respectively, p = 0.009 and p = 0.05). Interestingly, the Del allele and the homozygous Del/Del genotype have been revealed as independent prognostic factors for poor EFS in patients with CRC. Additionally, haplotypes analysis revealed that DelG haplotype was linked with significant increase in CRC risk (log-rank; EFS: p = 0.02). Inversely, the InsC haplotype was associated with a significant reduced CRC risk (log-rank; Overall survival (OS): p < 10^–6; EFS: p = 0.01). Multivariate Cox regression analysis revealed that the InsC haplotype was independently associated with significantly longer EFS (p = 0.021, HR = 0.636, 95% CI = 0.433–0.935).These findings support the implication of HLA-G polymorphisms in the CRC susceptibility suggesting HLA-G as a potent prognostic and predictive indicator for CRC. Insight into mechanisms underlying HLA-G polymorphisms could allow for the development of targeted care for CRC patients according to their genetic profile.     

The HLA-G low expressor genotype is associated with protection against bipolar disorder

Implication of immune processes in bipolar disorder (BD) has recently gained increasing attention. Tolerogenic molecules, among which HLA-G plays a prominent role, mediate the modulation of such processes. The HLA-G locus is characterized by a high number of polymorphisms including a functionally relevant 14 base pair (bp) insertion/deletion (Ins/Del) allele affecting the HLA-G expression. Here, we analyzed the distribution of this polymorphism in 561 BD patients and 161 healthy and found that the HLA-G 14bp Ins/Ins genotype was significantly more prevalent in healthy controls than in patients (corrected p; pc = 0.032) and that the prevalence of such protective genotype is lower among patients born during the winter season as compared to those born in other periods (pc = 0.006). Possible mechanisms between low HLA G expression and resistance to infections as well as potential relationships between infections in early life and susceptibility to BD are discussed.     

Role of TLR4 C>1196T (Thr399Ile) and TLR4 A>896G (Asp299Gly) polymorphisms in a North Indian population with asthma: a case‐control study

Toll‐like receptor 4 (TLR4) is the most important TLR among the pattern recognition receptors which recognizes lipopolysaccharide of gram‐negative bacteria. They identify a highly conserved structure of microbes called pathogen‐associated molecular patterns and activate immune and inflammatory responses that have been shown to be involved in the pathogenesis of asthma. The role of TLR4 gene polymorphisms in asthma was detected in a total of 964 individuals, including 483 healthy controls and 481 asthma patients from a North Indian population. The genotyping was carried out using polymerase chain reaction–restriction fragment length polymorphism method. Statistical analysis revealed that the heterozygous genotype as well as the mutant (T) allele of the TLR4 C>1196T (Thr399Ile) polymorphism shows resistance towards asthma with OR = 0.70, 95% CI (0.49–0.99), P corrected value = 0.046 and OR = 0.72, 95% CI (0.52–0.98), P corrected value = 0.039, respectively. However, no association was found between the TLR4 A>896G (Asp299Gly) polymorphism and asthma patients (P > 0.05). This is the first study conducted in India conferring TLR4 (Thr399Ile) polymorphism resistance towards asthma, while lack of association was found between TLR4 (Asp299Gly) polymorphism and asthma in the studied North Indian population.     

The HLA-G 14-bp insertion/deletion polymorphism is associated with chronic hepatitis B in Southern Brazil: A case-control study

There is growing evidence that the non-classical HLA-G has a role in the process of the immune response against pathogens, including HBV and HIV. Previous studies demonstrated that a 14-bp insertion/deletion (indel) polymorphism at 3′-untranslated region of HLA-G gene interferes in the mRNA stability and expression. The present study aimed to evaluate the association of the 14-bp indel polymorphism (rs371194629) with HBV infection in chronic hepatitis B (CHB) mono-infected and HBV/HIV co-infected patients from Southern Brazil. A total of 817 individuals were analyzed, including 357 CHB patients, 134 HBV/HIV co-infected patients and 326 healthy controls. The 14-bp indel polymorphism was analyzed by DNA amplification using PCR. Logistic regression models were performed to compute adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs). To control for multiple comparisons, the Bonferroni correction was applied to the p-values. The 14-bp Ins allele was observed in 47.6% of the CHB mono-infected patients and in 41.6% of the controls (aOR = 1.33; 95% CI: 1.05–1.60; p = 0.02; p _corrected = 0.08). The results also showed that the 14-bp Ins/Ins genotype was present in 21.8% of the CHB mono-infected patients and in 12.9% of the controls (aOR = 1.91; 95% CI: 1.21–3.01; p < 0.01; p _corrected = 0.02). There was significant association between the 14-bp indel and CHB monoinfection, but not in HBV/HIV co-infection. In conclusion, the 14-bp indel polymorphism was associated with CHB in this specific population.     

Genetic polymorphism of human leucocyte antigen and susceptibility to multidrug‐resistant and rifampicin‐resistant tuberculosis in Han Chinese from Hubei Province

We determined the high‐resolution allele and haplotype frequencies at the human leucocyte antigen (HLA)A, B and DRB1 loci in the Han population of Hubei province, the TB endemic area of Central China, with pulmonary tuberculosis (PTB), and established the relationship between HLA‐A, B and DRB1 alleles as well as haplotypes and susceptibility to multidrug‐resistant and rifampicin‐resistant tuberculosis (MDR/RR‐TB). Blood samples were drawn from 174 patients with MDR/RR‐TB and 838 patients with drug‐susceptible PTB in ethnic Han population from Hubei province (central China). Four‐digit allele genotyping of HLA‐ A, B and DRB1 loci was performed using polymerase chain reaction with sequence‐specific oligonucleotide probes (PCR‐ SSOP). The allele and haplotype frequencies of HLA‐A, B and DRB1 were determined and compared between patients with MDR/RR‐TB and patients with drug‐susceptible PTB. Statistical analysis of the generated data indicated no departure from expectation of Hardy–Weinberg equilibrium (HWE) at all loci of the control group. Multivariate analysis identified allele DRB1*08:01 (p < .0001; OR = 174.5, 95% CI 15.3–1987.2) as independent predictor of MDR/RR‐TB, except for old age (p < .0001; OR = 10. 9, 95% CI 7.6–15.8), previous treatment history (p < .0001; OR = 11.0, 95% CI 7.2–16.7) and poor compliance to treatment (p < .0001; OR = 12.9, 95% CI 8.4–20.0). While in the subgroup of new TB cases, DRB1*08:01 (p < .0001; OR = 80.3, 95% CI 7.0–917.1) and older age (p < .0001; OR = 3.9, 95% CI 2.4–6.4) were independent susceptibility factors for primary MDR/RR‐TB. Our results suggest that a combination of clinical and host genetic information about tuberculosis patients may contribute to prediction and early detection of MDR/RR‐TB.     

IL‐1A rs1800587, IL‐1B rs1143634 and IL‐1R1 rs2234650 polymorphisms in Iranian patients with systemic sclerosis

Systemic Sclerosis (SSc) is a systemic autoimmune disorder, with ambiguous pathogenesis. Genetic and environmental factors were proved to be correlated with SSc aetiology. Single nucleotide polymorphisms (SNPs) in cytokine genes can alter the structure and function of the cytokines and consequently may increase the susceptibility to a specific disease. In this study, we investigated SNPs of the IL‐1 gene cluster in Iranian SSc patients. We obtained blood samples from 170 SSc patients and 213 healthy individuals. Cytokine genotyping results were obtained by polymerase chain reaction with sequence‐specific primers (PCR‐SSP). IL‐1A rs1800587, IL‐1B rs1143634 and IL‐1R1 rs2234650 were evaluated for SNP study. The frequency of the IL‐1B rs1143634 CT genotype was significantly lower in SSc patients compared to the controls (OR = 0.584; 95% CI = 0.385–0.886; P‐value = 0.023), so we propose that CT genotype of this allele might be protective. According to our haplotype analysis, CCC haplotype frequency is higher in the control group compared to SSc patients (OR = 1.575; 95% CI = 1.176–2.111; P‐value = 0.008) and in contrast, CTC haplotype frequency is lower in the control group compared to SSc patients (OR = 0.152; 95% CI = 0.047–0.484; P‐value = 0.002), so they might decrease and increase the susceptibility of having SSc, respectively. In addition, we reported two significant diplotypes frequency differences among SSc patients and healthy individuals. It is highly important that there is not much resemblance between the IL‐1 gene cluster polymorphism in different populations, so we can indicate that SNPs may play critical roles when they are combined with other genetic and environmental factors.     

The association of CTLA‐4 A49G polymorphism with colorectal cancer risk in a Chinese Han population

Cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4) is expressed in T cells and plays an important role in the regulation of T cell. CTLA‐4 has long been considered to be associated with various kinds of diseases. With the attempt to examine the association between CTLA‐4 A49G polymorphism and colorectal cancer risk in a Chinese Han population, we employed TaqMan assay to genotype the CTLA‐4 A49G polymorphism in 311 colorectal cancer cases and 389 cancer‐free controls. We found evidence of the association between CTLA‐4 A49G polymorphism and colorectal cancer risk (GG vs. AA: OR = 2.01, 95% CI = 1.29–3.07, P = 0.002; GA vs. AA: OR = 2.32, 95% CI = 1.53–3.57, P = 0.001; GA + GG vs. AA: OR = 2.16, 95% CI = 1.46–3.21, P = 0.001). Next, we performed a meta‐analysis to comprehensively examine the association between CTLA‐4 A49G polymorphism and colorectal cancer risk. We found a significant association between CTLA‐4 A49G polymorphism and colorectal cancer risk among Asians, which is consistent with our result. However, we found no evidence for the association between CTLA‐4 A49G polymorphism and colorectal cancer risk among Caucasians. In conclusion, we demonstrated that the CTLA‐4 A49G polymorphism increased the susceptibility of colorectal cancer in Asian population.     

Association of IL‐1β +3954 C/T and IL‐10‐1082 G/A Cytokine Gene Polymorphisms with Susceptibility to Tuberculosis

Tuberculosis (TB) constitutes the major cause of death due to infectious diseases. Cytokines play a major role in defence against Mycobacterium tuberculosis infection. Polymorphisms in the genes encoding various cytokines have been associated with tuberculosis susceptibility. Household contacts (HHC) are at increased risk of developing the disease. In this study, we examined the association of IL‐1β and IL‐10 cytokine gene polymorphisms with risk of developing tuberculosis in TB patients, their HHC and healthy controls (HC) using JavaStat and SPSS. Multifactor dimensionality reduction (MDR) analyses were performed to explore the potential gene–gene interactions. The genotype and allele frequencies of IL‐1β +3954C/T polymorphism did not vary significantly between TB patients and HC. GG (P < 0.005, OR = 0.219 and 95% CI = 0.059–0.735) and GA (P < 0.0001, OR = 2.938 and 95% CI = 1.526–5.696) genotypes of IL‐10‐1082 G/A polymorphism were found to be significantly associated with patients versus HC. HHC with CC (P < 0.03, OR = 1.833 and 95% CI = 1.1–3.35) genotype in IL‐1β and GA (P < 0.0001, OR = 4.612 and 95% CI = 2.225–9.702) genotype in IL‐10 were at increased risk of developing tuberculosis. MDR tests revealed high‐risk genotypes in IL‐1β and IL‐10 based on the association model. Our results demonstrate that the polymorphisms of IL‐1β and IL‐10 genes may be valuable markers to predict the risk for the development of TB in household contacts.     

Association Between TNF‐α Promoter −308 A/G Polymorphism and Systemic Lupus Erythematosus Susceptibility: A Case–Control Study and Meta‐Analysis

The tumour necrosis factor‐α (TNF‐α) promoter −308 A/G polymorphism plays an important role in the aetiology of systemic lupus erythematosus (SLE). Several studies have estimated the association between TNF‐α −308 A/G and SLE risk. However, results were inconsistent. A case–control study was carried out to explore the association between TNF‐α −308 A/G and the SLE risk in a Chinese Han population. Meta‐analysis combining present with previous studies was conducted to further explore the association. Our case–control study included 556 patients with SLE along with 570 matched healthy controls. TNF‐α −308 A allele was significantly increased in patients with SLE compared with controls (OR = 2.184, 95% CI: 1.718–2.778, P < 0.001). Genotypes AA and AG were associated with the susceptibility to SLE as compared with the GG genotype, as well as the dominant model (AA+AG versus GG), respectively. The meta‐analysis included 41 comparative studies involving 4799 patients and 6635 controls. An association between SLE and allele A was found in the overall populations (OR = 1.70, 95% CI: 1.46–1.98, P < 0.001). In addition, we discussed the correlation between this polymorphism and lupus nephritis (LN) risk, showing that allele A was significantly related to LN in the overall populations (OR = 1.80, 95% CI: 1.21–2.68, P = 0.004). The results from our case–control study and the meta‐analysis indicate that the TNF‐α −308 A allele is significantly associated with an increased risk of SLE/LN.     

Association between human leucocyte antigen alleles and risk of stroke in Iranian population

Previous studies have demonstrated associations between human leucocyte antigen (HLA) and some types of ischaemic stroke. In the present study, we genotyped HLA‐A,‐B and ‐DRB1 alleles in 140 Iranian patients with history of ischaemic stroke and 140 age‐/sex‐matched healthy subjects. No significant difference has been found in the distribution of HLA‐A and B alleles between cases and controls. The DRB1*16 allele was significantly over‐represented in patient group compared with control group (Adjusted p value = 0.048). Other HLA‐DRB1 alleles were not associated with stroke risk. The HLA‐B*35,B*52 genotype was significantly more prevalent among patients compared with controls (Adjusted p value = 0.03, OR [95% CI] = 9.3 [1.3, 407.2]). Several HLA haplotypes were associated with risk of stroke in the assessed population. The current study provides further evidences for participation of HLA in conferring risk of ischaemic stroke.     

MICA‐129 Met/Val polymorphism could be a genetic biomarker for Familial Breast Cancer in the Tunisian population

Identification of candidate genes associated with susceptibility of breast cancer can have a significant impact at a cancer management national healthcare systems level, making genetic testing more affordable and cost‐effective. We have previously shown that the major histocompatibility complex class I‐related chain A (MICA) was related to breast cancer and plays an important role in modulating immune response mechanisms through NKG2D receptor activation. Compared to our previous study, in this work, we recruited a new cohort composed of 354 unrelated Tunisian women affected by breast cancer and 380 age‐matched women as controls, all genotyped for MICA‐129 Met/Val (rs 1051792). Subsequently, we exanimated the distribution of this polymorphism in ten families. As a result, an association was found between the Val allele and Val/Val genotype and the risk of breast cancer (p = 2.5 × 10^–15; OR = 2.40; p = 6.5 × 10^–13; OR = 3.03, respectively). Stratified analysis with age and family history of cancer revealed an association between the Val/Val genotype and younger patients <40 years (p = .003; OR = 2.03). Among those patients having a family history of cancer, 68% had a Val/Val genotype (p = .02; OR = 1.82). In the family study, an analyse of pedigrees revealed that the majority of families showed the development of breast cancer at a young age. Moreover, all patients diagnosed with early‐onset breast cancer had a Val/Val genotype. Our results lead us to propose that this polymorphism may be an inherited genetic biomarker contributing to an increased breast cancer risk in Tunisian women.     

CTLA‐4 49 A/G dimorphism and type 1 diabetes susceptibility: a French case–control study and segregation analysis. Evidence of a maternal effect

Several studies have demonstrated an association of cytotoxic T lymphocyte‐associated molecule 4 (CTLA‐4) (IDDM 12) alanine 17 with type 1 diabetes, but we wished to study the parental effect of CTLA‐4 49 A/G dimorphism in diabetic families. The CTLA‐4 exon 1 polymorphism (49 A/G), HLA‐DRB1 and insulin gene (INS) variable number tandem repeats (VNTR) were analysed in 134 type 1 diabetic patients vs. 273 control subjects. The segregation analysis for transmission was carried out in 70 informative diabetic families using the transmission distortion test (TDT). All genotyping was performed by PCR‐RFLP. CTLA‐4 49 G allele frequency was not increased in diabetic patients compared to controls (41 vs. 38%, not significant). The distribution of GG, AG and AA CTLA‐4 genotypes was similar in the two groups (13, 57 and 30% vs. 11, 54 and 35%, respectively) and was independent of HLA‐DRB1 or INS VNTR polymorphism. The CTLA‐4 49 G allele showed weak distorted transmission to the diabetic offspring, whereas random transmission was observed in unaffected offspring. This distortion is attributable to a maternal effect (71% compared to the 50% expected ratio; tdt = 4.8; P < 0.03). The combined transmission of maternal CTLA‐4 G with HLA‐DRB1*03 (90%; tdt = 6.4; P < 0.01) and VNTR class I (80%; tdt = 5.4; P < 0.02) enhanced the susceptibility effect of each marker separately. We noted a slight CTLA‐4 49 G and HLA‐DRB1*04 distortion of transmission shared in paternal and maternal diabetic meiosis. In non‐diabetic offspring, the CTLA‐4 49 A allele confers a protective effect in the presence of maternal HLA‐DRB1*03 and paternal HLA‐DRB1*04 alleles. Despite the absence of a positive association of the CTLA‐4 49 G allele with type 1 diabetes, our segregation analysis supports the hypothesis of a modulation by CTLA‐4 49 G/A dimorphism of the susceptibility conferred by maternal HLA‐DRB1*03 inheritance. This potential parental effect needs to be confirmed in a larger data set.