Interferon-gamma +874 T/A and interleukin-10 -1082 A/G single nucleotide polymorphism in Egyptian children with tuberculosis

The aim was to investigate the association of interferon-gamma (IFN-γ) +874 T/A and interleukin-10 (IL-10)-1082 A/G single nucleotide polymorphisms with tuberculous infection and post-BCG lymphadenitis in Egyptian children. IFN-γ +874 T/A and IL-10 -1082 A/G polymorphism detection by amplification refractory mutation system technique was carried out for 110 patients with TB, 40 patients with post-BCG lymphadenitis and 118 healthy controls. IFN-γ +874 A allele was higher in TB and post-BCG patients than those in healthy controls (Pc=0.006 and 0.002, respectively). IFN-γ +874 genotype AA was significantly higher in patients with TB than that in control (Pc=0.015), in extrapulmonary than patients with pulmonary TB (PTB) (Pc=0.009), and young children with TB below 5 years (Pc=0.024). No statistically significant differences were observed between patients with TB and controls for the frequency of IL-10(-1082) alleles or genotypes (P>0.05); however, a statistically significant difference in the frequency of IL-10 (-1082) GG genotype was found between patients with pulmonary and extrapulmonary TB (Pc=0.003). Low producer IFN-γ +874 A/A genotype is associated with post-BCG lymphadenitis and TB disease especially in younger children below 5 years. IL-10-1082 G/G genotype did not exhibit significant association except for increased GG frequency in PTB. Both cytokine polymorphisms have no relation to tuberculin reaction in patients with TB.     

AKT1 polymorphisms are associated with tuberculosis in the Chinese population

AKT1, a serine/threonine kinase, plays a critical role in the controlling of intracellular growth of Mycobacterium tuberculosis. In this study, we investigated whether polymorphisms in AKT1 affect susceptibility to tuberculosis (TB). Two single nucleotide polymorphisms of AKT1, IVS3+18C>T and +726G>A were genotyped in Chinese patients with pulmonary TB by polymerase chain reaction-restriction fragment length polymorphism. Patients with pulmonary TB had significantly lower IVS3+18 C/C genotype and higher C/T genotype compared with age-, gender- and ethnically matched controls (P < 0.05). The T–A haplotype frequency was significantly higher in patients than in controls (P < 0.05). In conclusion, our result indicates that AKT1 polymorphisms are associated with susceptibility to pulmonary TB.     

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.     

IL6 and FAS/FASL gene polymorphisms may be associated with disease progression in HIV-1-positive ethnically mixed patients

The progression of AIDS depends on the complex host and virus interactions. The most important disease progression hallmarks are immune activation and apoptosis. In this study, we address the prevalence of polymorphisms related to proinflammatory and apoptotic genes, such as IFNG (+874T/A), TNF (308G/A), IL6 (−174G/C), IL8 (−251A/T), FAS (−670A/G), and FASL (−124A/G) in 160 ethnically mixed HIV-1-infected patients from multicentre cohorts with different clinical outcomes (13 elite controllers [EC], 66 slow long-term non-progressors [LTNPs], and 81 progressors [P]). The genotyping was accomplished by TaqMan-qPCR. Among all the polymorphisms analyzed in the cytokines, the IL6 −174G/C polymorphism showed a higher frequency of GG genotype in the LTNP and LTNP+EC groups as compared to the P group. Moreover, there was a significantly higher frequency of the G allele in the LTNP and LTNP+EC groups as compared to the P group. On the other hand, the levels of CD4⁺ T lymphocytes were higher among individuals showing the AA and AG genotypes for the FASL −124A/G polymorphism as compared to the GG genotype. Furthermore, the AG and AA genotypes were more frequent, as compared to the GG genotype, in individuals showing a lower viral load. In contrast, for the FAS −670A/G polymorphism, a significantly higher viral load was observed in individuals with the AG genotype as compared to the GG genotype. In conclusion, we found three genetic allelic variants of the IL6 −174G/C, FASL −124A/G, and FAS −670A/G polymorphisms that were related to disease progression and immunological and virological markers in cohorts of HIV-1-positive ethnically mixed patients.     

The −786 T/C polymorphism of the <Emphasis Type="Italic">NOS3</Emphasis> gene is associated with elite performance in power sports

The NOS3 gene is a candidate to explain individual variations in health and exercise related phenotypes. We compared genotypic and allelic frequencies of the NOS3 −786 T/C polymorphism (rs2070744) in three groups of men of the same Caucasian (Spanish) descent: (i) elite endurance athletes (cyclists, runners; N = 100); (ii) elite power athletes (jumpers, throwers, sprinters; N = 53) and (iii) non-athletic controls (N = 100). The frequency of the TT genotype was significantly higher in power athletes (57%) than in the endurance (33%, P = 0.017) or control group (34%, P = 0.026). The frequency of the T allele was also higher in power sportsmen (71%) than in their endurance (55%, P = 0.003) and control referents (56%, P = 0.015). No differences were observed between control and endurance groups. In summary, the −786 T/C polymorphism of the NOS3 gene seems to be associated with elite performance in power-oriented athletic events (throwing, jumping, sprinting), with the T allele exerting a beneficial effect. The mechanism by which this allele variant might benefit power performance remains to be elucidated.     

Mothers' distress exposure and children's withdrawn behavior – A moderating role for the Interferon Gamma gene (IFNG)

The dysregulation of the inflammatory response, including pro-inflammatory molecules, produces neuropsychiatric symptoms and depression-like behavior, including withdrawal from the physical and social environment. Genetic variants that enhance immune reactivity may thus increase inflammatory and withdrawn reactions to stress. Here we investigated a functional polymorphism of Interferon Gamma gene ( IFNG  +874 T > A, rs2430561) as moderator of the relationship between mothers’ distress exposure and children's withdrawn behavior at preschool age. Participants were 198 Portuguese preschool children (mean age = 57.98 months). Exposure to mother's distress was assessed using the Brief Symptom Inventory, and withdrawn behavior with the Caregiver Teacher Report Form. All children provided saliva samples for genotyping. Contrary to expecations based on prior work, the rs2430561 AA genotype—not the T variant—interacted with (high levels of) mothers’ distress exposure, to increase children's withdrawn behavior. No significant main effects were detected. The polymorphism in Interferon Gamma gene showed specific environmental stressor-dependent effects on withdrawn behavior during childhood, ones which are interpreted in light of the "behavioral immune system" hypothesis, and which proved inconsistent with diathesis-stress thinking.     

The association of interferon‐gamma,interleukin‐4 and interleukin‐17 single‐nucleotide polymorphisms with susceptibility to tuberculosis

Susceptibility to tuberculosis and progression of the disease depend on interactions between the bacterial agent, host immune system, and environmental and genetic factors. In this case‐controlled study, we aimed to determine the role of single‐nucleotide polymorphisms of interferon‐gamma, interleukin‐4 and interleukin‐17 in susceptibility to tuberculosis. Genomic DNA was extracted from peripheral blood samples of patients and controls. The association of single‐nucleotide polymorphisms in interleukin‐4 (?590C/T), interleukin‐17 (?152A/G) and interferon‐gamma (+874T/A) was investigated by polymerase chain reaction (PCR)‐restriction fragment length polymorphism and amplification refractory mutation system‐PCR. A total of 76 tuberculosis patients and 119 healthy individuals were included in this study. The interferon‐gamma (+874T/A) TA genotype was significantly associated with susceptibility to tuberculosis in patients compared to controls (OR = 1.76; 95%CI = 0.84–3.71; p = 0.007), while the interferon‐gamma (+874T/A) TT genotype (OR = 0.51; 95%CI = 0.19–1.36; p = 0.007) had protective effects against tuberculosis and was related to a low risk of tuberculosis development. The difference between allelic and genotypic frequencies of interleukin‐4 (?590C/T) between patients and controls was not significant (p = 0.46). Multivariate logistic regression analysis revealed that the interleukin‐17 (?152A/G) AG genotype (OR = 2.27; 95%CI = 1.19–4.34; p = 0.03) and AA genotype (OR = 1.03; 95%CI = 0.43–2.44; p = 0.03) were significantly different between patients and controls. In conclusion, single‐nucleotide mutations in different cytokine genes may have protective effects or increase the risk of tuberculosis.     

Association of the IFN-γ (+874A/T) Genetic Polymorphism with Paranoid Schizophrenia in Tunisian Population

Since growing evidence suggests a significant role of chronic low-grade inflammation in the physiopathology of schizophrenia, we have hypothesized that functional genetic variant of the IFN gamma (IFN-γ; +874A/T; rs2430561) gene may be involved in the predisposition to schizophrenia. This research is based on a case–control study which aims to identify whether polymorphism of the IFN-γ gene is a risk factor for the development of schizophrenia. The RFLP-PCR genotyping of the IFN-γ gene was conducted on a Tunisian population composed of 218 patients and 162 controls. The IFN-γ (+874A/T) polymorphism analysis showed higher frequencies of minor homozygous genotype (TT) and allele (T) in all patients compared with controls (11.5 vs. 4.9%; p = 0.03, OR = 2.64 and 30.7 vs. 24.1%, p = 0.04, OR = 1.4, respectively). This correlation was confirmed for male but not for female patients. Also, the T allele was significantly more common among patients with paranoid schizophrenia when compared with controls (25.8 vs. 4.9%, p = 0.0001; OR = 6.7). Using the binary regression analysis to eliminate confounding factors as age and sex, only this last association remained significant (p = 0.03; OR = 1.76, CI = 1.05–2.93). In conclusion, our results showed a significant association between +874A/T polymorphism of IFN-γ and paranoid schizophrenia, suggesting that this single nucleotide polymorphism (SNP) or another at proximity could predispose to paranoid schizophrenia. Since the minor allele of this polymorphism was correlated with an increased expression of their product, our study validates the hypothesis of excessive pro-inflammatory cytokine in the physiopathology of paranoid schizophrenia.     

CTLA4 exon 1 dimorphism in bullous and cicatricial pemphigoid

The human cytotoxic T‐lymphocyte antigen 4 (CTLA4) gene encodes proteins regulating the immune response. The polymorphism of this gene is associated with some autoimmune diseases. In this study, we analysed the distribution of the dimorphisms of exon 1 (+ 49 A/G) in bullous pemphigoid (BP) and cicatricial pemphigoid (CP), two types of autoimmune bullous skin diseases that occur in elderly people. The frequency of the exon 1 A‐G genotype was marginally decreased in patients (36.4%; n = 55) compared with controls (52.8%, n = 53), but the results were not statistically significant (P = 0.09).     

Effect of Cytokine Genes in the Pathogenesis and on the Clinical Parameters for the Treatment of Multiple Myeloma

In this study, we aimed to explore the association among gene variants of five cytokines, tumor necrosis factor alpha (TNF-α), transforming growth factor beta-1 (TGF-β1), interferon gamma (IFN-γ), interleukin-6 (IL-6), and interleukin-10 (IL-10), and clinical parameters and prognosis in patients with multiple myeloma (MM) treated with novel therapeutic drugs in Turkish population for the first time except TNF-α. We analyzed five cytokine genes in 113 cases with MM and 113 healthy controls. Cytokine genotyping was performed by the polymerase chain reaction–sequence-specific primer method (PCR-SSP). AG genotype associated with high expression in TNF-α gene (–308) variant was found to be significantly higher (p = 0.019), and GG genotype associated with low expression in TNF-α gene (–308) variant was significantly lower in MM group as compared with controls (p = 0.012). IFN-γ (+874) variant TT genotype was increased (p = 0.037), and AA genotype was decreased (p = 0.002) in MM group in contrast to controls. IFN-γ (+874) T allele was higher in MM patients compared with controls (OR = 1.985, p = 0.000), while A allele was significantly lower (OR = 0.5037, p = 0.0005). Multivariate analysis revealed that factors associated with 5-year overall survival (OS) were only IPI III (RR = 1.630, p = 0.018) and thrombocytopenia (RR = 2.207, Cox p = 0.021), while 5-year event-free survival (EFS) was associated with IPI III (RR = 1.524, p = 0.022), thrombocytopenia (RR = 2.902, p = 0.002), APSCT treatment (RR = 1.729, p = 0.035), and female gender (RR = 0.435, p = 0.002) with negative prognostic values. Our results suggested that TNF-α gene (–308) AG genotype and IFN-γ (+874) TT genotype and T allele may have a role on MM, while other cytokines were not associated with the risk of MM.     

Genotype frequencies of the +874T→A single nucleotide polymorphism in the first intron of the interferon‐γ gene in a sample of Sicilian patients affected by tuberculosis

In the light of the key role played by interferon (IFN)‐γ in the control of tuberculosis, in the present paper we have evaluated the distribution of the functional +874T → A IFN‐γ single nucleotide polymorphism (SNP) in Sicilian patients affected by tuberculosis. Our aim was to determine whether there is an association between the TT genotype, which has been suggested to be linked to an increased production of IFN‐γ, and resistance to chronic tuberculosis. DNA samples were obtained from 45 patients and 97 healthy controls. Polymorphism at +874 was identified using amplification refractory mutational system methodology. The +874T SNP was less frequent in patients than in controls (0.42 vs. 0.50) but the difference was not significant. The +874TT genotype, which has been suggested to be associated with high IFN‐γ production, was significantly decreased in the patients. Thus, resistance to chronic lung tuberculosis might be associated with a genetically determined high IFN‐γ production capacity. In conclusion, the present data add another piece of evidence to the complex puzzle of genetic and environmental factors involved in control of infectious diseases. Studies on cytokine gene polymorphisms may elucidate the complex network of trans‐interactive genes influencing the type and strength of responses to environmental stressors and may help to identify the genetic factors that affect survival in humans.     

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 of cytokine genetic polymorphisms with the humoral immune response to recombinant vaccine against HBV in infants

The prevention of hepatitis B by vaccination is one the most efficient tools to avoid the transmission of the virus, although a considerable variability to the anti‐HBsAg antibody response has been described. Recently, polymorphisms of cytokine regulating genes have been described which seem to influence the immune response to various antigens. This article's objective was to evaluate the influence of cytokine genetic polymorphisms onto the humoral immune response to hepatitis B vaccine in infants. Vaccinated children were classified according to the level of anti‐HBsAg antibody titles. The genotyping for TNF (?308), TGFB1 (+869, +915), IL‐10 (?1082, ?819, ?592), IL‐6 (?174), and IFNG (+874) was accomplished by the PCR‐SSP technique. The TNF (?308) allele A presented a lower but not statistically significant frequency at 5% level in high responder patients (3.7% vs. 12.3%, P = 0.0919). The same was seen for the TNF (?308) genotype GA (7.4% vs. 24.5%, P = 0.0757). Further studies in other populations and evaluation of a greater number of individuals may contribute for a better understanding of the cytokine gene polymorphism influence in general and TNF polymorphism more specifically in the humoral immune response to the HBsAg vaccination in newborn children. J. Med. Virol. 82:929–933, 2010. © 2010 Wiley‐Liss, Inc.     

Interleukin‐17F single‐nucleotide polymorphism (7488T>C) and its association with susceptibility to leprosy

The objective of this study was to investigate the association, if any, between the interleukin‐17F (7488T>C) (rs763780) polymorphism and susceptibility to leprosy and to elucidate the relationship between IL‐17F genotypes and clinical profile of the disease. DNA was extracted from the peripheral venous blood of leprosy cases (n = 140), which were classified as per WHO classification into paucibacillary (PB) (n = 53) and multibacillary (MB) (n = 87) categories and healthy controls (n = 84) without any signs and symptoms of leprosy. The IL‐17F (7488 T/C) polymorphism was genotyped using amplification refractory mutation system – polymerase chain reaction (Allele‐specific amplification). In both PB and MB categories of leprosy cases, the homozygous TT genotype frequency was significantly higher than that of the healthy controls (78.70% vs. 29.76%, P < 0.05). The heterozygous TC genotype was higher in the controls than in the leprosy cases (57.14% vs. 17.68%, P < 0.05). TT genotype was more associated with the type 1 reactional states and tuberculoid/borderline tuberculoid groups in leprosy than the TC genotype. This study reveals that the IL‐17F (7488T>C) single‐nucleotide polymorphism is associated with susceptibility to leprosy and polymorphism confers decrease in risk of contracting leprosy in the north Indian cohort.     

Association of interferon gamma and interleukin 10 genes with tuberculosis in Hong Kong Chinese

Interferon gamma (IFN-gamma) and interleukin 10 (IL-10) are believed to play opposing roles in host immunity against mycobacterial infection. IFN-gamma activates macrophages, while IL-10 downregulates the expression of T helper type 1 cytokines, MHC class II antigens and costimulatory molecules on macrophages. Associations of IFN-gamma -179 (G/T), +874 (A/T), +875 miscrosatellite CA repeats and +4766 (C/T), and IL-10 -1082 (A/G), -819 (C/T) and -592 (C/A) with tuberculosis (TB) were investigated in 385 HIV-negative patients and 451 controls in a Hong Kong Chinese population. The frequency of a low IFN-gamma-producing +874 A/A genotype was significantly over-represented in the patient group (P<0.001, OR=3.79, 95% CI=1.93-7.45). We identified 10 alleles in the IFN-gamma CA repeats and observed a significant difference in allele frequency distribution between patients and controls (P<0.001). By grouping alleles into 12 and non-12 CA repeats, the non-12/non-12 genotype yielded a similar significant result (P<0.001, OR=4.56, 95% CI=2.21-9.43) as observed in +874 A/A genotype. Weak associations of the IL-10 GCC/- genotype (P=0.04) and the low IFN-gamma-producing A/A genotype (P=0.06) with TB relapse/extrapulmonary cases were found. This study suggests the possible role of interferon gamma in TB susceptibility.     

Polymorphisms in the genes encoding interferon‐γ and interferon‐γ receptors in multiple sclerosis

Genome screens suggest that several genes, each contributing to a small extent, are involved in multiple sclerosis (MS) susceptibility. Simultaneous analysis of related genes may improve the power to detect such small effects. Interferon‐γ (IFN‐γ), mediating its effects through the IFN‐γ receptor, is a pleiotropic, pro‐inflammatory cytokine for which a detrimental effect on the course of MS has been reported. The role of IFN‐γ receptor 1 (IFNGR1) and IFN‐γ receptor 2 (IFNGR2) gene polymorphisms has not been studied in MS, and, for the IFNG gene polymorphism there is only one previous study, which incorporates clinical, but not imaging, data. The aim of this study was to investigate whether polymorphisms in the IFNG and IFNGR1 and IFNGR2 genes are associated with susceptibility to MS, or disease characteristics, as defined by clinical and imaging criteria. Genotypes for IFNG, IFNGR1 and IFNGR2 were determined in 509 patients with MS and in 193 healthy controls. Patient files were reviewed for disease course, age at onset of disease, and rate of progression. Serial magnetic resonance imaging (MRI) data were available for 107 patients. No significant differences in the distribution of IFNG, IFNGR1 and IFNGR2 genotype and allele frequencies were found between patients and controls. A progressive, as opposed to a relapsing, onset was significantly more frequent in carriers of the IFNGR2 allele Arg64 (P = 0.028). Moreover, IFNGR2 allele Arg64 carriers had a lower black hole ratio than non‐carriers (P = 0.016). No other associations with clinical parameters, such as age at onset or rate of progression, or with imaging parameters, were observed. The IFNG intron 1 gene polymorphism studied is unlikely to play a major role in MS susceptibility or disease course. The IFNGR1 and IFNGR2 gene polymorphisms studied do not exert an important influence on MS susceptibility, but allele IFNGR2*Arg64 may be associated with a progressive disease onset.     

CD38+CD8+ and CD38+CD4+ T Cells and IFN Gamma (+874) Polymorphism Are Associated with a Poor Virological Outcome

The main objective of the work was to evaluate the use of CD38 on T lymphocytes, IFNγ (+874 A/T), and IL-10 (?1082 A/G) polymorphisms in HIV-infected patients under antiretroviral (ARV) therapy. Sixty-one patients were selected at the outpatient clinic for HIV infection at the Hospital São José de Doenças Infecciosas, Fortaleza, Ceará, Brazil. The patients were classified into two groups, according to viral load after one year of ARV therapy. In the aviremic group (group I), a reduction of 35.5% of CD38+CD4+ T cells was observed (p = 0.02) and 49.3% of CD38+CD8+ T cells (p = 0.001). In the viremic group (group II), a reduction of 37.2% of CD38+CD4+ T cells (p = 0.067), and 21.4% of CD38+CD8+ T cells (p = 0.60) occurred. No association was found between IL-10 (?1082) polymorphism and the type of response to ARV therapy. Regarding the gene polymorphism on IFNγ (+874 T/A), 73.34% of group I and 33.3% of group II presented the AA genotype. The relative risk of the individuals carrying AA genotype or the A allele and not being able to suppress the viral load level after one year of ARV therapy was 3.44 (1.25–9.45; p = 0.014) or 2.35 (1.05–5.26; p = 0.027), respectively. Our data suggested that an augmented frequency of activated CD38+CD8+ T cells as well as the presence of the A allele of IFNγ polymorphism could contribute to a reduced virological suppression in patients under antiretroviral therapy.     

Association of genetic polymorphisms in the IL12-IFNG pathway with susceptibility to and prognosis of pulmonary tuberculosis in a Chinese population

Cytokines are crucial in activation of the cell-mediated immunity required for eliminating pathogens and controlling intracellular growth of Mycobacterium tuberculosis (TB). Genetic variants in the IL12-IFNG axis are hypothesized to be involved in the development and progression of TB. Genetic polymorphisms of rs2243115 and rs568408 in IL12A, rs3212227 in IL12B and rs2430561 in IFNG(+874) were detected in 522 pulmonary TB cases and 527 controls recruited from Yangzhong and Wujin County of China. It was found that genetic variants TG/GG of rs2243115(IL12A) were associated with a decreased risk of TB, with odds ratio (95% confidence interval) of 0.70 (0.49–0.99), whereas variant genotypes AT/TT of rs2430561(IFNG) conferred 82% less risk for treatment failure, with a hazard ratio of 0.18 (95% confidence interval 0.04–0.73). Cumulative effects analysis revealed that the risk of TB increased significantly with the number of unfavorable genotypes in IL12 genes. Furthermore, MDR analysis showed potential higher-order gene–gene and gene–environment interactions and indicated different outcomes based on distinct genotype profiles. Results from this study demonstrate that genetic polymorphisms of the IL12-IFNG pathway may individually or jointly contribute to the susceptibility to and prognosis of pulmonary TB.     

Association of Cytokine Gene Polymorphisms in Patients with Tuberculosis and Their Household Contacts

Cytokine gene polymorphisms are known to be associated with functional differences in cytokine regulation and may affect host susceptibility to tuberculosis (TB). Contacts are important group in developing tuberculosis infection and are 10–60 times more likely to develop TB than general population. The present study was carried out in patients with TB (N = 176), their household contacts (HHC; N = 155) from Free Chest TB Clinic PPM DOTS (1TU) covering 500,000 population at Mahavir Hospital and Research Centre, Hyderabad, and healthy controls (HC; N = 170) also included. The association of single‐nucleotide polymorphisms (SNPs) in the promoter region of TNF‐α (?308G/A), IL‐2 (?330T/G), IL‐4 (?589C/T) and in exon region of TGF‐β1 (+869T/C) genes was assessed by ARMS & PCR‐RFLP using specific primers in the above‐mentioned subjects. The differences in allelic or genotypic frequencies of TNF‐α (?308G/A) between patients, their HHC and HC were not statistically significant (P > 0.05). IL‐2 (?330T/G) TG genotype was significantly different between patients, HHC compared to HC (P < 0.002, OR‐1.997, 95%CI‐1.260‐3.168, P < 0.03, OR‐1.602, 955CI‐1.003‐2.561).IL‐4 (?589C/T) CC genotype was significantly different between patients and HC (P < 0.03, OR‐1.791, 95%CI‐1.009‐3.189) as well as between HHC and HC at P < 0.0001, OR‐2.56, 95%CI‐1.448‐4.545. In addition, the TGF‐β 1 (+869T/C) TC genotype was significantly associated with susceptibility to tuberculosis in patients when compared against HC(P < 0.0001, OR‐3.416, 95%CI‐2.063‐5.670) and HHC (P < 0.0001, OR‐2.357, 95%CI‐1.439‐3.868), respectively.MDR analysis indicated that TT genotype of TGF‐β1 with TT and CT genotypes of IL‐4 showed high risk with GA, TT genotypes of TNF‐α, IL‐2, respectively. Our results suggest that IL‐2 (‐330T/G), IL‐4 (‐589 C/T) and TGF‐β1 (+869T/C) gene polymorphisms may be associated with TB susceptibility.     

Polymorphism of the interferon-gamma gene and risk of tuberculosis in a southeastern Chinese population

The aim of this study is to examine the influence of the +874 A/T and +875 CA microsatellite single nucleotide polymorphisms (SNPs) of the interferon-gamma gene (IFNG) on patients with tuberculosis (TB) in the southeastern Chinese population. Genomic DNA from patients with TB (n = 301) and ethnically matched controls (n = 310) was genotyped for the two SNPs by DNA sequencing and short tandem repeat-polymerase chain reaction (PCR) method. Our results demonstrated the AA genotype of +874 A/T IFNG was associated with TB (odds ratio, 1.98; 95% confidence interval = 1.08-3.63; p = 0.035). By grouping alleles into 12 and non-12 CA repeats at the +875 CA microsatellite, the homozygous non-12/non-12 CA repeats genotype yielded the same significant trend as that observed in the +874 AA genotype. The results indicate a positive association of IFNG polymorphism with TB. Data also provide genetic evidence supporting the multiple disease hypothesis, which emphasizes that many disease genes have been involved.