High levels of proinflammatory cytokines IL-6, IL-8, TNF-Α, IL-23, and IFN- in Tunisian patients with type 1 autoimmune hepatitis.

Autoimmune hepatitis (AIH) is a chronic hepatitis of unknown etiology and several cytokines have been implicated in its pathogenesis and onset. Our objective was to determine the profile of pro and anti-inflammatory cytokines, including IL-1ß, IL-6, IL-8, IL-23, IFN-, TNF-α, IL-10 in autoimmune hepatitis and their association with HLA gene polymorphisms. Serum cytokine levels were determined in 50 autoimmune hepatitis patients and one hundred fifty controls using chemiluminescence and ELISA techniques and HLA genotyping performed by PCR SSP. The levels of IL-6 (12 pg/mL vs. 5.5 pg/mL, p = 0.017), IL-8 (24.1 pg/mL vs. 7.8 pg/mL, p = 0.006), and TNF-α (61.1 pg/mL vs. <4.00 pg/mL, p = 0.002) were significantly higher in AIH patients in pretreatment phase compared to levels after remission and in controls. HLA*DRB15 was significantly associated with higher levels of IL-8. IL-6, IL-8, and TNF-α may be biomarkers of AIH activity. HLA gene expression may play a role in higher cytokine production and could allow an earlier diagnosis and better management of the disease.

Association of STAT4, TGFß1, SH2B3 and PTPN22 polymorphisms with autoimmune hepatitis.

The physiopathology of autoimmune hepatitis (AIH) is complex and still not fully elucidated. The genes localized outside the histocompatibility complex involved in regulation and signal transduction of the immune system SH2B3, TGFß1, STAT4 and PTPN22 could be associated to the susceptibility and hepatocyte lysis mechanism of this lethal autoimmune disorder. PATIENTS AND METHODS: We investigated four polymorphic sites in SH2B3 (rs3184504), TGFß1 (rs1800471), STAT4 (rs7574865) and PTPN22 (rs2476601) in 45 AIH patients and 150 healthy controls from Tunisia using real-time PCR. RESULTS: Significant associations were found for SH2B3 T allele (OR = 1.861; p = 0.015, pc = 0.366) and PTPN22 A allele (OR = 7.070; p = 0.026; pc = 1.00) and AIH with opposite homozygous being protective against the disease (CC genotype with OR = 0.420, p = 0.025; GG genotype with OR = 0.136, p = 0.025, respectively). No statistically significant associations were found for the TGFß1 and STAT4 polymorphisms with AIH susceptibility. CONCLUSION: Our work enlarges information on non-HLA genes that are associated with AIH by focusing in a region of the world that was poorly molecularly characterized for this disease.

Cytotoxic T lymphocyte antigen-4 gene polymorphisms and susceptibility to type 1 autoimmune hepatitis in the Tunisian population.

Genetic factors and gene polymorphisms leading to the onset of autoimmune response in autoimmune hepatitis (AIH) are still not full elucidated. Since the CTLA-4 molecule is a key modulator of the lymphocytes responses we hypothezied that deficiencies or mutations in the gene encoding CTLA4 protein may be involved in AIH susceptibility and trigger the autoimmune response. We investigated 3 distinct polymorphic sites (+49A > G, CT60 G > A and -318C > T) of the CTLA4 gene in 50 AIH patients and 100 healthy controls using the KASP genotyping technology. A significant positive association with AIH susceptibility was found for the GG genotype in +49 position of the CTLA4 gene which was significantly higher in AIH patients compared to controls (28% vs 9%, p = 0.003, OR = 3.93 [1.56-9.88]). The CTLA4 A/A genotype in position CT60 was more significantly frequent in controls comparing to AIH patients and could be considered as a protective genotype for the tunisian patients. CTLA4 genotyping in position -318 did not show any statistically significant difference in genotype or allele distribution. The CTLA4 gene polymorphism in position +49 is associated to AIH susceptibility in the Tunisian population. Mutation in the CTLA4 gene may lead to a modification of the CTLA4 protein structure that could have functional relevance in AIH pathogenesis and onset.

Association of TNF-α-308 Polymorphism with Susceptibility to Autoimmune Hepatitis in Tunisians.

Autoimmune hepatitis (AIH) is a chronic hepatitis of unknown etiology and several proinflammatory cytokines are implicated in its pathogenesis. The association of TNF-α gene polymorphism with AIH onset is not fully elucidated especially in the Tunisian population. The aim of this study was to determine the association of TNF-α (-308 G > A) polymorphism with AIH susceptibility and with TNF-α expression or clinical manifestations of AIH. A total of 50 AIH patients and 150 controls were included. Evaluation of TNF-α polymorphism was performed by ARMS PCR method. A significantly higher frequence of the AA genotype was found in AIH patients compared to controls (34 vs. 8%, p = 0.00002, OR 5.88). The frequency of the A-allele was significantly higher in patients with AIH compared to controls (55 vs. 37.3%, p = 0.002, OR 2.05). The G-allele was significantly more frequent in healthy controls compared to AIH patients [43 vs. 61.3%, p = 0.001, OR 0.47 (0.3-0.75)]. There was a positive correlation between the A/A genotype and a higher serum expression of TNF-α. The TNF*A allele confer susceptibility to AIH in the Tunisian patients and is associated with increased production of TNF-α. Anti-TNF antibodies could be an alternative to the use of corticotherapy and may avoid the exacerbated immune response in AIH.

Interleukin-1 Gene Cluster Polymorphisms and its Haplotypes may Predict the Risk to Develop Cervical Cancer in Tunisia.

Our study aimed to evaluate the association between IL-1α (4845 G/T), IL-1ß (-511C/T) and IL-1RN (VNTR) polymorphisms and risk of cervical cancer. This case-control study investigates three polymorphisms in 130 patients and 260 controls by PCR-restriction fragment length polymorphism (RFLP). The IL-1RN (VNTR) A1/A3 genotype appear as a cervical cancer risk factor (p = 0.048; OR = 2.92; 95 % CI = 1.00-8.74), moreover, the L/2* decreased the risk (p = 0.011; OR = 0.47; 95 % CI = 0.25-0.88) and may be a protective factor against this pathology. Stratified analysis according to the FIGO stage subgroup revealed that the IL-1ß-511 T/T genotype and T allele may be a protective factors against cervical cancer development for patients with early stage (p = 0.030; OR = 0.46; 95 % CI = 0.22-0.96) (p = 0.020; OR = 0.68; 95 % CI = 0.48-0.97). However, for the patients with advanced FIGO stage, IL-1RN-VNTR L/2* genotype appear as a protective factor for this pathology (p = 0.023; OR = 0.29; 95 % CI = 0.08-0.99). The (G-T-L) haplotype showed a significant decreased frequency in cervical cancer patients as compared to controls (p = 0.032; OR = 0.53; 95 % CI = 0.29-0.95). In contrast, the (T-T-2*) combination appear a risk factor for the development of cervical cancer (p = 0.018; OR = 1.57; 95 % CI = 1.07-2.30). Our study suggested that IL1 cluster polymorphisms and haplotypes may be a genetic risk factor for cervical cancer.

HLA class II susceptibility to cervical cancer among Tunisian women.

The variability in host immunogenetic background, especially in human major histocompatibilty genes, has been shown to influence the susceptibility to human papillomavirus (HPV) infection and cervical neoplasia. Here, we conducted a case-control study in Tunisian women to examine the effect of genetic variation in HLA class II DRB1 and DQB1 genes on invasive cervical cancer (ICC) and squamous cell carcinoma (SCC). HLA genotyping was performed by PCR sequence-specific primers technique. The data revealed significant positive and negative associations, suggesting either predisposing or protective effects of these genes in the disease outcome. DRB1*15, alone or linked to DQB1*06, was associated with a 2.7- and 3.5-fold increase in risk for ICC, respectively. DRB1*13-DQB1*03 showed a similar 3.5 risk effect. Concerning SCC, we observed a relatively higher, about 1.2 times more, risk effect for these genetic markers. In contrast, only one haplotype - DRB1*13-DQB1*06 - provides evidence for a weak protection (about 0.3-fold reduction) of ICC and SCC. In conclusion, we suggest that HLA class II polymorphisms are involved in the genetic susceptibility to cervical cancer in Tunisian women.