Interleukin-4 and Interleukin-4 Receptor Alpha Gene Polymorphisms in Recurrent Aphthous Stomatitis.

BACKGROUND: Recurrent aphthous stomatitis (RAS) is a common oral condition with a major impact on the quality of life. The condition is thought to be due to the overexpression of T helper-1(Th1)-related cytokines. Since interleukin-4 (IL-4) and its receptor (IL-4Rα) are antagonistic to Th-1 pathways, polymorphisms in their genes may also be involved in the pathogenesis of aphthous stomatitis. METHODS: Sixty-four patients diagnosed with minor RAS and 141 (age- and sex-matched) healthy controls were assessed for 3 single-nucleotide polymorphisms (SNPs) within the promoter region of the IL-4 gene (-1098G/T, -590C/T, and -33C/T), and 1 SNP in IL-4Rα gene (+1902 A/G). RESULTS: No significant differences were detected between the patient and the control group regarding IL-4 allele frequencies. However, the patient group demonstrated a higher frequency of IL-4 -590 CC genotype and a lower rate of IL-4 -590 TC genotype. The TCT, GTT, GCT, and GTC haplotypes of the IL-4 gene (-1098, -590, -33) were significantly more frequent in the patients and the GCC, and TTT haplotypes were more common in healthy controls. No significant differences were found in IL-4Rα gene polymorphism between the 2 groups. CONCLUSIONS: Certain polymorphisms of IL4 gene could predispose individuals to RAS.

PTPN22 Single-Nucleotide Polymorphisms in Iranian Patients with Type 1 Diabetes Mellitus.

BACKGROUND: PTPN22 plays a crucial role in regulating the function of various cells of the immune system, particularly T cells. Polymorphisms of the PTPN22 gene have been associated with many autoimmune diseases, including type 1 diabetes (T1D) which is a T-cell-mediated disease. OBJECTIVE: The present study was aimed at genotyping of an Iranian population for five polymorphisms of the PTPN22 gene. METHODS: The study population consisted of 99 T1D patients and 100 healthy controls. We genotyped five single-nucleotide polymorphisms (SNPs) (rs12760457, rs1310182, rs1217414, rs33996649, and rs2476601) of the PTPN22 gene. RESULTS: Regarding the variant rs2476601, genotypes AG and GG were increased and decreased in T1D patients compared with controls, respectively. Further, alleles G and A of this SNP were found to be decreased and increased in T1D patients, respectively (p value = 0.001). However, T1D and control groups did not differ on genotype distribution or allele frequency for other investigated SNPs. CONCLUSIONS: The PTPN22 rs2476601 minor allele (A) was associated with T1D in Iran, accounting for its pathophysiology in autoimmune diseases.

The analysis of association between SNCA, HUSEYO and CSMD1 gene variants and Parkinson's disease in Iranian population.

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder. Both genetic and environmental factors are involved in the etiology of the disease. Many studies have revealed the susceptibility genes and variations for PD which need further confirmation. Here we evaluated the association of variations in SNCA, HUSEYO and CSMD1 genes with PD. A case-control study was conducted with 489 PD patients and 489 healthy controls. DNA was extracted from peripheral blood of all subjects and rs356220 and rs11931074 in SNCA, rs2338971 in HUSEYO and rs12681349 in CSMD1 were genotyped using PCR-RFLP method. The genotypes and allele frequencies were significantly different between case and control groups for rs356220, rs11931074 and rs2338971 but not for rs12681349. We provided further evidence that rs356220 is associated with increased risk of PD supporting previous studies in Caucasian-based and Japanese populations. The association of rs11931074 with decreased risk of PD was also significant. This study revealed the first evidence of the association of rs2338971 with increased risk of PD in the Iranian population. Nevertheless, these findings need further validation via more replication studies.

Association of IL-10 and TGF-beta cytokine gene polymorphisms with autoimmune hepatitis.

BACKGROUND AND AIMS: Autoimmune hepatitis is a chronic immune-mediated liver injury caused by dysregulated immune response to liver antigens. Genetic susceptibility is affected by multiple single nucleotide polymorphisms in immune-related genes. There are few reports on the association of TGF-ß and IL-10 genetic variants with autoimmune hepatitis. METHODS: Allele frequency and genotype status of IL-10 -1082, -819, -592 and TGF-ß +869 and +915 polymorphisms were investigated in 57 unrelated patients with autoimmune hepatitis and 140 healthy controls by polymerase chain reaction with sequence-specific primers. RESULTS: IL-10 -592 and -819 allele frequencies and genotypes were not associated with autoimmune hepatitis in our population, while IL-10 -1082 genotypes were. IL-10 -1082/-819/-592 "high-producing" haplotype GCC was significantly less frequent in patients. TGF-ß +869 "high-producing" allele C and genotype CC were significantly more in autoimmune hepatitis, compared to controls; whereas, TGF-ß +915 "low-producing" allele C and genotype CC were significantly more in autoimmune hepatitis compared to control. TGF-ß +869/+915 haplotype TG was significantly less frequent in patients while CC haplotype was significantly more frequently observed in patients. CONCLUSION: We identified a significant association between IL-10 -1082/-819 and TGF-ß +869/+915 genotypes and haplotypes with autoimmune hepatitis in Iranians.

Autosomal dominant deficiency of the interleukin-17F in recurrent aphthous stomatitis: Possible novel mutation in a new entity.

Recurrent Aphthous Stomatitis (RAS) is a common oral inflammatory disease with unknown pathogenesis. Although the immune system alterations could be involved in predisposition of individuals to oral candidiasis, precise etiologies of RAS have not been understood yet. A recent study showed that autosomal dominant IL17F deficiency could cause chronic mucocutaneous candidiasis. Considering the inflammatory nature of interleukin (IL)-17F and RAS, this study was performed to check any disease-associated mutation in a number of patients with RAS. Sixty-two Iranian individuals with RAS were investigated in this study. After DNA extraction using a phenol-chloroform method from the whole blood, amplification was accomplished by polymerase chain reaction and the products were sequenced using a 3730 ABI sequencer. The results of sequencing revealed a missense, heterozygous mutation of IL17F, converting a threonine to proline in a patient with RAS (T79P). The Poly-phen software suggested a damaging probability predicting this substitution to have a harmful effect on IL-17F protein function. This mutation was checked in fifty healthy individuals, and was not detected in any of them. This is the first study showing that a mutation in IL-17F is associated with susceptibility to RAS. However, functional studies and further studies on more patients with RAS are required to confirm such association.

Autoimmune hepatitis association with single nucleotide polymorphism of interleukin-2, but not interferon-gamma.

BACKGROUND: Autoimmune hepatitis (AIH) is a chronic inflammation in hepatocellular tissues associated with circulating autoantibodies. Imbalance in T-cells population and dysregulation in several cytokine profiles has been implicated in pathogenesis of AIH. This study was performed to assess potential association of AIH with interleukin-2 (IL-2) and interferon-gamma (IFN-γ) genes single nucleotide polymorphisms (SNPs). METHODS: Fifty-six patients with AIH and 139 healthy individuals were enrolled in this study. IL-2 and IFN-γ typing was performed, using polymerase chain reaction with sequence-specific primers (PCR-SSP) assay. The frequencies of alleles, genotypes and haplotypes in AIH patients were compared to healthy controls. RESULTS: IL-2 T allele at position +166 (rs2069763) showed significant higher frequency in AIH group (36%), compared to the controls (21%) (OR=2.06; 95% CI, 1.24-3.43, P-value<0.01). The frequency of IL-2 TT genotype at +166 position was also associated with AIH (OR=18.68, 95% CI 3.74-126.04, P-value<0.01). G/T alleles of IL-2 at -330 (rs2069762) and A/T alleles on UTR +5644 position at IFN-γ and their subsequent haplotypes, did not show significant association with AIH. CONCLUSIONS: This study identified IL-2T allele at +166 position and TT genotype as susceptibility gene in AIH which would provide better understandings into the mechanisms of AIH and potential immune modulation therapies.

Association of Transforming Growth Factor-Beta Gene Polymorphisms in Recurrent Aphthous Stomatitis.

This study has been conducted to evaluate the allele, genotype and haplotype frequencies of the polymorphic gene coding TGF-ß in recurrent aphthous stomatitis (RAS). TGF-ß gene typing was done by polymerase chain reaction with sequence-specific primers (PCR-SSP) assay. Allele frequencies were estimated by direct gene counting. C allele at codon 25 was significantly increased, while G allele at this position was significantly decreased in patients compared to the controls. A significantly higher frequency of CG genotype at codon 25 was found in control group. CC genotype and TT genotype at codon 10 of the gene was significantly decreased, while CT genotype at the same position was significantly increased in patients, indicating that CT heterozygosity at codon 10 TGF-ß is associated with greater risk of RAS. CG and TG haplotypes were significantly decreased while CC and TC haplotypes were significantly increased in patients compared with controls. This study indicates the TGF-ß single nucleotide polymorphisms could play a role in RAS pathogenesis. Thereby certain SNPs of TGF-ß gene have an association with RAS pathogenesis.

HLA-DRB and HLA-DQB Allele and Haplotype Frequencies in Iranian Patients with Recurrent Aphthous Stomatitis.

Recurrent aphthous stomatitis (RAS) is known as the most common chronic disease of the oral cavity, which affects a range of 5-25% of the population. RAS appears to be associated with some human leukocyte antigen (HLA) class II alleles and haplotypes. This study attempts to survey the distribution of HLA-DRB and -DQB alleles among Iranian RAS patients and healthy controls. In order to evaluate the association of HLA-DR and DQ alleles and haplotypes, 54 patients with RAS and 100 unrelated healthy subjects as control group were investigated. Our data indicated that DRB1*13:17, DRB1*15:01, and DRB5*01 were significantly more frequent in RAS patients in comparison to controls. However, DRB3:01allele frequency was higher in the controls compared to the patients. The significantly frequent allele in the patients compared with the healthy subjects was HLA-DQB1*03:02. However, both HLA-DQB1*02:01 and HLA-DQB1*03:01 alleles were most frequent in the healthy individuals rather than the patients. The DRB*04/DQB1*03:01 and DRB*01:01/DQB1*02:01 haplotypes were significantly distributed in healthy subjects compared with patients. However, DRB*07:01/DQB1*03:02 haplotype was found to be significantly frequent in patients than controls. In respect of HLA genes, factors are involved in the incidence of RAS; various HLA-DRB and HLA-DQB1 alleles and the related haplotypes are suggested to be the three main RAS susceptibility factors in our population study.

IL4 gene polymorphisms in Iranian patients with autoimmune hepatitis.

BACKGROUND: Autoimmune hepatitis (AIH) is a chronic long-lasting hepatocellular inflammation associated with circulating auto antibodies. In addition to the genetic component, several cytokines have been implicated to be involved in AIH. This study was performed to investigate potential associations of AIH with IL4 gene variants. METHOD: The studied alleles and genotypes included: IL4G/T allele polymorphisms at position -1098 and C/T allele polymorphisms at two positions (-33 and -590) on the IL4 gene, in addition to the A/G allele polymorphisms at position +1902 on the IL4RA gene. RESULT: The IL4 C allele and CC genotype at position -590 and TT genotype at position -33 had a significantly higher frequency in AIH patients. CONCLUSION: This study identified the IL4 C allele and CC genotype susceptibility gene in AIH, which will provide better insights into the mechanisms of AIH and potential therapeutic interventions.

SNAP-25 gene variations and attention-deficit hyperactivity disorder in Iranian population.

OBJECTIVES: Attention deficit hyperactivity disorder (ADHD) is a common psychiatric condition of childhood characterized by persistent symptoms of hyperactivity, inattention, and impulsivity. The objective of this study was to investigate the association of synaptosomal-associated protein of 25 kDa (SNAP-25) gene variants with ADHD. METHODS: A case-control study with a total of 150 children with ADHD (mean age 9.61; range 6-16; gender ratio 105m/45f) and 150 normal children (mean age 10.02; range 6-16; gender ratio 98m/52f) was conducted. Genomic DNA was extracted from peripheral blood of all samples and SNPs rs78428954 and rs3746544 located in SNAP-25 gene were genotyped. RESULTS: Our analysis indicated that there is no significant association between none of studied variants in SNAP-25 and ADHD. DISCUSSION: To our knowledge, it is the first report of SNAP-25 genotyping in Iranian patients with ADHD. Further investigations with larger populations are needed in order to clarify the exact role of SNAP-25 variations in susceptibility to ADHD.