Association of STAT4, TGFβ1, 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, TGF beta 1, 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), TGF beta 1 (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 TGF beta 1 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.