Problem: Endometriosis has been suggested to be an autoimmune disease and recently, an allelic variation of the PTPN22 (C1858T) gene was revealed to be associated with the development of autoimmunity. The aim of the study was to determine the frequency of the PTPN22 (C1858T) polymorphism in Brazilian women with endometriosis as compared with controls.
Method of study: Case-control study included 140 women with endometriosis and a control group consisting of 180 healthy fertile women without a history of endometriosis and/or autoimmune diseases from the ABC School of Medicine. The PTPN22 (C1858T) polymorphism was studied by restriction fragment length polymorphism polymerase chain reaction (RFLP-PCR).
Results: Genotypes CC, CT and TT of PTPN22 polymorphism presented frequencies of 67.9, 30.0 and 2.1% in the women with endometriosis (P = 0.008); 76.2, 19.0 and 4.8% in women with minimal/mild endometriosis (P = 0.173); 61.0, 39.0 and 0.0% in women with moderate/severe endometriosis (P < or = 0.001) and 82.8, 16.1 and 1.1% in control group. Allele C and T were present in 82.9 and 17.1%; 85.7 and 14.3%; 80.5 and 19.5%; and 90.8 and 9.2% respectively, in women with endometriosis (P = 0.004), women with minimal/mild endometriosis (P = 0.148), women with moderate/severe endometriosis (P = 0.002) and control group.
Conclusion: The data suggest that in Brazilian women polymorphism PTPN22 (C1858T) may be an important genetic predisposing factor for endometriosis, especially, in advanced disease.