The association between no-synthases gene polymorphisms and post-traumatic knee ostearthritis development among Rostov region residents

Background. Knee osteoarthritis (OA) is a common chronic degenerative disease. The risk factors for the development of knee OA are joint trauma and genetic predisposition. The aim of the present work was to study the associations between gene polymorphisms -84G > A nNOS and -786T > C eNOS and the risk of post-traumatic knee osteoarthritis (PTOA) development among Rostov region residents and to define the interactions between these polymorphisms and nitrite level in the plasma and synovial fluid (SF) and chondrocyte apoptosis in patients with PTOA. Materials and Methods. Case-control study involved 117 post-traumatic knee OA patients and 94 healthy controls. The nNOS and eNOS polymorphisms were determined by polymerase chain reaction. The nitrite concentrations in the plasma and synovial fluid were defined using Griess reaction. Chondrocyte apoptosis in cartilage sections was assessed morphologically by electron microscopy. Results. The G-84A nNOS genotype showed statistical differences between groups. The A allele is associated with PTOA development (OR 2,02, CI 1,08-3,76, p = 0,02). The eNOS genotype did not show statistical difference between groups. The NOx- concentration was higher both in plasma (p = 0,022) and synovial fluid (p = 0,014) of PTOA patients compared with plasma of healthy subjects. Multiple regression analyses demonstrated that the nitrite level in the SF is linked with -786T > C NOS3 genotype; the -786С allele leaded to the decreasing in NOx- concentration. The electron microscopy confirmed the presence of early and late apoptotic chondrocytes in PTOA cartilage tissue. Conclusion. The G-84A nNOS polymorphism may be associated with PTOA development and chondrocyte apoptosis intensification. The -786С allele of -786T > C NOS3 is associated with reduced NOx- concentration in the synovial fluid