Association of the A Allele of the TNF-Alpha-308 G/A Gene Polymorphism with Radiographic Progression in Rheumatoid Arthritis

Abstract

Summary To examine whether the presence of the rare A allele of the TNF-Alpha-308 G/A gene polymorphism is associated with erosive arthritis and rapid radiological progression of the disease. The examined group included 131 patients with early RA. Using the PCR-RFLP method, the TNF-Alpha-308 G/A gene polymorphism was determined for all patients. In relation to the presence of the A allele of the examined polymorphism, the patients were divided into two subgroups: subgroup A (G/A and A/A genotypes) and subgroup G (G/G genotype). Based on the presence of the destructive changes in joints found in the initial radiographs, the findings were classified as erosive and non-erosive RA. Radiological progression was assessed on the basis of the annual change in the Larsen score – LS (0-200). Group A comprised 62 (47.33%) patients, while group G comprised 69 (52.67%) patients. The presence of cysts and erosions in subgroups A and G was compared before the start of the methotrexate therapy. It was determined that erosions (erosive RA) were statistically significantly more frequent in group A (83.87% of patients) in comparison with group G (44.93% of patients), p < 0,001. Group A patients had a higher value of the Larsen score in relation to the group G both before and after methotrexate was administered for a year (before therapy, LS in group A: 48.58 ± 20.54; in group G 20.73 ± 12.31; p < 0.01; after MTX therapy, LS in group A: 58.32 ± 22.25; in group G 25.35 ± 14.57; p < 0.001). The average value of the annual LS change in group A was statistically significantly greater than the change in group G patients (9.98 ± 4.95 to 5.23 ± 2.72) (p < 0.05). The presence of the A allele of the TNF-Alpha-308 G/A gene polymorphism is associated with the occurrence of early erosive joint changes and more rapid radiological progression of the disease.