Association of rs7574865 polymorphism of the <i>STAT4</i> gene with spinal syndesmophytes in patients with ankylosing spondylitis

Abstract

Objective. The aim of the investigation was to study the possible association of the rs7574865 polymorphism of the STAT4 gene with syndesmophytes (SMP) of the spine in patients with ankylosing spondylitis (AS).Subjects and methods. The study included a cohort of 100 patients, 79 men and 21 women with a diagnosis of AS.All patients were positive for the HLA-B27 antigen, had a mean age of 39.6±10.9 years and a mean disease duration of 60,4±28,4 months. The association of the rs7574865 polymorphism of the STAT4 gene with the SMP of the cervical, thoracic and lumbar spine was studied. For genotyping of the rs7574865 polymorphism, the method of allele-specific polymerase chain reaction in real time (RT-PCR) was used.Results. Spearman’s correlation analysis showed a statistically significant positive relationship between SMP in the thoracic spine and rs7574865 polymorphism of the STAT4 gene (r=0.23; p=0.022). The frequency of GT genotype carriers in the group of patients with thoracic spine trSMP(+) was statistically significantly lower than in the alternative group trSMP(–) (28.2% and 50.8%, respectively; p=0.025). Carriage of the GT genotype in patients with AS reduced the risk of trSMP(+) formation in the thoracic spine (OR=0.31) and this genotype was protective. No reliably significant association of the studied polymorphism with SMP of the cervical and lumbar spine was found. Patients with trSMP(+) were statistically significantly older in age, had a longer duration of the disease and a higher functional BASFI index compared with patients without trSMP(–).Conclusion. Genetic testing of the rs7574865 G/T polymorphism of the STAT4 gene in patients with AS opens up the possibility of using this polymorphism as a genetic marker-predictor – X-ray progression of structural changes in the thoracic spine.

Keywords

• ankylosing spondylitis
• stat4 gene polymorphism
• syndesmophytes