Rheumatoid arthritis (RA) is an important public health problem because this disease often causes disability. RA is a chronic, destructive autoimmune disease that leads to joint destruction and the development of extraarticular manifestations. 
We examined 422 patients with RA and 338 healthy subjects as the control group.
Among RA patients, there was a statistically significant increase in the frequency of 
The results suggest an association between 