Extraskeletal manifestations and the indicators of inflammatory activity and severity in ankylosing spondylitis

Extraskeletal manifestations (ESMs) are commonly observed in ankylosing spondylitis (AS). The available data on the association of ESMs with the inflammatory activity and other clinical parameters of AS are contradictory.Objective: to assess the association of ESMs with the inflammatory activity and other manifestations of AS.Patients and methods. The investigators of the V.A. Nasonova Research Institute of Rheumatology examined a total of 452 patients (363 men and 89 women) diagnosed with AS meeting the New-York criteria (1984). The patients' median age was 31.5 [24; 41] years; median disease onset age, 19.5 [15; 23] years; and disease duration, 11.5 [7; 18] years. HLA B27 was identified in 442 (97.7%) patients. In addition to standard laboratory and instrumental examinations, 172 patients underwent transthoracic echocardiography; Rehberg's test, if indicated; IgA test; histological examination of subcutaneous fat tissue or duodenal mucosa for amyloid; renal ultrasound; colonoscopy; and consultations by an ophthalmologist, a dermatologist, a nephrologist, an urologist, and a gastroenterologist. Uveitis, cardiac involvement (cardiac conduction disturbance, aortic and valvular changes), inflammatory bowel disease (IBD), glomerulonephritis, and psoriasis were considered to be ESMs. The latter were detected in 218 (48%) of the 452 patients; there was uveitis in 140 (30%), cardiac conduction disturbance in 61 (13.4%), psoriasis in 17 (3.7%), IBD in 16 (3.5%), nephritis in 16 (3.5%), and aortic and valvular changes in 71 (41.2%) of the 172 patients. The groups of patients with ESM (n = 218) and without ESM (n=234) were compared with regard to the onset age of AS, the presence of HLA- 27, peripheral arthritis, coxitis, enthesitis, syndesmophytis, fever, anemia, the need for biological agents (BAs) and/or systemic glucocorticoids (GCs), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and erythrocyte sedimentation rate (ESR). Results. The ESM and non-ESM groups were matched for gender, age, duration of AS, and the presence of HLA-В27. No significant differences were found in ESR, BASDAI, and the frequency of coxitis, enthesitis, and syndesmophytis in the spine. The ESM group versus non-ESM group was significantly more frequently observed to have peripheral arthritis in 148 (67.8%) of the 218 patients and in 70 (33.2%) of the 234 patients, respectively (p<0.0001); fever in 34 (15.6%) and 12 (5.1%), respectively (p<0.0001), anemia in 58 (26.6%) and 26 (11.1%), respectively (p<0.0001); GAs and/or systemic GCs were taken by 121 (55.5%) and 58 (24.8%) patients, respectively (p<0.0001). Conclusion. ESMs in patients with AS are associated with peripheral arthritis and inflammatory activity indicators