The frequency and severity of extraskeletal manifestations of ankylosing spondylitis

To assess the frequency and severity of extraskeletal manifestations (ESMs) of AS in the authors' own clinical practice. Subjects and methods. 452 patients (363 men and 89 women) with AS fulfilling the 1984 relevant New York criteria were examined at the V.A. Nasonova Research Institute of Rheumatology in 2005 and 2014. The patients' median age was 31.5 [24; 41] years; median disease onset age, 19 [15; 23] years; disease duration, 11 [7; 18] years; HLA B27 was identified in 442 (97.7%) patients. In addition to standard laboratory and instrumental examinations, transthoracic echocardiography was performed in 172 patients. Rehberg's test, IgA test, histological examination of subcutaneous fat tissue or duodenal mucosa for amyloid, and renal ultrasound were made if there were urinary abnormalities and elevated creatinine levels. If indicated, there were consultations by an ophthalmologist with an appropriate instrumental examination (with evidence of uveitis in the history), a dermatologist, a nephrologist, an urologist, a gastroenterologist, and a endoscopist. Uveitis, cardiac involvement (conduction disturbance, aortic and valvular changes), inflammatory bowel disease (IBD), glomerulonephritis, and psoriasis were borne in mind as ESMs. The absolute number and percentage of patients having any ESM over the follow-up period were estimated. The number of exacerbations per year and that of complications were taken into account when evaluating uveitis; the magnitude of valvular regurgitation and the presence of prosthetic valves and a pacemaker were considered when assessing cardiac damage; the total body surface area (BSA) and the psoriasis areas and severity index (PASI) were estimated in psoriasis; the presence and stage of chronic kidney disease (CKD) and/or macrohematuria were kept in mind in nephropathy; when evaluating IBD, the Harvey-Bradshaw index (HBI) was determined on the basis of a stool frequency, the presence of blood in the stool, abdominal pain, and general well-being. Results and discussion. ESMs were detected in 218 (48%) of the 452 patients. Uveitis was present in 140 (30%) patients; in one-fourth of them, it relapsed frequently: three or more exacerbations per year and more than 10 during the disease; 41 (29%) patients had uveitis complications accompanied by visual impairment. Cardiac conduction disturbance was revealed in 61 (13%) patients. Five of them underwent pacemaker implantation. 71 (41.2%) patients were found to have aortic and valvular changes, including aortic root dilatation/thickening in 60 (34.8%) patients and aortic/mitral valve leaflet thickening in 63 (36.6%). Grades 3 and 4 valvular regurgitation was noted in 10 (5.8%) patients; valve replacement was carried out in 9 (5.2%) cases. Nephritis was diagnosed in 16 (3.5%) patients, 4 of them had Stage 2 or above of CKD. Psoriasis was present in 17 (3.7%) patients; 2 of them had severe psoriasis (BSA >10%). IBD (ulcerative colitis or Crohn's disease) was diagnosed in 16 (3.5%) patients, including 4 who showed a severe course. 79 (36%) patients were observed to have a concurrence of two or more ESMs; that of uveitis and heart disease was most commonly seen. Conclusion. ESMs are observed in nearly half (48%) of the patients with AS and can be concurrent; the most common ESMs of AS are uveitis, aortic root and heart valve lesions, and cardiac conduction disturbance. ESMs worsen the course and prognosis of AS.