Author/Editor     Rozman, B; Čučnik, S; Sodin-Šemrl, S; Czirjak, L; Varju, C; Distler, O; Huscher, D; Aringer, M; Steiner, G; Kveder, T
Title     Prevalence and clinical associations of anti-KU antibodies in patients with systemic sclerosis: a European EUSTAR - initiated multicentre case-control study
Type     članek
Source     Ann Rheum Dis
Vol. and No.     Letnik 67, št. 9
Publication year     2008
Volume     str. 1282-86
Language     eng
Abstract     Objectives: To determine the prevalence of anti-Ku antibodies in 625 patients with systemic sclerosis (SSc) from six European rheumatologic centres and to evaluate their clinical and serologic characteristics. Methods: Sera of 625 consecutive patients with either limited cutaneous or diffuse cutaneous SSc were tested for antibodies to Ku antigen together with other extractable nuclear antigens by counter-immunoelectrophoresis. A case-control design with calculation of Bootstrap 95% confidence intervals derived from anti-Ku negative control patients was used to evaluate clinical associations of anti-Ku antibodies. Sera of anti-Ku positive SSc patients and control group were additionally tested by immunofluorescence on Hep-2 cell substrates and line immunoassay. Results: Anti-Ku antibodies were found in sera of 14/625 (2.2%) SSc patients. Ten out of fourteen anti-Ku positive SSc patients had no other anti-ENA antibodies detected by counterimmuno-electrophoresis. Using the case control design, anti-Ku antibodies were significantly associated with musculoskeletal manifestations such as clinical markers of myositis, arthritis, and joint contractures. In addition, a significant negative correlation of anti-Ku antibodies was found with vascular manifestation such as fingertip ulcers and teleangiectasias. There was a striking absence of anti-centromere antibodies as well as anti-PM/Scl antibodies in anti-Ku positive patients. As expected, anti-Scl-70 and punctate nucleolar immunofluorescence pattern were present only in single cases. Conclusion: This is the largest cohort to date focusing on the prevalence of anti-Ku antibodies in SSc patients. The case control approach was able to demonstrate a clinically distinct subset of anti-Ku positive SSc patients with only relative clinical differences in skeletal features. However, the notable exceptions were signs of myositis. (Abstract truncated at 2000 characters)
Descriptors     SCLERODERMA, SYSTEMIC
AUTOANTIBODIES
AUTOANTIGENS
COUNTERIMMUNOELECTROPHORESIS
CASE-CONTROL STUDIES
MULTICENTER STUDIES