Relevance of clinical and autoantibody profiles in systemic sclerosis among Thais

Autoantibody profiles in systemic sclerosis (SSc) and their relative clinical association vary between studies. The rate for being anti-topoisomerase-I (ATA) positive and the association with diffuse cutaneous the SSc subset (dcSSc) is higher among Thais than among Caucasians. The objective was to evaluate the relevance of clinical presentation, namely being positive for one or more autoantibodies among Thai SSc patients.

A retrospective, cohort study was performed among SSc patients over 18 years of age at Srinagarind Hospital, Khon Kaen University, Thailand, during January 2006 to December 2013. Autoantibodies comprising 13 SSc-specific antigens were evaluated using the EUROIMMUN AG (Lübeck, Germany) in order to define their clinical association(s).

Two hundred and eighty-five scleroderma patients (200 female; 85 male) were included. The majority (66.7%) were dcSSc subset. ATA was the most common antibody profile in our patients (231 cases; 81.1%), followed by anti-Ro 52 (87 cases; 30.5%). Eleven of our patients (3.9%) were negative for all antibody profiles and 44 cases (15.4%) were negative for ATA and anti-centromere antibody (anti-CENP). Almost 40% (112 cases) were positive for at least two autoantibodies. There was an association between the presence of ATA and hand deformity (odds ratio [OR] 3.94; 95% CI 1.12-13.84), anti-CENP and hand deformity (OR 0.20; 95% CI 0.02-0.90), anti-Ku and scleroderma-polymyositis overlap syndrome (OR 6.58; 95% CI 2.16-19.39) and the absence of both ATA and anti-CENP with female sex (OR 2.90; 95% CI 1.12-7.51), limited cutaneous SSc subset (OR 2.70; 95% CI 1.30-5.55) and scleroderma-polymyositis overlap syndrome (OR 2.53; 95% CI 1.04-6.16). Neither ATA nor anti-CENP were associated with the SSc subset.

ATA and anti-CENP were not helpful in differentiating the SSc subset in Thai SSc patients, albeit they were good for predicting hand function. Coexisting ATA and anti-CENP negativity were associated with less extensive skin tightness and SSc overlap syndrome.