Background Sjögren's syndrome (SjS) is a systemic autoimmune disease presenting dryness symptoms and various extraglandular manifestations. Anti-centromere antibody (ACA)-positive SjS is considered as a distinct clinical subgroup in SjS. [1–2] While ACA is often detected in sera from other autoimmune diseases, such as limited cutaneous systemic sclerosis (SSc) and primary biliary cirrhosis, the role of ACA in their pathogenesis still remains unclear. In addition, comprehensive and enough clinical information from the point of view of ACA positive cases have not been accumulated.
Objectives To clarify clinical and immunological features of ACA-positive SjS and their association with autoantibodies.
Methods Patients with discrete-speckled pattern in anti-nuclear antibody (ANA) test and/or positive ACA, who visited to our service between 2012 and 2015, were enrolled. Clinical information and immunological tests including serum autoantibodies and immunoglobulins (Ig) were collected and statistically analyzed.
Results Discrete-speckled pattern in ANA test and/or positive ACA were identified in 198 patients. There were 190 female and 8 male and the average age was 59. 142 patients were classified into any autoimmune disease. In the 142 patients, 59 patients and 19 patients were diagnosed with SSc without SjS and SSc/SjS overlap cases, respectively. Another 33 patients were diagnosed with primary SjS and 17 patients were diagnosed with rheumatoid arthritis. Proportion of concomitant ANA patterns in 142 patients were speckled (15%), homogenous (11%), cytoplasmic (6%) and/or nucleolar (4%) pattern. Focusing on ACA positive two dominant diseases, SSc and SjS, no significant difference was not observed in age. All patients except one were female. Raynaud's phenomenon and sclerodactyly were less frequent in SjS patients (65% and 18%) than SSc patients and SSc/SjS overlap patients (100% and 100%, 76% and 84%) (p<0.01 and p<0.01, p<0.01 and p<0.01). Dryness symptoms were more frequent in SjS patients (96%) and SSc/SjS overlap patients (84%) than SSc patients (20%) (p<0.01 and p<0.01). Examining autoantibodies, serum anti-SS-A/Ro antibodies were positive in 39% of SjS patients and SSc/SjS overlap patients (30%), which were significantly higher than SSc patients (11%, p<0.01 and p<0.01). In laboratory parameters, peripheral leukocyte count in SjS patients was lower than in SSc patients (p=0.014). Other laboratory findings including platelets, hemoglobin, serum IgG, A, M, C3, C4 and CH50 did not significantly differ between SjS and SSc patients. Interestingly, leukocyte count and C4 in anti-SS-A/Ro antibody positive SjS patients were lower than the negative SjS and SSc patients (p=0.017). Anti-SS-A/Ro negative SjS patients and SSc/SjS overlap patients did not differ from SSc patietns without SjS in all laboratory parameters.
Conclusions Our cross-sectional cohort study confirmed that ACA-positive cases were dominantly classified into SSc and/or SjS, presenting different clinical characteristics. Our data suggested that ACA-positive SjS was immunologically characterized by low peripheral leukocyte counts different from other ACA-positive diseases, and additional anti-SSA/Ro positivity critically determined serum level of C4 and leucocyte count in ACA-positive patients.
J Rheumatol 2001; 28: 2238
Int J Rheum Dis 2015; 18: 776
Disclosure of Interest M. Tsukamoto: None declared, K. Suzuki Grant/research support from: Eisai, BMS, T. Takeuchi Grant/research support from: Abbott Japan Co., Ltd., Astellas Pharma, Bristol–Myers K.K., Chugai Pharmaceutical Co, Ltd., Daiichi Sankyo Co., Ltd., Eisai Co., Ltd., Janssen Pharmaceutical K.K., Mitsubishi Tanabe Pharma Co., Pfizer Japan Inc., Sanofi–Aventis K.K., Santen Pharmaceutical Co., Ltd., Teijin Pharma Ltd., abbvie GK, Asahikasei Pharma Corp., Taisho Toyama Pharmaceutical Co., Ltd. Janssen Pharmaceutical K.K., Astra Zeneca K.K., Eli Lilly Japan K.K., Novartis Pharma K.K., Abbvie GK