articleAnti-centromere antibody-seropositive Sjögren ' s syndrome differs from conventional subgroup in clinical and pathological study

Background: To clarify the clinicopathological characteristics of primary Sjögren's syndrome (pSS) with anticentromere antibody (ACA). Methods: Characteristics of 14 patients of pSS with ACA were evaluated. All patients were anti-SS-A/Ro and SS-B/La antibodies negative (ACA+ group) without sclerodactyly. The prevalence of Raynaud's phenomenon (RP), titer of IgG and focus score (FS) in the minor salivary glands (MSGs) were determined. Quantification analysis of Azan Mallory staining was performed to detect collagenous fiber. Forty eight patients in whom ACA was absent were chosen as the conventional (ACA-) pSS group. Results: Prevalence of ACA+ SS patients was 14 out of 129 (10.85%) pSS patients. RP was observed in 61.5% of the patients with ACA. The level of IgG in the ACA+ group was significantly lower than that of the ACAgroup (p = 0.018). Statistical difference was also found in the FS of MSGs from the ACA+ group (1.4 ± 1.0) as compared with the ACAgroup (2.3 ± 1.6) (p = 0.035). In contrast, the amount of fibrous tissue was much higher in the ACA+ group (65052.2 ± 14520.6 μm2 versus 26251.3 ± 14249.8 μm2 ) (p = 1.3 × 10-12). Conclusions: Low cellular infiltration but with an increase in fibrous tissues may explain the clinical feature of a high prevalence of RP and normal IgG concentration in ACA+ pSS. Background Primary Sjögren's syndrome (pSS) is characterized by sicca symptoms and various extraglandular manifestations that are usually accompanied by autoantibodies, especially anti-SS-A/Ro and SS-B/La antibodies (Abs) [1]. Except for anti-SS-A/Ro or SS-B/La antibodies, some autoantibodies including anti-α-fodrin antibody or antitype 3 muscarinic acetylcholine receptor antibodies are found in pSS [2,3]. Anti-centromere antibody (ACA) recognizes several centromere antigens of human chromosomes (CENP), in which CENP-B is a highly conserved mammalian protein and is used for detection by enzymelinked immunosorbent assay (ELISA) [4]. Recent studies [5,6] have demonstrated that ACA is also associated with pSS. Although the prevalence of anti-SS-A/Ro or SS-B/La Abs in pSS is 60-70%, ACA is reported to appear in 1626% of patients with pSS. Some reports [7] have shown the clinical characteristics of ACA-positive (ACA+) pSS, and a high frequency of Raynaud' s phenomenon (RP) has been repeatedly reported. In addition to the low prevalence of RP, Katano et al [8] reported a low titer of IgG in an ACA+ and anti-SS-A/Ro antibody-negative pSS population. The appearance of ACA is commonly described in CREST syndrome (calcinosis, RP, esophageal dysmotility, sclerodactyly, telangiectacia) or the limited type of systemic sclerosis (SSc) [9]. Although the presence of ACA is considered to be related to fibrosis of various organs, no relationship between fibrosis and ACA in pSS is reported. In the present study, we found the predominance of fibrotic change of minor salivary glands (MSG) histologically in ACA+ pSS patients. Interestingly, cellular infiltra* Correspondence: nakamura_hideki911@yahoo.co.jp 1 Unit of Translational Medicine, Department of Immunology and Rheumatology, Nagasaki University Graduate School of Biomedical Sciences, 17-1 Sakamoto, Nagasaki City, Nagasaki 852-8501, Japan Full list of author information is available at the end of the article © 2010 Nakamura et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Nakamura et al. BMC Musculoskeletal Disorders 2010, 11:140 http://www.biomedcentral. com/1471-2474/11/140 Page 2 of 5 tion was less prevalent in ACA+ pSS patients. These differences are suggested to lead to the clinical characteristics of ACA+ pSS.