Characteristics of Sjögren’s syndrome associated with rheumatoid arthritis ============================================================================= * Nolan Hassold * Raphaele Seror * Xavier Mariette * Gaetane Nocturne * rheumatoid arthritis * sjogren's syndrome * autoimmunity Sjögren Syndrome (SS) classically associates sicca syndrome, pain and asthenia. Systemic manifestations may develop with potentially severe organ damage including pulmonary, neurological, renal involvement and lymphoma.1 2 SS can be associated with rheumatoid arthritis (RA). Despite this frequent association, few studies have investigated differences between primary Sjögren syndrome (pSS) and SS associated with RA(SS/RA).3 4 We have conducted a retrospective single-centre case-controls study. Patients were identified in the Paris-Saclay cohort, a prospectively collected database. Cases were patients fulfilling both ACR/EULAR 2016 criteria for SS and ACR 2010 criteria for RA and followed between 2000 and 2019. For each case, two controls from our local pSS cohort were randomly assigned and matched on disease duration. Disease activity was assessed using the EULAR Sjögren’s Syndrome Disease Activity Index (ESSDAI)5 and ESSDAI cumulative score (Cumulative ESSDAI). The latter was calculated considering for each domain, the highest value reached by the patient during his/her follow-up. SS/RA and pSS patients were compared using a Chi-square test for non-normal binary variables and Mann-Whitney-Wilcoxon test for non-normal numeric variables. The p was retained as significant in the statistical analyses if <0.05. Sixty-two SS/RA patients were compared with 124 pSS patients (table 1). There were more women among the pSS group (p=0.03). We observed a higher disease activity in the SS/RA group when considering ESSDAI and cumulative ESSDAI. We also performed analyses excluding joint involvement: there was no more difference between the two groups, which reflects the weight of the articular domain in the activity of the disease in the SS/RA group. There was higher prevalence of arthralgia and arthritis in the SS/RA group. Pulmonary involvement was also significantly more frequent in SS/RA group; 9/62 (14.5%) patients (six interstitial lung disease (ILD): 4 non-specific interstitial pneumonia (NSIP) and two non-specific ILD), 1 bronchiectasis, 1 bronchial disorder and one pulmonary cysts) were compared with 7/123 (5.7%) patients in the pSS group (3 ILD: 2 NSIP and one non-specific ILD, 3 bronchiectasis and one obstructive bronchial disorder). pSS patients presented more skin or vaginal dryness and parotid gland enlargement. We found higher ESR levels and higher rate of RF positivity in the SS/RA group compared with pSS. Even though numerically higher in the pSS group, the frequency of lymphoma did not significantly differ between groups (p=0.267). There was no difference between the two groups on the other parameters. View this table: [Table 1](http://rmdopen.bmj.com/content/8/1/e002234/T1) Table 1 Comparison of pSS and SS/RA Our study confirms previous reports showing that pSS patients have more frequently parotid gland enlargement.4 6 As described by He *et al,* we found that patients with SS/RA have more frequently articular and pulmonary involvement.4 It is difficult to decipher if articular involvement was linked to RA or to SS in these patients. Of note, in our study, more than 50% of the RA/SS patients had erosions. Regarding lung involvement, discrimination between SS linked or RA linked manifestations is also challenging. ILD complicating pSS tends to give more NSIP while ILD complicating RA tends to give usual interstitial pneumonia (UIP). In our study, pulmonary involvement seemed to be mainly due to SS in the SS/RA group since there was no UIP. This study shows that patients with pSS and SS/RA have the same level of systemic disease activity. Thus, in RA patients, sicca symptoms should not be neglected and should be explored in order to detect an associated SS and to adapt the follow-up accordingly especially concerning pulmonary involvement and risk of lymphoma. ## Ethics statements ### Patient consent for publication Consent obtained directly from patient(s) ### Ethics approval This study involves human participants and was approved by local ethic committee Participants gave informed consent to participate in the study before taking part. ## Footnotes * Contributors All of the authors have contributed substantially to the manuscript, agree with the data and the interpretations of the manuscript content, and have given their permission to submit the attached version of the manuscript. None of the authors have conflicts of interest with any aspect of the manuscript. This manuscript has not been published elsewhere and, if accepted in your journal, will not be republished in any other journal in the same or similar form without consent from the Editor of RMD Open. * Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors. * Competing interests None declared. * Provenance and peer review Not commissioned; externally peer reviewed. * Accepted January 25, 2022. * © Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. [http://creativecommons.org/licenses/by-nc/4.0/](http://creativecommons.org/licenses/by-nc/4.0/) This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: [http://creativecommons.org/licenses/by-nc/4.0/](http://creativecommons.org/licenses/by-nc/4.0/). ## References 1. Mariette X, Criswell LA. Primary Sjögren's syndrome. N Engl J Med 2018;378:931–9.[doi:10.1056/NEJMcp1702514](http://dx.doi.org/10.1056/NEJMcp1702514)pmid:http://www.ncbi.nlm.nih.gov/pubmed/29514034 [CrossRef](http://rmdopen.bmj.com/lookup/external-ref?access_num=10.1056/NEJMcp1702514&link_type=DOI) [PubMed](http://rmdopen.bmj.com/lookup/external-ref?access_num=http://www.n&link_type=MED&atom=%2Frmdopen%2F8%2F1%2Fe002234.atom) 2. Nocturne G, Mariette X. Sjögren syndrome-associated lymphomas: an update on pathogenesis and management. Br J Haematol 2015;168:317–27.[doi:10.1111/bjh.13192](http://dx.doi.org/10.1111/bjh.13192) [CrossRef](http://rmdopen.bmj.com/lookup/external-ref?access_num=10.1111/bjh.13192&link_type=DOI) [PubMed](http://rmdopen.bmj.com/lookup/external-ref?access_num=25316606&link_type=MED&atom=%2Frmdopen%2F8%2F1%2Fe002234.atom) 3. Kollert F, Fisher BA. Equal rights in autoimmunity: is Sjögren’s syndrome ever ‘secondary’? Rheumatology 2020;59:1218–25.[doi:10.1093/rheumatology/keaa009](http://dx.doi.org/10.1093/rheumatology/keaa009) 4. He J, Ding Y, Feng M, et al. Characteristics of Sjogren’s syndrome in rheumatoid arthritis. Rheumatology 2013;52:1084–9.[doi:10.1093/rheumatology/kes374](http://dx.doi.org/10.1093/rheumatology/kes374) [CrossRef](http://rmdopen.bmj.com/lookup/external-ref?access_num=10.1093/rheumatology/kes374&link_type=DOI) [PubMed](http://rmdopen.bmj.com/lookup/external-ref?access_num=23382356&link_type=MED&atom=%2Frmdopen%2F8%2F1%2Fe002234.atom) [Web of Science](http://rmdopen.bmj.com/lookup/external-ref?access_num=000319460000015&link_type=ISI) 5. Seror R, Ravaud P, Bowman SJ, et al. EULAR Sjögren’s syndrome disease activity index: development of a consensus systemic disease activity index for primary Sjögren’s syndrome. Ann Rheum Dis 2010;69:1103–9.[doi:10.1136/ard.2009.110619](http://dx.doi.org/10.1136/ard.2009.110619) [Abstract/FREE Full Text](http://rmdopen.bmj.com/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6MTE6ImFubnJoZXVtZGlzIjtzOjU6InJlc2lkIjtzOjk6IjY5LzYvMTEwMyI7czo0OiJhdG9tIjtzOjI1OiIvcm1kb3Blbi84LzEvZTAwMjIzNC5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=) 6. Moutsopoulos HM, Webber BL, Vlagopoulos TP, et al. Differences in the clinical manifestations of sicca syndrome in the presence and absence of rheumatoid arthritis. Am J Med 1979;66:733–6.[doi:10.1016/0002-9343(79)91110-0](http://dx.doi.org/10.1016/0002-9343(79)91110-0)pmid:http://www.ncbi.nlm.nih.gov/pubmed/443249 [CrossRef](http://rmdopen.bmj.com/lookup/external-ref?access_num=10.1016/0002-9343(79)91110-0&link_type=DOI) [PubMed](http://rmdopen.bmj.com/lookup/external-ref?access_num=443249&link_type=MED&atom=%2Frmdopen%2F8%2F1%2Fe002234.atom) [Web of Science](http://rmdopen.bmj.com/lookup/external-ref?access_num=A1979GV12100006&link_type=ISI)