Development of lymphoma in patients with primary Sjögren syndromes

Background: Lymphoma is the main complication of primary Sjogren syndrome (pSS). The aim of this study was to describe the prevalence and incidence rate of lymphoma in patients with pSS in eleven centers in Argentina. To determine the frequency of commitment of the domains of the baseline clinical ESSDAI in the patients who developed lymphoma in the course of their follow-up and compare it with the rest of the sample. Methods and findings: We included patients older than 18 years with a diagnosis of pSS according to American College of Rheumatology/European League against Rheumatism (ACR/EULAR)2002/2016 criteria, included in a multi-center Argentine database. Patients diagnosed with another associated autoimmune rheumatic disease were excluded. Six hundred and eighty one patients were included, 95% female, with a mean age of 54.41 years (± 13.70). Sixteen patients presented lymphoma (prevalence: 2.35%, 95% CI: 1.2-3.4%). The average follow-up time was 4.7 years (± 4.94). Six hundread and thirty three patients contributed data for the survival analysis. The incidence rate of lymphoma was 0.54 per 100 patient-years (95% CI: -0,26 a 1,34). The most frequently lymphoma type was MALT. Patients who developed lymphoma had a higher frequency of involvement of most of the domains of the baseline clinical ESSDAI compared to patients who did not present this complication, observing statistically significant differences in glandular (68,75% vs 28.69%, p:0,001), and cutaneous (31.25% vs 10.99%, p: 0.01) domains. The glandular domain of clinical ESSDAI was the main domain associated lymphoma development (H.R: 4.54, 95% CI: 1.57-13.12). Conclusion: This was the first study with data on the population of Argentina about the prevalence of lymphoma in patients diagnosed with Sjogrenu0027s syndrome. The prevalence of lymphoma in our cohort was lower than previously published. Despite observing a lower frequency of lymphoma in our study, we found an association with risk markers described in the literature, such as baseline parotidomegaly and cutaneous involvement.