Igg4-Related Disease Or Primary Sjogren Syndrome? Organ-Specific Involvement And Immunological Profile Are Clues In Differentiating Two Diseases With A Common Clinical Presentation

Background IgG4-related disease and primary Sjogren syndrome (SS) share clinical presentations (sicca features, enlarged exocrine glands) and systemic organ involvement, with histopathological demonstration of IgG4+ infiltrative cells being the key differential feature. Objectives To compare epidemiological, clinical and analytical features in patients with primary SS and IgG4-related disease. Methods The GEAS-SS multicenter registry, founded in 2005, includes 921 consecutive Spanish patients fulfilling the 2002 primary SS classification criteria. IgG4-related disease patients fulfilling the 2012 criteria (Umehara et al) were collected by systematic review (2000-2013, 23 studies including 662 patients). Results Primary SS patients had a similar mean age at diagnosis (54 vs 60 years, p>0.05) and were more frequently female (94% vs 40%, p 0.001), with a clear predominance of submaxillar (71% vs 15%, p 135 mg/dL) (p Conclusions Although IgG4-related disease and primary SS share similar clinical presentations, significant differences in epidemiological features, organ-specific involvement and immunological profiles may aid early clinical diagnosis, with raised serum IgG4 levels and tissular infiltration by IgG4+ cells being key differentiating features. A clinical score including the parameters identified could aid differentiation between IgG4-related disease and primary SS in daily paractice. Disclosure of Interest : None declared DOI 10.1136/annrheumdis-2014-eular.5099