Clinical and laboratory features of primary Sjögren's syndrome complicated with mild to severe thrombocytopenia.

Background: Patients with thrombocytopenia accompanied by positive Ro/SS-A and/or La/SS-B autoantibodies have a possible diagnosis of Sjögren's syndrome (SS). Owing to its low prevalence, large-sample controlled studies on thrombocytopenia in primary SS (pSS) are scarce. Thus, this study aimed to investigate the clinical and laboratory characteristics of pSS complicated with mild to severe thrombocytopenia, and compared them with pSS patients without thrombocytopenia. Methods: This medical records review study analyzed the demographic data, clinical manifestations, laboratory examinations, and other results of 88 patients diagnosed with pSS between March 2007 and March 2018 in the Department of Rheumatology of The First Affiliated Hospital of Soochow University. A platelet (PLT) count of peripheral blood below 50×10 Results: Of the 88 pSS patients, 43 developed mild to severe thrombocytopenia (thrombocytopenia group) and 45 had no thrombocytopenia (control group). No significant difference was found in the levels of autoantibodies and inflammatory markers between the thrombocytopenia group and the control group. Dry mouth (P<0.01) and dry eyes (P<0.01) were not frequently observed in the thrombocytopenia group, but the level of complement C4 dropped significantly (P<0.05). In contrast, the control group was more likely to have leukopenia (P=0.01) and interstitial lung disease (P<0.01). Conclusions: In pSS patients with mild to severe thrombocytopenia, the incidence of xerostomia, xerophthalmia, and lung involvement was markedly reduced. Knowledge about the features of pSS associated with thrombocytopenia will lead to earlier and better diagnosis and treatment.