SAT0299 PREVALENCE OF PERIPHERAL EOSINOPHILIA AND CLINICAL ASSOCIATIONS IN THAI SYSTEMIC SCLEROSIS PATIENTS

Background Eosinophilia has been reported in systemic sclerosis (SSc) and localized scleroderma, so it might be part of the immune response in the pathogenesis of the disease. Objectives To determine the prevalence and clinical associations with peripheral eosinophilia in Thai SSc patients. Methods A cross-sectional study was conducted among Thai adult SSc patients, followed up at the Scleroderma Clinic, Khon Kaen University, Thailand, between November 1, 2016 and November 30, 2017. We excluded patients who had clinical overlap with other connective tissue disease, coexisting with localized scleroderma, eosinophilic fasciitis, or eosinophilia myalgia syndrome, and other diseases that cause eosinophilia. Peripheral eosinophilia is defined when total eosinophil count (TEC) is greater than 500 cells/mm3. Clinical, laboratory tests for tissue parasite, cytokines, and others for evaluation the cause of eosinophilia were done on the study date. Results A total of 185 SSc patients were enrolled. Fifty-seven cases (10.1%) were peripheral eosinophilia of which 21 had the causes of eosinophilia identified by laboratory without clinical symptoms (viz., 9 adrenal insufficiency, 2 tuberculosis, and 10 parasitic infection). The total prevalence of the unknown causes of peripheral eosinophilia in SSc was 21.9% (95%CI 15.9-29.1) (36 of 164 cases). Five of the patients had TEC above 1500 cells/mm3. Of the 164 SSc patients, the majority (70.6%) had diffuse cutaneous SSc, and the female to male ratio was 2.3:1. The respective median age and median duration of the disease was 57.0 years (IQR 52.2-63.9) and 6.5 years (IQR 2.9-10.5). According to a multivariate analysis, being male and duration of disease increasing every year were significantly associated with peripheral eosinophilia in SSc patients (OR 3.46 (95%CI 1.11-10.73) and 1.16 (95%CI 1.03-1.30), respectively), while Raynaud’s phenomenon had a significantly negative correlation with peripheral eosinophilia in SSc (OR 0.27: 95%CI 0.09-0.84). Other parameters—such as SSc subset, severity of skin tightness, serology, cytokines (transforming growth factor-β, interleukin-5)—were not correlated with peripheral eosinophilia. Conclusion Peripheral eosinophilia of unknown cause can be detected 1 in 5 SSc patients. The factors associated with peripheral eosinophilia are longer disease duration and being male while vasculopathy has a negative association. References [1] Falanga V, Medsger TA. Frequency, levels, and significance of blood eosinophilia in systemic sclerosis, localized scleroderma, and eosinophilic fasciitis. J Am Acad Dermatol. 1987Oct;17(4):648–56. [2] Giordano M, Ara M, Valentini G, Chianese U, Bencivenga T. Presence of eosinophilia in progressive systemic sclerosis and localized scleroderma. Arch Dermatol Res. 1981;271(4):411–7. [3] Tefferi A, Patnaik MM, Pardanani A. Eosinophilia: secondary, clonal and idiopathic. Br J Haematol. 2006Jun;133(5):468–92. [4] Mejia R, Nutman TB. Evaluation and differential diagnosis of marked, persistent eosinophilia. Semin Hematol. 2012Apr;49(2):149–59. [5] Kargili A, Bavbek N, Kaya A, Kosar A, Karaaslan Y. Eosinophilia in rheumatologic diseases: a prospective study of 1000 cases. Rheumatol Int. 2004Nov;24(6):321–4. [6] Gustafsson R, Fredens K, Nettelbladt O, Hallgren R. Eosinophil activation in systemic sclerosis. Arthritis Rheum. 1991Apr;34(4):414–22. Acknowledgement The Scleroderma Research Group and Faculty of Medicine, Khon Kaen University (Grant Number GR60101) Disclosure of Interests None declared