Severe Fever with Thrombocytopenia Syndrome Virus Infection Associated with Hemophagocytic Lymphohistiocytosis as Poor Prognostic Factor

BACKGROUND: Severe fever with thrombocytopenia (SFTS) is an emerging infectious disease caused by a novel bunyavirus designated SFTS virus (SFTSV) with a high fatality rate. Hemophagocytic lymphohistiocytosis (HLH) is an immune-mediated life-threatening disease triggered by infections, neoplasms and noninfectious inflammatory diseases. A few HLH associated with SFTSV were reported. According to the diagnostic criteria of HLH, 11 patients with SFTS were reviewed. METHODS: During last 2 years (2015–2016), 11 SFTS patients were diagnosed at the Wonju Severance Christian Hospital, Yonsei University Wonju College of Medicine, Wonju, South Korea. Clinical features were analyzed using diagnostic criteria of 2004-HLH trial. We described if the prognosis of SFTSV-infected patients was associated with clinical features of HLH. RESULTS: Of 11 patients, four patients were fulfillled the diagnostic criteria of 2004-HLH trial (five of eight criteria). Two patients were fulfilled the four criteria. Five patients were fulfilled three or less criteria. Three of six patients who fulfilled four or more criteria were died. There was no mortality in five patients who fulfilled three or less criteria. Hemophagocytosis in bone marrow (BM) was observed in all six patients who were taken BM study. CONCLUSION: In SFTS, HLH was severe clinical feature and it might be associated with poor prognosis. DISCLOSURES: All authors: No reported disclosures.