The Study Of Clinical Risk Factors And Plasma Thrombopoietin Levels In Patients With Severe Fever With Thrombocytopenia Syndrome

Backgrounds: Severe fever with thrombocytopenia syndrome is a new infectious diseases which caused by a new Bunia virus called severe fever with thrombocytopenia syndrome virus. In early stage, the clinical facture is mainly for fever, fatigue and other nonspecific clinical manifestation. As the disease continues to advance, thrombocytopenia, leukopenia, swelling lymph nodes, and multiple organ dysfunction would be the main clinical manifestations, and the severe patients would die. However, the risk factors related to prognosis of SFTS are still unclear. The reasons of the patients with thrombocytopenia are unclear, the mainly treatment is platelet transfusions. The other method is give thrombopoietin to stimulate the platelet production. We aimed to assess the risk factors for server and death SFTS, and the relationship between platelet and thrombopoietin levels, in order to provide clue for clinical treatment and prediction of outcome.Methods:The SFTS patient who were admitted to the department of infectious diseases of Wuhan Union Hospital between April 1, 2015 and October 30, 2015 were included. All patients were in accordance with "the server fever with thrombocytopenia syndrome prevention guide(2010 edition) " of the diagnostic criteria. We collected the clinical date and laboratory test index, then analysed the correlation between the prognosis and clinical indicators with the Spearman correlation analysis, analysed the discriminatory power of clinical dates were tested with the area under the receiver-operating characteristic(ROC) curve. Serum thrombopoietin levels was detected in patients with SFTS disease and healthy controls by ELISA method. Then we evaluated the relationship between thrombopoietin( TPO) levels and platelet, in order to provide clue for clinical treatment.Results: Among 164 patients with SFTS, there were 28 cases(20.6%) died. The average age of died patients in the study was(64.46±0.07), increased significantly(t=-3.609,P<0.001) compared with recovered patients with(56.97±10.22). All patients showed varying degrees of fever, fatigue, anorexia, and Some with multiple organ dysfunction. Laboratory results suggest all patients with a drop in serum calcium, WBC and PLT count; with a rise in AST, ALT, LDH,CK,APTT,D-dimer levels. The nucleic acid quantification of SFTSV suggests death patients(5.83±0.98) was significantly higher than the recovered patients(3.96±1.08), with statistically difference(t = 8.49, P < 0.001). Serum thrombopoietin level of Untreated patients with SFTS(462.5782 ±281.2090)pg/ml was significantly higher than the healthy controls(40.0954±4.6993)pg/ml, with statistically difference(t=6.718,P<0.001).Conclusions: The study suggests that age, the nucleic acid quantification of SFTSV, PLT count, AST, ALT, CK, LDH, APTT,D-dimer, serum calcium are factors can be used to predict prognosis of SFTS. SFTS patients serum TPO is in high level. It suggests patients with thrombocytopenia is not caused by a lack of TPO generated. So the clinical treatment of giving exogenous TPO injection for promoting the recovery of the level of platelet may have no theoretical basis.