The Effect Of PLR And NLR On The Prognosis Of Severe Fever With Thrombocytopenia Syndrome

ObjectiveSevere fever with thrombocytopenia syndrome(SFTS)is a newly emerging tick-borne disease that is caused by a new type of bunyavirus,and characterized by fever,anorexia,nausea,vomiting,abdominal pain,diarrhea,leukopenia and thrombocytopenia.In critically ill patients,skin ecchymosis,gastrointestinal bleeding,body tremor,and disturbance of consciousness may occur,and may die due to multiple organ failure such as shock and DIC..As the systemic inflammation index,platelet to lymphocyte ratio(PLR)and neutrophil to lymphocyte ratio(NLR)have been studied in the progression of some inflammation-related diseases,while there is no research on the role of severe fever with thrombocytopenia syndrome in the development and progression.The objective of our study is to investigate the association of PLR and NLR with disease severity and prognosis in patients with severe fever with thrombocytopenia syndrome.MethodThe peripheral bloods samples of 80 SFTS patients who were diagnosed with SFTS in the Department of Infectious Diseases,Union Hospital of Tongji Medical College,Huazhong University of Science and Technology from April 18 to November 20,2016,and60 healthy donors were collected and tested.We recruit clinical and laboratory data through the electronic medical record system,including gender,age,body temperature,and laboratory data.The patients comply with the diagnostic criteria of “ severe fever with thrombocytopenia syndrome prevention and treatment guidelines(2010 Edition)” issued by the Ministry of Health of the People's Republic of China.According to the clinicalsymptoms and prognosis,the patients were divided into two groups: common patients and severe patients.By comparing the PLR,NLR and other related indicators between the patients and the,normal control the relationship between PLR,NLR and severity and prognosis of severe fever with thrombocytopenia syndrome was analyzed.Results1.The PLR of the SFTS group was significantly lower than that of the normal control(73.88 vs.150.70,P<0.05).There was no significant difference of the NLR between patients and the normal group(2.73 vs.1.86,P>0.05).In addition,the white blood cell count(WBC),platelet count(PLT),neutrophil count(N),and lymphocyte count(L)of the diseased group were lower than the normal group,while ALT and AST were significantly higher than the normal group,and the differences were statistically significant(all P <0.01).2.Comparing with the common patients,the PLR of the severe patients group decreased significantly(59.26 vs.80.39,P<0.05),and there was no significant difference in NLR(2.08 vs.2.76,P>0.05).The mean age,viral load,ferritin,ALT,AST,AST/ALT,D-dimer,APTT,CK,LDH,and pulmonary infection in severe patients were significantly higher,but platelet count,blood calcium were significantly lower than in common patients.,(all P < 0.05).3.The PLR of the common patients significantly increased(119.68 vs.80.39,P<0.05),and NLR decreased significantly after treatment(1.54 vs.2.76,P<0.05);while PLR of severe patients continued to decline after treatment(59.26 vs.17.78,P<0.01)),and the difference of NLR was not statistically significant(1.60 vs.2.08,P>0.05).4.PLR was negatively correlated with ferritin,ALT,AST and LDH,but positively correlated with PLT;and viral load was positively correlated with ferritin,APTT and LDH,while negatively correlated with PLT.ConclusionPLR in peripheral blood of patients with SFTS is more meaningful than NLR in predicting the severity of the disease.By comparing the differences in PLR and NLR between the groups,we confirmed that the smaller the PLR,the more severe the patient's condition,and the worse the prognosis.Monitoring the peripheral blood PLR of patients with SFTS is simple and easy,so PLR can be used as an important indicator for predicting the severity and prognosis of SFTS in the early stage of clinical practice.