NLR, A Convenient Early-Warning Biomarker of Fatal Outcome in Patients With Severe Fever With Thrombocytopenia Syndrome

Abstract

BackgroundSevere fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease that greatly threatens public health. This study aimed to examine a convenient early-warning biomarker of fatal outcomes in patients with SFTS to reduce mortality.MethodsA retrospective cohort study was performed, and patients with confirmed SFTS were enrolled in the top two hospitals in Anhui Province, China from 1 May 2016 to 31 October 2019. The clinical symptoms, laboratory indicators, and treatment data of patients with SFTS were evaluated. All patients with SFTS were followed up till 28 days from the start of admission. The laboratory indicators that could be used to predict the fatal outcome were identified.ResultsA total of 228 patients with SFTS were enrolled, 177 patients were enrolled in the survival group, and 51 patients in the death group. The median age of all 228 patients with SFTS was 63 years. Five laboratory indicators (SFTSV viral load, neutrophil to lymphocyte ratio (NLR), aspartate transaminase (AST)/alanine aminotransferase (ALT), ALT, and blood urea nitrogen (BUN)) were identified as the predicting factors of the fatal outcome of patients with SFTS. The area under the receiver operating characteristic (ROC) curve (AUC) of SFTSV viral load was the highest (0.919), then NLR (0.849), followed by AST/ALT (0.758), AST (0.738), and BUN (0.709). The efficacy of SFTVS viral load and NLR in predicting fatal outcomes was significantly higher than AST/ALT, AST, and BUN. The Kaplan–Meier survival curves show that the case fatality rate was significantly increased in patients whose SFTSV viral load was higher than 500,000 or NLR higher than 2.0. Gamma-globulin treatment showed a significant difference between the survival group and the death group, and the duration of gamma-globulin that had been proposed should not be <3 days.ConclusionThe SFTSV viral load and NLR showed great efficacy in predicting the fatal outcome of patients with SFTS, and NLR is a convenient and efficient early-warning biomarker that helps healthcare workers focus on patients with high risks of fatal outcomes. The efficacy of gamma-globulin provided a new idea for the treatment of SFTS, which needs further analysis in future studies.

The dose–response relationship between smoking and the risk factor for invasive pulmonary aspergillosis in patients with severe fever with thrombocytopenia syndrome

“…From the perspective of laboratory indicators, high viral load has been revealed as one of the indicators of poor prognostic for SFTS in several studies, but studies performed to explore the association between viral RNA loads of DBV and the occurrence of IPA are currently lacking (Wei et al, 2022). Bae et al (2020) reported that the viral load level was significantly higher in the IPA group, which corresponded with our result but did not go into more detail via regression analysis.…”

A High Viral Load in Urine Correlates With Acute Kidney Injury and Poor Outcomes in Hospitalized Patients With Severe Fever With Thrombocytopenia Syndrome: A Noninvasive and Convenient Prognostic Marker

“…Several studies have described early hematological predictors of poor outcomes in SFTS, including viral load [ 16 ]; organ damage indicators such as platelet (PLT), lactate dehydrogenase (LDH), creatine kinase (CK), activated partial thromboplastin time (APTT), and blood urea nitrogen (BUN) [ 17–19 ]; and inflammatory-related indicators such as neutrophil counts, lymphocyte counts, interleukin (IL)-10, IL-1β, interferon inducible protein (IP)-10, and IL-6 [ 20 , 21 ]. Among these indicators, viral load is the most important prognostic indicator, its concentration directly reflects the replication of pathogens in vivo to evaluate the severity of disease.…”

High C‐reactive protein to lymphocyte ratio predicts mortality outcomes of patients with severe fever with thrombocytopenia syndrome: A multicenter study in China

“…The NLR is an inflammatory indicator that assesses the severity and prognoses of SFTS. Wei et al identified that NLR was one independent prognostic factor for SFTS mortality with convenience and lower expense 18 . Liu et al revealed that an elevated NLR correlated with higher incidences of MODS and increased risks of short‐term mortality in SFTS patients 24 .…”