Neutrophil-lymphocyte ratio as a prognostic factor in severe hand, foot and mouth disease

Objective To investigate the clinical implication of the neutrophil to lymphocyte ratio (NLR) in predicting the severity of hand, foot and mouth disease (HFMD). Methods From May 2008 to December 2017, a total of 1 593 children with HFMD were collected from The Second Affiliated Hospital of Xi’an Jiaotong Univesity and Xi’an Children’s Hospital. According to the degree of illness, they were divided into mild HFMD group (929 cases) and severe HFMD group (664 cases). The best critical value of neutrophil/lymphocyte ratio (NLR) for predicting the severity of HFMD was calculated by receiver operating characteristic curve (ROC curve). According to NLR, 1 593 children were divided into high NLR group and low NLR group. Multivariate two-classification Logistic regression analysis was used to analyze the correlation between the factors and the severity of children with HFMD. Results Fever, hyperpyrexia, nervous system symptom, circulatory system symptom, leukocyte (WBC), NLR, procalcitonin (PCT), blood sugar, enterovirus 71 IgM antibody (EV71-IgM) positive and infection with Epstein-Barr virus (EBV) were all with significant differences in severe HFMD group compared with those of mild HFMD group (all P 39 ℃), positive EV71-IgM, complicated with EBV infection, blood glucose > 8.3 mmol/L, PCT > 0.1 ng/ml and NLR > 1.59 were all risk factors for severe HFMD. The ratio of odds ratio (OR) were 1.557, 5.124, 3.533, 7.323, 1.727 and 2.031, respectively (all P < 0.01). Conclusions NLR > 1.59 is closely related to the severity of HFMD, which has important predictive value. NLR is one of the clinical indexes to guide the clinical decision and treatment of children with HFMD. Key words: Hand, foot and mouth disease; Neutrophil-to-lymphocyte ratio; Severity; Risk factor