The Predictive Value of Interleukin-6 and Neutrophil-Lymphocyte Ratio in Patients with Severe and Extremely Severe Oral and Maxillofacial Space Infections

Objective. To investigate the correlation between clinical manifestation and neutrophil-lymphocyte ratio, C-reactive protein (CRP), and interleukin-6 (IL-6) in the patients with severe and extremely severe oral and maxillofacial space infection (OMSI). Methods. In this retrospective study, we included 18 patients with severe and extremely severe OMSI from November 2012 to October 2018. Pearson or Spearman correlation coefficients were calculated to measure the association between the number of complications and locations and the number and percentage of lymphocyte, leukocyte, neutrophil, eosinophil, basophil, monocyte, CRP, and IL-6. A multivariable regression model was used to predict the number of complications and locations from these measures. Results. IL-6 was positively correlated with neutrophil-lymphocyte ratio ( $r_{\text{s}}=0.773$ , $P=0.005$ ), percentage of neutrophil ( $r_{\text{s}}=0.927$ , $P=0.001$ ), and the number of neutrophil ( $r_{\text{s}}=0.627$ , $P=0.039$ ). It was negatively correlated with percentage of monocyte ( $r_{\text{s}}=-0.773$ , $P=0.005$ ). CRP was positively correlated with neutrophil-lymphocyte ratio ( $r_{\text{s}}=0.556$ , $P=0.020$ ) and percentage of neutrophil ( $r_{\text{s}}=0.515$ , $P=0.035$ ). It was negatively correlated with the number of lymphocyte ( $r_{\text{s}}=-0.517$ , $P=0.017$ ), percentage of lymphocyte ( $r_{\text{s}}=-0.578$ , $P=0.015$ ), number of eosinophil ( $r_{\text{s}}=-0.560$ , $P=0.020$ ), percentage of eosinophil ( $r_{\text{s}}=-0.504$ , $P=0.039$ ), number of basophil ( $r_{\text{s}}=-0.504$ , $P=0.039$ ), and percentage of basophil ( $r_{\text{s}}=-0.548$ , $P=0.023$ ). The number of the involved organs was positively correlated with neutrophil-lymphocyte ratio ( $r_{\text{s}}=0.511$ , $P=0.030$ ). The number of complications was positively correlated with the percentage of neutrophils ( $r=0.738$ , $P=0.001$ ), the neutrophil-lymphocyte ratio ( $r=0.576$ , $P=0.012$ ), IL-6 ( $r_{\text{s}}=0.907$ , $P=0.001$ ), and CRP ( $r_{\text{s}}=0.599$ , $P=0.011$ ). Multivariable regression analysis showed that the neutrophil-lymphocyte ratio ( $\beta =0.080$ ) was a significant predictor of the number of the involved organs and the neutrophil-lymphocyte ratio ( $\beta =0.099$ ). In addition, IL-6 ( $\beta =0.002$ ) was a significant predictor of the number of complications. Conclusions. The neutrophil-lymphocyte ratio and IL-6 contributed to the assessment of general condition in severe and profound OMSI patients. These parameters can be used as predictors to evaluate the severity of OMSI.