Urokinase-type plasminogen activator receptor combined with modified Alvarado scoring system and C-reactive protein for diagnosis of acute appendicitis in children

Objective To investigate the serum level of urokinase-type plasminogen activator receptor (uPAR) in children with acute appendicitis and assess the diagnostic value of uPAR combined with C-reactive protein (CRP) and modified Alvarado score for acute appendicitis. Methods We analyzed the clinical data of 57 children with pathologically confirmed acute appendicitis and 44 children with nonappendicitis abdominal pain (control group) admitted in our hospital between June 2017 and June 2019. We compared the age, gender, white blood cell count, neutrophil/lymphocyte ratio (NLR), CRP level, percentage of neutrophils, modified Alvarado score and serum uPAR level between the 2 groups. The correlation of serum uPAR level with CRP and modified Alvarado score was evaluated, and receiving-operator characteristic (ROC) curve was used to analyze their diagnostic efficacy, either alone or in combination, for acute appendicitis. The diagnostic value of each combined model was evaluated according to net reclassification improvement (NRI) and integrated discrimination index (IDI). Results White blood cell count, NLR, modified Alvarado score, CRP and uPAR levels were significantly higher in children with acute appendicitis than those in the control group. Serum uPAR level showed significantly positive correlations with modified Alvarado score and CRP level. The areas under the ROC curve of CRP combined with modified Alvarado score and uPAR combined with both CRP and modified Alvarado score were 0.819 (0.730~0.888) and 0.823 (0.734~0.891), respectively; the NRI and IDI of uPAR combined with CRP and modified Alvarado score was 0.653 (0.316~0.990) and 0.086 (0.036~0.136), respectively. Conclusion Serum uPAR level combined with modified Alvarado score and CRP can be used as an effective diagnostic indicator for acute appendicitis in children.