Assessment of Perforation of Acute Appendicitis using the Delta Neutrophil Index Reflecting Peripheral Immature Granulocyte Count

ABSTRACT

PURPOSE: The delta neutrophil index corresponds to calculated immature granulocyte counts and severity of sepsis. This study was conducted in order to investigate the diagnostic value of the delta neutrophil index as a preoperative laboratory marker for appendiceal perforation in patients with acute appendicitis. METHODS: This study was conducted as a retrospective analysis of patients confirmed pathologically as appendicitis at two hospitals from November 2009 to September 2010. Delta neutrophil index was automatically calculated as a subset of routine complete blood count testing. The diagnostic performance of the delta neutrophil index for perforated appendicitis was evaluated. RESULTS: During the study period, 308 patients were enrolled. Among them, 32 patients (10.4%) were confirmed as perforated appendicitis. The delta neutrophil index was significantly higher in the perforated group, compared with the non-perforated group (4.8+/-7.1% vs 2.0+/-2.0%, p<0.05). Sensitivity and specificity of the delta neutrophil index for prediction of perforated appendicitis was 25.0% and 96.7%, respectively, at a cutoff level of 5% with an area under the curve of 0.78 on the ROC (receiver operating characteristics) curve. CONCLUSION: Results of this study suggested an association of the delta neutrophil index with perforated appendicitis. However, the sensitivity was not high enough for use as clinical guidance.