Evaluation of Platelet Indices and Red Cell Distribution Width as New Biomarkers for the Diagnosis of Acute Appendicitis

Abstract

Background: Debate around the value of laboratory tests in establishing the diagnosis of acute appendicitis (AA) still continues. This prospective study aimed to investigate the changes in mean platelet volume (MPV), platelet distribution width (PDW), and red cell distribution width (RDW) with the diagnosis of acute appendicitis.

Method: 200 patients who underwent emergency appendectomy were included. According to postoperative histology, patients were divided into three groups: acute non-complicated, acute complicated appendicitis (positive appendicectomy groups), and negative appendectomy group. White blood cell (WBC), neutrophil, lymphocyte count, neutrophil-to-lymphocyte ratio (NLR), platelets (PLT) count, MPV, PDW, RDW, and C-reactive protein (CRP) were compared among the groups.

Results: One hundred twenty-five (62.5%) patients had non-complicated acute appendicitis, 20 (10%) had complicated acute appendicitis, while 55 (27.5%) had normal appendix. WBC (p <.001), neutrophil (p <.001), NLR (p <.001), PDW (p =.003), and CRP (p =.001) were higher, while lymphocyte (p <.001) and PLT counts (p =.020) were lower in positive appendectomy compared with negative appendectomy patients. MPV levels were insignificantly different across the groups. RDW level was significantly higher in complicated compared with non-complicated acute appendicitis (p =.006); however, no significant difference was found between positive and negative appendectomy groups. Using receiver operating characteristic analysis, sensitivity, specificity, and diagnostic accuracy respectively were 44.83, 100.0, and 72.415% for WBC count, 72.41, 81.82, and 77.115% for neutrophil count, 48.28, 90.91, and 69.595% for PDW, 89.66, 63.64, and 76.65% for CRP.

Conclusions: Increased PDW combined with elevated WBC and neutrophil counts maybe used as diagnostic tests in the cases of acute appendicitis, while MPV and RDW levels were not useful diagnostic markers.