Evaluation of the Diagnostic Accuracy of Plasma Markers for Early Diagnosis in Patients Suspected for Acute Appendicitis

• Published in: Academic emergency medicine 2013-07, Vol.20 (7), p.703-710
• Main Authors: Schellekens, Dirk H. S. M., Hulsewé, Karel W. E., Acker, Bernadette A. C., Bijnen, Annemarie A., Jaegere, Tom M. H., Sastrowijoto, Suprapto H., Buurman, Wim A., Derikx, Joep P. M., Lewis, Lawrence
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Appendectomy - methods; Appendicitis; Appendicitis - blood; Appendicitis - diagnosis; Appendicitis - surgery; Biomarkers; Biomarkers - blood; C-Reactive Protein - metabolism; Case-Control Studies; Child; Child, Preschool; Confidence Intervals; Early Diagnosis; Emergency medical care; Emergency Service, Hospital; Enzyme-Linked Immunosorbent Assay; Female; Follow-Up Studies; Humans; Leukocyte Count; Leukocyte L1 Antigen Complex - blood; Leukocytes; Male; Middle Aged; Proteins; Radiology; ROC Curve; Sensitivity and Specificity; Serum Amyloid A Protein - metabolism; Severity of Illness Index; Statistics, Nonparametric; Treatment Outcome; Young Adult
• ISSN: 1069-6563; 1553-2712
• DOI: 10.1111/acem.12160

Objectives The main objective of this study was to evaluate the diagnostic accuracy of two novel biomarkers, calprotectin (CP) and serum amyloid A (SAA), along with the more traditional inflammatory markers C‐reactive protein (CRP) and white blood cell count (WBC), in patients suspected of having acute appendicitis (AA). The secondary objective was to compare diagnostic accuracy of these biomarkers with a clinical scoring system and radiologic imaging. Methods A total of 233 patients with suspected AA, presenting to the emergency department (ED) between January 2010 and September 2010, and 52 healthy individuals serving as controls, were included in the study. Blood was drawn and CP and SAA−1 concentrations were measured using enzyme‐linked immunosorbent assay (ELISA). CRP and WBC concentrations were routinely measured and retrospectively ed from the electronic health record, together with physical examination findings and radiologic reports. The Alvarado score was calculated as a clinical scoring system for AA. Final diagnosis of AA was based on histopathologic examination. The Mann‐Whitney U‐test was used for between‐group comparisons. Receiver operating characteristic (ROC) curves were used to measure the diagnostic accuracy for the tests and to determine the best cutoff points. Results Seventy‐seven of 233 patients (33%) had proven AA. Median plasma levels for CP and SAA−1 were significantly higher in patients with AA than in those with another final diagnosis (CP, 320.9 ng/mL vs. 212.9 ng/mL; SAA−1, 30 mg/mL vs. 0.6 mg/mL; p