title: Admission levels of serum amyloid a and procalcitonin are more predictive of the diagnosis of acute appendicitis compared with C-reactive protein.
abstract: BACKGROUND
  Acute appendicitis is the commonest surgical emergency, but its diagnosis can be elusive with a negative appendicectomy rate of 20%. The aims of this study were to investigate the potential value of the markers of acute inflammation, serum amyloid A (SAA), and serum procalcitonin (ProCT), in the diagnosis of acute appendicitis in adults and to compare that with the commonly used serum C-reactive protein (CRP).
  
  
  METHODS
  Adult patients presenting with acute right lower abdominal pain and a clinical suspicion of acute appendicitis were included. Blood samples were obtained within 6 hours of admission for rapid serum CRP assay and for end-of-recruitment batch analysis of SAA and serum ProCT concentrations.
  
  
  RESULTS
  A total of 147 patients (81 males) with a mean (±SD) age of 36 (±17) years were recruited. Appendicitis was confirmed histologically in 61 of 72 patients (84.7%) who underwent appendicectomy. A post hoc analysis revealed a diagnostic sensitivity and specificity for SAA of 92% and 72%, ProCT of 85% and 74%, and CRP of 75% and 72%, respectively. The receiver operator characteristics for the area under the curves showed that SAA (P=0.011) and ProCT (P=0.037) significantly exceeded CRP in the prediction of acute appendicitis on admission.
  
  
  CONCLUSIONS
  The measurement of SAA and serum ProCT on admission in patients with clinically suspected acute appendicitis seems to outperform serum CRP in aiding that diagnosis.
authors.affiliation: *Manchester Royal Infirmary Hospital ‡Department of Bariatric and HPB Surgery, Salford Royal Hospitals, Salford †General/ Colorectal Surgeon, Fairfield General Hospital, Bury, UK.
authors.forename: Muhammad H
authors.initials: MH
authors.lastname: Abbas
authors.forename: Muhammad N
authors.initials: MN
authors.lastname: Choudhry
authors.forename: Numan
authors.initials: N
authors.lastname: Hamza
authors.forename: Baqar
authors.initials: B
authors.lastname: Ali
authors.forename: Ali A
authors.initials: AA
authors.lastname: Amin
authors.forename: Basil J
authors.initials: BJ
authors.lastname: Ammori
mesh_terms: D000208:Acute Disease; D000328:Adult; D001064:Appendicitis / Q000175:diagnosis*; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism*; D002116:Calcitonin / Q000378:metabolism*; D015740:Calcitonin Gene-Related Peptide; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000378:metabolism*; D012372:ROC Curve; D000685:Serum Amyloid A Protein / Q000378:metabolism*
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D000685:Serum Amyloid A Protein; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide