title: Relative quantification of albumin and fibrinogen modifications by liquid chromatography tandem mass spectrometry in the diagnosis and monitoring of acute pancreatitis.
abstract: The increasing availability of liquid chromatography tandem mass spectrometry (LC-MS/MS) in clinical laboratories provides the opportunity to replace or complement present underperforming immuno- and chemometric assays. Amylase and lipase show limited specificity and sensitivity for pancreatic inflammation and lack the capacity of monitoring the disease due to their short half-lives. Previous findings suggested that cleavage products of the pancreatic enzyme carboxypeptidase A could be a more suitable indicator for defining and classifying pancreatic inflammation. The plasma proteins albumin and β-fibrinogen were digested with trypsin and truncated forms (des-Leu-albumin, and des-Gln-β-fibrinogen) quantified against their non-truncated forms by LC-MS/MS. Four hundred fifty eight samples from 83 patients were used to evaluate the novel method and affirm its suitability for detecting acute pancreatitis. A robust, selective, precise and accurate LC-MS/MS method was set up to measure the proportion of truncated proteins. Reference ranges for the proportion of the truncated albumin and β-fibrinogen were from 2% to 9% and 3% to 25%, respectively. Acute pancreatitis patients had values above these ranges and were distinctly separated from reference control individuals. The longer circulating half-lives of albumin and fibrinogen compared to pancreatic enzymes themselves provide the potential to diagnose pancreatitis more specifically over a longer time period, to monitor the course of the disease, and to track recurrent complications. The wide range of the proportion and the differential half-life of both truncated proteins could also be used for assessing the severity of pancreatitis.
authors.affiliation: Steroid and Immunobiochemistry Unit, Canterbury Health Laboratories, 524 Hagley Avenue, Christchurch 8011, New Zealand. Electronic address: ulrich.lankes@cdhb.health.nz.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Lankes
authors.affiliation: Molecular Pathology Laboratory, University of Otago Christchurch, Christchurch 8011, New Zealand.
authors.forename: Stephen O
authors.initials: SO
authors.lastname: Brennan
authors.affiliation: Clinical Biochemistry, Canterbury Health Laboratories, 524 Hagley Avenue, Christchurch 8011, New Zealand.
authors.forename: Trevor A
authors.initials: TA
authors.lastname: Walmsley
authors.affiliation: Clinical Biochemistry, Canterbury Health Laboratories, 524 Hagley Avenue, Christchurch 8011, New Zealand.
authors.forename: Peter M
authors.initials: PM
authors.lastname: George
mesh_terms: D000208:Acute Disease; D002853:Chromatography, Liquid / Q000379:methods*; D005340:Fibrinogen / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D010195:Pancreatitis / Q000097:blood* / Q000175:diagnosis*; D010446:Peptide Fragments / Q000097:blood* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000737:chemistry; D000075462:Serum Albumin, Human; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C115499:BBeta fibrinogen; D010446:Peptide Fragments; D012709:Serum Albumin; C580994:human serum albumin, des-leucyl(585)-; D005340:Fibrinogen; D000075462:Serum Albumin, Human
keywords: Albumin; Fibrinogen; LC–MS/MS; Mass spectrometry; Pancreatitis; Tryptic digest