Affinity Purification Coupled to Stable Isotope Dilution LC-MS/MS Analysis to Discover IgG4 Glycosylation Profiles for Autoimmune Pancreatitis.
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ABSTRACT:
SUBMITTER: Chen MX
PROVIDER: S-EPMC8584136 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Background & aimsType 1 autoimmune pancreatitis (AIP) is an IgG4-related disease whose diagnosis is challenging. The aim of this study was to investigate the diagnostic value of circulating total and IgG4+ plasmablasts in differentiating this condition from the other main pancreatic diseases.MethodsPatients with type 1 AIP (n = 19) were prospectively enrolled in a tertiary center together with patients suffering from type 2 or not otherwise specified (NOS) AIP (n = 10), pancreatic adenocarcinoma (n = 17), chronic pancreatitis (n = 20), and intraductal papillary mucinous neoplasia or chronic asymptomatic pancreatic hyperenzymemia (n = 21) as control groups. Flow cytometry was used to measure the total plasmablast and IgG4+ plasmablast number by gating peripheral blood CD45+CD19+CD38hiCD20-CD24-CD27+ and CD45+CD19+CD38hiCD20-CD24-CD27+IgG4+ cells, respectively. In patients with AIP, these cell populations were also evaluated after 1 month of therapy, after 2-4 months from the end of treatment, and after 1 year from the enrollment. The study was approved by the local ethics committee (protocol number: 59133, 30/11/2017).ResultsTotal plasmablast quantification was capable of discriminating type 1 AIP from all the other pancreatic disorders with a sensitivity of 47% and a specificity of 81%, according to a cutoff of 4500 cells/mL (AUC = 0.738), whereas IgG4+ plasmablast count distinguished type 1 AIP from all the other pancreatic disorders with a sensitivity of 80% and a specificity of 97% when applying a cutoff of 210 IgG4+ cells/mL (AUC = 0.879). The basal IgG4+ plasmablast number was significantly higher (P = .0001) in type 1 AIP than in type 2/NOS AIP, decreased after steroid therapy, and increased at disease relapse.ConclusionIgG4+ plasmablast count represents a potentially useful biomarker to differentiate type 1 from type 2/NOS AIP and from other pancreatic diseases.
| S-EPMC11307817 | biostudies-literature
Project description:IntroductionPancreatic ductal adenocarcinoma (PDAC) is the fifth most common cause of cancer-related death in Europe with a 5-year survival rate of <5%. Chronic pancreatitis (CP) is a risk factor for PDAC development, but in the majority of cases malignancy is discovered too late for curative treatment. There is at present no reliable diagnostic marker for PDAC available.ObjectivesThe aim of the study was to identify single blood-based metabolites or a panel of metabolites discriminating PDAC and CP using liquid chromatography-mass spectrometry (LC-MS).MethodsA discovery cohort comprising PDAC (n = 44) and CP (n = 23) samples was analyzed by LC-MS followed by univariate (Student's t test) and multivariate (orthogonal partial least squares-discriminant analysis (OPLS-DA)) statistics. Discriminative metabolite features were subject to raw data examination and identification to ensure high feature quality. Their discriminatory power was then confirmed in an independent validation cohort including PDAC (n = 20) and CP (n = 31) samples.ResultsGlycocholic acid, N-palmitoyl glutamic acid and hexanoylcarnitine were identified as single markers discriminating PDAC and CP by univariate analysis. OPLS-DA resulted in a panel of five metabolites including the aforementioned three metabolites as well as phenylacetylglutamine (PAGN) and chenodeoxyglycocholate.ConclusionUsing LC-MS-based metabolomics we identified three single metabolites and a five-metabolite panel discriminating PDAC and CP in two independent cohorts. Although further study is needed in larger cohorts, the metabolites identified are potentially of use in PDAC diagnostics.
| S-EPMC5376388 | biostudies-literature