Biliary hCGβ Is a Potential Novel Marker for Prediction of Biliary Neoplasia in Primary Sclerosing Cholangitis Patients

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease, which is associated with an increased risk of cholangiocarcinoma (CCA). Novel markers, to complement or replace CA19-9, are urgently needed for the screening of PSC-associated biliary neoplasia. Previous studies have suggested that serum trypsinogen-2 and human chorionic gonadotropin β-subunit (hCGβ) may serve as such markers. Using highly specific in-house immunoassays, we studied trypsin(ogen)-2 and -3, SPINK1 and hCGβ in bile samples of 214 patients, referred for endoscopic retrograde cholangiography. We found that biliary trypsinogen-2 was decreased (p = 0.027) and hCGβ was elevated (p < 0.001) in PSC patients who were diagnosed 1.6 years (median, range 0.1–8.8 years) later with CCA or in whom biliary dysplasia was observed at least twice in brush cytology (n = 11) as compared to PSC patients without CCA or repeated dysplasia (n = 171). The other studied markers did not show significant differences between these groups. Our results warrant further evaluation of hCGβ as a predictive marker for PSC-associated biliary neoplasia.

Exocrine Pancreatic Enzymes Are a Serological Biomarker for Type 1 Diabetes Staging and Pancreas Size

Exocrine pancreas abnormalities are increasingly recognized as features of type 1 diabetes. We previously reported reduced serum trypsinogen levels and in a separate study, smaller pancreata at and prior to disease onset. We hypothesized that three pancreas enzymes (amylase, lipase and trypsinogen) might serve as serological biomarkers of pancreas volume and risk for type 1 diabetes. Amylase, lipase, and trypsinogen were measured from two independent cohorts, together comprising 800 serum samples from single-autoantibody positive (1AAb+) and multiple-AAb+ (≥2AAb+) subjects, individuals with recent-onset or established type 1 diabetes, their AAb negative (AAb-) first-degree relatives, and AAb- controls. Lipase and trypsinogen were significantly reduced in ≥2AAb+, recent-onset, and established type 1 diabetes subjects versus controls and 1AAb+, while amylase was reduced only in established type 1 diabetes. Logistic regression models demonstrated trypsinogen plus lipase (AUROC=81.4%) performed equivalently to all three enzymes (AUROC=81.4%) in categorizing ≥2AAb+ versus 1AAb+ subjects. For Cohort 2 (n=246), linear regression demonstrated lipase and trypsinogen levels could individually and collectively serve as indicators of BMI-normalized relative pancreas volume (RPV_BMI, <i>P</i><0.001), previously measured by magnetic resonance imaging. Serum lipase and trypsinogen levels together provide the most sensitive serological biomarker of RPV_BMI and may improve disease staging in pre-type 1 diabetes.

Exocrine Pancreatic Enzymes Are a Serological Biomarker for Type 1 Diabetes Staging and Pancreas Size

Exocrine pancreas abnormalities are increasingly recognized as features of type 1 diabetes. We previously reported reduced serum trypsinogen levels and in a separate study, smaller pancreata at and prior to disease onset. We hypothesized that three pancreas enzymes (amylase, lipase and trypsinogen) might serve as serological biomarkers of pancreas volume and risk for type 1 diabetes. Amylase, lipase, and trypsinogen were measured from two independent cohorts, together comprising 800 serum samples from single-autoantibody positive (1AAb+) and multiple-AAb+ (≥2AAb+) subjects, individuals with recent-onset or established type 1 diabetes, their AAb negative (AAb-) first-degree relatives, and AAb- controls. Lipase and trypsinogen were significantly reduced in ≥2AAb+, recent-onset, and established type 1 diabetes subjects versus controls and 1AAb+, while amylase was reduced only in established type 1 diabetes. Logistic regression models demonstrated trypsinogen plus lipase (AUROC=81.4%) performed equivalently to all three enzymes (AUROC=81.4%) in categorizing ≥2AAb+ versus 1AAb+ subjects. For Cohort 2 (n=246), linear regression demonstrated lipase and trypsinogen levels could individually and collectively serve as indicators of BMI-normalized relative pancreas volume (RPV_BMI, <i>P</i><0.001), previously measured by magnetic resonance imaging. Serum lipase and trypsinogen levels together provide the most sensitive serological biomarker of RPV_BMI and may improve disease staging in pre-type 1 diabetes.

Specific Immunoassay Reveals Increased Serum Trypsinogen 3 in Acute Pancreatitis

BACKGROUND Trypsinogen 3 is a minor trypsinogen isoform in the pancreas. In contrast with trypsin 1 and 2, trypsin 3 degrades pancreatic secretory trypsin inhibitor, which may lead to an excess of active trypsin and acute pancreatitis (AP). We developed an immunoassay for trypsinogen 3 and studied whether an assay of serum trypsinogen 3 is of clinical utility in the diagnosis of AP. METHODS Monoclonal antibodies were generated using recombinant human trypsinogen 3 as the antigen and used to establish a sandwich-type immunoassay. We analyzed serum trypsinogen 3 concentrations in 82 patients with AP and 63 patients with upper abdominal pain (controls). The reference interval was determined using serum samples from 172 apparently healthy individuals. RESULTS The measuring range of the trypsinogen 3 assay was 1.0–250 μg/L. Intra- and interassay CVs were &lt;11%, and cross-reactivity with other trypsinogen isoenzymes was &lt;0.1%. The median trypsinogen 3 concentration in serum from healthy individuals was &lt;1.0 μg/L, and the upper reference limit was 4.4 μg/L. We observed increased trypsinogen 3 concentrations in patients with mild (median 9.5 μg/L) and severe (15.0 μg/L) AP; in both groups, the concentrations were significantly higher than in controls (median &lt;1.0 μg/L) (P &lt; 0.0001). In ROC analysis, the area under the curve of trypsinogen 3 for separation between AP and controls was 0.90 (P &lt; 0.0001). CONCLUSIONS We established for the first time a specific immunoassay for trypsinogen 3 using monoclonal antibodies. Patients with AP were found to have increased serum concentrations of trypsinogen 3. The availability of this assay will be useful for studies of the clinical utility of trypsinogen 3.