Micelle-based fluorogenic sensing of trypsin: a sensitive method in pancreatic disease diagnosis.

Protamine-mediated micellar aggregates, featuring an AIE-based fluorescent sensor, facilitate efficient detection of trypsin activity. This method enables the detection of trypsin at exceptionally low concentrations (0.01-0.1 µg mL-1) in urine, demonstrating its potential for early clinical diagnosis of trypsin-related pancreatic diseases.

Impact of renal dysfunction on the diagnosis of acute pancreatitis using urinary trypsinogen-2: A retrospective study.

AIM: Early diagnosis of acute pancreatitis is crucial, and urinary trypsinogen has been recently reported as a useful biomarker for diagnosing acute pancreatitis. We aimed to evaluate the impact of renal dysfunction on the diagnostic performance of urinary trypsinogen-2 for acute pancreatitis. METHODS: We conducted a retrospective study using the clinical data of patients who visited the Department of Emergency and Critical Care at the University of Tokyo Hospital between 1 October, 2021, and 30 June, 2022. Patients with available data on qualitative urinary trypsinogen-2 levels were identified. We compared the urinary trypsinogen-2 levels among patients who were clinically diagnosed with acute pancreatitis. We further stratified the patients according to renal function parameters, such as serum creatinine level, blood urea nitrogen level, and estimated glomerular filtration rate, and evaluated the performance of urinary trypsinogen-2 as a biomarker for acute pancreatitis. RESULTS: Within 9 months, 35 patients were identified. Of them, 22 patients showed positive results and 13 showed negative results on the urinary trypsinogen-2 test. The sensitivity, specificity, positive predictive value, and negative predictive value were 0.80, 0.40, 0.18, and 0.92, respectively. Based on the blood urea nitrogen level and estimated glomerular filtration rate, the prevalence of false-positive results was significantly higher in patients with reduced renal function than in those with normal renal function. CONCLUSION: In patients with reduced renal function, the urinary trypsinogen-2 qualitative test results might be interpreted with caution when used for diagnosing acute pancreatitis.

A Paper-Based Near-Infrared Optical Biosensor for Quantitative Detection of Protease Activity Using Peptide-Encapsulated SWCNTs.

A protease is an enzyme that catalyzes proteolysis of proteins into smaller polypeptides or single amino acids. As crucial elements in many biological processes, proteases have been shown to be informative biomarkers for several pathological conditions in humans, animals, and plants. Therefore, fast, reliable, and cost-effective protease biosensors suitable for point-of-care (POC) sensing may aid in diagnostics, treatment, and drug discovery for various diseases. This work presents an affordable and simple paper-based dipstick biosensor that utilizes peptide-encapsulated single-wall carbon nanotubes (SWCNTs) for protease detection. Upon enzymatic digestion of the peptide, a significant drop in the photoluminescence (PL) of the SWCNTs was detected. As the emitted PL is in the near-infrared region, the developed biosensor has a good signal to noise ratio in biological fluids. One of the diseases associated with abnormal protease activity is pancreatitis. In acute pancreatitis, trypsin concentration could reach up to 84 µg/mL in the urine. For proof of concept, we demonstrate the feasibility of the proposed biosensor for the detection of the abnormal levels of trypsin activity in urine samples.

Urinary trypsinogen-2 level and local complications of acute pancreatitis.

BACKGROUND AND AIM: Local complications of acute pancreatitis (AP) carry risks of morbidity/mortality. This study aimed to assess whether urinary trypsinogen-2 levels and Bedside Index for Severity in Acute Pancreatitis (BISAP) score on admission predicted subsequent local complications. METHODS: One hundred and forty-four consecutive patients with AP were prospectively followed till 6 months after discharge. Urinary trypsinogen-2 levels were measured within 24 h of admission. Local complications (acute peripancreatic fluid collection, acute necrotic collection, pseudocyst, and walled-off necrosis) were diagnosed by abdominal computed tomography. Cut-off for trypsinogen-2 level was assessed using receiver operating characteristic curve, and predictors of local complications were analyzed by logistic regression. RESULTS: Thirty-seven (25.7%) patients developed local complications. Urinary trypsinogen-2 levels were significantly higher in patients with local complications compared with those without local complications (median [interquartile range], 3210 [620-9764.4] µg/L vs 627.3 [72.3-5895] µg/L, P = 0.006). Urinary trypsinogen-2 significantly outperformed BISAP score in predicting local complications (area under the receiver operating characteristic curve 0.65 [95% CI: 0.55-0.75] vs 0.48 [95% CI: 0.38-0.58], P = 0.005). At the optimal cut-off of 500 µg/L, the sensitivity, specificity, positive predictive value, and negative predictive value of trypsinogen-2 level were 78.4%, 45.8%, 33.3%, and 86.0%, respectively. Urinary trypsinogen-2 level > 500 µg/L was an independent predictor of local complications (adjusted odds ratio, 3.72; 95% CI: 1.42-9.76; P = 0.007). By contrast, BISAP score ≥ 3 and pleural effusion predicted organ failure but not local complications. CONCLUSION: In a prospective cohort, urinary trypsinogen-2 level > 500 µg/L independently predicted local complications of AP.

A fluorometric sensing method for sensitive detection of trypsin and its inhibitor based on gold nanoclusters and gold nanoparticles.

In this work, a facile, label-free, and sensitive fluorometric strategy for detection of trypsin and its inhibitor was established on the basis of the fluorescence resonance energy transfer (FRET) between mercaptoundecanoic acid functionalized gold nanoclusters (AuNCs) and gold nanoparticles (AuNPs) via protamine as a bridge. Protamine can trigger the aggregation of AuNPs and link AuNCs with aggregated AuNPs through electrostatic interaction. Compared with monodisperse AuNPs, the UV-vis absorption band of aggregated AuNPs overlapped considerably with the emission spectrum of AuNCs. Thus, the fluorescence of AuNCs was obviously quenched by the aggregated AuNPs through FRET. In the presence of trypsin, protamine was hydrolyzed into small fragments, leading to the deaggregation of AuNPs and breaking of the short distance between AuNPs and AuNCs, so the FRET process was inhibited, and the fluorescence of AuNCs was recovered. The increase in the fluorescence intensity of AuNCs was directly related to the amount of trypsin. Hence trypsin can be determined on the basis of the variation of fluorescence intensity, with a linear range of 5-5000 ng mL-1 and a detection limit of 1.9 ng mL-1. In addition, this system was used for the detection of trypsin inhibitor by application of the inhibitor isolated from soybean as a model. The sensing method was applied for trypsin detection in human urine and commercial multienzyme tablet samples with satisfactory results. Graphical abstract ᅟ.

Acinar cell density at the pancreatic resection margin is associated with post-pancreatectomy pancreatitis and the development of postoperative pancreatic fistula.

BACKGROUND: There has been recent evidence supporting post-pancreatectomy pancreatitis as a factor in the development of postoperative pancreatic fistula (POPF). The aims of this study were to evaluate: (i) the correlation of the acinar cell density at the pancreatic resection margin with the intra-operative amylase concentration (IOAC) of peri-pancreatic fluid, postoperative pancreatitis, and POPF; and (ii) the association between postoperative pancreatitis on the first postoperative day and POPF. METHODS: Consecutive patients who underwent pancreatic resection between June 2016 and July 2017 were included for analysis. Fluid for IOAC was collected, and amylase concentration was determined in drain fluid on postoperative days 1, 3, and 5. Serum amylase and lipase and urinary trypsinogen-2 concentrations were determined on the first postoperative day. Histology slides of the pancreatic resection margin were scored for acinar cell density. RESULTS: Sixty-one patients were included in the analysis. Acinar cell density significantly correlated with IOAC (r = 0.566, p < 0.001), and was significantly associated with postoperative pancreatitis (p < 0.001), and POPF (p = 0.003). Postoperative pancreatitis was significantly associated with the development of POPF (OR 17.81, 95%CI 2.17-145.9, p = 0.001). DISCUSSION: The development of POPF may involve a complex interaction between acinar cell density, immediate leakage of pancreatic fluid, and postoperative pancreatitis.

Serum amylase and lipase and urinary trypsinogen and amylase for diagnosis of acute pancreatitis.

BACKGROUND: The treatment of people with acute abdominal pain differs if they have acute pancreatitis. It is important to know the diagnostic accuracy of serum amylase, serum lipase, urinary trypsinogen-2, and urinary amylase for the diagnosis of acute pancreatitis, so that an informed decision can be made as to whether the person with abdominal pain has acute pancreatitis. There is currently no Cochrane review of the diagnostic test accuracy of serum amylase, serum lipase, urinary trypsinogen-2, and urinary amylase for the diagnosis of acute pancreatitis. OBJECTIVES: To compare the diagnostic accuracy of serum amylase, serum lipase, urinary trypsinogen-2, and urinary amylase, either alone or in combination, in the diagnosis of acute pancreatitis in people with acute onset of a persistent, severe epigastric pain or diffuse abdominal pain. SEARCH METHODS: We searched MEDLINE, Embase, Science Citation Index Expanded, National Institute for Health Research (NIHR HTA and DARE), and other databases until March 2017. We searched the references of the included studies to identify additional studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively. We also performed a 'related search' and 'citing reference' search in MEDLINE and Embase. SELECTION CRITERIA: We included all studies that evaluated the diagnostic test accuracy of serum amylase, serum lipase, urinary trypsinogen-2, and urinary amylase for the diagnosis of acute pancreatitis. We excluded case-control studies because these studies are prone to bias. We accepted any of the following reference standards: biopsy, consensus conference definition, radiological features of acute pancreatitis, diagnosis of acute pancreatitis during laparotomy or autopsy, and organ failure. At least two review authors independently searched and screened the references located by the search to identify relevant studies. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data from the included studies. The thresholds used for the diagnosis of acute pancreatitis varied in the trials, resulting in sparse data for each index test. Because of sparse data, we used -2 log likelihood values to determine which model to use for meta-analysis. We calculated and reported the sensitivity, specificity, post-test probability of a positive and negative index test along with 95% confidence interval (CI) for each cutoff, but have reported only the results of the recommended cutoff of three times normal for serum amylase and serum lipase, and the manufacturer-recommended cutoff of 50 mg/mL for urinary trypsinogen-2 in the abstract. MAIN RESULTS: Ten studies including 5056 participants met the inclusion criteria for this review and assessed the diagnostic accuracy of the index tests in people presenting to the emergency department with acute abdominal pain. The risk of bias was unclear or high for all of the included studies. The study that contributed approximately two-thirds of the participants included in this review was excluded from the results of the analysis presented below due to major concerns about the participants included in the study. We have presented only the results where at least two studies were included in the analysis.Serum amylase, serum lipase, and urinary trypsinogen-2 at the standard threshold levels of more than three times normal for serum amylase and serum lipase, and a threshold of 50 ng/mL for urinary trypsinogen-2 appear to have similar sensitivities (0.72 (95% CI 0.59 to 0.82); 0.79 (95% CI 0.54 to 0.92); and 0.72 (95% CI 0.56 to 0.84), respectively) and specificities (0.93 (95% CI 0.66 to 0.99); 0.89 (95% CI 0.46 to 0.99); and 0.90 (95% CI 0.85 to 0.93), respectively). At the median prevalence of 22.6% of acute pancreatitis in the studies, out of 100 people with positive test, serum amylase (more than three times normal), serum lipase (more than three times normal), and urinary trypsinogen (more than 50 ng/mL), 74 (95% CI 33 to 94); 68 (95% CI 21 to 94); and 67 (95% CI 57 to 76) people have acute pancreatitis, respectively; out of 100 people with negative test, serum amylase (more than three times normal), serum lipase (more than three times normal), and urinary trypsinogen (more than 50 ng/mL), 8 (95% CI 5 to 12); 7 (95% CI 3 to 15); and 8 (95% CI 5 to 13) people have acute pancreatitis, respectively. We were not able to compare these tests formally because of sparse data. AUTHORS' CONCLUSIONS: As about a quarter of people with acute pancreatitis fail to be diagnosed as having acute pancreatitis with the evaluated tests, one should have a low threshold to admit the patient and treat them for acute pancreatitis if the symptoms are suggestive of acute pancreatitis, even if these tests are normal. About 1 in 10 patients without acute pancreatitis may be wrongly diagnosed as having acute pancreatitis with these tests, therefore it is important to consider other conditions that require urgent surgical intervention, such as perforated viscus, even if these tests are abnormal.The diagnostic performance of these tests decreases even further with the progression of time, and one should have an even lower threshold to perform additional investigations if the symptoms are suggestive of acute pancreatitis.

[Clinical and laboratory diagnosis of an acute biliary pancreatitis].

In 126 patients, suffering an acute biliary pancreatitis (ABP), clinical examination was conducted. In 65 patients (1-st group) the isolated cholecystolithiasis was noted; in 35 (2-nd group)--cholelithiasis, which did not cause obturation of common biliary duct; in 26 (3-rd group)--cholelithiasis, which caused the biliary ways obturation (including calculi, which were incorporated into the duodenal papilla magna ostium). Clinical course of an ABP have differed depending on localization of calculi of extrahepatic biliary ducts. In patients, suffering ABP, a biochemical signs of hepatocytes functional disorders were observed, impacting the need for hepatoprotector preparations inclusion into complex of perioperative conservative therapy. Determination of activity of pancreatic α-amylase in the blood serum and conduction of the ACTIM Pancreatitis test con- stitute the most sensitive and specific methods of the ABP biochemical diagnosis.

Urinary trypsinogen-2 for diagnosing acute pancreatitis: a meta-analysis.

BACKGROUND: Currently, serum amylase and lipase are the most popular laboratory markers for early diagnosis of acute pancreatitis with reasonable sensitivity and specificity. Urinary trypsinogen-2 (UT-2) has been increasingly used but its clinical value for the diagnosis of acute pancreatitis and post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis has not yet been systematically assessed. DATA SOURCES: A comprehensive search was carried out using PubMed (MEDLINE), Embase, and Web of Science for clinical trials, which studied the usefulness of UT-2 as a diagnostic marker for acute pancreatitis. Sensitivity, specificity and the diagnostic odds ratios (DORs) with 95% confidence interval (CI) were calculated for each study and were compared with serum amylase and lipase. Summary receiver-operating curves were conducted and the area under the curve (AUC) was evaluated. RESULTS: A total of 18 studies were included. The pooled sensitivity and specificity of UT-2 for the diagnosis of acute pancreatitis were 80% and 92%, respectively (AUC=0.96, DOR=65.63, 95% CI: 31.65-139.09). The diagnostic value of UT-2 was comparable to serum amylase but was weaker than serum lipase. The pooled sensitivity and specificity for the diagnosis of post-ERCP pancreatitis were 86% and 94%, respectively (AUC=0.92, DOR=77.68, 95% CI: 24.99-241.48). CONCLUSIONS: UT-2 as a rapid test could be potentially used for the diagnosis of post-ERCP pancreatitis and to an extent, acute pancreatitis. Further studies are warranted to confirm these results.

Point-of-care urine trypsinogen-2 test for diagnosis of acute pancreatitis.

OBJECTIVES: To assess a point-of-care urine trypsinogen-2 (UT) test for the diagnosis of acute pancreatitis. METHODS: This was a prospective study of patients presenting to the emergency department with abdominal pain suggestive of acute pancreatitis. A 3-minute point-of-care UT test (Actim Pancreatitis; Medix Biochemica, Kauniainen, Finland) was compared with final diagnosis of acute pancreatitis, which was based on suggestive clinical features, serum lipase and/or amylase levels and imaging. RESULTS: Of 124 patients included in this study, 69 patients had final diagnosis of acute pancreatitis. The sensitivity and specificity of UT were, respectively, 73.9% (95% CI 61.9% to 83.8%) and 94.6% (95% CI 84.9% to 98.9%). CONCLUSIONS: The point-of-care UT test for acute pancreatitis had good sensitivity and specificity, and can be used reliably at the bedside to make a positive diagnosis.

A comparative study of the urinary trypsinogen-2, trypsinogen activation peptide, and the computed tomography severity index as early predictors of the severity of acute pancreatitis.

BACKGROUND/AIMS: The aim of the study was to establish the value of urinary trypsinogen-2 in predicting the severity of acute pancreatitis (AP) and to compare it with the accuracy of the urinary trypsinogen activation peptide (TAP) and the computed tomography severity index (CTSI). METHODOLOGY: The study population consisted of 187 consecutive patients with AP, of whom 38 had severe disease. The predictive values of urinary trypsinogen-2, TAP and CTSI were assessed within 24 h of the onset of symptoms. RESULTS: The mean values of predictive markers in the mild and severe pancreatitis groups were: urinary trypsinogen-2, 59/90 and 25/13 (p < 0.001); urinary TAP, 13.2 +/- 3.3nmol/l and 66.2 +/- 19.3 nmol/l (p < 0.001); and computed tomography severity index, 1.42 +/- 1.1 and 5.31 +/- 2.6 (p < 0.001). The sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratios were calculated for the urinary trypsinogen-2 (65.7%, 66.4%, 33.3%, 88.4%, 1.9, and 0.51), for TAP (greater than 35 nmol/l: 63.2%, 65.8%, 32.0%, 87.5%, 1.9, and 0.58) and for CTSI (greater than 3: 47.4%, 95.3%, 69.2%, 87.7%, 9.0 and 0.55). To differentiate between severe and mild AP, urinary trypsinogen-2 (AUC 0.724) was slightly better than TAP (AUC 0.722), and they were both clearly better than CTSI (AUC 0.597) (p < 0.05). Urinary trypsinogen-2 had significantly lower cost (p < 0.001) than TAP and computed tomography. CONCLUSION: Urinary trypsinogen-2 was superior to CTSI and was as good as or even better than urinary TAP in the early prediction of severity in AP. This suggests that this simple and quick method deserves routine clinical application.

The role of urine trypsinogen-2 test in the differential diagnosis of acute pancreatitis in the Emergency Department.

BACKGROUND: The aim of the study was to investigate the role and importance of the urine trypsinogen-2 dipstick test in the differential diagnosis of acute pancreatitis in the Emergency Department and to compare results with those of conventional tests. METHODS: The study was performed prospectively in the patients admitting to the Emergency Department due to upper abdominal pain. Thirty-two of the 87 patients included in the study had acute pancreatitis diagnosis. Serum amylase, lipase, C-reactive protein (CRP) and urine trypsinogen-2 using Actim pancreatitis dipstick were studied in all patients. The statistical analysis was performed using SPSS 11.5 package program. RESULTS: Urine trypsinogen-2 was found positive in 21 (65.6%) of 32 patients. The sensitivity of the test for pancreatitis was identified as 64%, specificity as 85%, positive predictive value as 72%, and negative predictive value as 81%. These values were statistically significant compared to the control group (p<0.01). CONCLUSION: Although it has lower sensitivity and specificity compared to amylase and lipase, we suggest that urine trypsinogen-2 test may be an important diagnostic tool in excluding the diagnosis of acute pancreatitis, since it provides results within 5 minutes in the Emergency Department, is cheaper, has a higher negative predictive value, and is easy to use.

Usefulness of urinary trypsinogen-2 and trypsinogen activation peptide in acute pancreatitis: A multicenter study in Japan.

BACKGROUND: Rapid urinary trypsinogen-2 dipstick test and levels of urinary trypsinogen-2 and trypsinogen activation peptide (TAP) concentration have been reported as prognostic markers for the diagnosis of acute pancreatitis. AIM: To reconfirm the validity of all these markers in the diagnosis of acute pancreatitis by undertaking a multi-center study in Japan. METHODS: Patients with acute abdominal pain were recruited from 17 medical institutions in Japan from April 2009 to December 2012. Urinary and serum samples were collected twice, at enrollment and on the following day for measuring target markers. The diagnosis and severity assessment of acute pancreatitis were assessed based on prognostic factors and computed tomography (CT) Grade of the Japanese Ministry of Health, Labour, and Welfare criteria. RESULTS: A total of 94 patients were enrolled during the study period. The trypsinogen-2 dipstick test was positive in 57 of 78 patients with acute pancreatitis (sensitivity, 73.1%) and in 6 of 16 patients with abdominal pain but without any evidence of acute pancreatitis (specificity, 62.5%). The area under the curve (AUC) score of urinary trypsinogen-2 according to prognostic factors was 0.704, which was highest in all parameter. The AUC scores of urinary trypsinogen-2 and TAP according to CT Grade were 0.701 and 0.692, respectively, which shows higher than other pancreatic enzymes. The levels of urinary trypsinogen-2 and TAP were significantly higher in patients with extended extra-pancreatic inflammation as evaluated by CT Grade. CONCLUSION: We reconfirmed urinary trypsinogen-2 dipstick test is useful as a marker for the diagnosis of acute pancreatitis. Urinary trypsinogen-2 and TAP may be considered as useful markers to determine extra-pancreatic inflammation in acute pancreatitis.

Randomized clinical trial to assess the efficacy of ulinastatin for postoperative pancreatitis following pancreaticoduodenectomy.

BACKGROUND AND OBJECTIVES: Ulinastatin, an intrinsic trypsin inhibitor, has proved to be effective for the prevention of acute pancreatitis after endoscopic retrograde cholangiopancreatography. The aim of this study was to assess the efficacy of ulinastatin for postoperative pancreatitis following pancreaticoduodenectomy in a randomized clinical trial. METHODS: Patients undergoing pancreaticoduodenectomy were randomized to receive perioperative ulinastatin or placebo. Levels of serum amylase, drain amylase, and urine trypsinogen-2 were measured. RESULTS: A total of 42 patients were enrolled (20 in the ulinastatin group, 20 in the placebo group, 2 excluded). Two patients in the ulinastatin group and nine patients in the placebo group developed hyperamylasemia (P = 0.013) No patient in the ulinastatin group and five patients in the placebo group developed pancreatitis (P = 0.016). One patient in the ulinastatin group and two patients in the placebo group developed grade A pancreatic fistula (P = 0.548). Serum amylase levels at 4 hr and postoperative days 1, 2, and 3, and drain amylase levels on days 2 and 3 were significantly lower in the ulinastatin group than in the placebo group. CONCLUSIONS: Prophylactic administration of ulinastatin reduced the levels of serum and drain amylase and the incidence of postoperative pancreatitis following pancreaticoduodenectomy.

Effectivity of qualitative urinary trypsinogen-2 measurement in the diagnosis of acute pancreatitis: a randomized, clinical study.

BACKGROUND: There is no any definite diagnostic test for acute pancreatitis. In the present study we investigated the value of the qualitative urinary trypsinogen-2 measurement in the diagnosis of acute pancreatitis by an immuno-chromatographic dipstick test. METHODS: A prospective, randomized, clinical trial was planned on 99 patients (53 male, 46 female; male/female : 1.11; age range: 16-83; mean age: 37.4). Patients were divided into two groups: 50 cases were referred to our emergency surgical unit due to abdominal pain and diagnosed with acute pancreatitis by abdominal computerized tomography (CT) (Group 1); 49 cases were referred to our emergency surgical unit due to abdominal pain and whose abdominal CTs did not show any sign of acute pancreatitis (Group 2). Qualitative urinary trypsinogen-2 measurement, abdominal CT and blood amylase values were obtained in all cases. RESULTS: In group 1, urinary trypsinogen-2 measurement was found positive in 28 cases out of 50 cases diagnosed with acute pancreatitis (56% sensitivity). In group 2, results were found positive in 3 out of 49 patients with abdominal pain, who lacked an acute pancreatitis diagnosis (90.9% specificity). Severe intra-abdominal inflammation was present in three cases of group 2 where we obtained false positive results which may stimulate the pancreatic exocrine secretion. CONCLUSION: Qualitative measurements of urinary trypsinogen-2 in patients with abdominal pain may be useful in the diagnosis of acute pancreatitis. It is an easy, inexpensive, rapid and noninvasive method.

Simple and label-free liquid crystal-based sensor for detecting trypsin coupled to the interaction between cationic surfactant and BSA.

Trypsin plays a central role in catalyzing the hydrolysis of peptide bonds, so a technique with simple operation is needed to monitor the activity of trypsin. Here a simple and label-free senor based on liquid crystals (LCs) was developed by employing bovine serum albumin (BSA) as the enzyme substrate and dodecyl trimethyl ammonium bromide (DTAB) as the controller for the alignment of LC. It was found that DTAB could form a self-assembled monolayer at the aqueous/LC interface to produce the dark optical images of LCs. And the addition of BSA could disturb the monolayer, so that the optical signal of LCs turned bright from dark. But the hydrolysis of BSA by trypsin resulted in the dark appearance. The sensing platform allows detection as low as 1 U/mL under the polarized light microscope based on at least three measurements. Moreover, this method was successfully applied in the detection of trypsin in human urines, suggesting its potential applications in clinic diagnosis.

Ultrasensitive detection of trypsin activity and inhibitor screening based on the electron transfer between phosphorescence copper nanocluster and cytochrome c.

Trypsin, as one of important proteases, is specific for catalyzing the hydrolysis of peptide and ester bonds containing lysine and arginine residues at the C-terminus. The level of trypsin in biological fluids can serve as a reliable and specific diagnostic biomarker for pancreatic function and its pathological changes. Herein, we demonstrate the application of phosphorescent Cu NCs for trypsin detection for the first time depending on the electron transfer between Cu NCs and cyt c. Cyt c and Cu NCs were selected as the quencher and the fluorophore, respectively. Cu NCs could bind to the positively charged cyt c through electrostatic and hydrophobic interactions, and the phosphorescence of Cu NCs was efficiently quenched by the metal-containing heme of cyt c. In the presence of trypsin, cyt c was digested, thus phosphorescence of Cu NCs remained. Therefore, a new and continuous phosphorescence assay for the detection of trypsin activity and its inhibitor screening was established. The plot of relative fluorescence versus trypsin concentration obtains a good linear detection range from 0 to 20 ng/mL (R2 = 0.9657), and a detection limit of 2 ng/mL, which is much lower than 20 ng/mL of the sensor in buffer solution because of urine amplifying the phosphorescence signal of Cu NCs based on the FRET strategy. This assay still has been successfully applied to trypsin inhibitor screening, demonstrating its potential application in drug discovery.

Pancreatic cellular injury after cardiac surgery with cardiopulmonary bypass: frequency, time course and risk factors.

Although often clinically silent, pancreatic cellular injury (PCI) is relatively frequent after cardiac surgery with cardiopulmonary bypass; and its etiology and time course are largely unknown. We defined PCI as the simultaneous presence of abnormal values of pancreatic isoamylase and immunoreactive trypsin (IRT). The frequency and time evolution of PCI were assessed in this condition using assays for specific exocrine pancreatic enzymes. Correlations with inflammatory markers were searched for preoperative risk factors. One hundred ninety-three patients submitted to cardiac surgery were enrolled prospectively. Blood IRT, amylase, pancreatic isoamylase, lipase, and markers of inflammation (alpha1-protease inhibitor, alpha2-macroglobulin, myeloperoxidase) were measured preoperatively and postoperatively until day 8. The postoperative increase in plasma levels of pancreatic enzymes and urinary IRT was biphasic in all patients: early after surgery and later (from day 4 to 8 after surgery). One hundred thirty-three patients (69%) experienced PCI, with mean IRT, isoamylase, and alpha1-protease inhibitor values higher for each sample than that in patients without PCI. By multiple regression analysis, we found preoperative values of plasma IRT >or=40 ng/mL, amylase >or=42 IU/mL, and pancreatic isoamylase >or=20 IU/L associated with a higher incidence of postsurgery PCI (P < 0.005). In the PCI patients, a significant correlation was found between the 4 pancreatic enzymes and urinary IRT, total calcium, myeloperoxidase, alpha1-protease inhibitor, and alpha2-macroglobulin. These data support a high prevalence of postoperative PCI after cardiac surgery with cardiopulmonary bypass, typically biphasic and clinically silent, especially when pancreatic enzymes were elevated preoperatively.

Early diagnosis and prediction of severity in acute pancreatitis using the urine trypsinogen-2 dipstick test: a prospective study.

AIM: To evaluate the use of the trypsinogen-2 dipstick (Actim Pancreatitis) test for early diagnosis and prediction of severity in acute pancreatitis (AP). METHODS: Ninety-two patients with AP were included in this study. The control group was 25 patients who had acute abdominal pain from non-pancreatic causes. Urine trypsinogen-2 dipstick test (UTDT) and conventional diagnostic tests were performed in all patients. Patients were divided by the Atlanta classification into two groups as having mild or severe pancreatitis. RESULTS: UTDT was positive in 87 (94.6%) of the AP patients and in two (8%) controls (P < 0.05). Positive UTDT was found in 61 (92.4%) of 66 (71.7%) patients with mild pancreatitis and in all (100%) of the 26 (28.3%) with severe pancreatitis (P > 0.05). UTDT positivity lasted longer in severe pancreatitis compared with that in mild pancreatitis (6.2 +/- 2.5 d vs 2.0 +/- 1.43 d, P < 0.05). The sensitivity, specificity, positive predictive value, negative predictive value (NPV), positive likelihood ratio (PLR) and negative likelihood ratio (NLR) of UTDT were 91%, 72%, 96.6%, 70.4%, 3.4 and 0.1, respectively. CONCLUSION: UTDT is a simple, rapid and reliable method for use on admission. It has high specificity and low NLR for early diagnosis and prediction of severity in AP. However, its relatively low NPV does not allow trypsinogen-2 dipstick test to be a stand-alone tool for diagnosis of acute pancreatitis; the use of other conventional diagnostic tools remains a requirement.

Use of the urinary trypsinogen-2 dip stick test in early diagnosis of pancreatitis after endoscopic retrograde cholangiopancreatography.

BACKGROUND: This study aimed to prove that the urinary trypsinogen-2 dip stick test can be used for early diagnosis of pancreatitis after endoscopic retrograde cholangiopancreatography (ERCP). METHODS: For this prospective, blinded, pilot study, urine samples were collected before ERCP, 1 h after ERCP, and 4 h after ERCP. The urine dipstick test was used to detect trypsinogen-2 on the basis of immunochromatography. The dipstick results were compared with those of current methods used to diagnose post-ERCP pancreatitis. Once the patient disposition was finalized, pancreatic enzymes, clinical findings, and final diagnosis were obtained from the chart and compared with the urine trypsinogen-2 test findings. The sensitivity, specificity, and positive and negative predictive values were calculated. RESULTS: The urine trypsinogen dip stick test was performed for 30 patients (15 men and 15 women). Post-ERCP pancreatitis was diagnosed in 5 of 29 patients by clinician assessment, serum pancreatic enzyme levels, or both. The amylase and lipase levels for post-ERCP patients with and without pancreatitis were 650 +/- 145 vs 134 +/- 26 (p = 0.023) and 1,658 +/- 594 vs 84 +/- 17 (p = 0.057), respectively. This statement proves that patients who developed post ERCP pancreatitis had significant elevation of amylase and lipase compared to patients who did not have pancreatitis. For the dip stick test, 6 of 28 patients had positive results in 1 h and 6 of 29 patients had positive results in 4 h. The sensitivity of the 1-h test was 1.0, and the specificity was 0.91. The positive predictive value (PPV) was 0.66, and the negative predictive value (NPV) was 1.0. The sensitivity of the 4-h test was 1.0, and the specificity was 0.96. The PPV was 0.8, and NPV value was 1.0. CONCLUSION: The urinary trypsinogen-2 dip stick test is useful for early diagnosis of post-ERCP pancreatitis and allows the testing physicians to begin management early in its course.