Support of the diagnosis of pancreatitis by enzyme tests--old problems, new techniques

A scoping review on acute gastrointestinal surgical complications in immunocompromised pediatric patients

Background

Gastrointestinal complications are becoming increasingly more common and pose a significant risk on the health of children with compromised immunity caused by various etiologies such as chemotherapy and posttransplantation immunosuppression. We aim to review abdominal complications in immunocompromised children and their respective management.

Main body

This is a scoping review of the literature. PubMed, MEDLINE, Google Scholar, and Scopus libraries were searched for relevant articles. Extracted data included the etiologies of immunocompromised immunity, gastrointestinal and abdominal complications in immunocompromised children, diagnosis, and treatment of these pathologies. Examples of gastrointestinal complications in immunocompromised children include, but not limited to, neutropenic enterocolitis, acute appendicitis, bowel perforation, acalculous cholecystitis, and acute pancreatitis. Our literature review showed that bacterial and fungal infections are the major causes of exacerbation and mortality. The main cause of immunosuppression in children with neutropenic enterocolitis and acute pancreatitis is chemotherapy, and management of these pathologies using intravenous fluids, antibiotic therapy, and granulocyte-stimulating factors is the current standard of care. Surgical intervention is uncommon and reserved for complicated cases. That said, in acute appendicitis and bowel perforation, laparoscopy is the mainstay treatment. However, in systemic infections, nonsurgical interventions such as transfusion and bowel rest are the gold standard. As for acalculous cholecystitis, percutaneous cholecystectomy is superior to laparotomy and other surgical interventions.

Conclusion

Timely diagnosis and management of gastrointestinal complications in the immunocompromised children is key in reducing mortality and morbidity. Both surgical and nonsurgical interventions are needed and should be further studied in order to improve outcomes.

The 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester (DGGR) lipase assay in cats and dogs is not specific for pancreatic lipase

BACKGROUND

The measurement of pancreatic lipase is important for the diagnosis of feline and canine pancreatitis. Recent studies have claimed that lipase assays using the 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester (DGGR) as a substrate are more specific for measuring pancreatic lipase than traditional lipase assays. However, the analytical specificity of this assay for pancreatic lipase has not been demonstrated.

OBJECTIVES

We aimed to determine whether hepatic and/or lipoprotein lipases can interfere with the DGGR-based assay results in cats and dogs. We, therefore, compared plasma lipase activities measured using DGGR-based and pancreatic lipase immunoreactivity (PLI) assays before and after administering heparin, known to cause the release of hepatic and lipoprotein lipases, in cats and dogs.

METHODS

Heparin was administered in six cats and six dogs. Blood was collected at baseline and 10, 20, 30, 60, and 120 minutes after heparin administration. Lipase activity was measured using a DGGR-based assay, and PLI concentrations were measured using the Spec fPL and cPL assays for cats and dogs, respectively.

RESULTS

Plasma lipase activities, as measured using the DGGR-based assay, increased significantly 10 minutes after heparin administration in both cats (P = .003) and dogs (P = .006) and returned to baseline by 120 minutes. In contrast, PLI concentrations showed no significant changes after heparin administration.

CONCLUSIONS

DGGR is not only hydrolyzed by pancreatic lipase but also by hepatic lipase, lipoprotein lipase, or both, in cats and dogs. Since these extrapancreatic lipases are also naturally present in cats and dogs, they could contribute to the lack of analytical specificity for the DGGR-based assays.

Homogeneous probing of lipase and α-amylase simultaneously by AIEgens

An AIE dual-reactive supramolecular probe has been devised to simultaneously measure endogenous lipase and α-amylase activity in a homogeneous system. Fluorescence quantitative analysis of lipase and α-amylase in real biological samples enables rapid and accurate diagnosis of diseases.

Identification of Pancreatic Injury in Patients with Elevated Amylase or Lipase Level Using a Decision Tree Classifier: A Cross-Sectional Retrospective Analysis in a Level I Trauma Center

Background: In trauma patients, pancreatic injury is rare; however, if undiagnosed, it is associated with high morbidity and mortality rates. Few predictive models are available for the identification of pancreatic injury in trauma patients with elevated serum pancreatic enzymes. In this study, we aimed to construct a model for predicting pancreatic injury using a decision tree (DT) algorithm, along with data obtained from a population-based trauma registry in a Level I trauma center. Methods: A total of 991 patients with elevated serum levels of amylase (>137 U/L) or lipase (>51 U/L), including 46 patients with pancreatic injury and 865 without pancreatic injury between January 2009 and December 2016, were allocated in a ratio of 7:3 to training (n = 642) or test (n = 269) sets. Using the data on patient and injury characteristics as well as laboratory data, the DT algorithm with Classification and Regression Tree (CART) analysis was performed based on the Gini impurity index, using the rpart function in the rpart package in R. Results: Among the trauma patients with elevated amylase or lipase levels, three groups of patients were identified as having a high risk of pancreatic injury, using the DT model. These included (1) 69% of the patients with lipase level ≥306 U/L; (2) 79% of the patients with lipase level between 154 U/L and 305 U/L and shock index (SI) ≥ 0.72; and (3) 80% of the patients with lipase level <154 U/L with abdomen injury, glucose level <158 mg/dL, amylase level <90 U/L, and neutrophil percentage ≥76%; they had all sustained pancreatic injury. With all variables in the model, the DT achieved an accuracy of 97.9% (sensitivity of 91.4% and specificity of 98.3%) for the training set. In the test set, the DT achieved an accuracy of 93.3%, sensitivity of 72.7%, and specificity of 94.2%. Conclusions: We established a DT model using lipase, SI, and additional conditions (injury to the abdomen, glucose level <158 mg/dL, amylase level <90 U/L, and neutrophils ≥76%) as important nodes to predict three groups of patients with a high risk of pancreatic injury. The proposed decision-making algorithm may help in identifying pancreatic injury among trauma patients with elevated serum amylase or lipase levels.

Utility of serum pancreatic enzyme levels in diagnosing blunt trauma to the pancreas: a prospective study with systematic review

INTRODUCTION

Reliability of serum pancreatic enzyme levels in predicting pancreatic injuries has been a parameter of interest and the present recommendations on its utility are based primarily on anecdotal observations. The aim of this study was to evaluate the utility of serum pancreatic enzyme assessment in predicting blunt pancreatic injury with imaging and surgical correlation and compare our results with a systematic review of literature till date.

METHODS

A prospective cohort study conducted over 4 years in a tertiary care referral centre with 164 consecutive patients who presented to the emergency department with a history of blunt abdominal trauma and had serum pancreatic enzyme assessment, USG and subsequent diagnostic CECT were analyzed. The CT findings and AAST grade of pancreatic injury, various intra-abdominal injuries and time elapsed since injury and other associated factors were correlated with serum pancreatic enzyme levels. For systematic review of literature MEDLINE database was searched between 1940 and 2012, also the related citations and bibliographies of relevant articles were analyzed and 40 articles were included for review. We compared our results with the systematic critique of literature till date to formulate recommendations.

RESULTS

33(21%) patients had pancreatic injury documented on CT and were graded according to AAST. Statistically significant elevated serum amylase levels were observed in patients with pancreatic and bowel injuries. However, elevated serum lipase was observed specifically in patients with pancreatic injury with or without bowel injury. Combined serum amylase and lipase showed 100% specificity, 85% sensitivity in predicting pancreatic injury. Elevated (n=28, 85%) vs. normal (n=5, 15%) serum amylase and lipase levels showed sole statistically significant association with time elapse since injury to admission, with a cutoff of 3h.

CONCLUSIONS

Based on our results and the systematic review of the literature till date we conclude, persistently elevated or rising combined estimation of serum amylase and lipase levels are reliable indicators of pancreatic injury and is time dependent, nondiagnostic within 6h or less after trauma. In resource constrained countries where CT is not available everywhere it may support a clinical suspicion of pancreatic injury and can be reliable and cost-effective as a screening tool.

Evaluation of amylase and lipase levels in blunt trauma abdomen patients

BACKGROUND

There are studies to prove the role of amylase and lipase estimation as a screening diagnostic tool to detect diseases apart from acute pancreatitis. However, there is sparse literature on the role of serum and urine amylase, lipase levels, etc to help predict the specific intra-abdominal injury after blunt trauma abdomen (BTA).

AIM

To elucidate the significance of elevation in the levels of amylase and lipase in serum and urine samples as reliable parameters for accurate diagnosis and management of blunt trauma to the abdomen.

MATERIALS AND METHODS

A prospective analysis was done on the trauma patients admitted in Jai Prakash Narayan Apex Trauma Center, AIIMS, with blunt abdomen trauma injuries over a period of six months. Blood and urine samples were collected on days 1, 3, and 5 of admission for the estimation of amylase and lipase, liver function tests, serum bicarbonates, urine routine microscopy for red blood cells, and complete hemogram. Clinical details such as time elapsed from injury to admission, type of injury, trauma score, and hypotension were noted. Patients were divided into groups according to the single or multiple organs injured and according to their hospital outcome (dead/discharged). Wilcoxon's Rank sum or Kruskal-Wallis tests were used to compare median values in two/three groups. Data analysis was performed using STATA 11.0 statistical software.

RESULTS

A total of 55 patients with median age 26 (range, 6-80) years, were enrolled in the study. Of these, 80% were males. Surgery was required for 20% of the patients. Out of 55 patients, 42 had isolated single organ injury [liver or spleen or gastrointestinal tract (GIT) or kidney]. Patients with pancreatic injury were excluded. In patients who suffered liver injuries, urine lipase levels on day 1, urine lipase/amylase ratio along with aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) on days 1, 3, and 5, were found to be significant. Day 1 serum amylase, AST, ALT, hemoglobin, and hematocrit levels were found significant in patients who had spleen injury. Serum amylase levels on day 5 and ALP on day 3 were significant in patients who had GIT injury. Urine amylase levels on day 5 were found to be statistically significant in patients who had kidney injury. In patients with isolated organ injury to the liver or spleen, the levels of urine amylase were elevated on day 1 and gradually decreased on days 3 and 5, whereas in patients with injury to GIT, the urine amylase levels were observed to gradually increase on days 3 and 5.

CONCLUSION

Although amylase and lipase levels in the serum and urine are not cost-effective clinical tools for routine diagnosis of extra-pancreatic abdominal injuries in BTA, but when coupled with other laboratory tests such as liver enzymes, they may be significant in predicting specific intra-abdominal injury.

Laboratory diagnosis of acute pancreatitis: in search of the Holy Grail

Acute pancreatitis is an acute inflammatory condition of the pancreas, which might extend to local and distant extrapancreatic tissues. The global incidence varies between 17.5 and 73.4 cases per 100,000 and the pathogenesis recognizes alcohol exposure and biliary tract disease as the leading causes, ahead of post-endoscopic retrograde cholangiopancreatography, drugs and abdominal trauma. The diagnosis of acute pancreatitis is substantially based on a combination of clinical signs and symptoms, imaging techniques and laboratory investigations. Contrast-enhanced computed tomography is the reference standard for the diagnosis, as well as for establishing disease severity. The assessment of pancreatic enzymes, early released from necrotic tissue, is the cornerstone of laboratory diagnosis in this clinical setting. Although there is no single test that shows optimal diagnostic accuracy, most current guidelines and recommendations indicate that lipase should be preferred over total and pancreatic amylase. Although a definitive diagnostic threshold cannot be identified, cut-offs comprised between ≥ 2 and ≥ 4 times the upper limit of the reference interval are preferable. The combination of amylase and lipase has been discouraged as although it marginally improves the diagnostic efficiency of either marker alone, it increases the cost of investigation. Some interesting biomarkers have been also suggested (e.g., serum and urinary trypsinogen-1, -2 and -3, phospholipase A2, pancreatic elastase, procalcitonin, trypsinogen activated protein, activation peptide of carboxypeptidase B, trypsin-2-alpha1 antitrypsin complex and circulating DNA), but none of them has found widespread application for a variety of reasons, including the inferior diagnostic accuracy when compared with the traditional enzymes, the use of cumbersome techniques, or their recent discovery. The promising results of recent proteomics studies showed that this innovative technique might allow the identification of changes characterizing pancreatic tissue injury, thus highlighting new potential biomarkers of acute pancreatitis.

Epidemiological characteristic of acute pancreatitis in Trzebnica district

Acute pancreatitis is one of the most common surgical disease, and thus cause of hospitalization. Incidence and etiology of this condition demonstrates large regional differences. This situation is a substantial financial burden forhospital district, and changes in organization structure and funding medical service should be taken under consideration.The aim of the study was to record the epidemiology with etiology, diagnosis and treatment of acute pancreatitis in large district (77 000 inhabitants).Material and methods. A meta-analysis study of all 298 patients admitted to Hospital St Hedwig in Trzebnica, in the six-year period from 2005 to 2010, with acute pancreatitis was performed.Results. Acute pancreatitis was diagnosed in 298 patients in the six - year period, giving an estimated incidence of 64.4 per 100 000. Among the group of 441 admissions for acute pancreatitis in 298 patients was confirmed. Severe acute pancreatitis developed in 22.5% (67/298) of patients, more often in males 56/208 (27%) than in females 11/90 (12%). Gallstones were found as an etiological factor in 27% (80/298), and alcohol intake in 49% of patients. 211/298 (70%) patients had only one attack, whereas 29% (87/298) were readmitted with 230 relapses. The risk of recurrent pancreatitis was 48% in alcohol induced and 6,25% in gallstone induced pancreatitis. 53/298 patients (17%) were operated, ERCP procedures were performed in 24.Performed operations: necrosectomy in 25/53 (47%), elective cholecystectomy in 16/53 (30%), open drainage of abdominal abscess in 5/53 (9%), open drainage of cysts in 5/53 (9%), Jurasz's operation in 2/53 (3%). Majority surgical treatment was carried out in 68% cases with severe acute pancreatitis. Mortality due to acute pancreatitis was 3% (10/298); 15% in severe pancreatitis.Conclusions. 1. Acute pancreatitis continues to be an important clinical problem. 2. Severe, necrotic acute pancreatitis is associated with high mortality rates. 3. The ethanol-intake-related episodes of acute pancreatitits are much more prevalent than the gall-stone-related ones. 4. After the exclusion of ethanol- and gall-stones-related etiologies, the subsequent diagnostic process should aim at excluding neoplastic process of the head of pancreas.

Acute pancreatitis

Acute pancreatitis (AP) is an important cause of morbidity and mortality worldwide and the annual incidence appears to be increasing. It presents as a mild self-limiting illness in 80% of patients. However, one-fifth of these develop a severe complicated life-threatening disease requiring intensive and prolonged therapeutic intervention. Alcohol and gallstone disease remain the commonest causes of AP but metabolic abnormalities, obesity and genetic susceptibility are thought be increasingly important aetiological factors. The prompt diagnosis of AP and stratification of disease severity is essential in directing rapid delivery of appropriate therapeutic measures. In this review, the range of diagnostic and prognostic assays, severity scoring systems and radiological investigations used in current clinical practice are described, highlighting their strengths and weaknesses. Increased understanding of the complex pathophysiology of AP has generated an array of new potential diagnostic assays and these are discussed. The multidisciplinary approach to management of severe pancreatitis is outlined, including areas of controversy and novel treatments.

Effect of pentoxifylline and/or alpha lipoic acid on experimentally induced acute pancreatitis

Acute pancreatitis is a sudden inflammation of the pancreas that may be life threatening disease with high mortality rates; particularly in presence of systemic inflammatory response and multiple organ failure despite of the conventional antibiotic and symptomatic treatment. Oxidative stress has been shown to be involved in the pathophysiology of acute pancreatitis. This study was designed to investigate the possible effect of pentoxifylline and alpha lipoic acid respectively and in combination on rats with L-arginine induced acute pancreatitis. Rats were divided as follow; Group 1: served as control, Group 2 and Group 3: sacrificed after 24h and 7 days; respectively, from induction of acute pancreatitis by L-arginine 250 mg/100g, Group 4 and Group 5: rats treated by pentoxifylline (12 mg/kg) and sacrificed after 24h and 7 days; respectively, from induction of acute pancreatitis, Group 6 and Group 7: treated by alpha lipoic acid (1mg/kg) and sacrificed after 24h and 7 days; respectively, from induction of acute pancreatitis, Group 8 and Group 9: treated by pentoxifylline and alpha lipoic acid and sacrificed after 24h and 7 days; respectively, from induction of acute pancreatitis. Serum samples were collected to assay levels of amylase enzyme, C-reactive protein, IL-6, catalase enzyme activity, malondialdehyde and pancreases were excised for histopathological examination and assay of pancreatic myeloperoxidase. L-arginine induced-acute pancreatitis was evident by increased in serum marker enzymes and by histopathological findings compared to control group. Pentoxifylline and alpha lipoic acid respectively provided protection against L-arginine induced acute pancreatitis possibly by their antioxidant and anti-inflammatory effect. Treatment with alpha lipoic acid exhibited pronounced improvement in the course of pancreatitis when compared to treatment with pentoxifylline. Moreover, the combination of pentoxifylline and alpha lipoic acid offered the most evident protection when compared to groups that received monotherapy; pointing to the effectiveness of such combination therapy.

Acute pancreatitis

Acute pancreatitis is a common disease most frequently caused by gallstone disease or excess alcohol ingestion. Diagnosis is usually based on characteristic symptoms, often in conjunction with elevated serum pancreatic enzymes. Imaging is not always necessary, but may be performed for many reasons, such as to confirm a diagnosis of pancreatitis, rule out other causes of abdominal pain, elucidate the cause of pancreatitis, or to evaluate for complications such as necrosis or pseudocysts. Though the majority of patients will have mild, self-limiting disease, some will develop severe disease associated with organ failure. These patients are at risk to develop complications from ongoing pancreatic inflammation such as pancreatic necrosis, fluid collections, pseudocysts, and pancreatic duct disruption. Validated scoring systems can help predict the severity of pancreatitis, and thus, guide monitoring and intervention.Treatment of acute pancreatitis involves supportive care with fluid replacement, pain control, and controlled initiation of regular food intake. Prophylactic antibiotics are not recommended in acute pancreatitis if there is no evidence of pancreatic infection. In patients who fail to improve, further evaluation is necessary to assess for complications that require intervention such as pseudocysts or pancreatic necrosis. Endoscopy, including ERCP and EUS, and/or cholecystectomy may be indicated in the appropriate clinical setting. Ultimately, the management of the patient with severe acute pancreatitis will require a multidisciplinary approach.

Serum elastase in the diagnosis of acute pancreatitis: a prospective study

BACKGROUND

The aim of the present study was to evaluate the usefulness of the elastase 1 (E1) enzyme-linked immunosorbent assay (ELISA) in the diagnosis of acute pancreatitis. This is the first Australian evaluation of the E1 ELISA.

METHODS

Three groups of patients were prospectively assessed: control patients, patients with acute pancreatitis, and patients with acute non-pancreatitic abdominal pain. Serum was collected on all patients on admission and the sensitivity, specificity and diagnostic accuracy of serum elastase, amylase and lipase was determined.

RESULTS

Twenty-nine patients with 30 episodes of pancreatitis, 38 patients with acute non-pancreatitic abdominal pain and 121 control patients were studied. For all patient episodes E1 ELISA at a cut-off of 3.5 ng/mL had a sensitivity of 80%, specificity of 96% and an efficiency of 94% in the diagnosis of acute pancreatitis. For episodes more than 48 h after onset of symptoms, sensitivity was 100%, specificity was 96% and diagnostic efficiency was 96%. This performance was equivalent to amylase but inferior to lipase.

CONCLUSION

Of the biochemical markers for pancreatitis currently available, lipase is the most useful. The relatively inferior sensitivity and problematic reference range for the ELISA E1, together with its limitations in measuring total elastase, currently prevent its widespread use.

Potential diagnostic value of pancreatic isoamylases for pancreaticobiliary maljunction with mild biliary dilatation in patients and a porcine model

PURPOSE

The aim of this study was to evaluate the diagnostic value of serum pancreatic isoamylases for pancreaticobiliary maljunction (PBM) with mild biliary dilatation.

METHODS

Serum and bile from 8 children with PBM and mild biliary dilatation (6 to 11 mm in diameter) and 4 young pigs with an anastomosis constructed between an isolated pancreas-duodenal segment and the gallbladder were studied for pancreatic isoamylases. Using an electrophoretic technique, the assay of pancreatic isoamylases was expressed by peak appearance rate (PAR). Serum from 20 healthy children served as normal controls.

RESULTS

In the serum of the patients, preoperatively there were 5 pancreatic peaks with PAR as follows: P1, 100%; P2, 100%; P3, 100%; P4, 100%; and P5, 66.7%. These abnormal pancreatic isoamylases disappeared 2 weeks after operative treatment. In normal controls, there were only P1 (PAR, 40%) and P2 (PAR, 100%). Mild cylindrical dilatation (6 to 8 mm in diameter) of the common bile duct developed in the porcine PBM model. There were P1 (PAR, 100%) and P2 (PAR, 100%) in the porcine serum preoperatively. Thirty days and 60 days after establishing the model, there appeared in the serum 6 pancreatic peaks with PAR as follows: P1, 100%; P2, 100%; P3, 75%; P4, 100%; P5, 100%, and P6; 75%. The bile patterns of pancreatic isoenzymes in the patients and pigs were similar to those in serum.

CONCLUSIONS

Abnormal pancreatic isoamylases are characteristically present in the serum from both children and a porcine model of PBM and mild biliary dilatation. Assay for these abnormalities is promising to recognize this subset of patients in whom diagnosis remains a challenge.

Critical evaluation of a specific ELISA and two enzymatic assays of pancreatic lipases in human sera

BACKGROUND AND AIMS

Human pancreatic lipases (HPL) include the classical HPL, and two related proteins known as pancreatic lipase-related proteins 1 and 2 (HPLRP1 and 2). The aim of this study was to develop an ELISA for specifically quantifying the classical-HPL level in sera of patients with and without pancreatic disorders.

METHODS

The specific activity of various human (including classical-HPL) and microbial lipases was measured using Lipa Vitros and potentiometric (pH-stat) assays. A double sandwich ELISA was also set up, using an anti-classical-HPL polyclonal antibody and a biotinylated monoclonal antibody (mAb 146-40) specific to the classical-HPL. Sera (n = 53) were collected from patients with and without pancreatic disorders. The lipase concentration was deduced from the measured lipolytic activity and compared with the corresponding classical-HPL concentration, measured with the ELISA.

RESULTS

Both the purified HPLRP2 and 3 lipases of microbial origin were found to have a significant and unexpected lipolytic activity under the standard Lipa Vitros assay, whereas the ELISA test developed in the present study was found to be specific for the classical-HPL, due to the absence of cross-reactivity between mAb 146-40, HPLRP1 and HPLRP2. The efficiency of the ELISA was assessed in terms of its reproducibility and accuracy. The lower detection limit of classical-HPL was found to be 0.03 microg/l. A good correlation was found to exist between the lipase concentrations obtained in the ELISA, pH-stat and Lipa Vitros tests, in both the control and pathological groups.

CONCLUSION

This is the first time a specific method of measuring classical-HPL in human serum has been proposed. Using this ELISA, we established with the 53 sera selected in the present study, that the Lipa Vitros assay as well as the pH-stat assay were mostly detecting classical pancreatic lipase. However, it is possible that other lipases such as HPLRP2 or lipases of microbial origin, present in some pathological sera, may well interfere with the Lipa Vitros assay.

A critical evaluation of laboratory tests in acute pancreatitis

An ideal laboratory test in the evaluation of a patient with acute pancreatitis (AP) should, in addition to accurately establishing the diagnosis of AP, provide early assessment of its severity and identify the etiology. None of the tests available today meet all these criteria, and presently there is no biochemical test that can be considered the "gold standard" for the diagnosis and assessment of severity of AP. In the diagnosis of AP, serum amylase and lipase remain important tests. Advantages of amylase estimation are its technical simplicity, easy availability, and high sensitivity. However, its greatest disadvantage is its low specificity. A normal amylase would usually exclude the diagnosis of AP, with the exception of AP secondary to hyperlipidemia, acute exacerbation of chronic pancreatitis, and when the estimation of amylase is delayed in the course of the disease. The major advantage of lipase is an increased sensitivity in acute alcoholic pancreatitis and in patients who initially present to the emergency room days after the onset of the disease, as lipase remains elevated longer than amylase. Although once considered to be specific for AP, nonspecific elevations of lipase have been reported in almost as many disorders as amylase, thus decreasing its specificity. Simultaneous estimation of amylase and lipase does not improve the accuracy. Other enzymes for the diagnosis of AP--pancreatic isoamylase, immunoreactive trypsin, and elastase--are more cumbersome and expensive and have no clear role in the diagnosis of AP. No enzyme assay has a predictive role in determining the severity or etiology of AP. Once the diagnosis of AP is established, daily measurements of enzymes have no value in assessing the clinical progress of the patient or ultimate prognosis and should be discouraged. A host of new serological and urinary markers have been investigated in the last few years. Their main use is in predicting the severity of AP. At present, serum C-reactive protein at 48 h is the best available laboratory marker of severity. Urinary trypsinogen activation peptides within 12-24 h of onset of AP are able to predict the severity but are not widely available. Serum interleukins 6 and 8 seem promising but remain experimental.

Treatment of anticholinergic-induced ileus with neostigmine

A 33-year-old man with a history of recreational benztropine abuse presented to the emergency department with confusion, abdominal pain, and distention. An abdominal radiograph revealed gross fecal loading. He was initially treated with intravenous fluids and opiate analgesia. Subsequently, a diagnosis of anticholinergic poisoning was made, based on tachycardia, delirium, dry mucosa, and reduced bowel sounds. Treatment with tacrine reversed the delirium, and a history of repeated benztropine use was obtained. Persistent ileus was treated with repeated doses of neostigmine, and gastrointestinal motility returned with prompt defecation. Neostigmine appears to be useful in reversing ileus caused by anticholinergic drug overdose. Theoretically, it may be useful in reversing anticholinergic ileus resulting from acute drug overdose, allowing or enhancing decontamination, but the safety and potential efficacy of neostigmine in this scenario have not been established.

Nonspecific hyperamylasemia and hyperlipasemia in diabetic ketoacidosis: incidence and correlation with biochemical abnormalities

OBJECTIVES

Amylase and lipase estimations are the standard tests to diagnose acute pancreatitis (AP). Elevation of amylase and lipase < or = 3 times normal may be nonspecific, but elevation of either one > 3 times normal is reported to be diagnostic of AP. The aim of this study was to evaluate the incidence and magnitude of nonspecific elevations of amylase and lipase in diabetic ketoacidosis (DKA) and to correlate their elevation with known metabolic derangements of DKA.

METHODS

A total of 150 consecutive episodes of DKA in 135 patients were evaluated for serum amylase, lipase, and biochemical markers of DKA on admission and 24 h later. Patients were divided according to the following: 1) Clearly nonspecific amylase elevation (CNSA): Amylase elevation < 3 times normal plus normal or < 3 times lipase; 2) Clearly nonspecific lipase elevation (CNSL): Lipase elevation < 3 times normal plus normal or < 3 times amylase; and 3) Probably nonspecific amylase or lipase elevation (PNSA or PNSL): > 3 times elevation of amylase or lipase or both with normal abdominal CT.

RESULTS

Elevated amylase and lipase levels ranged from 111 to 1257 IU/L (normal 30-110 IU/L) and 25-529 IU/dl (normal < 24 IU/dl) (CT-proven AP = 16, excluded). Nonspecific amylase elevation (CNSA + PNSA) = 25 (16.6%) cases, CNSA in 10 (6.6% of all DKA or 27% of amylase elevations), and PNSA in 15 (10% of all DKA or 41% of amylase elevations). Nonspecific lipase elevation (CNSL + PNSL) = 36 (24%), CNSL in 23 (15.3% of all DKA or 47% of all lipase elevations), and PNSL in 13 (8.7% of all DKA or 26.5% of all lipase elevations). Multiple regression analyses showed significant correlation of pH and serum osmolality with amylase elevation. Lipase elevation showed positive correlation with serum osmolality alone.

CONCLUSIONS

In DKA nonspecific elevations of amylase and lipase occur in 16-25% of cases. Amylase elevation is correlated with pH and serum osmolality, but lipase elevation is correlated with serum osmolality alone. Diagnosis of AP based soley on elevated amylase or lipase, even > 3 times normal, is not justifiable.

Routine α-Amylase Assay Using Protected 4-Nitrophenyl-1,4-α-d-maltoheptaoside and a Novel α-Glucosidase

Background: In contrast to numerous methods for measuring α-amylase activity, the approved IFCC reference method offers an invariable time-independent constant product pattern, thus avoiding possibly changing stoichiometric calculations. However, reference methods do not lend themselves to routine use, so that such methods need to be modified.

Methods: Ethylidene-blocked 4-nitrophenylmaltoheptaoside (EPS-G7) is degraded to glucose and 4-nitrophenol in a coupled assay with a bacterial α-glucosidase under the following measurement conditions: 3.5 mmol/L EPS-G7, 7.1 kU/L α-glucosidase, 70 mmol/L sodium chloride, 1 mmol/L calcium chloride, 50 mmol/L HEPES, pH 7.15, at 37 °C. The increase of absorbance is continuously monitored for 3 min at 405 nm after a lag phase of 2 min.

Results: Catalytic concentrations up to 15-fold higher than the upper reference limit can be determined without dilution. Precision studies in manual performance show CVs of 1.4–2.6% (within-run) and 1.9–2.8% (day-to-day). There was no interference from 100 mmol/L glucose, 30 mmol/L triacylglycerols, 610 μmol/L bilirubin, and 2.95 g/L hemoglobin. The method closely correlates with other chromogenic assays. The preliminary 0.95 reference interval for adults, not dependent on age and sex, is 33.6–96.2 U/L.

Conclusion: The procedure is a robust adaptation of the reference method to routine use at 37 °C with increased sensitivity, fewer interferences, and reduced cost.

Amylase normal, lipase elevated: is it pancreatitis? A case series and review of the literature

OBJECTIVE

This study was undertaken to identify clinical scenarios in which the lipase is significantly elevated (three times above the upper limit of normal) but the amylase is normal, and to examine whether or not pancreatitis is the likely cause for this seemingly unusual constellation of laboratory results.

METHODS

Twenty-five patients were retrospectively identified over a 2-yr period, which fulfilled the above criteria. A thorough review of their charts was conducted. In addition, a critical review of the literature was performed.

RESULTS

It appears that isolated elevation of lipase in this case series was either related to renal insufficiency (two patients), to nonpancreatic sources of lipolytic enzymes due to malignant tumors (two), to acute cholecystitis (two) or esophagitis (one), to delayed blood withdrawal (at least five patients), to hypertriglyceridemia (two), or to subclinical pancreatitis in patients without abdominal pain (three).

CONCLUSIONS

1. An elevated lipase should not be equated with evidence for pancreatitis if the amylase is normal. 2. A simultaneous determination of both amylase and lipase is recommended for the evaluation of patients with abdominal pain.