What is the best biochemical test to diagnose acute pancreatitis? A prospective clinical study

Viscosity-Based Flow Sensor on Paper for Quantitative and Label-Free Detection of α-Amylase and Its Inhibitor

α-Amylase (AMS) in human serum is a critical biomarker for the early diagnosis of pancreatic damage. In addition, the inhibition of α-amylase has long been thought to decrease the occurrence of diabetes. Thus, it is critical to construct a facile and convenient method for the determination of AMS and its inhibitor. In this study, we demonstrate a novel amylase sensor based on translating the viscosity change of the aqueous solution into the difference of the water diffusion length on a pH paper strip. AMS can be quantitatively detected by measuring the viscosity change of the amylopectin solution in the presence of AMS with different concentrations. The paper-based AMS sensor has a very high sensitivity with a detection limit of 0.017 U/mL and also shows excellent specificity. In addition, the inhibitory effect of acarbose on AMS is demonstrated with the IC₅₀ value determined to be 21.66 ± 1.13 μg/mL. Furthermore, it is also evaluated for the detection of AMS in human serum samples of healthy people and acute pancreatitis patients. The difference in amylase levels between the two groups is unambiguously distinguished. Overall, this study provides a very simple, cost-effective, equipment-free, high-throughput, and label-free method for rapid and quantitative detection of α-amylase and may have significant applications in the diagnosis of acute pancreatitis and the screening of AMS inhibitors.

The importance of acoustic radiation force impulse (ARFI) elastography in the diagnosis and clinical course of acute pancreatitis

BACKGROUND/AIMS

Acute pancreatitis (AP) is characterized by acute inflammation of the pancreas and it has a highly variable clinical course. The aim of our study was to evaluate the value of acoustic radiation force impulse (ARFI) elastography in the diagnosis and clinical course of AP.

MATERIALS AND METHODS

Consecutive patients with a diagnosis of AP (patients group) and healthy subject (control group) were prospectively enrolled to the study. Demographic features and clinical, laboratory, and radiological data were recorded. Virtual Touch Tissue Quantification (VTQ) was used to implement ARFI elastography. The tissue elasticity is proportional to the square of the wave velocity (SWV).

RESULTS

A total of 108 patients (age, 57±1.8 y) and 79 healthy subjects (age, 53.6±1.81 y) were included in the study. There were 100 (92.5%) edematous and 8 (7.4%) necrotizing AP. The mean SWV was significantly higher in the patient group than in the control group (2.43±0.08 vs. 1.27±0.025 m/s, p < 0.001). There was not significant difference between patient and control group regarding age and gender. SWV cutoff value of 1.63 m/s was associated with 100% sensitivity and 98% specificity for the diagnosis of AP. There was not significant difference between patients with and without complications and patients with edematous and necrotizing AP regarding mean SWV value. There was also not significant correlation between mean SWV value and age, mean length of hospital stay, and mean amylase level.

CONCLUSION

ARFI elastography may be a feasible method for the diagnosis of AP, but it has no value for the prediction of clinical course of AP.

Total pancreatectomy for recurrent acute and chronic pancreatitis: a critical review of patient selection criteria

PURPOSE OF REVIEW

Critical review of the indications for total pancreatectomy and highlight limitations in current diagnostic criteria for chronic pancreatitis.

RECENT FINDINGS

The diagnosis of noncalcific chronic pancreatitis remains controversial because of an overreliance on nonspecific imaging and laboratories findings. Endoscopic ultrasound, s-magnetic resonance cholangiopancreatography, and/or endoscopic pancreatic function testing are often used to diagnose noncalcific chronic pancreatitis despite the fact that there is no gold standard for this condition. Abdominal pain is not specific for chronic pancreatitis and is more likely to be encountered in patients with functional gastrointestinal disorders based on the high incidence of these conditions. The duration of pain and opioid analgesic use results in central sensitization that adversely affects pain outcomes after total pancreatectomy. An alcoholic cause is associated with poorer pain outcomes after total pancreatectomy.

SUMMARY

The lack of a gold standard for noncalcific chronic pancreatitis limits the diagnostic accuracy of imaging and laboratory tests. The pain of chronic pancreatitis is nonspecific and is affected by duration, preoperative opioid use, and cause. These factors will need to be considered in the development of future selection criteria for this morbid surgery.

Fluorometric probing of the lipase level as acute pancreatitis biomarkers based on interfacially controlled aggregation-induced emission (AIE)

As a sudden inflammation of the pancreas, acute pancreatitis presents severe complications and a high mortality rate, despite treatment. Lipase in serum serves as an essential biomarker of acute pancreatitis and even pancreatic cancer. Therefore, developing robust, convenient and sensitive probing of lipase levels is greatly needed. In this work, we present glutamate functionalized tetraphenylethylene (TPE) as a "turn-on" fluorescent probe (S1) based on the aggregation-induced emission (AIE) mechanism for lipase levels with new recognition units. In heterogeneous media, the hydrophilic amino and carboxyl groups in the probe were specifically introduced to facilitate its full access to lipase at the oil-water interface and achieve an interfacially controlled AIE process. The linear response of fluorescence ranging from 0 to 80 U L-1, which included the concentration range of the lipase level in human serum, considering the dilution factor if necessary, the limit of detection as low as 0.13 U L-1, and the fast response time (7 min) were determined. The value of the apparent Michaelis-Menten constant (Km) was obtained as 4.23 μM, which indicated superior affinity between lipase and the probe molecule. The selectivity, photostability, dynamic monitoring of the enzymatic reaction, and preliminary commercial enzyme activity screening were summarized. As far as we know, this is the fastest, easiest and most sensitive method for lipase level probing in the reported literature. Finally, probing the lipase level for the first time in real human serum samples was also conducted successfully.

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.

Optical visualization and quantification of enzyme activity using dynamic droplet lenses

In this paper, we describe an approach to measuring enzyme activity based on the reconfiguration of complex emulsions. Changes in the morphology of these complex emulsions, driven by enzyme-responsive surfactants, modulate the transmission of light through a sample. Through this method we demonstrate how simple photodetector measurements may be used to monitor enzyme kinetics. This approach is validated by quantitative measurements of enzyme activity for three different classes of enzymes (amylase, lipase, and sulfatase), relying on two distinct mechanisms for coupling droplet morphology to enzyme activity (host-guest interactions with uncaging and molecular cleavage).

Inflammatory bowel disease on the risk of acute pancreatitis: A population-based cohort study

BACKGROUND AND AIMS

To determine whether inflammatory bowel disease (IBD) influences the risk of acute pancreatitis.

METHODS

We identified 11,909 patients diagnosed with IBD between 2000 and 2010 from Taiwan National Health Insurance Research Database as the study cohort. A comparison cohort comprised 47,636 age-matched patients without IBD. Both cohorts were followed-up until the end of 2010 or until being censored. Cox proportional hazards regression models were used to study the effects of IBD on the risks of acute pancreatitis.

RESULTS

The overall incidence of acute pancreatitis was 3.56-fold higher in the study cohort than in the comparison cohort (31.8 vs 8.91 per 10,000 person-years, crude hazard ratio [HR] = 3.56, 95% confidence interval [CI] = 2.96-4.28). After adjustment for age, sex, and comorbidities, namely alcohol-related disease, biliary stone, hypertension, hyperlipidemia, diabetes mellitus, obesity, hepatitis B, hepatitis C, hypertriglyceridemia, cardiovascular diseases, chronic kidney disease, chronic obstructive pulmonary disease, and hypercalcemia, the adjusted HR for acute pancreatitis was 2.93-fold higher (95% CI = 2.40-3.58) in the study cohort than in the comparison cohort.

CONCLUSIONS

IBD is a risk factor for acute pancreatitis.

Use of acoustic radiation force impulse elastography to diagnose acute pancreatitis at hospital admission: comparison with sonography and computed tomography

OBJECTIVES

To compare the diagnostic success rate of acoustic radiation force impulse (ARFI) elastography with those of sonography and computed tomography (CT) for acute pancreatitis at hospital admission.

METHODS

B-mode sonography and ARFI elastography were performed on 88 patients with symptoms of acute pancreatitis and 50 healthy control participants who were admitted to our hospital between February 2013 and July 2013. Acute pancreatitis was verified in the 88 patients based on clinical and laboratory findings. Computed tomography was performed on 41 patients, and the CT results from these patients were compared with those of ARFI elastography. The appearances of the pancreases of the patients were classified into 6 groups using visual color encodings obtained with ARFI elastography. The elasticity values of pancreatic head, body, and tail regions were evaluated with Virtual Touch imaging and Virtual Touch tissue quantification (Siemens Medical Solutions, Mountain View, CA). The success rates of sonography, CT, and ARFI elastography for diagnosing acute pancreatitis at hospital admission were compared.

RESULTS

Forty-six of the 88 patients had a diagnosis of pancreatitis by B-mode sonography; pancreatitis was diagnosed in all patients by ARFI elastography; and 10 of 41 patients could not be diagnosed by CT. The sensitivity and specificity of Virtual Touch tissue quantification were 100% and 98%, respectively, when a cutoff value of 1.63 m/s was used. The control group had color scores of 1 or 2, whereas all patients with pancreatitis had color scores of 3 to 6 on color scale evaluation with Virtual Touch imaging.

CONCLUSIONS

Acoustic radiation force impulse elastography is a rapid, radiation-free, and noninvasive tool for diagnosis of acute pancreatitis at initial hospital admission, with a higher success rate for diagnosis of acute pancreatitis than the grayscale sonography and CT.

Update to the management of pediatric acute pancreatitis: highlighting areas in need of research

Acute pancreatitis is an emerging problem in pediatrics, with an incidence that is rising in the last 2 decades. Data regarding the optimal management and physician practice patterns are lacking. We present a literature review and updates on the management of pediatric pancreatitis. Prospective multicenter studies defining optimal management of pediatric pancreatitis are needed to guide care and improve outcomes for this patient population.

Incretin-mimetics associated pancreatitis: evidence from the spontaneous adverse drug reactions reporting in Italy

OBJECTIVE

New incretin-mimetics increased the treatment options for type 2 diabetes mellitus. Studies on the safety of incretin-based therapy showed a risk of hypersensitivity reactions, acute pancreatitis, renal failure, infection, thyroid and pancreas cancer. We contributed to safety assessment of these new drugs by evaluating the spontaneous adverse drug reactions (ADRs) reporting in Italy.

RESEARCH AND METHODS

Reports of suspected ADRs associated with incretin-mimetics were selected from the Italian Spontaneous ADR Reporting Database. For a subgroup of cases belonging to the Hospital of Cento (Ferrara), levels of pancreatic enzymes, amylase and lipase, before and after the therapy with the incretin-mimetics were available.

RESULTS

As of December 2012, the reports of ADR associated with hypoglycemic drugs (excluding insulin) were 2443, 1169 (47.85%) concerned the incretin-mimetics. A total of 90 reports described pancreatitis (44) and elevated pancreatic enzymes (46). Out of 90 cases, 34 were serious (37%). Data on amylase/lipase values for 10 patients were provided and an analysis of the published literature was performed.

CONCLUSIONS

Our data from the daily clinical practice add up and confirm the information available on the association between incretin-mimetics and pancreatic damage and suggest caution in the prescribing of these new drugs and a close monitoring of exposed patients.

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.

Pregnancy associated pancreatitis revisited

OBJECTIVES

To evaluate the demographics, risk factors and outcomes of pregnancy associated pancreatitis (PAP).

STUDY DESIGN

A retrospective chart review was done using ICD-9 Code 577.0 (acute pancreatitis) from January 2005 through December 2009. Women aged 18 to 45 years, who were pregnant and 6 months after delivery were considered for the study. For each case, two women of the same age (± 4 years) with no history of pancreatitis were matched as control. Demographics, etiology, diagnostic modality and intervention were obtained.

RESULTS

During the 5 years of study, 29 cases of PAP occurred among 25,600 total hospital deliveries, yielding prevalence of 0.001%: Hispanics 48%, Caucasians 24%, African Americans 17.2%, and Asian/Pacific Islanders 13% (P<0.05). Sixty-five percent of those with pre-pregnancy body mass index (BMI) more than 30 kg/m(2) had PAP, versus 24% with BMI between 25 and 30 kg/m(2) and 10% with BMI less than 25 kg/m(2) (P<0.05). An increasing trend of PAP was seen with gestational age and number of pregnancy.

CONCLUSION

Gallstone disease is the most frequent etiology for PAP and tends to occur more often in Hispanics in New Jersey.

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.

Retrospective study of patients with acute pancreatitis: is serum amylase still required?

OBJECTIVES

To assess the role of serum amylase and lipase in the diagnosis of acute pancreatitis. Secondary aims were to perform a cost analysis of these enzyme assays in patients admitted to the surgical admissions unit.

DESIGN

Cohort study.

SETTING

Secondary care.

PARTICIPANTS

Patients admitted with pancreatitis to the acute surgical admissions unit from January to December 2010 were included in the study.

METHODS

Data collated included demographics, laboratory results and aetiology. The cost of measuring a single enzyme assay was £0.69 and both assays were £0.99.

RESULTS

Of the 151 patients included, 117 patients had acute pancreatitis with gallstones (n=51) as the most common cause. The majority of patients with acute pancreatitis had raised levels of both amylase and lipase. Raised lipase levels only were observed in additional 12% and 23% of patients with gallstone-induced and alcohol-induced pancreatitis, respectively. Overall, raised lipase levels were seen in between 95% and 100% of patients depending on aetiology. Sensitivity and specificity of lipase in the diagnosis of acute pancreatitis was 96.6% and 99.4%, respectively. In contrast, the sensitivity and specificity of amylase in diagnosing acute pancreatitis were 78.6% and 99.1%, respectively. Single lipase assay in all patients presenting with abdominal pain to the surgical admission unit would result in a potential saving of £893.70/year.

CONCLUSIONS

Determining serum lipase level alone is sufficient to diagnose acute pancreatitis and substantial savings can be made if measured alone.

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.

Critical Care of the Patient with Acute Pancreatitis

Acute pancreatitis is an inflammatory process of the pancreas with variable involvement of regional tissues and remote organs. This review gives a comprehensive overview of the aetiology, pathophysiology, diagnosis and therapy of acute pancreatitis relevant to the intensivist. Recent international guidelines on the management of acute pancreatitis are summarised.

Eighty percent of acute pancreatitis episodes are related either to gallstones or to alcohol abuse. Independent of its aetiology, the pathophysiologic hallmark of acute pancreatitis is the premature activation of trypsin, which leads to massive pancreas inflammation, systemic overproduction of pro-inflammatory mediators and ultimately remote organ dysfunction. All guidelines agree that the diagnosis of acute pancreatitis should include clinical symptoms, increased serum amylase or lipase levels and/or characteristic findings on computed tomography. Endoscopic retrograde cholangiopancreatography is recommended as a causative therapy in patients with acute cholangitis or a strong suspicion of gallstones. All guidelines underline the importance of vigorous fluid resuscitation and supplemental oxygen therapy and prefer enteral over parenteral nutrition, with the majority favouring the nasojejunal route. In view of lacking scientific evidence, antibiotic prophylaxis to prevent infection of pancreatic necroses is discouraged by most guidelines. Computed tomography-guided fine needle aspiration is the technique of choice to differentiate between sterile and infected pancreas necrosis. While sterile pancreatic necrosis should be managed conservatively, infected pancreatic necrosis requires debridement and drainage supplemented by antibiotic therapy. Surgical necrosectomy is the traditional approach, but less invasive techniques (retroperitoneal or laparoscopic necrosectomy, computed tomography-guided percutaneous catheter drainage) may be equally effective.

Acute pancreatitis

Acute pancreatitis is an inflammatory disease of the pancreas. Acute abdominal pain is the most common symptom, and increased concentrations of serum amylase and lipase confirm the diagnosis. Pancreatic injury is mild in 80% of patients, who recover without complications. The remaining patients have a severe disease with local and systemic complications. Gallstone migration into the common bile duct and alcohol abuse are the most frequent causes of pancreatitis in adults. About 15-25% of pancreatitis episodes are of unknown origin. Treatment of mild disease is supportive, but severe episodes need management by a multidisciplinary team including gastroenterologists, interventional radiologists, intensivists, and surgeons. Improved understanding of pathophysiology and better assessments of disease severity should ameliorate the management and outcome of this complex disease.

Clinical laboratory assessment of acute pancreatitis

BACKGROUND

Several biochemical markers in blood and urine have been investigated to establish their clinical application in patients with acute pancreatitis (AP). The relevant studies are reviewed and critically appraised.

METHODS

Medline and the World Wide Web were searched and the relevant literature was classified under the following categories: (1) diagnosis of AP and (2) prediction of: a) disease severity, b) pancreatic necrosis and its secondary infection, c) organ failure and death, and d) disease etiology.

RESULTS AND CONCLUSIONS

Serum lipase is a more reliable diagnostic marker of AP than serum amylase. Urinary strip tests for trypsinogen activation peptide (TAP) and trypsinogen-2 provide a reliable early diagnosis of AP. Useful predictors of severity may include serum procalcitonin and urinary TAP and trypsinogen-2 on admission, serum interleukins-6 and -8 and polymorphonuclear elastase at 24 h, and serum C-reactive protein (CRP) at 48 h. Other markers such as amyloid A and carboxypeptidase B activation peptide (CAPAP) need further investigation. Biochemical prediction of pancreatic necrosis requires 72 h to reach reliability and is impractical. However, the daily monitoring of serum procalcitonin provides a non-invasive detection of infected necrosis; the promising role of phospholipase A(2) in this regard requires further investigation. Early transient hypertransaminasemia reliably predicts biliary etiology, while serum carbohydrate-deficient transferrin and trypsin may predict an alcoholic etiology.

Determination of plasma glycoprotein 2 levels in patients with pancreatic disease

CONTEXT

Blood tests possessing higher diagnostic accuracy are needed for all the major pancreatic diseases. Glycoprotein 2 (GP2) is a protein that is specifically expressed by the pancreatic acinar cell and that has previously shown promise as a diagnostic marker in animal models of acute pancreatitis.

OBJECTIVE

This study describes the development of an assay for GP2, followed by the determination of plasma GP2 levels in patients with acute pancreatitis, chronic pancreatitis, and pancreatic cancer.

DESIGN

Rabbit polyclonal antisera and mouse monoclonal antibodies were generated against human GP2 and used to develop an enzyme-linked immunosorbent assay. The assay was tested in patients with an admitting diagnosis of pancreatic disease at 2 tertiary care facilities. The diagnosis of acute or chronic pancreatitis and pancreatic cancer was determined using previously established criteria that incorporated symptoms, radiology, pathology, and serology. Plasma GP2 levels were determined in 31 patients with acute pancreatitis, 16 patients with chronic pancreatitis, 36 patients with pancreatic cancer, and 143 control subjects without pancreatic disease. Amylase and lipase levels were also determined in patients with acute pancreatitis.

RESULTS

The GP2 assay's sensitivity values were 0.94 for acute pancreatitis, 0.81 for chronic pancreatitis, and 0.58 for pancreatic cancer, which were greater than the 0.71 for acute pancreatitis and 0.43 for chronic pancreatitis (P =.02) observed for amylase. The lipase assay sensitivity for acute pancreatitis was 0.66. The accuracy of the GP2 assay was greater than that of the amylase or lipase assays for acute pancreatitis (GP2 vs lipase, P =.004; GP2 vs amylase, P =.003) when analyzed using receiver operator characteristic curves. When daily serial blood samples were obtained for 13 patients with acute pancreatitis, GP2 levels remained abnormally elevated for at least 1 day longer than the amylase or lipase levels.

CONCLUSION

The GP2 assay is a useful new marker for acute and chronic pancreatitis.

Non-specific hyperamylasemia in shosin beri-beri

Several reports demonstrate non-specific hyperamylasemia in cardiac surgery or diabetic ketoacidosis. We report here for the first time non-specific hyperamylasemia in a cardiovascular beri-beri case who showed shock with severe metabolic acidosis. Her echocardiography revealed hyperkinetic wall motion of the small left ventricle. Despite intravascular volume expansion in parallel with dopamine administration, her blood pressure did not recover. Abdominal computed tomography (CT) did not reveal pancreatic swelling or any other signs of acute pancreatitis. Her history suggested a possibility of cardiovascular beri-beri due to chronic alcoholism. Thiamine administration dramatically reversed her haemodynamic derangements, metabolic acidosis and even relieved her abdominal pain. Isozyme examinations for hyperamylasemia showed that most of the serum amylase consisted of salivary type. This case report expands our information on non-specific hyperamylasemia encountered in the emergency setting.

Inflammatory pancreatic diseases in older patients: recognition and management

The aging process influences and modifies the clinical picture and treatment modalities of inflammatory pancreatic diseases in elderly patients. The two major categories of inflammatory exocrine pancreatic diseases seen in the elderly are acute pancreatitis (AP) and chronic pancreatitis (CP). In elderly patients with AP, the presence of concomitant diseases affecting renal, hepatic and cardiopulmonary function make the early clinical assessment of the severity of AP inaccurate at the time of admission to hospital. In addition, the classical multifactorial scoring system routinely utilised in clinical practice to determine the severity of AP may overscore elderly patients because increasing age is associated with more points. Contrast-enhanced computed tomography is particularly useful in assessing the severity of AP and is required in all patients suspected with severe AP. It should be repeated after a certain time period to monitor the disease. The most important aspect of the management of elderly patients with severe AP is the prevention and treatment of systemic and local complications. Treatment of AP should address the removal of aetiological factor(s) and support of organ systems and hydroelectrolytic/caloric balance; specific treatments (antiproteases, antibacterials) should also be administered to patients with severe AP. Surgery is indicated mainly when infection occurs following pancreatic necrosis and/or fluid collection. However, in selected patients with a high anaesthetic risk, alternative, less invasive drainage options (percutaneous, endoscopic) should be considered. CP rarely occurs in older age, and it should be suspected based on clinical findings. The greatest challenge is the differentiation between CP and pancreatic cancer. Treatment of CP in the elderly should be directed at controlling the symptoms, by management of diabetes and exocrine insufficiency because pain and complications are rare in elderly patients with CP. Compliance with treatment should be periodically assessed if insulin and/or oral enzyme supplementation is required. Careful evaluation of nutritional status and its prompt correction is also important.

New laboratory tests in acute pancreatitis

Acute pancreatitis (AP) is a common disease with wide variation of severity. The diagnosis of AP is usually based on high serum amylase or lipase values but the accuracy of these methods is considered unsatisfactory. One in five of the patients develops a severe disease and carries a considerable risk of development of organ failure and high mortality. Early detection of patients with severe AP and especially those with increased risk of organ failure is importance since such patients seem to benefit from treatment in an intensive care unit started as soon as possible after presentation. In addition to enzymological methods, increasing interest has been focused on laboratory markers reflecting the level of inflammatory response in AP. At present, in routine clinical work the most commonly used severity marker is serum C-reactive protein, the concentration of which rises too slowly to be used for early prediction of severity. New therapies aiming at modifying the course of systemic inflammation in AP are being developed and therefore monitoring the patient's immune inflammatory status is needed. In this review article we present the current knowledge of laboratory tests, which has been evaluated for diagnostic and prognostic purposes in AP.

Optimising outcomes in acute pancreatitis

Acute pancreatitis is a common cause for presentation to emergency departments. Common causes in Western societies include biliary pancreatitis and alcohol (the latter in the setting of chronic pancreatitis). Acute pancreatitis also follows endoscopic retrograde pancreatography in 5 to 10% of patients, a group that could potentially benefit from prophylactic treatment. Although episodes of pancreatitis usually run a relatively benign course, up to 20% of patients have more severe disease, and this group has significant morbidity and mortality. Therefore, attempts have been made to identify, at or soon after presentation, those patients likely to have a poor outcome and to channel resources to this group. The mainstay of treatment is aggressive support and monitoring of those patients likely to have a poor outcome. Pharmacotherapy for acute pancreatitis (both prophylactic and in the acute setting) has been generally disappointing. Efforts initially focused on protease inhibitors, of which gabexate shows some promise as a prophylactic agent. Agents that suppress pancreatic secretion have produced disappointing results in human studies. Infection of pancreatic necrosis is associated with high mortality and requires surgical intervention. In view of the seriousness of infected necrosis, the use of prophylactic antibacterials such as carbapenems and quinolones has been advocated in the setting of pancreatic necrosis. Similarly, data are accumulating to support the use of prophylactic antifungal therapy. Recently, it has become apparent that the intense inflammatory response associated with acute pancreatitis is responsible for much of the local and systemic damage. With this realisation, future efforts in pharmacotherapy are likely to focus on suppression or antagonism of pro-inflammatory cytokines and other inflammatory mediators. Similarly, animal studies have demonstrated the importance of oxidative stress in acute pancreatitis, although to date there is a paucity of information regarding the efficacy of antioxidants. Although the clinical course for most patients with acute pancreatitis is mild, severe acute pancreatitis continues to be a clinical challenge, requiring a multidisciplinary approach of physician, intensivist and surgeon.

Acute pancreatitis in the postpartum period: a population-based case-control study

OBJECTIVE

To determine relationships among pregnancy (during and postpartum), acute pancreatitis, and gallstones.

PATIENTS AND METHODS

In this retrospective population-based case-control study, we identified all 12- to 50-year-old Rochester, Minn, females diagnosed between 1976 and 1991 as having acute pancreatitis (cases). For each case, we matched 4 women of the same age (+/- 6 years) with no history of acute pancreatitis (controls). Acute pancreatitis was defined as associated with pregnancy if it occurred from 10 months prior to delivery to delivery and with the postpartum period if it occurred within 10 months of the date of delivery. Logistic regression was used to assess associations between pregnancy-related acute pancreatitis, age, gallstone occurrence, and alcohol use.

RESULTS

In a cohort of 61 women who developed acute pancreatitis and 244 controls, the relative risk for acute pancreatitis associated with pregnancy was 1.43 (95% confidence interval, 0.61-3.40). All 10 cases of acute pancreatitis associated with pregnancy occurred in the postpartum period. Gallstones were present in 6 of them compared with 13 of 51 women with non-pregnancy-related acute pancreatitis (P < .05). Women with postpartum-related pancreatitis were younger than those with non-pregnancy-related pancreatitis (mean, 28 vs 36 years; P < .05). Alcohol was not associated with pregnancy-related pancreatitis.

CONCLUSIONS

Acute pancreatitis during the postpartum period is not directly related to pregnancy but is associated with gallstones and occurs in younger women.

The C-reactive protein

C-reactive protein (CRP) was identified in 1930 and was subsequently considered to be an "acute phase protein," an early indicator of infectious or inflammatory conditions. Since its discovery, CRP has been studied as a screening device for inflammation, a marker for disease activity, and as a diagnostic adjunct. Improved methods of quantifying CRP have led to increased application to clinical medicine. In the emergency department (ED), CRP must be interpreted in the clinical context; no single value can be used to rule in or rule out a specific diagnosis. We conclude that CRP has limited utility in the ED. It may be a useful adjunct to serial examinations in equivocal presentations of appendicitis in those centers without ready access to computed tomography (CT) scan. It may be elevated with complications or treatment failures in patients with pneumonia, pancreatitis, pelvic inflammatory disease (PID), and urinary tract infections. In patients with meningitis, neonatal sepsis, and occult bacteremia, CRP is usually elevated. However, CRP has no role in diagnosing these clinical entities, and a normal CRP level should never delay antibiotic coverage.

Phospholipase A2: its usefulness in laboratory diagnostics

Phospholipase A2 (PLA2) is an enzyme that catalyzes the hydrolysis of membrane phospholipids. This article reviews the source and structure of PLA2, the involvement of the enzyme in various biological and pathological phenomena, and the usefulness of PLA2 assays in laboratory diagnostics. Of particular importance is the role of PLA2 in the cellular production of mediators of inflammatory response to various stimuli. Assays for PLA2 activity and mass concentration are discussed, and the results of enzyme determinations in plasma from patients with different pathological conditions are presented. The determination of activity and mass concentration in plasma is particularly useful in the diagnosis and prognosis of pancreatitis, multiple organ failure, septic shock, and rheumatoid arthritis. A very important result is the demonstration that PLA2 is an acute phase protein, like CRP. Indeed, there is a close correlation between PLA2 mass concentration and CRP levels in several pathological conditions. Although the determination of C-reactive protein is much easier to perform and is routinely carried out in most clinical laboratories, the assessment of PLA2 activity or mass concentration has to be considered as a reliable approach to obtain a deeper understanding of some pathological conditions and may offer additional information concerning the prognosis of several disorders.

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.