Evaluation of a fecal pancreatic elastase-1 enzyme-linked immunosorbent assay: Assessment versus an established assay and implication in classifying pancreatic function

Micronutrient Deficiencies in Heart Failure and Relationship with Exocrine Pancreatic Insufficiency

BACKGROUND

Micronutrient deficiencies are common and play a significant role in the prognosis of many chronic diseases, including heart failure (HF), but their prevalence in HF is not well known. As studies have traditionally focused on causes originating within the intestines, exocrine pancreatic insufficiency (EPI) has been overlooked as a potential contributor. The exocrine pancreas enables the absorption of various (fat-soluble) micronutrients and may be insufficient in HF. We hypothesize that EPI contributes to micronutrient deficiencies in HF.

OBJECTIVES

To evaluate micronutrient concentrations in HF cases and their association with clinical characteristics and EPI.

MATERIALS AND METHODS

Plasma samples from 59 consecutive hospitalized patients with HF were analyzed for vitamins A, D, and E and the minerals selenium and zinc. EPI was defined as fecal elastase 1 level < 206 μg/g.

RESULTS

The mean age of patients was 59 ± 14 years, with 24 (41%) being women, and a median NT-proBNP concentration of 3726 [2104-6704] pg/mL was noted. Vitamin A deficiency occurred in eight (14%) of the patients, and 12 (20%) exceeded the upper limit. More than half (51%) were vitamin D-deficient. No patients showed vitamin E deficiency, but 14 (24%) had elevated levels. Selenium deficiency was common, affecting 36 (61%) patients, while zinc was below the normal range in seven patients (12%). Micronutrient levels did not differ significantly based on the presence of EPI.

CONCLUSIONS

This study provides novel insights into the micronutrient status of patients with HF. Deficiencies in vitamins A and D, selenium, and zinc are prevalent in HF, but these findings are not associated with exocrine pancreatic function.

Preanalytical and analytical factors affecting elastase quantitation in stool

Exocrine pancreatic insufficiency (EPI) is a condition caused by a deficiency of exocrine pancreatic enzymes, resulting in malabsorption of nutrients. Clinical manifestations of EPI may include steatorrhea, weight loss, diarrhea, and abdominal pain. Although direct testing is the most sensitive and specific for EPI, these tests are invasive, time consuming, expensive, and not well standardized. Fecal elastase (FE-1) has been shown to be an indirect marker of the exocrine secretory capacity of the pancreas and has become the most commonly employed indirect test for diagnosis of EPI. Measurement of fecal elastase consists of two main phases, a preanalytical phase and analytical phase. The preanalytical phase involves stool collection, storage and handling. The second phase is the analytical phase, which includes the actual assay processes and products used to produce a result. For FE-1 this includes sample extraction and measurement on an immunoassay. Each step in the process can influence the result and contribute to heterogeneity in FE-1 measurement, potentially impacting clinical diagnosis and management. Thus, this paper provides an overview of the preanalytical and analytical factors that can affect measurement and interpretation of FE-1 results.

Clinical and Analytical Comparison of Monoclonal and Polyclonal Immunoassays for Fecal Pancreatic Elastase

BACKGROUND

Numerous immunoassays have been commercialized to determine pancreatic elastase (PE) in feces in screening for exocrine pancreatic insufficiency (EPI), but how the different assays compare to one another is controversial, especially in the context that all methods use the same cut-off values for interpreting the results obtained on the presence or absence of EPI or the degree of insufficiency if it is present. Our aim was to analytically verify a new method for determining PE, compare the results with a previous method, and verify the declared cut-off values for interpretation of the results.

METHODS

PE in the stool was assayed using a previous monoclonal enzyme-linked immunosorbent assay ("ScheBo ELISA") and a new polyclonal particle-enhanced turbidimetric immunoassay ("Bühlmann PETIA"). The direct method comparison of two immunoassays was performed in 40 samples. Clinical comparisons were conducted against each other for the binary determination of "abnormal/normal" elastase levels and the three-way determination of "severe/moderate/no" EPI in 56 samples. The indirect comparison method used external quality assessment (EQA) data to compare the monoclonal and polyclonal immunoassays for PE, and additionally compare the monoclonal ScheBo ELISA to a monoclonal chemiluminescence immunoassay ("DiaSorin CLIA").

RESULTS

Precision in the series and intra-laboratory precision for Bühlmann PETIA met the manufacturer's specifications for the concentration range of limit/lower values and the range of normal values. The Bühlmann PETIA immunoassay on different analytical platforms yielded comparable results and nearly perfect agreement in the case of three-way classification (kappa = 0.89 with 95%CI from 0.79 to 1.00. ScheBo ELISA tends to generate higher values of pancreatic elastase than the Bühlmann PETIA; agreement between the methods was moderate in the case of binary classification (kappa = 0.43; 95% CI 0.25 to 0.62), and substantial in the case of three-way classification (kappa = 0.62; 95% CI 0.50 to 0.75). EQA data analysis showed a statistically significant difference between ScheBo ELISA and Bühlmann PETIA peer groups (p = 0.031), as well as the DiaSorin CLIA and ScheBo ELISA peer groups (p = 0.010).

CONCLUSION

The ScheBo ELISA and Bühlmann PETIA do not appear to be commutable in the analytical and clinical context. Our data address a discordance between different mono- and polyclonal immunoassays for pancreatic elastase and the potential of misclassification using its universal cut-off values in screening suspected patients for exocrine pancreatic insufficiency.

Utilising Pancreatic Exocrine Insufficiency in the Detection of Resectable Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is usually diagnosed late, leading to a high mortality rate. Early detection facilitates better treatment options. The aim of this UK-based case-control study was to determine whether two validated tests for pancreatic exocrine insufficiency (PEI), namely, the 13C-mixed triglyceride breath test (13C-MTGBT) and a faecal elastase (FE-1) test, can discriminate between patients with resectable PDAC versus healthy volunteers (HVs) along with a comparison group with chronic pancreatitis (CP). Discrimination between disease states and HVs was tested with receiver operator characteristic (ROC) curves. In total, 59 participants (23 PDAC (16 men), 24 HVs (13 men) and 12 CP (10 men)) were recruited, with a similar age in each population, and a combined median (IQR) age of 66 (57-71). The areas under the ROC curve for discriminating between PDAC and HVs were 0.83 (95% CI: 0.70-0.96) for the 13C-MTGBT, and 0.85 (95% CI: 0.75-0.95) for the FE-1 test. These were similar to CP vs. HV. In conclusion, PEI occurs in resectable PDAC to a similar extent as in CP; further large-scale, prospective studies using these tests in the primary care setting on high-risk groups are warranted.

Stool Elastase as an Independent Prognostic Factor in Patients with Pancreatic Head Cancer

(1) Background: Patients with pancreatic exocrine insufficiency (PEI) have an increased risk of malnutrition, which in turn increases morbidity and mortality and is frequent in pancreatic head cancer. This study aimed to analyze the utility of PEI measured using the stool elastase (SE) level to predict the prognosis of patients with pancreatic head cancer. (2) Methods: Patients who underwent pancreaticoduodenectomy for pancreatic cancer at our institution between 2011 and 2015 were included. Only patients with data on preoperative SE levels were analyzed. Patients were classified into low and high SE groups based on preoperative SE levels (low < 100 µg/g < high). (3) Results: The median preoperative SE level was 67.2 µg/g, and 84 of 143 (58.7%) patients were included in the low SE group. The two groups had significantly different overall survival (OS) and disease-free survival (DFS), and the low SE group had a worse prognosis. In multivariate analysis, SE level < 100 µg/g and lymph node metastasis were independent poor prognostic factors for OS and DFS. (4) Discussion: PEI measured using SE levels is an independent prognostic factor in patients with pancreatic head cancer undergoing pancreaticoduodenectomy. Since poor nutritional status may be related to prognosis in patients with low levels of stool elastase preoperatively, aggressive treatment may be required.

Screening for gastrointestinal and pancreatic diseases

Diagnosis of chronic gastrointestinal and pancreatic diseases is challenging because patients generally present with nonspecific symptoms, such as abdominal pain and chronic diarrhea, some of which can last for many years. Although stool assays are more sensitive than serum assays, the former has unique limitations that healthcare providers should be aware of. One algorithm to screen for chronic gastrointestinal and pancreatic issues is to perform stool testing to assess inflammatory, watery (osmotic) and malabsorptive conditions. This chapter will discuss several stool-based screening tests, the major disorders they screen for and clinical performance. Sections on assay and sample limitations are also included. Stool testing can provide valuable diagnostic, prognostic and treatment response information if both the laboratory and clinician understand the benefits and limitations of these assays.

Clinical and Analytical Characterization of the DiaSorin and ScheBo Fecal Pancreatic Elastase 1 Assays

OBJECTIVES

Fecal pancreatic elastase (PE) assays are screening tests for exocrine pancreatic insufficiency (EPI). We analytically evaluated a new PE assay and retrospectively analyzed data from an academic hospital and reference laboratory to understand the clinical utility.

METHODS

Forty stool samples with different PE concentrations were tested on the ScheBo enzyme-linked immunosorbent assay (ELISA) versus DiaSorin LIAISON immunoassay; a simple-to-use extraction device was assessed. The cross-reactivity of porcine enzymes was investigated in the immunoassay. Charts of 207 patients with PE results less than 250 μg/g at an academic hospital were reviewed, and data were analyzed for 5136 patients with repeat PE results from a reference laboratory.

RESULTS

The LIAISON immunoassay gave comparable results to the ScheBo ELISA, with 87.5% agreement of PE results in classifying as sufficient, mild/moderate insufficiency, or severe insufficiency. The extraction device worked well compared with manual weighing, and no cross reactivity with porcine enzymes was observed. In agreement with prior studies, our clinical data suggested that PE assays were most useful in detecting severe EPI.

CONCLUSIONS

The new DiaSorin LIAISON immunoassay preforms similarly to the well-known ScheBo ELISA. Pancreatic elastase assays can help identify patients with severe EPI but are not as useful in classifying mild/moderate EPI.

Risk factors deteriorating severe exocrine pancreatic insufficiency measured by stool elastase after pancreatoduodenectomy and the risk factors for weight loss

Purpose

The measurement of stool elastase (SE) level is useful for evaluating pancreatic exocrine function. This study aimed to determine the risk factors for severe exocrine pancreatic insufficiency (EPI) after pancreatoduodenectomy (PD), and analyze serial changes in nutritional markers and weight based on the SE level.

Methods

Among patients who underwent PD for periampullary disease, patients whose preoperative and postoperative SE levels were measured were included in the study. The deteriorated (exocrine function) group comprised patients whose SE levels decreased from ≥100 µg/g preoperatively to <100 µg/g postoperatively. Patients whose weight 12 months postoperatively was greater than that 3 months postoperatively were classified into the weight-recovery group.

Results

Of the 202 included patients, the deteriorated group had a higher incidence of preoperative SE level above 200 µg/g, benign pathology, and the presence of a clinically relevant postoperative pancreatic fistula than the maintained group. Patients who did not undergo weight recovery had a higher rate of history of adjuvant radiotherapy compared to the no-recovery group.

Conclusion

The evaluation of EPI by measuring SE alone is not sufficient because it does not reflect the nutritional status of patients, and a comprehensive approach that considers other parameters is required for EPI management.

Fluorescence Determination of Peptidase Activity Based on the Quenching of a Fluorophore-Labelled Peptide by Graphene Oxide

In this study, a fluorescence detection strategy is reported for the peptidase activity assay, which is based on fluorescence resonance energy transfer (FRET) from a fluorophore-labelled peptide to graphene oxide (GO). By the hydrolysis of the peptide, the fluorophore-labelled peptide releases the fluorophore 5-carboxyfluorescein, which can avoid quenching from GO. Thus, the increased intensity of the obtained fluorescence signal in the assay is directly dependent on the peptidase activity. As a model case of the developed strategy, the activity determination of pancreatic elastase (PE) is performed. Under the optimal experimental conditions at an excitation wavelength of 494 nm, the activity of PE can be determined in the range from 0.003 to 0.10 U/mL, with a detection limit of 0.001 U/mL at the emission wavelength of 518 nm. This is ultra-sensitive for the determination of PE. The specificity of the method is demonstrated by the analysis of PE under complex conditions using fetal bovine serum as the substrate. Hence, the developed method might provide an intrinsically convenient, sensitive platform for the PE activity assay and related biochemical studies due to its homogeneous, and fluorescence-based detection strategy.

Simvastatin in the Prevention of Recurrent Pancreatitis: Design and Rationale of a Multicenter Triple-Blind Randomized Controlled Trial, the SIMBA Trial

Background: One in every four patients with a first episode of non-gallstone-related acute pancreatitis (AP) develops recurrent disease. Recurrent episodes of AP or acute flares of chronic pancreatitis (CP) are associated with decreased quality of life and progression of the disease. Besides removing the etiology of pancreatitis (which sometimes is not possible), there are no effective measures to prevent recurrence. Meta-analyses of randomized controlled trials, as well as epidemiological and cohort studies, suggest that statins may be protective against the development of index AP. Methods: The SIMBA study is a triple-blind randomized placebo-controlled, parallel-group multicenter trial. Patients with recurrent AP or with acute flares of CP (at least two episodes in the last 12 months) will be randomized to receive simvastatin 40 mg daily or placebo. During a 3-year study period, 144 patients (72 per arm of treatment) from 26 centers will be enrolled. The patients will receive the study treatment for 1 year. The primary aim is to compare the recurrence of AP or acute flares in CP. Secondary endpoints include the incidence of new-onset diabetes mellitus, new-onset exocrine pancreatic insufficiency (EPI), new-onset imaging signs of CP, frequency of all-cause hospital admissions, severity of AP, adherence to treatment, and frequency of adverse events. Discussion: The SIMBA trial will ascertain whether simvastatin, a safe, widely used and inexpensive drug, can change the natural course of recurrent pancreatitis. Trial Registration: ClinicalTrials.gov Identifier: NCT04021498.

Acute recurrent and chronic pancreatitis in children

Acute recurrent pancreatitis (ARP) is defined as two distinct episodes of acute pancreatitis (AP), whereas chronic pancreatitis (CP) is caused by persistent inflammation of the pancreas. In children they are caused by genetic mutations, autoimmune pancreatitis, congenital pancreatic abnormalities, and other conditions. Acute recurrent pancreatitis is frequently a precursor to CP, and both are thought to be on the same disease continuum. In particular, genetic factors are associated with early progression of ARP to CP. The diagnosis of CP, as in AP, is based on clinical findings, biochemical tests, and imaging studies. Findings of exocrine pancreatic dysfunction are also important in the diagnosis of CP. A step-up strategy has become increasingly standard for the treatment of patients with CP. This strategy starts with endoscopic treatment, such as pancreatic sphincterotomy and stenting, and progresses to surgery should endoscopic therapy fail or prove technically impossible. Non-opioid (e.g. ibuprofen / naproxen) and opioid (e.g. oxycodone) forms of analgesia are widely used in pediatric patients with AP or CP, whereas pancreatic enzyme replacement therapy may be beneficial for patients with abdominal pain, steatorrhea, and malnutrition. Despite the disparity in the age of onset, pediatric CP patients display some similarities to adults in terms of disease progress. To reduce the risk of developing pancreatic exocrine inefficiency, diabetes and pancreatic cancer in the future, clinicians need to be aware of the current diagnostic approach and treatment methods for ARP and CP and refer them to a pediatric gastroenterologist in a timely manner.

Pancreatic exocrine insufficiency after pancreaticoduodenectomy: Current evidence and management

Pancreaticoduodenectomy (PD) is the commonest procedure performed for pancreatic cancer. Pancreatic exocrine insufficiency (PEI) may be caused or exacerbated by surgery and remains underdiagnosed and undertreated. The aim of this review was to ascertain the incidence of PEI, its consequences and management in the setting of PD for indications other than chronic pancreatitis. A literature search of databases (MEDLINE, EMBASE, Cochrane and Scopus) was carried out with the MeSH terms "pancreatic exocrine insufficiency" and "Pancreaticoduodenectomy". Studies that analysed PEI and its complications in the setting of PD for malignant and benign disease were included. Studies reporting PEI in the setting of PD for chronic pancreatitis, conference abstracts and reviews were excluded. The incidence of PEI approached 100% following PD in some series. The pre-operative incidence varied depending on the characteristics of the patient cohort and it was higher (46%-93%) in series where pancreatic cancer was the predominant indication for surgery. Variability was also recorded with regards to the method used for the diagnosis and evaluation of pancreatic function and malabsorption. Pancreatic enzyme replacement therapy is the mainstay of the management. PEI is common and remains undertreated after PD. Future studies are required for the identification of a well-tolerated, reliable and reproducible diagnostic test in this setting.

Pharmacokinetics of omega-3 fatty acids in patients with severe sepsis compared with healthy volunteers: A prospective cohort study

BACKGROUND

Pharmacokinetics (PK) of pharmaceuticals and pharmaconutrients are poorly understood in critically ill patients, and dosing is often based on healthy subject data. This might be particularly problematic with enteral medications due to metabolic abnormalities and impaired gastrointestinal tract absorption common in critically ill patients. Utilizing enteral fish oil, this study was undertaken to better understand and define PK of enteral omega-3 fatty acids (eicospentaenoic acid [EPA] and docosahexaenoic acid [DHA]) in critically ill patients with severe sepsis.

MATERIALS AND METHODS

Healthy volunteers (n = 15) and mechanically ventilated (MV) adults with severe sepsis (n = 10) were recruited and received 9.75 g EPA and 6.75 g DHA daily in two divided enteral doses of fish oil for 7 days. Volunteers continued their normal diet without other sources of fish oil, and sepsis patients received standard enteral feeding. Blood was collected at frequent intervals during the 14-day study period. Peripheral blood mononuclear cells (PMBCs) and neutrophils were isolated and analyzed for membrane fatty acid (FA) content. Mixed linear models and t-tests were used to analyze changes in FA levels over time and FA levels at individual time points, respectively. PK parameters were obtained based on single compartment models of EPA and DHA kinetics.

RESULTS

Healthy volunteers were 41.1 ± 10.3 years; 67% were women. In patients with severe sepsis (55.6 ± 13.4 years, 50% women), acute physiologic and chronic health evaluation (APACHE) II score was 27.2 ± 8.8 at ICU admission and median MV duration was 10.5 days. Serum EPA and DHA were significantly lower in sepsis vs. healthy subjects over time. PBMC EPA concentrations were generally not different between groups over time, while PBMC DHA was higher in sepsis patients. Neutrophil EPA and DHA concentrations were similar between groups. The half-life of EPA in serum and neutrophils was significantly shorter in sepsis patients, whereas other half-life parameters did not vary significantly between healthy volunteers and sepsis patients.

CONCLUSIONS

While incorporation of n-3 FAs into PBMC and neutrophil membranes was relatively similar between healthy volunteers and sepsis patients receiving identical high doses of fish oil for one week, serum EPA and DHA were significantly lower in sepsis patients. These findings imply that serum concentrations and EPA and DHA may not be the dominant driver of leukocyte membrane incorporation of EPA and DHA. Furthermore, lower serum EPA and DHA concentrations suggest that either these n-3 FAs were being metabolized rapidly in sepsis patients or that absorption of enteral medications and pharmaconutrients, including fish oil, may be impaired in sepsis patients. If enteral absorption is impaired, doses of enteral medications administered to critically ill patients may be suboptimal.

Residual pancreatic function after pancreaticoduodenectomy is better preserved with pancreaticojejunostomy than pancreaticogastrostomy: A long-term analysis

BACKGROUND

Pancreatico-enteric anastomosis after pancreaticoduodenectomy can be performed using either a pancreaticojejunostomy (PJ) or pancreaticogastrostomy (PG). Differences in surgical outcomes are still a matter of debate, and less is known about long-term functional outcomes.

METHODS

Twelve years after the conclusion of a comparative study evaluating the surgical outcomes of PJ and PG (Bassi et al., Ann Surg 2005), available patients underwent morphological and functional pancreatic assessment: pancreatic volume and duct diameter measured by MRI, impaired secretion after secretin, fecal fat, fecal elastase-1 (FE-1), serum vitamin D and endocrine function. Quality of life and symptom scores were evaluated with the EORTC QLQ-C30 questionnaire.

RESULTS

Only 34 patients were available for assessment. No differences were found in terms of BMI variation, endocrine function, quality of life or symptoms. Exocrine function was more severely impaired after PG than after PJ (fecal fats 26.6 ± 4.1 vs 18.2 ± 3.6 g/day; FE-1 121.4 ± 6.7 vs 170.2 ± 25.5 μg/g, vitamin D 18.1 ± 1.8 vs. 23.2 ± 3.1 ng/mL). MRI assessment identified a lower pancreatic volume (26 ± 3.1 vs. 36 ± 4.1 cm³) and a more dilated pancreatic duct (4.6 ± 0.92 vs. 2.4 ± 0.18 mm) in patients with PG compared to those with PJ.

CONCLUSION

Compared to PJ, PG is associated with a more severely impaired exocrine function long-term, but they result similar endocrine function and quality of life. In patients with a long life expectancy, this should be taken into account.

Screening and risk factors of exocrine pancreatic insufficiency in critically ill adult patients receiving enteral nutrition

Introduction

Malnutrition is a frequent problem associated with detrimental clinical outcomes in critically ill patients. To avoid malnutrition, most studies focus on the prevention of inadequate nutrition delivery, whereas little attention is paid to the potential role of exocrine pancreatic insufficiency (EPI). In this trial, we aim to evaluate the prevalence of EPI and identify its potential risk factors in critically ill adult patients without preexisting pancreatic diseases.

Methods

In this prospective cross-sectional study, we recruited 563 adult patients with critical illnesses. All details of the patients were documented, stool samples were collected three to five days following the initiation of enteral nutrition, and faecal elastase 1 (FE-1) concentrations were assayed using an enzyme-linked immunosorbent assay kit. Blood samples were also taken to determine serum amylase and lipase activity.

Results

The percentages of recruited patients with EPI (FE-1 concentration <200 μg/g) and severe EPI (FE-1 concentration <100 μg/g) were 52.2% and 18.3%, respectively. The incidences of steatorrhea were significantly different (P < 0.05) among the patients without EPI, with moderate EPI (FE-1 concentration = 100 to 200 μg/g) and severe EPI (FE-1 concentration < 100 μg/g). Both multivariate logistic regression analysis and z-tests indicated that the occurrence of EPI was closely associated with shock, sepsis, diabetes, cardiac arrest, hyperlactacidemia, invasive mechanical ventilation and haemodialysis.

Conclusions

More than 50% of critically ill adult patients without primary pancreatic diseases had EPI, and nearly one-fifth of them had severe EPI. The risk factors for EPI included shock, sepsis, diabetes, cardiac arrest, hyperlactacidemia, invasive mechanical ventilation and haemodialysis.

Trial registration

NCT01753024

Evolution of pancreatic function during the first year in infants with cystic fibrosis

OBJECTIVE

To describe pancreatic function during the first year of life in infants diagnosed with cystic fibrosis (CF) using serial fecal elastase measurements.

STUDY DESIGN

This was a longitudinal study of 82 infants diagnosed with CF through newborn screening. Monthly stool samples were sent to a central laboratory for fecal elastase measurements.

RESULTS

A total of 61 infants had an initial stool sample obtained at age <3.5 months and a final stool sample obtained at age >9 months. Twenty-six of 29 infants with a fecal elastase value <50 μg/g at study entry had a fecal elastase value <200 μg/g (the accepted cutoff value for pancreatic insufficiency) on all measurements during the year; all 29 had a value <200 μg/g at the end of the study. Of the 48 infants with initial fecal elastase value <200 μg/g, 13 had at least 1 fecal elastase value >200 μg/g but had a final stool fecal elastase value <200 μg/g; however, 4 infants with an initial fecal elastase value <200 μg/g ended the year with a value >200 μg/g. Eleven of 13 infants with an initial fecal elastase value of >200 μg/g still had a value >200 μg/g at the end of the first year.

CONCLUSION

Infants with CF exhibit variability in fecal elastase values during the first year. Infants with a fecal elastase level of 50-200 μg/g at diagnosis should be treated with pancreatic enzyme replacement therapy, but fecal elastase should be remeasured at age 1 year to ensure that those with a falsely low value do not continue to receive pancreatic enzyme replacement therapy unnecessarily. Those with a fecal elastase value >200 μg/g initially can become pancreatic insufficient with time.

Fecal elastase-1 is useful in the detection of steatorrhea in patients with pancreatic diseases but not after pancreatic resection

BACKGROUND

Fecal elastase-1(FE-1) has been suggested as an alternative to steatorrhea quantification to evaluate pancreatic insufficiency, but its diagnostic performance has not been compared with steatorrhea in chronic pancreatitis or after pancreatic resection.

METHODS

The relationship between steatorrhea and FE-1 was studied in patients with chronic pancreatic disorders or pancreatic resection. Student's t test and ANOVA were used for statistical analysis, accepting 0.05 as limit for significance.

RESULTS

Eighty-two patients were studied (42 non-operated; 40 previously submitted to pancreatic resection). Fat output was higher in operated than non-operated patients (29.2 ± 3.1 vs 9.9 ± 2.2 g/day, p < 0.001) FE-1 was more severely reduced in operated patients (202 ± 32.3 μg/g in non operated vs 68.6 ± 18.2 in operated patients; p < 0.001). Steatorrhea was significantly more severe in operated patients across different levels of FE-1. The relationship between FE-1 and steatorrhea was described by a power regression model, with a regression line significantly different in operated and non-operated patients (p < 0.001). A steatorrhea of 7 g (upper limit of normal range) was calculated by this regression line when FE-1 is 15 μg/g in non-operated, but as high as 225 μg/g in operated patients.

CONCLUSION

FE-1 is useful to identify pancreatic insufficiency. Steatorrhea is anticipated in non-operated patients only when FE-1 is below the limit for a confident measurement of our assay. In operated patients, steatorrhea may be present even if FE-1 is only slightly reduced, that suggests a role for non pancreatic factors. FE1 is not useful to identify operated patients at risk of malabsorption.

New faecal tests in gastroenterology

Most abdominal disorders present with a limited number of overlapping symptoms. Blood tests are not routinely available for use in diagnosis and so investigation tends to require complex imaging procedures or endoscopy and biopsy. These are invasive for the patient, may be associated with morbidity and mortality and have considerable resource implications. Biochemical tests on a single sample of faeces are therefore a valuable alternative. Measurement of faecal calprotectin has been shown to have a role in the diagnosis of inflammatory bowel disease and in its monitoring. Lactoferrin is also of benefit used in this way. Faecal elastase has been demonstrated to be of use in the diagnosis of pancreatic insufficiency. A number of faecal markers have been explored in colorectal cancer. Faecal occult blood testing is used for population screening, but the metabolomic marker tumour, M2-pyruvate kinase, has potential for use in both diagnosis and screening. DNA testing has advantages in colorectal cancer but the exact applications of such tests require further evaluation.

Stool studies: tried, true, and new

Much information can be obtained about a patient's gastrointestinal and overall nutritional status through stool samples. Important infectious processes and neoplastic processes are initially identified through diagnostic tests and screening of stool samples. Although in some arenas they are a source of embarrassment and distaste, the value of correctly obtained samples is unquestionable. Patient collaboration with a critical care nurse is integral to obtaining stool samples.

Exocrine and endocrine pancreatic function in 21 patients suffering from autoimmune pancreatitis before and after steroid treatment

BACKGROUND/AIM

Autoimmune pancreatitis (AIP) responds rapidly and dramatically to steroid therapy. The aim of this study was to evaluate pancreatic exocrine and endocrine function in patients suffering from AIP both before and after steroid therapy.

PATIENTS AND METHODS

Fecal elastase 1 and diabetes were evaluated before steroid therapy and within 1 month of its suspension in 21 patients (13 males and 8 females, mean age 43 +/- 16.5 years) diagnosed as having AIP between 2006 and 2008.

RESULTS

At clinical onset, fecal elastase 1 was 107 +/- 126 microg/g stool. Thirteen patients (62%) showed severe pancreatic insufficiency (<100 microg/g stool), 4 (19%) had mild insufficiency (100-200 microg/g stool), while 4 (19%) had normal pancreatic function (>200 microg/g stool). Before steroids, diabetes was diagnosed in 5 patients (24%), all of whom had very low levels of fecal elastase 1 (<19 microg/g stool). Following steroids, fecal elastase 1 increased in all patients (237 +/- 193 microg/g stool) and observed levels were significantly higher than those seen before steroids (p = 0.001).

CONCLUSIONS

Patients suffering from AIP display exocrine and/or endocrine pancreatic insufficiency at clinical onset. These insufficiencies improve after steroid therapy.