Fecal elastase-1 concentration: an indirect test of exocrine pancreatic function and a marker of an enteropathy regardless of cause

Image or scope: Magnetic resonance imaging and endoscopic testing for exocrine and endocrine pancreatic insufficiency in children

OBJECTIVES

We sought to evaluate associations between Magnetic Resonance Imaging (MRI) findings, exocrine pancreatic insufficiency (EPI) and endocrine insufficiency (prediabetes or diabetes) in children.

METHODS

This was a retrospective study that included patients<21 years of age who underwent MRI and endoscopic pancreatic function testing (ePFT; reference standard for pancreatic exocrine function) within 3 months. MRI variables included pancreas parenchymal volume, secreted fluid volume in response to secretin, and T1 relaxation time. Data were analyzed for the full sample as well as the subset without acute pancreatitis (AP) at the time of imaging.

RESULTS

Of 72 patients, 56% (40/72) were female with median age 11.4 years. A 5 mL decrease in pancreas parenchymal volume was associated with increased odds of exocrine pancreatic dysfunction by both ePFT (OR = 1.16, p = 0.02 full sample; OR = 1.29, p = 0.01 no-AP subset), and fecal elastase (OR = 1.16, p = 0.04 full sample; OR = 1.23, p = 0.02 no-AP subset). Pancreas parenchymal volume had an AUC 0.71 (95% CI: 0.59, 0.83) for predicting exocrine pancreatic dysfunction by ePFT and when combined with sex and presence of AP had an AUC of 0.82 (95% CI: 0.72, 0.92). Regarding endocrine function, decreased pancreas parenchymal volume was associated with increased odds of diabetes (OR = 1.16, p = 0.03), and T1 relaxation time predicted glycemic outcomes with an AUC 0.78 (95% CI: 0.55-1), 91% specificity and 73% sensitivity.

CONCLUSIONS

Pancreas parenchymal volume is an MRI marker of exocrine and endocrine pancreatic dysfunction in children. A model including sex, AP, and pancreas volume best predicted exocrine status. T1 relaxation time is also an MRI marker of endocrine insufficiency.

Chronic Pancreatitis: Epidemiology, Diagnosis, and Management Updates

Chronic pancreatitis is a clinical entity that results from the progressive inflammation and irreversible fibrosis of the pancreas resulting from the cumulative injury sustained by the pancreas over time. It is an illness with variable presentations that can severely impact quality of life, while its long-term complications such as exocrine pancreatic insufficiency (EPI), diabetes mellitus, and risk of pancreatic cancer can become life threatening. The diagnosis of chronic pancreatitis can be challenging as despite the recent advancements in imaging technology, the radiographic findings do not become prominent until late stages of disease. Thus, the physicians' clinical acumen in obtaining thorough history taking focusing on risk factors, clinical symptoms, in addition to high-quality imaging, often guide to the accurate diagnosis of chronic pancreatitis. Endoscopy also plays a pivotal role in the diagnosis and management of chronic pancreatitis. Endoscopic ultrasound (EUS) is believed to be the most sensitive modality for diagnosing chronic pancreatitis. Despite efforts, however, natural history studies have demonstrated that 61% of individuals with chronic pancreatitis will require at least one endoscopic intervention, while 31% will require a surgical procedure as part of their management strategy. Recent advancements in genomic studies have furthered our understanding of the genetic polymorphisms that are associated with the pathogenesis of chronic pancreatitis. Genetic testing offers the potential to reveal treatable pancreatitis-related disorders, and can inform decision making with regard to radical therapies for persistent or severe disease such as total pancreatectomy with islet autotransplantation (TPIAT). The management of patients suffering from chronic pancreatitis often requires a multi-disciplinary approach, addressing pertinent symptoms as well as the sequelae of chronic inflammation and fibrosis. Abdominal pain is the prevailing symptom and most common complication of chronic pancreatitis, and impairs quality of life. Although heavily dependent on a wide range of analgesia, endoscopic treatment such as endoscopic retrograde cholangiopancreatography (ERCP) and surgical intervention can offer long-lasting relief of symptoms. For EPI, treatment with pancreatic enzyme supplements offers marginal-to-moderate relief. The most feared complication of chronic pancreatitis-the development of pancreatic cancer-has no known prevention measure to date.

Endocrine and exocrine pancreatic insufficiency after acute pancreatitis: long-term follow-up study

BACKGROUND

Patients could develop endocrine and exocrine pancreatic insufficiency after acute pancreatitis (AP), but the morbidity, risk factors and outcome remain unclear. The aim of the present study was to evaluate the incidence of endocrine and exocrine pancreatic insufficiency after AP and the risk factors of endocrine pancreatic insufficiency through a long-term follow-up investigation.

METHODS

Follow-up assessment of the endocrine and exocrine function was conducted for the discharged patients with AP episodes. Oral Glucose Tolerance Test (OGTT) and faecal elastase-1(FE-1) test were used as primary parameters. Fasting blood-glucose (FBG), fasting insulin (FINS), glycosylated hemoglobin HBA1c, 2-h postprandial blood glucose (2hPG), Homa beta cell function index (HOMA-β), homeostasis model assessment of insulin resistance (HOMA-IR) and FE-1 were collected. Abdominal contrast-enhanced computed tomography (CECT) was performed to investigate the pancreatic morphology and the other related data during hospitalization was also collected.

RESULTS

One hundred thirteen patients were included in this study and 34 of whom (30.1%) developed diabetes mellitus (DM), 33 (29.2%) suffered impaired glucose tolerance (IGT). Moreover, 33 patients (29.2%) developed mild to moderate exocrine pancreatic insufficiency with 100μg/g

CONCLUSION

The integrated morbidity of DM and IGT after AP was 59.25%, which was higher than exocrine pancreatic insufficiency. 6.2% and 29.2% of patients developed severe and mild to moderate exocrine pancreatic insufficiency, respectively. The extent of pancreatic necrosis>50%, WON and insulin resistance were the independent risk factors of new onset diabetes after AP.

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Key Words

• Acute pancreatitis
• Endocrine pancreatic insufficiency
• Exocrine pancreatic insufficiency
• Follow-up study
• Insulin resistance
• Pancreatic necrosis

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MESH Headings

• Acute Disease
• Diabetes Complications
• Exocrine Pancreatic Insufficiency/etiology
• Female
• Follow-Up Studies
• Glucose Intolerance/complications
• Humans
• Male
• Middle Aged
• Pancreatitis/complications
• Regression Analysis
• Risk Factors

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Grants

• National Natural Science Foundation of China
• Science and Technology Foundation of Zhejiang Province

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Affiliation(s)

Jianfeng Tu Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002 China Zhejiang Provincial People’s Hospital, People’s Hospital of Hangzhou Medical College, Shangtang road 158#, Hangzhou, 310014 China
Jingzhu Zhang Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002 China
Lu Ke Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002 China
Yue Yang Hangzhou Medical College, Binwen road 481#, Hangzhou, 310053 China
Qi Yang Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002 China
Guotao Lu Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002 China
Baiqiang Li Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002 China
Zhihui Tong Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002 China
Weiqin Li Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002 China
Jieshou Li Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, 210002 China

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Diagnosing Chronic Pancreatitis

Diagnosing CP can range from routine in those with severe disease and obvious calcifications on CT imaging to elusive in those patients with early changes in CP. The workup of suspected CP should follow a progressively noninvasive to more invasive STEP-wise approach in a patient with a suspicious clinical presentation and risk factors that raise their pretest probability of disease. After a thorough history and physical examination, basic laboratories should be obtained such as lipase, amylase, metabolic panel, and indirect PFTs (fecal elastase-1, serum trypsin). Computed tomography remains the best initial imaging modality to obtain as it has good sensitivity for severe CP and may obviate the need for other diagnostic tests. When equivocal, an MRCP should be obtained for a more detailed evaluation of the both the pancreatic parenchyma and ducts. If the diagnosis remains in doubt, EUS should be performed with or without pancreas function testing. ERCP remains a last-line diagnostic test and seldom should be used outside of therapeutic purposes. Future advances should target optimizing current diagnostic tools to more accurately diagnose early CP, as it is in this population where the benefits of delaying progression of CP may have the most profound effect. Likely the best way at establishing a diagnosis in these patients is via pancreatic function testing in the setting of indeterminate EUS results. Biomarker studies of pancreas fluid may supplement diagnosis.

Faecal elastase-1 is an independent predictor of survival in advanced pancreatic cancer

BACKGROUND

The relationship between prognosis of advanced pancreatic cancer and exocrine secretion impairment is unknown.

AIM

To investigate a possible correlation between faecal elastase-1 value and survival in advanced pancreatic cancer.

METHODS

194 patients with advanced pancreatic cancer were prospectively enrolled between 2007 and 2009 and underwent faecal elastase-1 measurement. Exocrine pancreatic secretion was defined as "moderately reduced" (faecal elastase-1: 100-200 μg/g), "severely reduced" (faecal elastase-1<100 and >20 μg/g) and "extremely reduced" (faecal elastase-1≤20 μg/g).

RESULTS

Median faecal elastase-1 was 204 μg/g (interquartile range 19; 489). Overall, 48 patients (25%) had an extremely reduced exocrine pancreatic secretion, 28 (14%) a severely reduced exocrine pancreatic secretion and 21 (11%) a moderately reduced exocrine pancreatic secretion. Patients with extremely reduced exocrine pancreatic secretion had higher rates of pancreatic head localizations (P<0.01) and of jaundice (P<0.01). Median overall survival was 10.5 months. Patients with faecal elastase-1≤20 μg/g had a worse prognosis (median survival: 7 versus 11 months, P=0.031). Presence of metastases (Hazard ratio 1.81, P<0.0001), haemoglobin ≤12 g/L (Hazard ratio 2.12, P=0.001), albumin ≤40 g/L (Hazard ratio 1.64, P=0.010) and FE-1≤20 μg/g (Hazard ratio 1.59 P=0.023) resulted as independent predictors of survival in advanced pancreatic cancer patients.

CONCLUSIONS

A low value of faecal elastase-1 is strongly correlated with a poor survival in advanced pancreatic cancer.

Comparison of fecal elastase-1 and pancreatic function testing in children

OBJECTIVES

The fecal pancreatic elastase-1 (FE-1) test is considered a simple, noninvasive, indirect measure of pancreatic function. We aimed to evaluate the performance of the FE-1 test compared with the direct pancreatic function test (PFT) with secretin stimulation in children.

METHODS

Data of 70 children (6 months-17 years of age) who had both FE-1 test and PFT were analyzed.

RESULTS

The average FE-1 concentration was 403 ± 142 μg/g. Eleven children had concentrations below 200  μg/g, 23 between 201 to 500 μg/g, and 36 were above 500 μg/g. The average pancreatic elastase activity measured on direct stimulation was 49.1 ± 38.6  μmol · min (-1)· ml(-1) and 11 children had activity below the established cutoff (10.5 μmol · min(-1) · ml(-1)). Among the 11 children with pathologic PFT, 7 had normal FE-1, 4 were in the intermediate range (201-500 μg/g), and none were in the low range (<200 μg/g). Among the 59 children with normal direct PFT 11 (19%) had pathologic (<200 μg/g) and 19 (32%) had intermediate FE-1 tests. Twenty-nine children had both normal FE-1 concentration and normal PFT, giving a negative predictive value of 80%. The correlation between pancreatic elastase activity and FE-1 concentration was poor (r = 0.190). The sensitivity of the FE-1 test was found to be 41.7%, whereas the specificity was 49.2%. The positive predictive value of the FE-1 test was only 14%.

CONCLUSIONS

The FE-1 test is a simple, noninvasive, indirect method; however, ordering physicians should be aware of its limitations. It can give false-positive results and has low sensitivity in children with mild pancreatic insufficiency without cystic fibrosis and in those with isolated pancreatic enzyme deficiencies.

Chronic pancreatitis

PURPOSE OF REVIEW

We review important new clinical observations in chronic pancreatitis made in the past year.

RECENT FINDINGS

Tropical pancreatitis associates with SPINK1 and/or CFTR gene mutations in approximately 50% of patients, similar to the frequency in idiopathic chronic pancreatitis. Corticosteroids increase secretin-stimulated pancreatic bicarbonate concentrations in autoimmune pancreatitis (AIP) by restoring mislocalized CFTR protein to the apical ductal membrane. Most patients with asymptomatic hyperenzymemia have pancreatic lesions of unclear significance or no pancreatic lesions. Common pitfalls in the use of diagnostic tests for exocrine pancreatic insufficiency (EPI) confound interpretation of findings in irritable bowel syndrome and severe renal insufficiency. Further study is needed to improve the accuracy of endoscopic ultrasonography (EUS) to diagnose chronic pancreatitis. Celiac plexus block provides short-term pain relief in a subset of patients.

SUMMARY

Results of this year's investigations further elucidated the genetic associations of tropical pancreatitis, a reversible mislocalization of ductal CFTR in AIP, the association of asymptomatic pancreatic hyperenzymemia with pancreatic disorders, limitations of diagnostic tests for EPI, diagnosis of chronic pancreatitis by EUS and endoscopic pancreatic function testing and treatment of pain.

Subclinical exocrine pancreatic dysfunction resulting from decreased cholecystokinin secretion in the presence of intestinal villous atrophy

The aim of this study was to evaluate the concept that pancreatic dysfunction in patients having gluten sensitivity (celiac disease [CD]) or cow's milk protein enteropathy (CMPE) may result from the lack of pancreatic enzyme stimulation in the absence or decrease of cholecystokinin (CCK) secretion caused by villous atrophy.

PATIENTS AND METHODS

The following parameters were measured: plasma CCK in response to a fatty meal and human pancreatic fecal elastase in 24 patients with CD while on gluten-free diet and after gluten provocation and in 12 patients with CMPE at diagnosis and after a 6-month period of cow's milk-free diet. Intestinal mucosa morphology was examined by small bowel biopsy. Sixty-three controls having no organic gastrointestinal problems were investigated once at the time of diagnostic evaluation.

RESULTS

Fasting CCK, obtained at a time when patients with CD or CMPE had normal intestinal mucosa, was significantly different from postprandial and comparable to that of the control group. Fasting CCK obtained from patients with villous atrophy was also statistically different, but not significantly, from the postprandial. Fasting and postprandial plasma CCK and fecal pancreatic elastase values from patients having normal intestinal mucosa were significantly higher than those obtained from patients with villous atrophy. Significant correlation of intestinal mucosa morphology and CCK with fecal elastase concentration was documented.

CONCLUSION

Exocrine pancreatic dysfunction in individuals having villous atrophy may be the consequence of decreased CCK secretion. Cholecystokinin and pancreatic secretion is restored to normal, with intestinal mucosa regeneration.

[Fecal elastase-1: a useful test in pediatric practice]

AIM

To study fecal elastase-1 (E1F) and chymotrypsin (ChT) in stools for the diagnosis of pancreatic insufficiency in pediatric practice.

MATERIALS AND METHODS

E1F and ChT were measured in stools of 198 children divided in 3 groups: 49 children without any digestive disease (group A), 71 children with pancreatic diseases (group B), and 78 children with non-pancreatic digestive diseases (group C).

RESULTS

In group B, E1F values were very low in 64 children and normal in 7 children without pancreatic insufficiency (6 children with cystic fibrosis and 1 with chronic pancreatitis). ChT values were normal in children without pancreatic insufficiency but also in half of children treated with pancreatic enzymes. Decreased E1F values were seen in 2 children (4%) in the group A and 22 children (28%) in the group C, especially those with acute gastroenteritis or celiac disease.

CONCLUSION

E1F is a simple, non-invasive, useful tool for the diagnosis of pancreatic insufficiency in children with growth failure or chronic diarrhea, and those with cystic fibrosis. Nevertheless, low values may be found in diseases with villous atrophy or very liquid stools.

Use of fecal elastase-1 to classify pancreatic status in patients with cystic fibrosis

OBJECTIVE

To test the hypothesis that some patients with cystic fibrosis (CF) are misclassified as pancreatic insufficient, using fecal elastase-1 (FE-1) to define pancreatic status.

STUDY DESIGN

Subjects with CF at 33 CF centers filled out questionnaires and submitted a stool specimen that was analyzed for FE-1. Subjects taking pancreatic enzyme supplements (PES) were asked to discontinue them and perform a 3-day fecal fat balance study if their FE-1 was >200 microg/g stool and they had never had pancreatitis.

RESULTS

The median value for FE-1 in 1215 subjects was 0 microg/g stool (range, 0-867). There was a significant difference between patients who had been prescribed PES (n=1131) and those who had FE-1 <200 microg/g stool (n=1074; P<.0001). Sixty-seven subjects met criteria for discontinuation of PES. The mean coefficient of fat absorption for these subjects was 96.1%.

CONCLUSIONS

FE-1 is an accurate, easily obtained screening test to classify pancreatic status in patients with CF. This information is important for prognostication, treatment, and to avoid misclassification in clinical research. Measurement of FE-1 should become a standard of care for patients with CF.

Chronic pancreatitis

PURPOSE OF REVIEW

Clinicians are learning more about chronic pancreatitis but are entering an era of some confusion, primarily driven by uncovering new etiologies of chronic pancreatitis. Ideally, this knowledge will lead to better diagnosis and treatment, and abandonment of ill-conceived treatments. In contrast with previous reviews, this review highlights select contributions this year that may develop into true advances in chronic pancreatitis.

RECENT FINDINGS

Small steps have been made to understand better the molecular basis of chronic pancreatitis. Diagnosis of early chronic pancreatitis remains challenging. Rapid diagnosis by combining endoscopy and a direct stimulatory test of pancreatic function may lead to more widespread use of function testing, but this test is not ready for clinical use. Application of microarray and proteomic technologies may aid future diagnosis of chronic pancreatitis. The failure to account clearly for the phenotype of patients with chronic pancreatitis may confound delineating the etiologies of chronic pancreatitis. Clinical description and studies of autoimmune pancreatitis have led to the realization that steroids are an effective treatment for this form of chronic pancreatitis. Genetic-based studies have provided insight into the pathogenic mechanisms of chronic pancreatitis. Investigation of the role of stellate cells, an essential component fibrogenesis, has led to identification of potential novel treatments for chronic pancreatitis.

SUMMARY

Ongoing basic and clinical research this past year has characterized further the histologic, genetic, molecular, and clinical aspects of chronic pancreatitis, efforts that may translate into novel therapies once well-designed, controlled studies have been performed.

Serum lipase after secretin stimulation detects mild pancreatic involvement in cystic fibrosis

BACKGROUND

The assessment of severe pancreatic insufficiency in cystic fibrosis (CF) is not a diagnostic problem. However, identification of mild cases remains a challenge. The aim of this study was to assess the ability of serum lipase after secretin stimulation to identify mild pancreatic insufficiency in patients with CF.

MATERIAL AND METHODS

Thirty patients with CF and pancreatic insufficiency (CF-PI) and 30 patients with CF and pancreatic sufficiency (CF-PS) were studied. Thirty healthy subjects with no known gastrointestinal disease served as controls. In all subjects, fecal fat excretion, fecal elastase-1 (E1) concentration and basal and secretin-stimulated serum lipase concentration were measured.

RESULTS

All patients with CF-PI and 3 with CF-PS had abnormally low fecal E1 concentrations. The remaining 27 CF-PS patients and all controls had normal values. Basal and post-stimulation lipase levels were extremely low in patients with CF-PI. Mean basal and poststimulation serum lipase concentrations were significantly higher in CF-PS who had normal fecal E1 concentrations but were still below those of controls (P < 0.001). Among the 27 CF-PS patients with normal fecal elastase, high basal and poststimulation lipase values were found in 6 and 17 patients respectively.

CONCLUSION

In patients with CF-PS who have normal fecal elastase-1 concentration, the measurement of basal or secretin-stimulated lipase levels might be helpful in identifying the progression of the destructive process in the pancreas.