Assessment of pancreatic enzyme secretory capacity by a modified Lundh test

Summary Background. The Lundh test is a usual means of estimating the enzyme secretory capacity of the gland. During this procedure, however, a major proportion of the test meal is removed from the duodenum together with the gastric, duodenal, and pancreatic secretions and the bile. This study was undertaken to compare the pancreatic enzyme secretion induced by the Lundh procedure with that resulting from stimulation of the normal digestive process, by reinfusion of the aspirated duodenal juice. Methods. Nine men (mean age: 46.7, range 42–55 yr) free from pancreatic disease were studied. Pancreatic secretion was measured via a multiple lumen tube by aspiration of the duodenal juice. After a basal period the Lundh test meal was placed in the stomach and the duodenal juice was completely aspirated. On a separate day, the procedure was repeated, but the aspirated duodenal juice was reinfused into the upper jejunum. Results. In the first 30 min of the test period, the enzyme outputs were the same on both test days. In the 30–60-min period, the lipase output, and in the 75–90-min period, the amylase output was significantly lower during the Lundh test compared with the jejunal reinfusion test. The CCK levels were significantly above the basal level at 20 and 40 min, but the increase was significantly lower during the traditional Lundh test. No significant difference in gastrin release was observed during either the Lundh or the reinfusion test. Conclusions. In the traditional Lundh test, the trypsin secretory capacities of the gland are measured appropriately, but the lipase and amylase secretory capacity and the CCK release are not fully represented compared with the reinfusion test. An association between the lower CCK release and lipase amylase secretion is suggested.     

Volume and enzyme kinetics of human pancreatic secretion after endogenous stimulation with the Lundh test meal

The present study was undertaken to investigate the volume and enzyme kinetics of human pancreatic secretion, after endogenous stimulation with a Lundh test meal, and evaluate the most reliable enzyme and collection period. The prestimulatory volume rates did not differentiate normal from pathologic pancreatic function. After ingestion of the test meal, the immediate increase in volume secretion was identical in healthy subjects and patients with pancreatic insufficiency. The latter showed a drastic reduction of prestimulatory and postprandial enzyme secretion. Cimetidine taken orally 12 and 2 h before the test meal study had no effect on volume and enzyme secretion and endogenous CCK release. Especially in severe pancreatic insufficiency, this modification simplified the performance of the Lundh test. The estimation of lipase and trypsin gave a significant correlation between Lundh test and secretin-cerulein test. The endogenous stimulation by Lundh test meal is a reliable test for routine diagnostic and scientific purposes.     

Clinical evaluation of pancreatic excretion test with dimethadione and oral BT-PABA test in chronic pancreatitis

Further evaluation of the pancreatic excretion test with 5,5-dimethyl-2,4-oxazolidinedione (dimethadione, DMO) was made in comparison with the pancreozymin-secretin (PS) test on 100 normal subjects, 79 patients with chronic pancreatitis, and 83 patients with nonpancreatic disease. The diagnostic sensitivity of the oralN-benzoyl-l-tyrosyl-PABA (BT-PABA) test was estimated in 42 patients with chronic pancreatitis, on whom both PS and DMO excretion tests were performed as test of reference for exocrine pancreatic function. Pancreatic DMO excretion after secretin injection was significantly diminished in chronic pancreatitis. The DMO excretion test was more sensitive than the PS test to detect chronic pancreatitis and to distinguish between mild to moderate and advanced noncalcific chronic pancreatitis. The specificity of the DMO excretion test was more than adequate to find out pancreatic disease. The 6-hr urinary PABA excretion was significantly reduced in chronic pancreatitis. The BT-PABA test, however, showed the low sensitivity in mild to moderate chronic pancreatitis.     

Comparative study of secretin and Lundh tests

Exocrine pancreatic function in 19 patients with pancreatic disease and in 14 of 16 controls was measured by secretin stimulation and by the Lundh test on two different occasions. Peak bicarbonate concentration in the secretin test and mean trypsin concentration in the Lundh test emerged as the most reliable parameters. No additional diagnostic value was obtained by measuring enzymes after secretin injection. In 6 patients with chronic and in 8 of 13 patients with acute pancreatitis, both tests gave results that agreed with each other. The remaining 5 patients showed either an abnormal secretin value or an abnormal Lundh test. This is consistent with the wide variation seen in acute pancreatitis. It is concluded that the Lundh test as well as the secretin test were of value in the assessment of chronic pancreatic disease. The secretin test may be slightly more sensitive to mild and acute pancreatic damage than is the Lundh test. However stimulation of the pancreas by a test meal is easier to perform and more economic.Partly presented at the Annual Meeting of the American College of Gastroenterology in Hawaii, October, 1973.     

Assessment of pancreatic enzyme secretory capacity by a modified Lundh test.

BACKGROUND: The Lundh test is a usual means of estimating the enzyme secretory capacity of the gland. During this procedure, however, a major proportion of the test meal is removed from the duodenum together with the gastric, duodenal, and pancreatic secretions and the bile. This study was undertaken to compare the pancreatic enzyme secretion induced by the Lundh procedure with that resulting from stimulation of the normal digestive process, by reinfusion of the aspirated duodenal juice. METHODS: Nine men (mean age: 46.7, range 42-55 yr) free from pancreatic disease were studied. Pancreatic secretion was measured via a multiple lumen tube by aspiration of the duodenal juice. After a basal period the Lundh test meal was placed in the stomach and the duodenal juice was completely aspirated. On a separate day, the procedure was repeated, but the aspirated duodenal juice was reinfused into the upper jejunum. RESULTS: In the first 30 min of the test period, the enzyme outputs were the same on both test days. In the 30-60-min period, the lipase output, and in the 75-90-min period, the amylase output was significantly lower during the Lundh test compared with the jejunal reinfusion test. The CCK levels were significantly above the basal level at 20 and 40 min, but the increase was significantly lower during the traditional Lundh test. No significant difference in gastrin release was observed during either the Lundh or the reinfusion test. CONCLUSIONS: In the traditional Lundh test, the trypsin secretory capacities of the gland are measured appropriately, but the lipase and amylase secretory capacity and the CCK release are not fully represented compared with the reinfusion test. An association between the lower CCK release and lipase amylase secretion is suggested.     

A Rapid,Endoscopic Exocrine Pancreatic Function Test and the Lundh Test: A Comparative Study

Background/Aims: The diagnosis of chronic pancreatitis is often difficult in the early stages of the disease. Morphological tests may be normal, and reliable methods for the evaluation of the exocrine pancreatic function are time-consuming and troublesome. A new test for exocrine pancreatic function, using endoscopic aspiration of secretin-stimulated pancreatic juice, has been developed. We evaluated the test using the Lundh meal test as reference. Methods: The endoscopie secretin stimulation test (ESST) was performed in a consecutive row of 24 patients referred for pancreatic function testing because of clinical suspicion of chronic pancreatitis and in 23 healthy volunteers. The participants fasted overnight and secretin was given intravenously (1 CU/kg) as a bolus the following morning. Thirty minutes after administration of secretin, the tip of the duodenoscope was placed close to the ampulla of Vater and duodenal aspirate was drawn for 10 min. Intraduodenal concentrations of lipase, bicarbonate, elastase and zinc were measured. The concentration of lipase during the Lundh test (4 × 20 min aspiration) was used as reference test in the patients. Results: Judged from the Lundh test, the exocrine pancreatic function was nearly abolished in 5 patients (<10% of lower normal limit), reduced in 6 patients and normal in 13 patients. ESST failed in 1 patient (no aspirate). Lipase concentrations (KU/I) were significantly lower in the patients with nearly abolished function compared to patients with reduced or normal exocrine pancreatic function (NEPF; Mann-Whitney U test: p < 0.01), but an overlap was found between patients with reduced exocrine pancreatic function [100.1 (median); 60.0–225.0 (range)] patients with NEPF (145.7; 44.6–268.0) and healthy controls (175.0; 84.8–381.0). Bicarbonate concentrations (mEq/l) were significantly lower in patients with reduced exocrine pancreatic fuction (51.2; 32.5–69.6) compared to patients with NEPF (80.0; 48.1–101.8; Mann-Whitney U test: p < 0.05). Pancreatic elastase concentration was significantly lower in the group with nearly abolished exocrine function compared to patients with NEPF (Mann-Whitney U test: p < 0.05), but there was no difference between elastase concentrations among the other groups. We found significant correlation between lipase and bicarbonate concentrations during ESST and lipase concentrations during the Lundh test in all 23 patients (Spearman's Ranktest: p = 0.597 and 0.683, respectively, p < 0.01). By using receiver operating characteristic curves, best cut-off point for bicarbonate was estimated. Lipase and bicarbonate results in the healthy volunteers were not statistically different from results in patients with NEPF. No side effects were observed except for worsening of nausea and abdominal pain in 2 of the patients. Conclusion: The ESST is safe, and by combining the estimation of lipase and bicarbonate concentrations this test is a rapid, easy and useful diagnostic test for exocrine pancreatic function.     

Fecal chymotrypsin in alcoholic liver disease

Fecal chymotrypsin assays were done on 34 patients with alcoholic liver disease. Only one such patient had low fecal activity. Correlation of fecal chymotrypsin with fat malabsorption and duodenal drainage tests was undertaken. Although fat malabsorption was frequently encountered (13 of 34), the low incidence of abnormal fecal chymotrypsin suggests that severe pancreatic exocrine insufficiency is an unusual occurrence in this population. Six patients had pancreozymin-secretin tests and Lundh test meals and one showed abnormal results, but fecal chymotrypsin assays were uniformly normal in this small subgroup.     

Association between duodenal bulb ulceration and reduced exocrine pancreatic function

Seventy two patients admitted to a medical department with dyspepsia but without a previous diagnosis of peptic ulcer disease or chronic pancreatitis were studied consecutively. A pancreatic function test (Lundh meal test) and an upper endoscopy was made in all patients. There was no difference in age, sex ratio, occurrence of upper abdominal pain or chronic alcoholism between the groups of patients with reduced pancreatic function (20) and the group with normal function (52). Seven duodenal ulcers were found, two in patients with normal pancreatic function (2/52 = 3.8%; 95% conf lim: 0.5-13.2) and five in patients with reduced pancreatic function (5/20 = 25%; 95% conf lim: 8.7-49.1). This difference was statistically significant (p less than 0.01). Duodenitis occurred with equal frequency in the two groups.     

The diagnostic value of the oral pancreatic function test.

An oral pancreatic function test (PFT) using the synthetic peptide N-benzoyl-L-tyrosyl-p-aminobenzoic acid can assess pancreatic exocrine function, since urinary recovery of the ingested dose is an indirect index of chymotryptic activity. We have studied 34 subjects using this oral PFT, which correctly distinguished the control group (8 subjects) from the pancreatitis group (10 patients), results correlating well with Lundh test findings. However, the test was falsely abnormal on 9 out of 16 occasions in patients with bowel or liver disease. We therefore conclude that the present test cannot distinguish small-bowel disease from pancreatic disease, which is often the diagnostic problem, and is also frequently falsely abnormal in the presence of chronic liver disease.     

Diagnostic and therapeutic applications of bentiromide screening test for exocrine pancreatic insufficiency in patients with cystic fibrosis

The bentiromide test for exocrine pancreatic function was carried out in normal volunteers, patients with cystic fibrosis (CF) without clinical evidence of pancreatic dysfunction, and CF patients with clinically significant exocrine pancreatic insufficiency. The test was performed with and without the concomitant administration of a Lundh test meal.p-Aminobenzoic acid was given on a separate occasion to eliminate false positives due to factors unrelated to pancreatic disease. Correct classification of 25 CF patients with pancreatic insufficiency and 9 CF patients without clinical pancreatic dysfunction was possible by interpreting the results of the above three tests. Isoamylase determinations would have misclassified 20% of the CF patients with pancreatic insufficiency, but were able to detect the CF patients without clinical pancreatic dysfunction on the basis of an elevated pancreatic amylase isoenzyme. The bentiromide test results were normal in CF patients without clinical pancreatic dysfunction despite previous findings of decreased bicarbonate secretion in this group. However, the bentiromide test did appear to be useful in the evaluation of therapeutic intervention with exogenous pancreatic enzymes and other adjunctive therapy.This study was presented in part at the 8th International Congress on Cystic Fibrosis, Toronto, Ontario, May 1980.     

Factors influencing duodenal trypsin levels following a standard test meal as a test of pancreatic function

In this investigation, the measurement of trypsin levels in duodenal juice following a standard test meal (Lundh test) was evaluated as a test of pancreatic function, and a study was made of diseases and other factors which may influence its diagnostic efficiency. The method of trypsin assay, which required only basic laboratory equipment, gave a linear concentration-activity curve, with a threshold at 50 mug of crystalline trypsin per ml. Intestinal juice could be frozen and stored for up to six weeks with no detectable loss of tryptic activity.The normal control values were very similar to those found by other workers and were unaffected by the sex or age of the subject. When used to assess 32 patients in whom the presence or absence of pancreatic disease had been clearly established, the test had a diagnostic success rate of 94%.Retrospective analysis of results from 98 patients showed that trypsin levels were generally grossly reduced in patients with chronic pancreatitis or carcinoma of the head of the pancreas. Trypsin levels were normal in most patients with steatorrhoea not of pancreatic origin. Levels were generally depressed to intermediate levels in patients with a diabetic glucose tolerance, with or without steatorrhoea, but no other sign of pancreatic insufficiency. Some lowering of trypsin levels was also noted in patients having an obstruction of the common bile duct. A small but significant depression of tryptic activity was noted in patients with villous atrophy and no pancreatic disease.     

Trophic effect of cholecystokinin-octapeptide in man - a new way in the treatment of chronic pancreatitis?

The effect of 3-week CCK-OP treatment on test meal stimulated pancreatic secretion was investigated in chronic pancreatitis patients. One drop of a 1 mg/ml CCK-OP solution applied intranasally, three times daily during 3 weeks resulted in a significant increase in volume, trypsin, lipase and amylase secretion in response to the Lundh test meal. Augmentation of trypsin secretion was the most pronounced. Functional capacity of pancreatic enzyme secretion remained elevated for 3 months after treatment. Nearly all patients became symptom free during and for some time after treatment. The results were attributed to a trophic effect of CCK-OP on human pancreas.     

Plasma CCK levels in patients with pancreatic insufficiency

After stimulation with a Lundh test meal, plasma concentrations of cholecystokinin (CCK) and pancreatic polypeptide (PP) and output of pancreatic enzymes were measured in 33 patients with exocrine pancreatic insufficiency and 26 healthy subjects. Patients with impairment of pancreatic function were subdivided into those with moderate and severe insufficiency. Plasma CCK and PP were measured by radioimmunoassay. Fasting plasma CCK in patients with pancreatic insufficiency (5.8±1.1 pmol/liter) did not differ significantly from controls (4.2±0.6 pmol/liter). After endogenous stimulation with a Lundh meal, plasma CCK increased in both groups without significant differences over 2 hr. Basal and stimulated plasma levels of pancreatic polypeptide (PP) were markedly decreased only in patients with severe pancreatic insufficiency. Our results demonstrate that basal and meal-stimulated CCK levels in patients with pancreatic insufficiency do not differ from controls. Furthermore the extent of functional impairment of the exocrine pancreas did not influence basal and postprandial CCK release.     

Parotid salivary gland function in patients with exocrine pancreatic insufficiency

Parotid function tests were performed on 12 patients with pancreatic insufficiency due to chronic pancreatitis. The concentrations of sodium and bicarbonate in stimulated parotid juice were reduced compared to controls (p less than 0.001). The secretion of 75Se-selenomethionine by the parotid salivary gland and exocrine pancreas following a Lundh test meal was measured in 12 patients with normal pancreatic function and 16 patients with exocrine pancreatic insufficiency. Eight of these patients had chronic pancreatitis both parotid and pancreatic secretion of the isotope were impaired. In pancreatic carcinoma the pancreatic excretion was impaired with no significant impairment of parotid secretion. The combined pancreatic/parotid radio-selenium test may be useful in differentiating between chronic pancreatitis and pancreatic carcinoma as the cause of pancreatic insufficiency.     

The Lundh Test: A Review of its Clinical Use in the Diagnosis of Pancreatic Disease

Abstract: The clinical value of the Lundh test in the diagnosis of pancreatic disorders was reviewed retrospectively for 139 patients with proven pancreatic disease (15 acute and 72 chronic pancreatitis, 51 carcinoma of the pancreas and one partial pancreatectomy). There was a good separation between patients with pancreatic disease and those with other gastrointestinal disorders who presented with similar symptoms. The test was most helpful in patients with chronic pancreatitis (diagnostic rate 89%, mean tryptic activity (MTA) < 7 U), more particularly in those presenting with jaundice or steatorrhoea (100%) than pain (86%), but less successful (diagnostic rate 68%) in carcinoma of the pancreas (steatorrhoea 100%; jaundice 64%; pain 55%). Complete absence of bile from duodenal juice in jaundiced patients usually indicated pancreatic or hepatobiliary carcinoma. An abnormal but not diagnostic MTA (7 to < 10 U) was seen in 7% of patients with chronic pancreatitis, 13% with carcinoma of the pancreas and 11% with non-pancreatic disorders and suggested the need for further pancreatic investigation. Cytological examination of duodenal juice increased the usefulness of the test. Although malignant cells were rarely seen, characteristic (degenerate) cells were found in 22 of 44 (50%) patients with, but only five of 85 (6%) without pancreatic disease, even when the MTA was normal. The Lundh test can be conveniently combined with a jejunal biopsy at the same intubation for the investigation of diarrhoea or steatorrhoea.     

Time-related Enzyme Concentrations in Duodenal Aspirates after Ingestion of a Test Meal

The concentration of trypsin, pancreatic iso-amylase, phospholipase, and lipase were determined in intestinal content during the first two hours of digestion of a test meal. In normal subjects the concentration curves for all enzymes displayed a typical biphasic pattern. In patients with chronic pancreatic disease, the typical variations of the enzyme concentrations were markedly diminished. In patients with celiac disease, the initial peak of the trypsin and phospholipase activities seemed to be delayed, and in patients operated upon with a Polya gastric resection the concentrations of trypsin and phospholipase increased gradually. In these two disorders the lipase concentration curve was of quite a different, uncharacteristic pattern. It is suggested that the concentration curves of the enzymes reflect pancreatic secretion. Furthermore, the secretion of lipase in celiac disease and following gastric resection seems to be ‘non-parallel’. Owing to a fairly considerable variation in the values from different individuals, it seems reasonable to conclude that in clinical practice determination of enzyme concentration curves after a test meal probably does not improve the reliability of the conventional Lundh test.     

Radioselenium pancreozymin-secretin test as a clinical test for pancreatic exocrine function

The appearance of radioselenium in the protein fraction of duodenal aspirates has been studied after an intravenous injection of⁷⁵Se-selenomethionine. The continuous flow of pancreatic juice was stimulated by pancreozymin at 120 minutes and by secretin at 140 minutes. A good distinction between normal subjects and patients with pancreatic disease was obtained by measuring⁷⁵Se-radioactivity in the protein fraction of duodenal aspirates; either cumulative radioactivity during the combined 80-minute post-pancreozymin-secretin period, or maximum⁷⁵Se-specific activity during the postsecretin period was used as an index. The test presented here might be a useful and sufficiently reliable method for detecting abnormal pancreatic exocrine function. This test can be performed along with the conventional pancreozymin-secretin test, serum enzyme response to pancreozymin and secretin, and pancreatic scintiscanning.     

Oral administration of a chymotrypsin-labile peptide--a new test of exocrine pancreatic function in man (PFT).

One gram N-benzoyl-L-tyrosyl PABA was orally administered to 24 controls, 15 patients with chronic exocrine pancreatic disease, 13 patients after an attack of acute pancreatitis, two patients with gluten-sensitive enteropathy, and 10 patients with biliary tract disease, peptic ulcer, or other pathology of the gastrointestinal tract. In the presence of chymotrypsin, PABA is split from the peptide and excreted in the urine. The amount of PABA excreted serves as a parameter of exocrine pancreatic function. In 51 patients, exocrine pancreatic secretion was also assessed by the Lundh test. In the control group a mean of 59-6 +/- 12-2% (mean +/- 2 SD) of the peptide-PABA was excreted over a period of six hours. PABA excretion in exocrine pancreatic deficiency was significantly less (P less than 0.001) than in controls. With one exception no overlap of data was noted. In the group with exocrine pancreatic deficiency, a significant relationship was shown between the PFT and the Lundh test. Reproducibility in duplicate test was excellent. The present data justify further investigations of this procedure as a possible new oral test of exocrine pancreatic function.     

The Secretin-CCK Test and a Modified Lundh Test

A comparison has been made between a modified Lundh test and the secretin-CCK test. Thirty-four patients with pancreatic disease (chronic pancreatitis, n=25; recurrent pancreatitis, n = 5; and pancreatic carcinoma, n = 4) and 20 patients with other gastrointestinal disorders were studied. The results showed that estimation of trypsin secretion, irrespective of the mode of stimulation, had a low sensitivity in detecting pancreatic disease. Estimation of bicarbonate secretion after secretin stimulation provided a more sensitive test, especially for disclosing chronic pancreatitis.     

Effect of a liquid meal given as a bolus into the jejunum on human pancreatic secretion

Major features of pancreatic secretion stimulated by a meal depend on intestinal phase mechanisms. However, an intrajejunal (i.j.) meal infusion is widely used for the treatment of inflammatory pancreatic diseases when the resting of the gland is desired. This study was undertaken to compare the effects of an intragastric (i.g.) and an i.j. complete fluid (Lundh) test meal on pancreatic enzyme secretion. Eight men (mean age, 43 years; range, 31-48) free from pancreatic disease were studied. Pancreatic secretion was measured via a multiple-lumen tube by aspiration of the duodenal juice. After a fasting period, the Lundh test meal was placed in the stomach or the upper jejunum. After the i.g. administration of the test meal, the aspirated duodenal juice was reinfused into the jejunum. The effect of atropine infusion (0.5 microg/kg/h) on the pancreatic enzyme secretion was studied. The pancreatic amylase, trypsin, and lipase outputs were determined. The plasma levels of cholecystokinin (CCK) and of gastrin were measured by bioassay and radioimmunoassay, respectively. The trypsin, amylase, and lipase secretions increased significantly after either an i.g. or an i.j. test meal intake. The trypsin, amylase, and lipase outputs were significantly decreased during the i.j. perfusion as compared with i.g. administration. The gastrin levels increased significantly after i.g., but remained unchanged after i.j. administration. The CCK release attained its maximum 40 and 60 min after the i.g. and i.j. test meal, respectively. However, the CCK release was significantly lower during the i.j. administration as compared with i.g. perfusion. An atropine infusion significantly reduced the i.g. and i.j. test meal-stimulated enzyme outputs. An i.j.-administered meal stimulates the pancreatic enzyme secretion, but this effect is significantly lower than that which occurs on i.g. administration. The i.j. meal-stimulated secretion of pancreatic enzymes is subject to both cholinergic and peptidergic regulation. The deficiency of gastrin and the delayed and decreased CCK release are believed to account for the reduced enzyme output.