Fecal elastase-1 determination in the diagnosis of chronic pancreatitis

The diagnosis of chronic pancreatitis is based on morphological and functional data. To evaluate exocrine function, the secretin-cholecystokinin test is the gold standard but this is invasive and frequently unavailable. Recently, fecal elastase-1 determination has been investigated as an indirect test of pancreatic function.Objective: To evaluate the diagnostic value of fecal elastase-1 in chronic pancreatitis by comparing it with other indirect methods of evaluating pancreatic function such as the urine pancreolauryl test and fecal chymotrypsin determination. To do this, we analyzed the three diagnostic methods in four groups of patients: group I (14 patients with confirmed chronic pancreatitis); group II (5 patients with recurrent episodes of acute alcoholic pancreatitis; group III (9 patients with non-pancreatic diarrhea); group IV (8 patients with other gastrointestinal diseases).Results: Compared with the control groups (groups III and IV), patients in groups I and II presented lower levels of fecal elastase-1 (groups I-II: 88 mcg/g, groups III-IV: 635 mcg/g, p < 0.0001), fecal chymotrypsin (4.3 U/g and 29.3 U/g, respectively, p < 0.0001), and pancreolauryl (14% and 54%, respectively, p < 0,001). In the diagnosis of confirmed chronic pancreatitis (group I) the fecal elastase-1 and pancreolauryl tests showed a sensitivity of 85.6% and 78.5%, respectively. However, in group II, the most sensitive test was the pancreolauryl test (80% versus 60% for the chymotrypsin test and only 40% for the fecal elastase-1 test). In contrast, the fecal elastase-1 test showed the highest specificity (94.1% versus 88.2% for the fecal chymotrypsin test and 81.3% for the pancreolauryl test).Conclusion: Fecal elastase-1 determination is an effective indirect method in the diagnosis of patients with advanced chronic pancreatitis. However, when the disease is in the early stages, its sensitivity is no greater than that of other indirect tests. The greatest advantage of this test is its high specificity.     

Detection of pancreatic steatorrhea by oral pancreatic function tests

Pancreolauryl and NBT-PABA tests were performed in urine of 54 patients with exocrine pancreatic insufficiency and, additionally, in serum of 29 of these patients. All patients underwent a secretin-pancreozymin test and a 72-hr fecal fat analysis. Pancreatic steatorrhea occurred (with only three exceptions) when the pancreolauryl test revealed a T/C ratio [recovery of the fluorescein of the test (T) and the control (C) day] of <10, or when serum fluorescein concentrations were below 0.5 g/ml. The NBT-PABA test also showed a negative correlation between urinary PABA excretion or serum PABA concentration and fecal fat excretion, but there was no diagnostically useful cutoff limit indicating decompensation of exocrine pancreatic insufficiency. These findings indicate that the pancreolauryl test may facilitate clinical evaluation of patients with chronic pancreatitis by simultaneously assessing exocrine pancreatic insufficiency as a cause and predicting pancreatic steatorrhea as a sequel of maldigestion. In clinical practice, the pancreolauryl test can be used as a parameter for deciding whether to initiate pancreatic enzyme substitution if direct pancreatic function tests and fecal fat analysis are not available.     

Exocrine pancreatic function after gastrectomy. Specificity of indirect tests

We compared intraindividually the specificity of indirect pancreatic function tests before and after total (n = 4; Roux-en-Y) or subtotal (n = 6; Billroth II) gastrectomy. Before gastrectomy only 1 patient showed a falsely pathological result with the pancreolauryl test (90% specificity), while the results of all the other tests were correctly normal (100% specificity using the usual cutoff limits). After gastrectomy the respective specificities were as follows: pancreolauryl test 10%, bentiromide test 70%, fecal chymotrypsin 70%, and plasma amino acid consumption test 100%. There was no obvious difference in the reduction of specificity between subtotal and total gastrectomy. The respective preoperative to postoperative changes in the median test data were as follows: plasma amino acid consumption test +21%, bentiromide test -12%, fecal chymotrypsin -51%, and pancreolauryl test -53%. It is concluded that after gastrectomy only the plasma amino acid consumption test is unaffected by postoperative anatomic alterations.     

Pancreolauryl and NBT-PABA tests. Are serum tests more practicable alternatives to urine tests in the diagnosis of exocrine pancreatic insufficiency?

Serum fluorescein and p-aminobenzoic acid were measured during a urine pancreolauryl and an N-benzoyl-l-tyrosyl-p-aminobenzoic acid (NBT-PABA) test in 22 healthy controls, 17 patients with gastrointestinal nonpancreatic diseases (normal secretin-pancreozymin test), and 31 patients with abnormal exocrine pancreatic function due to chronic pancreatitis. The optimal cutoff point for separating normal from abnormal pancreatic function was after 210 min in the pancreolauryl test and after 150 min in the NBT-PABA test. The latter test was slightly less sensitive and specific than the pancreolauryl test. Serum tests seem to offer a practicable alternative to the established indirect pancreatic function tests in urine and may be used in the elderly and severely ill, as well as in outpatients in whom correct collection of the urine may be difficult.     

Fecal Elastase Test: Evaluation of a New Noninvasive Pancreatic Function Test

Objectives: Pancreatic elastase is highly stable along the intestinal tract. A new ELISA is commercially available to measure human specific elastase-1 concentration in stool. We evaluated the behavior of this fecal elastase test (FET) compared with other indirect pancreatic function tests in patients with chronic pancreatitis (CP).
Methods: A total of 69 patients were included in the study, 20 of whom were diagnosed with CP according to the findings on ERP and CT; 13 patients had other pancreatic diseases, and the remaining 36 patients had gastrointestinal or hepatic disorders. All patients' elastase-1 concentrations and chymotrypsin activities [fecal chymotrypsin test (FCT)] were measured, and the serum pancreolauryl test (PLT) was performed.
Results: Similar to PLT, fecal elastase concentration was significantly decreased in patients with moderate and severe CP (assessed by ERP) compared with patients with extra pancreatic disorders. However, and contrarily to PLT, FET was not affected by gastric resection, matabsorption due to intestinal disease, or marked alteration of the gastric motility. The sensitivity of FET was 100% for moderate to severe CP but 0% for mild CP; the specificity was 83%. Compared with other indirect pancreatic function tests, FET appears to be as sensitive as PLT and as specific as FCT, and it is clearly more specific than PLT and more sensitive than FCT. Unlike FCT, FET was not affected by oral enzyme supplementation.
Conclusion: FET is a simple and accurate functional test for CP, and it is hardly influenced by extrapancreatic disorders or therapy with exogenous enzymes.     

Fecal elastase-1 determination: 'gold standard' of indirect pancreatic function tests?

BACKGROUND: Tubeless pancreatic function tests measuring the content of elastase-1 and the activity of chymotrypsin in stool are used with different cut-off levels and with varying success in diagnosing functional impairment of the pancreas. The aim of our study was to re-evaluate the sensitivity and specificity of elastase-1 and chymotrypsin in stool in the assessment of exocrine pancreatic insufficiency. METHODS: In 127 patients displaying clinical signs of malassimilation, the secretin-caerulein test ('gold standard'), fecal fat analysis, fecal chymotrypsin activity and fecal elastase-1 concentration were performed. Exocrine pancreatic insufficiency was graded, according to the results of the secretin-caerulein test, into mild, moderate and severe. Chymotrypsin and elastase-1 in stool were estimated using two commercially available test kits. Fecal elastase-1 concentration of 200 and 100 microg/g stool and chymotrypsin activity of 6 and 3 U/g stool were used separately as cut-off levels for calculation. RESULTS: 1) In 65 patients, a normal pancreatic function was found using the secretin-caerulein test. In 62 patients, an exocrine pancreatic insufficiency was found and classified into severe (n = 25), moderate (n = 14) and mild (n = 23). 2) The correlation between fecal elastase-1 and chymotrypsin with duodenal enzyme outputs of amylase, lipase, trypsin, chymotrypsin and elastase-1 ranged between 33% and 55% and 25% and 38%, respectively. 3) Using a cut-off of 200 microg elastase-1/g, stool sensitivities of fecal elastase-1 and fecal chymotrypsin (cut-off: 6 U/g) were 100% and 76%, respectively (P < 0.0001 and P < 0.001 respectively) in severe exocrine pancreatic insufficiency, 89% and 47% respectively (P < 0.001; P = 0.34, respectively) in moderate and 65% for both in mild pancreatic insufficiency. Specificities of elastase-1 and chymotrypsin in stool were 55% and 47%, respectively. 4) Elastase-1 based diagnostic provided a positive predictive value of 50% using a cut-off' 200 microg/g stool in a representative group of consecutively recruited patients with gastroenterological disorders. CONCLUSION: Determination of fecal elastase-1 is highly sensitive in the diagnosis of severe and moderate exocrine pancreatic insufficiency and is of significantly higher sensitivity than fecal chymotrypsin estimation. Specificity for both stool tests is low. Correlation between elastase-1 and chymotrypsin in stool and duodenal enzyme outputs is moderate. Neither test is suitable for screening, as they provide a pathologic result in roughly half of 'non-pancreas' patients.     

A Single-Specimen Fecal Chymotrypsin Test in the Diagnosis of Pancreatic Insufficiency: Correlation with Secretin- Cholecystokinin and NBT-PABA Tests

An investigation of fecal chymotrypsin activity on spot fecal specimens was carried out in three groups of subjects, divided as follows: 45 healthy controls (group C); 36 patients with gastroenterological diseases of extrapancreatic origin (group VP); and 42 patients with chronic pancreatitis (group CP). Nineteen patients of group CP underwent pancreozymin-secretin and NBTPABA tests. The following results, expressed as mg of chymotrypsin/g of feces, were obtained: C = 0.610 ± 0.203; CP = 0.291 ± 0.154, p < 0.001; VP = 0.560 ± 0.234. FCT showed a sensitivity rate of 78.5% and a specificity rate of 71.6%. The fecal output of chymotrypsin correlated well with the pancreatic secretion of chymotrypsin (r = 0.59, p < 0.01) and with the percentage of recovery of urinary PABA (r = 0.44, p < 0.05). We conclude that chymotrypsin assay by the described method on spot stool specimens is a simple, reliable technique which may be considered a good screening test for pancreatic insufficiency. The test will not detect minimal pancreatic disease or minimal pancreatic dysfunction.     

Evaluation of exocrine pancreatic function by the haptocorrin degradation test of the duodenal fluid collected by endoscopy

Two groups of biological methods are commonly used to evaluate the exocrine pancreatic function: tests which require tubes for the collection of duodenal juice and the tubeless tests which are indirect tests of pancreatic function. In this study we have attempted to improve a new test: the test of haptocorrin degradation (THD). This test measures the transfer of labelled cobalamin from haptocorrin to the intrinsic factor which is provoked by the degradation of the haptocorrin by proteases in the duodenal juice. We present the results of this test in 90 patients with chronic pancreatitis. THD was first assayed with basal duodenal juice collected by naso duodenal tubing during secretin cerulein stimulation. In this study the sensitivity and specificity of THD was 0.86 and 0.93, respectively. In the second part of this study we demonstrated that the means of collecting duodenal juice had no effect on the results of THD. Duodenal juice was collected during a secretin cerulein test or during a routine upper gastrointestinal endoscopy after pancreatic stimulation with secretin. The sensitivity and specificity of THD was 0.90 and 0.94, respectively, when duodenal juice was collected during endoscopy. THD was significantly correlated with the NBT-PABA test, steatorrhea, and with the activity of trypsin and chymotrypsin in the duodenal juice. In this study, NBT-PABA was less sensitive than THD for the diagnosis of chronic pancreatitis (sensitivity was 0.70 and 0.89, respectively). The specificity of THD was estimated at 0.94. THD seemed to be a valuable adjunct to test pancreatic function. As upper gastrointestinal endoscopy is usually performed in patients with proved or suspected chronic pancreatitis, THD seems to have a place of choice among the other tests of pancreatic exocrine function. Further evaluation of this test by a multicentric prospective trial is now needed.     

The assay of chymotrypsin in stool as a simple and effective test of exocrine pancreatic activity in cystic fibrosis

The study evaluates two methods of assay of fecal chymotrypsin (titrimetric and spectrophotometric method) as an index of exocrine pancreatic function. The assay was performed on 101 control subjects and 128 cystic fibrosis (CF) patients by the first method, and 75 controls and 102 CF patients by the second method. CF subjects were subdivided into four groups based on pancreatic function: total pancreatic insufficiency in the first group, partial pancreatic insufficiency in the second group, normal pancreatic function in the third group, and pancreatic insufficiency plus enzymatic treatment in the fourth group. Fifty-four CF patients were examined in the first group, 27 in the second group, 19 in the third group, and 28 in the fourth group by the titrimetric method; 23, 25, 50, and 65, respectively by the spectrophotometric method. The spectrophotometric method was highly reproducible and more sensitive and specific. With such a method the assay on stool random sampling correlated with the duodenal output of chymotrypsin after hormonal stimulation as well as fecal output of 72 h. The test had sensitivity and specificity of 100% if referred to CF patients with total pancreatic insufficiency. It was calculated that CF patients with normal fecal chymotrypsin have a probability of 76% to have a normal pancreatic function and a probability of 24% to have a partially compromised pancreatic function. The assay separates distinctly CF patients with a fat absorption coefficient greater than 90% from those with a coefficient less than 90%. The test is proposed for current clinical use in diagnosis and treatment of pancreatic insufficiency in cystic fibrosis.     

The diagnostic validity of non-invasive pancreatic function tests--a meta-analysis

BACKGROUND: The paper discusses the non-invasive (tubeless) pancreatic function tests used to diagnose exocrine pancreatic insufficiency (EI). Studies evaluating the diagnostic validity of these tests are integrated into a meta-analysis, provided that they comply with the following criteria: The sensitivity (Ss) of a test has to be calculated by comparing it with an invasive function test which is accepted as the gold standard of pancreatic function diagnostics. Furthermore, the test must differentiate between slight (sl), moderate (md) and severe (sv) EI. For assessment of the specificity (Sp), the control group should not contain healthy persons but rather patients with other gastrointestinal diseases and a normal pancreatic function. In the statistical evaluation, each study was weighted according to the number of persons included. RESULTS: Tests (n = sum of persons included in all analysed studies): Fecal chymotrypsin: Ss (n = 169) 54 % (sl EI), 53 % (md EI), 89 % (sv EI), Sp (n = 202) 74 %. NBT-PABA test: Ss (n = 394) 49 % (sl EI), 64 % (md EI), 72 % (sv EI), Sp (n = 218) 83 %. Pancreolauryl test: Ss (n = 320) 63 % (sl EI), 76 % (md EI), 94 % (sv EI), Sp (n = 171) 85 %. Fecal elastase-1: Ss (n = 307) 54 % (sl EI), 75 % (md EI), 95 % (sv EI), Sp (n = 347) 79 %. Additional tests discussed but not included in the meta-analysis were fecal fat, (13)C breath tests, amino acid consumption test, serum tests. CONCLUSION: None of the non-invasive pancreatic function tests is sensitive enough to diagnose reliably a slight to moderate exocrine pancreatic insufficiency.     

Pancreatic function tests: When to choose, what to use

Although techniques for high-resolution imaging of the pancreas are constantly being improved, the evaluation of pancreatic function remains crucial for the workup of pancreatic diseases. More than 20 direct and indirect tests are available for the assessment of pancreatic function. Measurement of fecal elastase-1 is recommended as the most suitable test for the initial assessment of pancreatic function. Among other techniques, the pancreolauryl test, and alternatively the BT-PABA (N-benzoyl-L-tyrosyl-paminobenzoic acid) or the ¹³C-mixed-triglyceride test, yield the best sensitivity and specificity. Nevertheless, all indirect tests are of limited value in patients with mild to moderate impairment of pancreatic function. In these patients, the secretin-caerulein test remains the gold standard.     

Reliability of the Bz-Ty-PABA and the pancreolauryl test in the assessment of exocrine pancreatic function

The reliability of the para-aminobenzoic acid (PABA) test (performed in the conventional manner, i.e. without control day) and of the pancreolauryl test was assayed in respect of the exocrine pancreatic capacity measured by using the secretin-caerulein test in 57 subjects, 22 of which were suffering from chronic pancreatitis. When 50 and 20% urinary excretion of the orally administered Bz-Ty-PABA and pancreolauryl, respectively, were chosen as the lower normal limits, the PABA test showed a specificity quite similar to that of the pancreolauryl test (97 and 95%, respectively) despite the lack of a control day test, but a lower sensitivity (39 vs. 83%). The association of both tests was not advantageous compared with the pancreolauryl test alone.     

Serum lipase,isoamylase and pancreatic function test (PFT) in juvenile-onset insulin-dependent diabetes mellitus

Summary Significantly decreased activity of pancreatic isoamylase in serum was found in a group of 51 juvenile-onset insulin-dependent diabetics as compared to healthy subjects (p<0.005). No significant changes were observed for urinary p-aminobenzoic acid excretion in 20 of the juvenile-onset diabetics in whom the NBT-PABA test was performed, even though 25% of the values were below the normal limit. A highly significant decrease of serum lipase activity was found in juvenile-onset diabetics as compared to controls (p<0.001). No significant correlation was found in juvenile-onset diabetics between serum pancreatic isoamylase and lipase or marker of chymotrypsin activity expressed as the amount of p-aminobenzoic acid excreted into urine. The NBT-PABA test appears to be of small importance in the evaluation of changes of the exocrine pancreas in insulin-dependent diabetes mellitus. However, simultaneous evaluation of serum pancreatic isoamylase and lipase activities justified the suspicion of pancreatic damage in 50% of the patients tested.     

Faecal elastase 1: a novel, highly sensitive, and specific tubeless pancreatic function test.

BACKGROUND: Indirect pancreatic function tests available today are unreliable for clinical practice in early chronic pancreatitis due to their low sensitivity in mild and moderate exocrine pancreatic insufficiency. AIM: To evaluate the sensitivity, specificity, and practicability of faecal elastase 1 determination in patients with mild, moderate, and severe exocrine pancreatic insufficiency categorised according to the secretin-caerulein test as "gold standard'. PATIENTS AND METHODS: Faecal and duodenal elastase 1 concentration (commercial enzyme linked immunosorbent assay (ELISA)), faecal chymotrypsin activity, faecal fat analysis, and the secretin-caerulein test were performed on 44 patients with mild (n = 8), moderate (n = 14), and severe (n = 22) exocrine pancreatic insufficiency and 35 patients with gastrointestinal diseases of non-pancreatic origin. Fifty healthy volunteers were studied as normal controls. Morphological examinations were carried out to definitely confirm or exclude chronic pancreatitis. RESULTS: With a cut off of 200 micrograms elastase 1/g stool the sensitivity was 63% for mild, 100% for moderate, 100% for severe, and 93% for all patients with exocrine pancreatic insufficiency, and specificity was 93%. Values for chymotrypsin were 64% (sensitivity) and 89% (specificity). Significant (p < 0.001) correlations were found for faecal and duodenal elastase with duodenal lipase, amylase, trypsin, volume, and bicarbonate output. Individual day to day variations of faecal elastase 1 concentrations were very low (mean CV = 15%) and sample storage at room temperature is possible for at least one week. CONCLUSIONS: Faecal elastase 1 determination proved to be a highly sensitive and specific tubeless pancreatic function test.     

Value of combinations of pancreatic function tests to predict mild or moderate chronic pancreatitis

Pancreatic function tests share an insufficient accuracy concerning the detection of mild or moderate forms of chronic pancreatitis. It was evaluated here whether by combination of different assays the prediction or exclusion of chronic pancreatitis could be improved. METHODS: 62 patients with chronic abdominal pain and suspected chronic pancreatitis underwent an endoscopic retrograde pancreaticography. The duct alterations were classified according to the Cambridge criteria. In all individuals the pancreolauryl test in serum (PLT-S) and urine (PLT-U) was performed and elastase 1-immunoreactivity (E) as well as chymotrypsin (Chy) activity in stool were measured. Sensitivities, specificities, receiver-operator-curves as well as cut-off points at optimal accuracies were calculated for each single assay and all test combinations. Cut offs were optimized by a mathematical model to achieve highest accuracies. RESULTS: In 30 patients the pancreatic duct was normal and in 32 patients alterations of the duct system were found. These were classified as mild in 10 patients, as moderate in 8 patients and as severe in 14 patients. In those with mild and moderate disease all pancreatic function tests showed sensitivities/specificities of 60-65% and 65-70%, respectively. Only in severe chronic pancreatitis elastase was superior to the other tests. Combinations of function tests did not lead to improved accuracy. After mathematical optimization the accuracy (sensitivity 80%, specificity 80%) was best for the combination of PLT-S (cut off 4.7 micrograms/ml) and E (cut off 500 micrograms/g). Both parameters had to be below these newly defined cut offs to diagnose chronic pancreatitis. CONCLUSIONS: The accuracy of pancreatic function tests may be improved by use of altered cut offs and a combination of serum pancreolauryl test and elastase. These newly defined cut offs will have to be evaluated in a much larger study.     

Pancreatic function testing: serum PABA measurement is a reliable and accurate measurement of exocrine function.

A comparison between the NBT-PABA/14C-PABA test (NBT-PABA, n-benzoyl-tyrosyl para-aminobenzoic acid) using the PABA excretion index (PEI) and serum PABA estimation at 90 minutes has been made in 42 consecutive subjects attending for investigation of possible pancreatic disease to a District General Hospital (DGH). The PEI was unobtainable or incorrect on 38% of occasions compared with 9% for the serum test. Sensitivity, specificity, and efficiency for the PEI (n = 33 valid results) were 71%, 88%, and 79% respectively and for the serum PABA (n = 41 valid results), 95%, 90%, and 93% respectively. These results confirm that measurement of serum PABA is a simpler, more reliable, and a more accurate method of assessing pancreatic function.     

Fecal isoamylase activity in patients with pancreatic diseases.

Fecal isoamylase activity was studied in 93 consecutive patients (26 in the recovery stage of acute pancreatitis, 24 with chronic pancreatitis, 13 with pancreatic cancer, and 30 with other gastrointestinal diseases) and compared with fecal chymotrypsin activity and the results of the secretin test. Seventy-six healthy subjects were studied as controls. Both pancreatic (p)-type and salivary (s)-type isoamylase activities in stool were determined by inhibitor assay as well as cellulose acetate electrophoresis. The mean fecal amylase activity in healthy subjects was 757 +/- 88 IU/g (p-type isoamylase: 77 +/- 2%, s-type isoamylase: 23 +/- 2%). There was a good correlation between fecal p-type isoamylase and chymotrypsin activities (r = 0.625, p less than 0.001). Fecal p-type isoamylase activity in patients with chronic pancreatitis and pancreatic cancer was significantly lower than in healthy subjects (p less than 0.001). Patients with moderate and severe exocrine pancreatic insufficiency as determined by the secretin test had significantly lower fecal p-type isoamylase activity. Daily fat intake did not affect fecal amylase or isoamylase activities. Fecal s-type isoamylase activity in patients with hypoacidity was significantly higher than in patients with hyperacidity, but no difference in fecal p-type isoamylase activity was observed. It is concluded that analysis of fecal isoamylase activity is useful in the assessment of pancreatic function.     

Evaluation of the diagnostic value of serum tumor markers,and fecal k‐ras and p53 gene mutations for pancreatic cancer

OBJECTIVE: To evaluate the diagnostic value for pancreatic cancer of four serum tumor markers, carbohydrate antigen (CA) 199, CA242, CA50 and carcino‐embryonic antigen (CEA), and fecal k‐ras and p53 gene mutations. METHODS: From February 2002 to March 2004, 136 patients were consecutively diagnosed with pancreatic cancer in the three participating medical centers. The diagnosis was confirmed by pathology in 53 patients, of whom five were excluded because they did not have measurement of serum tumor marker. The remaining 48 patients comprised the case group in the study. Ninety‐six patients with benign digestive diseases diagnosed during the same period were recruited as control subjects. They were matched by sex and age. In both groups, serum CA199, CA242, CA50 and CEA were measured by ELISA, and fecal k‐ras and p53 gene mutations were measured by PCR‐restriction fragment length polymorphism and PCR‐single strand conformational polymorphism, respectively. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to compare their diagnostic value, as well as the sensitivity, specificity and likelihood ratio. Moreover, independent and sensitive tests from these non‐invasive approaches were selected to form a parallel test that may have further improved sensitivity for diagnosis of pancreatic cancer. RESULTS: The AUC of serum CA199 and CA242 were 0.821 (95%CI 0.725–0.917) and 0.821 (95%CI 0.723–0.919), respectively. The optimal diagnostic value of serum CA199 for pancreatic cancer was 93 U/mL, with a sensitivity of 73.7% and specificity of 91.4%. The positive likelihood ratio of CA199 was 8.57, and the negative likelihood ratio was 0.29. The optimal diagnostic value of serum CA242 was 25 U/mL, with a sensitivity of 71.1% and specificity of 93.5%. The positive likelihood ratio of CA242 was 10.94, and the negative likelihood ratio was 0.31. The sensitivity of fecal k‐ras gene mutation for diagnosis of pancreatic cancer was 77.4%, and the specificity was 81.2%. The positive and negative likelihood ratios of fecal k‐ras gene mutation were 4.12 and 0.28, respectively. The sensitivity and specificity of fecal p53 gene mutation were 25.8% and 95.3%, respectively, and its positive and negative likelihood ratios were 5.49 and 0.78. The rate of fecal k‐ras mutation was higher in patients with benign pancreatic diseases (57.14%) than that of controls with non‐pancreatic disorders. The values of serum tumor markers and fecal k‐ras and p53 gene mutation rates were not significantly different in subgroups according to site or stage of pancreatic cancer. The sensitivity and specificity of the parallel test of serum CA199 and fecal k‐ras gene mutation were 94.06% and 74.22%, respectively, while the sensitivity and specificity of the parallel test of serum CA242 and fecal k‐ras were 93.47% and 75.92%, respectively. CONCLUSIONS: Serum CA199 and CA242 are valuable diagnostic tools for pancreatic cancer. The diagnostic value is further improved when they are combined with fecal k‐ras gene mutation measurement.     

胰腺外分泌功能与胰腺癌分期、肿瘤大小关系的临床研究

目的 研究胰腺外分泌功能与胰腺癌分期、肿瘤大小的关系.方法 采用NBT-PABA试验测定39例胰腺癌、46例CP患者和20名正常人胰腺外分泌功能,分析其与胰腺癌JPS局部进展度(T因子)及肿瘤大小(Ts)的关系.结果 正常人PABA排泄率平均为(78.9±15.9)%;CP患者平均为(58.6±19.3)%,其中轻、中、重度CP的PABA排泄率分别为(75.5±23.6)%、(57.9±21.5)%、(45.5±16.7)%;胰腺癌患者PABA排泄率平均为(47.6±18.3)%.其中,L3+T4期胰腺癌患者PABA排泄率为(42.2±21.7)%,显著低于Tl+T2期患者的(64.8±11.1)%(P<0.05);TS3+TS4患者PABA排泄率为(34.8±17.2)%,显著低于TS1+TS2患者的(55.6±23.5)%(P<0.05);胰头癌PABA排泄率为(42.5±16.4)%,显著低于胰体尾癌的(71.8±9.6)%(P<0.05);33例胰头癌中,主胰管狭窄患者的PABA排泄率为(54.2±14.1)%,显著高于胰管中断患者的(37.6±14.1)%(P<0.05).胰腺癌与中、重度CP的胰腺外分泌功能无显著差异.结论 胰头癌患者的胰腺外分泌功能减低的程度与胰腺癌分期、肿瘤大小及部位有一定相关性,其中胰管中断为影响判定的因素.胰腺外分泌功能不能鉴别胰腺癌与中、重度CP.     

Clinical Utility of the Serum Pancreolauryl Test in Diagnosis and Staging of Chronic Pancreatitis

Indirect pancreatic function tests are frequently used in the clinical routine as complementary tools for the diagnosis of chronic pancreatitis (CP) because of their noninvasiveness and simplicity. We analyzed the clinical efficacy and routine application of a modified serum pancreolauryl test (PLT) in the diagnosis and staging of CP. We studied a total of 90 patients with CP diagnosed by endoscopic retrograde pancreatography and 54 patients with extrapancreatic gastrointestinal disorders as controls. Sensitivity and specificity of the serum PLT in the diagnosis of CP were 82% and 91 %, respectively, using a value of 4.5 μg/ml as cutoff. In the diagnosis of patients with mild to moderate morphological changes of CP, the sensitivity of the serum PLT (52%) was improved by the concomitant analysis of serum pancreatic amylase in a logistic model (70%). Serum PLT closely correlated with the degree of pancreatic ductal abnormalities ( p < 0.001), and showed a sensitivity of 81% and specificity of 89% in the staging of CP (mild-moderate vs. marked CP; cutoff 2.5 μg/ml). We conclude that the modified serum PLT is a reliable test which should be considered as a first-line option for the diagnosis and follow-up of patients with CP.