A degradation-sensitive anionic trypsinogen (PRSS2) variant protects against chronic pancreatitis.

Chronic pancreatitis is a common inflammatory disease of the pancreas. Mutations in the genes encoding cationic trypsinogen (PRSS1) and the pancreatic secretory trypsin inhibitor (SPINK1) are associated with chronic pancreatitis. Because increased proteolytic activity owing to mutated PRSS1 enhances the risk for chronic pancreatitis, mutations in the gene encoding anionic trypsinogen (PRSS2) may also predispose to disease. Here we analyzed PRSS2 in individuals with chronic pancreatitis and controls and found, to our surprise, that a variant of codon 191 (G191R) is overrepresented in control subjects: G191R was present in 220/6,459 (3.4%) controls but in only 32/2,466 (1.3%) affected individuals (odds ratio 0.37; P = 1.1 x 10(-8)). Upon activation by enterokinase or trypsin, purified recombinant G191R protein showed a complete loss of trypsin activity owing to the introduction of a new tryptic cleavage site that renders the enzyme hypersensitive to autocatalytic proteolysis. In conclusion, the G191R variant of PRSS2 mitigates intrapancreatic trypsin activity and thereby protects against chronic pancreatitis.

The variable phenotype of the p.A16V mutation of cationic trypsinogen (PRSS1) in pancreatitis families.

OBJECTIVE: To characterise the phenotypes associated with the p.A16V mutation of PRSS1. DESIGN: Clinical and epidemiological data were collected for any family in which a p.A16V mutation was identified, either referred directly to the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer or via a collaborator. DNA samples were tested for mutations in PRSS1, SPINK1, CFTR and CTRC. PATIENTS: Participants were recruited on the basis of either family history of pancreatitis (acute or chronic) or the results of genetic testing. Families were categorised as having hereditary pancreatitis (HP), idiopathic disease or pancreatitis in a single generation. HP was defined as >or=2 cases in >or=2 generations. Main outcome measures Onset of painful episodes of pancreatitis, death from pancreatic cancer, diagnosis of diabetes mellitus and exocrine pancreatic failure. RESULTS: Ten families with p.A16V mutations were identified (22 affected individuals): six HP families, three with idiopathic disease and one with only a single generation affected. The median age of onset, ignoring non-penetrants, was 10 years (95% CI 5 to 25). There were eight confirmed cases of exocrine failure, four of whom also had diabetes mellitus. There were three pancreatic cancer cases. Two of these were confirmed as p.A16V carriers, only one of whom was affected by pancreatitis. Those with p.A16V pancreatitis were compared to affected individuals with p.R122H, p.N29I and no PRSS1 mutation. No significant differences were proven using logrank or Mann-Whitney U tests. CONCLUSIONS: Penetrance of p.A16V is highly variable and family dependent, suggesting it contributes to multigenic inheritance of a predisposition to pancreatitis.

Is obesity an additional risk factor for alcoholic chronic pancreatitis?

BACKGROUND/AIMS: Obesity is a known risk factor for severe acute pancreatitis (AP). Since alcoholic chronic pancreatitis (ACP) is closely linked to alcoholic AP, overweight before disease onset might impact on incidence and outcome of ACP, and represent an additional risk factor for ACP. This issue has not been investigated, despite discussions on the 'hypercaloric-high-fat' hypothesis as an additional risk factor for ACP for many years. METHODS: The study is part of our prospective long-term study of a large, mixed, medical/surgical series of ACP patients. All cooperative patients were studied according to a protocol regarding clinical symptoms, physical status, routine laboratory tests, pancreatic function and pancreatic morphology (e.g. calcification) at yearly follow-ups. Our study includes 227 ACP patients with recorded body mass index (BMI) before disease onset followed up on average for 18 years from chronic pancreatitis (CP) onset. RESULTS: Males predominated (89.9%), age at onset averaged at 36 years, and exocrine insufficiency (97.4%) and calcification (88.1%) developed in virtually all patients. Surgery for B-type pain was performed in 57.7%, and death occurred in 62.8%. Overweight before disease onset was found in 54.2% (obesity in 15.0%) compared to 37.7% (3.1%) from a contemporary male control population. The highest BMI before disease onset did not impact on some major variables of ACP such as gender, age, progression of exocrine insufficiency, diabetes and calcification, and mortality from CP, except for a delayed progression rate of ACP indices in the surgical series. CONCLUSION: Overweight before disease onset appears to be another risk factor for ACP, supporting the 'hypercaloric-high-fat' hypothesis. and IAP.

Keratin 8 sequence variants in patients with pancreatitis and pancreatic cancer.

Keratin 8 (KRT8) is one of the major intermediate filament proteins expressed in single-layered epithelia of the gastrointestinal tract. Transgenic mice over-expressing human KRT8 display pancreatic mononuclear infiltration, interstitial fibrosis and dysplasia of acinar cells resulting in exocrine pancreatic insufficiency. These experimental data are in accordance with a recent report describing an association between KRT8 variations and chronic pancreatitis. This prompted us to investigate KRT8 polymorphisms in patients with pancreatic disorders. The KRT8 Y54H and G62C polymorphisms were assessed in a cohort of patients with acute and chronic pancreatitis of various aetiologies or pancreatic cancer originating from Austria (n=16), the Czech Republic (n=90), Germany (n=1698), Great Britain (n=36), India (n=60), Italy (n=143), the Netherlands (n=128), Romania (n=3), Spain (n=133), and Switzerland (n=129). We also studied 4,234 control subjects from these countries and 1,492 control subjects originating from Benin, Cameroon, Ethiopia, Ecuador, and Turkey. Polymorphisms were analysed by melting curve analysis with fluorescence resonance energy transfer probes. The frequency of G62C did not differ between patients with acute or chronic pancreatitis, pancreatic adenocarcinoma and control individuals. The frequency of G62C varied in European populations from 0.4 to 3.8%, showing a northwest to southeast decline. The Y54H alteration was not detected in any of the 2,436 patients. Only 3/4,580 (0.07%) European, Turkish and Indian control subjects were heterozygous for Y54H in contrast to 34/951 (3.6%) control subjects of African descent. Our data suggest that the KRT8 alterations, Y54H and G62C, do not predispose patients to the development of pancreatitis or pancreatic cancer.

Diagnosis and management of chronic pancreatitis: current knowledge.

This paper reviews the current literature on chronic pancreatitis (CP). Despite marked progress in diagnostic tools, predominately imaging methods, no consensus has been reached on the nomenclature of CP, ie diagnosis, classification, staging, pathomechanisms of pain and its optimal treatment. A major problem is that no single reliable diagnostic test exists for early-stage CP except histopathology (rarely available). This stage is characterised typically by recurrent acute pancreatitis +/- necrosis (eg pseudocysts). Acute pancreatitis is a well-defined condition caused in 80% of cases by gallstones or alcohol abuse. Alcoholic pancreatitis, in contrast to biliary pancreatitis, progresses to CP in the majority of patients. However, a definite CP-diagnosis is often delayed because progressive dysfunction and/or calcification, the clinical markers of CP, develop on average 5 years from disease onset. The progression rate is variable and depends on several factors eg aetiology, smoking, continued alcohol abuse. Repeated function testing eg by the faecal elastase test, is the best alternative for histology to monitor progression (or non-progression) of suspected (probable) to definite CP. The pathomechanism of pain in CP is multifactorial and data from different series are hardly comparable mainly because insufficient data of the various variables ie diagnosis, classification, staging of CP, pain pattern and presumptive pain cause, are provided. Pain in CP is rarely intractable except in the presence of cancer, opiate addiction or extra-pancreatic pain causes. Local complications like pseudocysts or obstructive cholestasis are the most common causes of severe persistent pain which can be relieved promptly by an appropriate drainage procedure. Notably, partial to complete pain relief is a common feature in 50-80% of patients with late-stage CP irrespective of surgery and about 50% of CP-patients never need surgery (or endoscopic intervention). The spontaneous "burn-out" thesis of CP is in accordance with this observation although precise data of this phenomenon are scarce. Recent observations indicate that the progression to late-stage CP is markedly delayed in non-alcoholic compared to alcoholic CP. Therefore, spontaneous pain relief is also delayed but it occurs in close association with severe exocrine insufficiency suggesting that aetiology has a major impact on the duration of early-stage CP and that the "burn-out" thesis appears valid both in uncomplicated alcoholic and nonalcoholic late-stage CP. For treatment of steatorrhea and diabetes the reader is referred to recent reviews. Mortality and survival are closely related to aetiology with an increased death rate of about 50% within 20 years from onset in alcoholic CP compared to a markedly better prognosis in hereditary and idiopathic "juvenile" CP. The risk of pancreatic cancer is increased particularly in nonalcoholic CP based on the longer survival, whereas the risk of extra-pancreatic (smoking-related) cancer is about 12-fold higher in alcoholic CP.

Outcome after Discontinuing Long-Term Benzimidazole Treatment in 11 Patients with Non-resectable Alveolar Echinococcosis with Negative FDG-PET/CT and Anti-EmII/3-10 Serology.

BACKGROUND/AIMS: Benzimidazoles are efficacious for treating non-resectable alveolar echinococcosis (AE), but their long-term parasitocidal (curative) effect is disputed. In this study, we prospectively analyzed the potential parasitocidal effect of benzimidazoles and whether normalization of FDG-PET/CT scans and anti-Emll/3-10-antibody levels could act as reliable "in vivo" parameters of AE-inactivation permitting to abrogate chemotherapy with a low risk for AE-recurrence. METHOD: This prospective study included 34 patients with non-resectable AE subdivided into group A (n = 11), followed-up after diagnosis and begin of chemotherapy at months 6, 12 and 24, and group B (n = 23) with a medium duration of chemotherapy of 10 (range 2-25) years. All patients were assessed by FDG-PET/CT examinations and anti-EmII/3-10 serology. Chemotherapy was abrogated in patients with normalization of FDG-PET/CT and serum anti-EmII/3-10 levels. These patients were closely followed-up for AE recurrence. Endpoint (parasitocidal efficacy) was defined by the absence of AE-recurrence >24 months after stopping treatment. RESULTS: Normalization of FDG-PET/CT scan and anti-EmII/3-10 levels occurred in 11 of 34 patients (32%). After abrogation of chemotherapy in these 11 patients, there was no evidence of AE-recurrence within a median of 70.5 (range 16-82) months. However, the patients' immunocompetence appears pivotal for the described long-term parasitocidal effect of benzimidazoles. CONCLUSIONS: The combination of negative FDG-PET/CT-scans and anti-EmII/3-10 antibody levels seem to be reliable parameters for assessing in vivo AE-larval inactivity after long-term benzimidazole chemotherapy. TRIAL REGISTRATION: clinicaltrials.gov: NCT00658294.

Late biliary complications in human alveolar echinococcosis are associated with high mortality.

AIM: To evaluate the incidence of late biliary complications in non-resectable alveolar echinococcosis (AE) under long-term chemotherapy with benzimidazoles. METHODS: Retrospective analysis of AE patients with biliary complications occurring more than three years after the diagnosis of AE. We compared characteristics of patients with and without biliary complications, analyzed potential risk factor for biliary complications and performed survival analyses. RESULTS: Ninety four of 148 patients with AE in Zurich had non-resectable AE requiring long-term benzimidazole chemotherapy, of which 26 (28%) patients developed late biliary complications. These patients had a median age of 55.5 (35.5-65) years at diagnosis of AE and developed biliary complications after 15 (8.25-19) years of chemotherapy. The most common biliary complications during long-term chemotherapy were late-onset cholangitis (n = 14), sclerosing cholangitis-like lesions (n = 8), hepatolithiasis (n = 5), affection of the common bile duct (n = 7) and secondary biliary cirrhosis (n = 7). Thirteen of the 26 patients had undergone surgery (including 12 resections) before chemotherapy. Previous surgery was a risk factor for late biliary complications in linear regression analysis (P = 0.012). CONCLUSION: Late biliary complications can be observed in nearly one third of patients with non-resectable AE, with previous surgery being a potential risk factor. After the occurrence of late biliary complications, the median survival is only 3 years, suggesting that late biliary complications indicate a poor prognostic outcome.

Alveolar echinococcosis: from a deadly disease to a well-controlled infection. Relative survival and economic analysis in Switzerland over the last 35 years.

BACKGROUND/AIMS: Alveolar echinococcosis (AE) is a serious liver disease. The aim of this study was to explore the long-term prognosis of AE patients, the burden of this disease in Switzerland and the cost-effectiveness of treatment. METHODS: Relative survival analysis was undertaken using a national database with 329 patient records. 155 representative cases had sufficient details regarding treatment costs and patient outcome to estimate the financial implications and treatment costs of AE. RESULTS: For an average 54-year-old patient diagnosed with AE in 1970 the life expectancy was estimated to be reduced by 18.2 and 21.3 years for men and women, respectively. By 2005 this was reduced to approximately 3.5 and 2.6 years, respectively. Patients undergoing radical surgery had a better outcome, whereas the older patients had a poorer prognosis than the younger patients. Costs amount to approximately Euro108,762 per patient. Assuming the improved life expectancy of AE patients is due to modern treatment the cost per disability-adjusted life years (DALY) saved is approximately Euro6,032. CONCLUSIONS: Current treatments have substantially improved the prognosis of AE patients compared to the 1970s. The cost per DALY saved is low compared to the average national annual income. Hence, AE treatment is highly cost-effective in Switzerland.

Human alveolar echinococcosis after fox population increase, Switzerland.

We analyzed databases spanning 50 years, which included retrospective alveolar echinococcosis (AE) case finding studies and databases of the 3 major centers for treatment of AE in Switzerland. A total of 494 cases were recorded. Annual incidence of AE per 100,000 population increased from 0.12-0.15 during 1956-1992 and a mean of 0.10 during 1993-2000 to a mean of 0.26 during 2001-2005. Because the clinical stage of the disease did not change between observation periods, this increase cannot be explained by improved diagnosis. Swiss hunting statistics suggested that the fox population increased 4-fold from 1980 through 1995 and has persisted at these higher levels. Because the period between infection and development of clinical disease is long, the increase in the fox population and high Echinococcus multilocularis prevalence rates in foxes in rural and urban areas may have resulted in an emerging epidemic of AE 10-15 years later.

Impact of smoking on patients with idiopathic chronic pancreatitis.

OBJECTIVES: Chronic pancreatitis is usually caused by heavy alcohol intake and, in many studies, also smoking. Because heavy drinkers usually smoke, making it difficult to separate the effects of these 2 factors, we thought to study the impact of smoking on the progression of nonalcoholic idiopathic chronic pancreatitis (ICP) METHODS: We used data from 83 patients with ICP in Switzerland and from 83 patients in Italy. We studied the impact of smoking on progression of disease as measured by the appearance of calcification and diabetes using Cox regression models. RESULTS: In both centers, the prevalence of smoking was significantly higher in patients with ICP than in the background population. In Italian patients, smoking increased the risk of pancreatic calcifications (hazard ratio = 2.09; 95% confidence interval, 1.07-4.10). Smoking also shortened the time to appearance of calcification. Heavy smoking (>20 cigarettes per day) was associated with the appearance of diabetes (hazard ratio = 3.94; 95% confidence interval, 1.14-13.6). For those patients who never reported consuming alcohol, smoking remains a significant risk factor. CONCLUSIONS: In nonalcoholic ICP, smoking is associated with disease progression as measured by the appearance of pancreatic calcification and, to a lower extent, of diabetes. These findings were chiefly observed in patients who were older than 35 years at the time of onset of disease.

Recurrent acute and chronic pancreatitis in two brothers with familial chylomicronemia syndrome.

The chylomicronemia syndrome is well recognized as a rare etiologic factor of acute pancreatitis; however, whether hypertriglyceridemia can cause chronic pancreatitis (CP) remains unclear. We describe the long-time course of 2 brothers with the familial chylomicronemia syndrome caused by identical compound heterozygous mutations in the lipoprotein lipase (LPL) gene with markedly reduced LPL activity. Other etiologic factors were excluded, including mutations in the PRSS1, SPINK1, and CFTR gene. Although both brothers had recurrent acute pancreatitis and the same LPL genotype, CP became evident in only one patient. Progression to CP was associated with a more severe disease course. Thus, the chylomicronemia syndrome may cause CP in the absence of other known causative factors, and similar to alcoholic and hereditary CP, a more severe disease course is associated with disease progression.

Immunosurveillance of alveolar echinococcosis by specific humoral and cellular immune tests: long-term analysis of the Swiss chemotherapy trial (1976-2001).

BACKGROUND/AIMS: Long-term chemotherapy with benzimidazoles is beneficial in non-resectable alveolar echinococcosis (AE). Criteria to track early therapeutic efficacy are lacking and the clinical impact of immunosurveillance is unsettled. We aimed to analyze this issue particularly for assessing the putative parasitocidal efficacy of chemotherapy. METHODS: The present study is part of our prospective Swiss trial outlined previously and comprises 57 patients with a median follow-up of 18.5 (3-30) years and with repeated tests of humoral and cell-mediated immunity. The series was subdivided into group A (n=23; curative surgery) and group B (n=34: non-resectable AE). RESULTS: Long-term survival was 87% (group A) and 76% (group B). The profiles of specific antibodies against EmII/3-10 antigen normalized within 3 years in most group A-patients, but remained above the cut-off value in 40% of group B-patients. This lack of normalization was associated with lower bioavailability of mebendazole. AE-recurrence after 'radical' surgery (up to 13 years) was associated with high anti-EmII/3-10 concentrations in 7 of 8 cases. Following abrogation of longterm chemotherapy in group B, no AE-recurrence occurred in 9/18 patients, suggestive of parasitocidal efficacy and documented by a normal EmII/3-10 profile. CONCLUSIONS: The EmII/3-10 profile is of value in monitoring AE after surgery and/or chemotherapy.

Mutations of the serine protease inhibitor, Kazal type 1 gene, in patients with idiopathic chronic pancreatitis.

OBJECTIVE: The pathogenesis of chronic pancreatitis (CP) is poorly understood. Genetic studies revealed mutations in the cationic trypsinogen gene and an increased frequency of cystic fibrosis gene mutations in patients with CP. Recently, a point mutation (N34S) in the gene encoding the serine protease inhibitor, Kazal type 1 (SPINK1), was found in approximately 20% of patients with CP. The aim of our study was to determine the frequency of the N34S SPINKI gene mutation in a well-defined patient cohort with idiopathic CP (ICP) and to compare the incidence with healthy controls. In addition, we investigated the impact of this mutation on the long-term course of CP. METHODS: Fourteen patients with early-onset and four patients with late-onset CP of our well-defined pancreatitis cohort were enrolled in the present study, and 397 healthy individuals served as a control population. Coding exonic and the flanking intronic sequences of SPINK1 were investigated by direct DNA sequencing. The mutations found were confirmed by melting curve analysis. In addition, the N34S mutation was detected by analyzing the DNA fragments generated by digestion with restriction enzyme TspR I. Clinical data of patients with the N34S mutation were compared with those without mutations. RESULTS: The N34S mutation was detected in six of 14 (43%) patients with early-onset ICP. One patient was homozygous, and five patients were heterozygous for this mutation. The N34S mutation in a heterozygous state was found in four of 397 healthy controls (1.0%). The different allele frequency observed (seven of 28 vs four of 794) was significant (odds ratio = 66, 95% CI = 18-242, p < 0.0001). The clinical course was similar in patients with a mutation compared with those without a mutation. No other SPINKI mutations were detected. The N34S mutation was not found in patients with late-onset ICP. CONCLUSIONS: Our results indicate that the N34S mutation in the SPINKI gene is strongly associated with ICP, especially with the early-onset type. The natural course is similar in patients with mutations compared with SPINK1 mutation-negative patients. The N34S mutation may easily be screened for by restriction digestion with TspR I.

European echinococcosis registry: human alveolar echinococcosis, Europe, 1982-2000.

Surveillance for alveolar echinococcosis in central Europe was initiated in 1998. On a voluntary basis, 559 patients were reported to the registry. Most cases originated from rural communities in regions from eastern France to western Austria; single cases were reported far away from the disease-"endemic" zone throughout central Europe. Of 210 patients, 61.4% were involved in vocational or part-time farming, gardening, forestry, or hunting. Patients were diagnosed at a mean age of 52.5 years; 78% had symptoms. Alveolar echinococcosis primarily manifested as a liver disease. Of the 559 patients, 190 (34%) were already affected by spread of the parasitic larval tissue. Of 408 (73%) patients alive in 2000, 4.9% were cured. The increasing prevalence of Echinococcus multilocularis in foxes in rural and urban areas of central Europe and the occurrence of cases outside the alveolar echinococcosis-endemic regions suggest that this disease deserves increased attention.