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

Alveolar echinococcosis is one of the mostly deadly human parasitic diseases if left untreated. The treatment of choice is surgical resection, followed by two years of benzimidazole treatment. Unfortunately, only about 30–40% of patients have a resectable disease, while the others require medical treatment with benzimidazoles. As this therapy is only considered to be parasitostatic and as there are not yet reliable tools to assess parasite viability, the treatment usually is life-long. In this study, we evaluated FDG-PET/CT and antibody levels against the recombinant Emll/3-10 antigen as markers for parasite viability, allowing to select patients in whom chemotherapy could be stopped with low risk of AE-recurrence. Eleven 11 patients were identified with negative FDG-PET/CT-scans and anti-EmII/3-10 antibody levels in whom benzimidazole treatment was stopped with no evidence of AE-recurrence within a median follow-up of 70.5 (range 16–82) months. Therefore, this study provides evidence that benzimidazole treatment is parasitocidal in a subset of patients.

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.

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.

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.

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

An increase in fox population has led to an increase in incidence of human alveolar echinococcosis.

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.

F-18-Fluorodeoxyglucose (FDG) Positron-Emission Tomography of Echinococcus multilocularis Liver Lesions: Prospective Evaluation of its Value for Diagnosis and Follow-up during Benzimidazole Therapy

BACKGROUND

Long-term benzimidazole therapy benefits patients with non-resectable alveolar echinococcosis (AE). Methods to assess early therapeutic efficacy are lacking. Recently, AE liver lesions were reported to exhibit increased F-18-fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET). To assess the value of FDG-PET for diagnosis and follow-up of AE patients.

PATIENTS/METHODS

Twenty-six consecutive patients with newly diagnosed AE were enrolled. Baseline evaluation included CT and FDG-PET. Thirteen patients (11 women; median age 50 years, range 40-76) were resected, the remaining 13 (8 women; median age 60 years, range 39-72) had non-resectable disease, were started on benzimidazoles, and CT and FDG-PET were repeated at 6, 12 and 24 months of therapy. Twelve consecutive patients with newly diagnosed cystic echinococcosis (CE) of the liver were also subjected to baseline FDG-PET.

RESULTS

In 21/26 AE patients, baseline PET scans showed multifocally increased FDG uptake in the hepatic lesions' periphery, while liver lesions were FDG negative in 11/12 CE patients. Thus, sensitivity and specificity of FDG-PET for AE vs. CE were 81% and 92%, respectively. In 5 of 10 non-resectable patients with increased baseline FDG uptake, the intensity of uptake decreased (or disappeared) during benzimidazole therapy, in 3 by >or=2 grades within the initial 6 months.

CONCLUSIONS

FDG-PET is a sensitive and specific adjunct in the diagnosis of suspected AE and can help in differentiating AE from CE. The rapid improvement of positive PET scans with benzimidazole therapy in some patients indicates that absent FDG uptake does not necessarily reflect parasite viability.

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.

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.

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.

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.

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.

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.

Evaluation of treatment and long-term follow-up in patients with hepatic alveolar echinococcosis

BACKGROUND

Alveolar echinococcosis is a rare disorder, which makes a comparison of different treatment modalities within a clinical trial difficult to perform. Data prospectively recorded over a period of 25 years were used to evaluate three therapeutic strategies: benzimidazole therapy alone, complete 'curative' resection followed by 2 years of adjuvant benzimidazole treatment, and partial debulking resection followed by continuous administration of a benzimidazole.

METHODS

Details of 113 patients with hepatic alveolar echinococcosis treated between 1976 and 2003 were analysed. Kaplan-Meier survival curves were constructed and, using a Cox regression model, patient age, year of initial treatment and PNM stage were entered as co-variates in the analysis.

RESULTS

Kaplan-Meier overall survival curves stratified for treatment strategy indicated an improved long-term survival in patients undergoing the debulking procedure (P = 0.061) or curative resection (P = 0.002) compared with benzimidazole therapy alone. However, when PNM stage, patient age and year of initial treatment were introduced into the analysis, there was a trend for survival advantage only with curative resection (P = 0.07 versus benzimidazole alone). Debulking resulted in a higher rate of progression of hepatic echinococcosis than curative surgery (P = 0.008). The incidence of parasite-related complications was similar for debulking resection and benzimidazole therapy alone (P = 0.706).

CONCLUSION

Debulking hepatic resections do not appear to offer any advantage in the treatment of patients with alveolar echinococcosis.

Cigarette smoking accelerates progression of alcoholic chronic pancreatitis

BACKGROUND

Smoking is a recognised risk factor for pancreatic cancer and has been associated with chronic pancreatitis and also with type II diabetes.

AIMS

The aim of this study was to investigate the effect of tobacco on the age of diagnosis of pancreatitis and progression of disease, as measured by the appearance of calcification and diabetes.

PATIENTS

We used data from a retrospective cohort of 934 patients with chronic alcoholic pancreatitis where information on smoking was available, who were diagnosed and followed in clinical centres in five countries.

METHODS

We compared age at diagnosis of pancreatitis in smokers versus non-smokers, and used the Cox proportional hazards model to evaluate the effects of tobacco on the development of calcification and diabetes, after adjustment for age, sex, centre, and alcohol consumption.

RESULTS

The diagnosis of pancreatitis was made, on average, 4.7 years earlier in smokers than in non-smokers (p = 0.001). Tobacco smoking increased significantly the risk of pancreatic calcifications (hazard ratio (HR) 4.9 (95% confidence interval (CI) 2.3-10.5) for smokers v non-smokers) and to a lesser extent the risk of diabetes (HR 2.3 (95% CI 1.2-4.2)) during the course of pancreatitis.

CONCLUSIONS

In this study, tobacco smoking was associated with earlier diagnosis of chronic alcoholic pancreatitis and with the appearance of calcifications and diabetes, independent of alcohol consumption.

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.

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.

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.

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.

Genetic aspects of chronic pancreatitis: insights into aetiopathogenesis and clinical implications

The recent genetic discoveries in CP support the hypothesis that inappropriate intrapancreatic activation of zymogens by trypsin results in autodigestion and pancreatitis. Two different protective mechanisms prevent activation of the pancreatic digestive enzyme cascade. First, SPINK1 inhibits up to 20% of potential trypsin activity and, second, trypsin itself activates trypsin-like enzymes readily degrading trypsinogen and other zymogens. Pancreatitis may therefore be the result of an imbalance between proteases and their inhibitors within the pancreatic parenchyma. The discovery of PRSS1 mutations in families with CP was the first breakthrough in the understanding of the underlying genetic mechanisms. Enhanced trypsinogen activation may be the common initiating step in pancreatitis caused by these mutations. The discovery of SPINK1 mutations underlines the importance of the protease inhibitor system in the pathogenesis of CP. Thus, gain-of-function in the cationic trypsinogen resulting in an enhanced autoactivation, or loss-of-function mutations in SPINK1 leading to decreased inhibitory capacity, may similarly disturb the delicate intrapancreatic balance of proteases and their inhibitors. The recent findings of SPINK1, CFTR, and PRSS1 mutations in CP patients without a family history have challenged the concept of idiopathic CP as a non-genetic disorder and the differentiation between HP and ICP. There is a clear mode of autosomal dominant inheritance for some mutations (R122H, N291, possibly MIT), whereas the inheritance pattern (autosomal recessive, complex, or modifying) of other mutations (A16V, N34S) is controverted or unknown. The lack of mutations in the above-mentioned genes in many patients suggests that CP may also be caused by genetic alterations in yet unidentified genes. Evaluation of CP patients without an obvious predisposing factor, e.g. alcohol abuse, should include genetic testing even in the absence of a family history of pancreatitis. Finally, identification of further disease-causing genes will create a better understanding of pathogenesis and may help to develop specific preventive and therapeutic strategies.

Mutations of the cystic fibrosis gene in patients with chronic pancreatitis

OBJECTIVE

Several studies have reported an increased frequency of cystic fibrosis gene mutations in idiopathic but not in alcoholic chronic pancreatitis. The impact of cystic fibrosis gene mutations on the long-term course of chronic pancreatitis has not been analyzed. The aim of our study was to determine the frequency of cystic fibrosis gene mutations in patients with chronic pancreatitis with long-term follow-up and to see whether patients with mutations have a clinically different natural course compared to those without mutations.

METHODS

Eighty two patients with chronic pancreatitis and 11 patients with recurrent acute pancreatitis of our well defined pancreatitis cohort were screened for the 31 most common cystic fibrosis gene mutations. The impact of cystic fibrosis gene mutations on the long-term course of chronic pancreatitis was assessed.

RESULTS

A cystic fibrosis gene mutation was detected in five of 49 patients with alcoholic chronic pancreatitis (10.2%; 2.3 times the expected frequency) and in three of 14 patients with idiopathic-juvenile chronic pancreatitis (21.4%; 4.8 times the expected frequency). No mutations were found in the remaining patients with chronic pancreatitis of rare causes, hereditary pancreatitis, and recurrent acute pancreatitis. The frequency of pancreatic calcifications was significantly higher in patients with alcoholic chronic pancreatitis without mutations. This result was not confirmed in patients with idiopathic-juvenile chronic pancreatitis. The duration of pain and the frequency of exocrine and endocrine insufficiency was comparable in both subgroups irrespective of the mutation status.

CONCLUSION

Our data indicate a significantly increased frequency of cystic fibrosis gene mutations both in patients with alcoholic and idiopathic-juvenile chronic pancreatitis. The natural course was similar in patients with mutations compared to those without mutations.

A family of 16-kDa pancreatic secretory stress proteins form highly organized fibrillar structures upon tryptic activation

A group of 16-kDa proteins, synthesized and secreted by rat pancreatic acinar cells and composed of pancreatic stone protein (PSP/reg) and isoforms of pancreatitis-associated protein (PAP), show structural homologies, including conserved amino acid sequences, cysteine residues, and highly sensitive N-terminal trypsin cleavage sites, as well as conserved functional responses in conditions of pancreatic stress. Trypsin activation of recombinant stress proteins or counterparts contained in rat pancreatic juice (PSP/reg, PAP I and PAP III) resulted in conversion of 16-kDa soluble proteins into 14-kDa soluble isoforms (pancreatic thread protein and pancreatitis-associated thread protein, respectively) that rapidly polymerize into insoluble sedimenting structures. Activated thread proteins show long lived resistance to a wide spectrum of proteases contained in pancreatic juice, including serine proteases and metalloproteinases. In contrast, PAP II, following activation with trypsin or pancreatic juice, does not form insoluble structures and is rapidly digested by pancreatic proteases. Scanning and transmission electron microscopy indicate that activated thread proteins polymerize into highly organized fibrillar structures with helical configurations. Through bundling, branching, and extension processes, these fibrillar structures form dense matrices that span large topological surfaces. These findings suggest that PSP/reg and PAP I and III isoforms consist of a family of highly regulated soluble secretory stress proteins, which, upon trypsin activation, convert into a family of insoluble helical thread proteins. Dense extracellular matrices, composed of helical thread proteins organized into higher ordered matrix structures, may serve physiological functions within luminal compartments in the exocrine pancreas.

The natural history of alcoholic chronic pancreatitis

An improved knowledge of the natural history is the indispensible basis for a rational concept in regard to the diagnosis, classification, understanding and management of pain in chronic pancreatitis. Unfortunately, data on the natural history of CP are scarce and conflicting. Some relevant observations of our prospective long-term study of a mixed medical-surgical cohort comprising 207 patients with alcoholic CP (mean follow-up 17 years from onset) are summarized. In early-stage CP, episodes of recurrent pancreatitis were predominant. Severe persistent pain was typically associated with local complications (mainly postnecrotic cysts in 54%; symptomatic cholestasis in 24%) relieved definitely by a drainage procedure. Lasting pain remission was documented in >80% of the whole cohort within 10 years from onset in association with marked pancreatic dysfunction. From our experience, the relief of "chronic" pain regularly follows selective surgery tailored to the presumptive pain cause or it occurs spontaneously in uncomplicated advanced CP (excluding narcotic addiction).

Trypsinogen gene mutations in patients with chronic or recurrent acute pancreatitis

Three-point mutations (R117H, N211, A16V) within the cationic trypsinogen gene have been identified in patients with hereditary pancreatitis (HP). A genetic background has also been discussed for idiopathic juvenile chronic pancreatitis (IJCP), which closely mimicks the clinical pattern of HP, and alcoholic chronic pancreatitis because only a small number of heavy drinkers develop pancreatitis. This prompted us to screen 104 patients in our well-defined pancreatitis cohort for the currently known cationic trypsinogen gene mutations. The R117H mutation was detected in seven patients (six patients of two clinically classified HP families, one patient with clinically classified IJCP) and the A16V mutation in one IJCP patient. No cationic trypsinogen gene mutations were found in the remaining 96 patients with chronic and recurrent acute pancreatitis of various etiologies. Our results demonstrate the need for genetic testing to exclude HP, particularly in the presence of an atypical or unknown family history. In addition, cationic trypsinogen gene mutations are no predisposing factor in patients with chronic and recurrent acute pancreatitis of different etiologies.

[Chemotherapy alone or as adjuvant treatment to surgery for alveolar and cystic echinococcosis]

An overview is presented of the various therapy options in cystic and alveolar echinococcosis based on the recent literature and upon personal experience with chemotherapy over the last 20 years. In regions with an optimal surgical infrastructure and relatively small patient cohorts, long-term chemotherapy is practically limited to patients with inoperable echinococcosis, i. e. < 10 % cystic and around 70 % alveolar echinococcosis.

The natural history of pain in alcoholic chronic pancreatitis

BACKGROUND & AIMS

The pain pattern of chronic pancreatitis (CP) and its surgical implications are discussed. The aim of this study was to (1) define typical pain patterns, (2) correlate pain patterns with the presumptive causes of the pain, and (3) compare the natural history of patients treated conservatively or surgically with respect to pain relief, pancreatic dysfunction, and clinical outcome.

METHODS

A cohort in this prospective long-term study included 207 patients with alcoholic CP (91 without and 116 with surgery for pain relief). A clinically based staging system was applied to characterize pain in the evolution from onset to end-stage CP.

RESULTS

Average duration of CP was 17 years. In early-stage CP, episodes of recurrent (acute) pancreatitis predominated. Chronic pain was typically associated with local complications (mainly pseudocysts, 84 of 155; 54%), relieved definitely by a single (drainage) procedure in approximately two thirds of patients. Additional surgery was required for late pain recurrence in 39 patients (34%), primarily symptomatic cholestasis (18 of 39; 46%). All patients achieved complete pain relief in advanced CP.

CONCLUSIONS

In our experience, relief of chronic pain regularly follows selective surgery tailored to the presumptive pain cause or occurs spontaneously in uncomplicated advanced CP.

[Swiss study of chemotherapy of alveolar echinococcosis--review of a 20-year clinical research project]

Alveolar echinococcosis (A. E.), caused by Echinococcus multilocularis, behaves biologically like a malignant tumour of the liver which is best treated by radical surgery. However, radical surgery can be performed only in about 20-30% of A. E. cases. The efficacy of chemotherapy with benzimidazole derivatives for inoperable cases is debated. The results of a prospective Swiss chemotherapy trial, which started in 1976, are reviewed. In the last 20 years a total of 110 patients has been included in our protocol and 74 of these patients had inoperable or palliatively operated A. E. (average observation time 12.8 years). The efficacy of long-term chemotherapy was documented by increase of 10-year survival compared to historical (untreated) A. E. cases (80 vs 6%) and by reduction or stabilisation of the liver lesions in 83% of cases during long-term chemotherapy. Several relevant problems remain to be clarified, e.g. optimal duration of chemotherapy, the controversy as to whether chemotherapy is parasitostatic or parasitocidal, the establishment of reliable routine methods for short-term assessment of therapeutic efficacy, and comparative studies between mebendazole and albendazole. Furthermore, additional studies are necessary in collaboration with basic science, for example on the impact of the increasing fox population, with invasion of large agglomerations, on infection risk in the Swiss population, and the importance of individual immune competence for susceptibility or resistance to A. E.

Alveolar echinococcosis of the liver: sequelae of chronic inferior vena cava obstructions in the hepatic segment

BACKGROUND

The clinical pattern and long-term course of chronic inferior vena cava (IVC) obstructions are variable and depend on the underlying cause, the segment involved, and the extension of secondary thrombosis. Pertinent data on IVC obstructions in well-defined series of patients are lacking. We report the sequelae of chronic IVC obstructions in the hepatic segment in 11 consecutive patients derived from a cohort of 104 patients with alveolar echinococcosis of the liver.

METHODS

Based on the results of computed tomography scans, 11 patients (7 men, 4 women; mean age, 53.4 years) with IVC obstructions were selected from an ongoing prospective long-term chemotherapy trial comprising 104 patients with alveolar echinococcosis studied at yearly intervals according to a protocol. Obstruction of the IVC in the 11 patients existed for a mean duration of 8.6 years. In these patients, magnetic resonance imaging was performed to assess the morphologic features and extension of the IVC obstruction, as well as the collateral venous pathways. Patency and valvular function of the femoropopliteal veins were analyzed by color-coded duplex ultrasonography.

RESULTS

Total occlusions of the IVC were evident in 8 patients (73%) and subtotal stenoses in 3 patients (27%). Only 4 patients (36%) exhibited signs and symptoms of chronic venous insufficiency of the lower extremities; 2 (18%) of the 4 had a history of swelling in the lower extremity. Seven patients (64%) had no lower extremity symptoms. One patient had a history of pulmonary embolism. Abdominal collateral veins were documented in 5 patients (45%) by using magnetic resonance imaging; however, they were clinically evident in only 3 patients (27%). In the 8 patients with IVC occlusion, thrombosis ended at the confluence of the hepatic veins. Obstruction of the IVC was limited to the hepatic segment in 2 patients (18%) and extended to the distal IVC or the iliofemoral veins in 6 patients (54%). Chronic venous insufficiency was present only if the femoropopliteal veins had been involved in the thrombotic process, showing residual venous obstruction, valvular incompetence, or both. Bilateral renal vein thrombosis with moderate proteinuria was observed in 2 patients (18%). The main collateral drainage was achieved through the ascending lumbar, azygos, and hemiazygos veins.

CONCLUSIONS

In patients with alveolar echinococcosis, obstruction of the IVC in the hepatic segment often develops asymptomatically and rarely leads to the impairment of renal function. The collateral circulation fully compensates for obstruction of the IVC. Thrombotic involvement and valvular incompetence of the femoropopliteal veins seems to determine the development of chronic venous insufficiency of the lower extremities.

Long-term mebendazole therapy may be parasitocidal in alveolar echinococcosis

Long-term chemotherapy of human alveolar echinococcosis with benzimidazole compounds (mebendazole, albendazole) has been shown to be primarily parasitostatic, but its curative (parasitocidal) efficacy is debated. This article reports on a 67-year-old male patient with non-resectable alveolar echinococcosis of the liver who had been continuously treated for 13 years with mebendazole (approximately 45-48 mg/kg body weight per day) and who was closely monitored according to a specific protocol. At the age of 80 years the patient died of oesophageal variceal bleeding. During treatment the hepatic lesion had decreased markedly in size in association with progression of perifocal calcification. At autopsy, a well-demarcated, necrotic, partially calcified, parasite-induced lesion of the right liver lobe and secondary biliary cirrhosis were found. Remnants of parasite tissue obtained from the periphery of the lesion showed a small-cystic structure, but it was not viable, as evidenced by transplantation of tissue blocks to rodents. The case is suggestive for a parasitocidal efficacy of mebendazole treatment carried out for 13 years, and is discussed in context with conflicting literature data.

HLA and alveolar echinococcosis

Evidence in animal intermediate hosts that susceptibility to larval infection with Echinococcus multilocularis is restricted to individual host factors prompted us to investigate the susceptibility markers in humans. Because antigens of the extracellular parasite E. multilocularis are possibly presented by MHC molecules in a restricted way, we speculated that MHC polymorphism may influence resistance of the host towards infection and course of disease. We studied HLA-A, -B, -DRB1, -DQB1 and -DPB1 polymorphism in 151 patients with alveolar echinococcosis. Patients with an observation period of more than 2 years were grouped according to the clinical follow-up into cured (no recurrence following surgery) patients and patients with regressive or progressive forms of disease during benzimidazole chemotherapy. By comparing phenotypic frequency between patients with alveolar echinococcosis and healthy controls, HLA-DRB1*11 was associated with a reduced risk for disease development (odds ratio=0.55, 95% confidence interval=0.34-0.88; P=0.01). HLA-DQB1*02 was more frequent in patients with progressive disease when compared with patients with regressive disease (54.3% vs 28.3%, P=0.02). The result suggests that HLA-DRB1*11 might confer protection against alveolar echinococcosis and that HLA-DQB1*02 may indicate a risk for progressive disease development. The findings may facilitate the search for immunodominant T-cell epitopes of E. multilocularis.

Cestodes. Echinococcus

This article deals with cystic echinococcosis (CE) and alveolar echinococcosis in humans caused by the cestode parasites Echinococcus granulosus and Echinococcus multilocularis. The life cycles of these parasites and their epidemiologic aspects are briefly discussed, and a detailed review is presented on clinical aspects of the diseases, including diagnosis and therapy. Considerable progress has been made in chemotherapy but the results are not yet satisfactory. A new alternative for treatment of CE is puncture of cysts, aspiration of fluid, injection of ethanol, and reaspiration of fluid (PAIR).

Course of alcoholic chronic pancreatitis: a prospective clinicomorphological long-term study

BACKGROUND & AIMS

The pathogenesis of alcoholic chronic pancreatitis and its relationship to alcoholic acute pancreatitis are debated. According to our recent clinical long-term study, alcoholic chronic pancreatitis seems to evolve from severe acute pancreatits. The aim of this study was to correlate clinical findings to the pancreatic histopathology at early and advanced stages of the disease.

METHODS

Morphological changes (pseudocysts, autodigestive necrosis, calcification, and perilobular and intralobular fibrosis) were recorded in 37 surgical and 46 postmortem pancreas specimens of 73 patients from our long-term series, who progressed from clinically acute to chronic pancreatitis (mean follow-up, 12 years). Pancreatic function was monitored at yearly intervals.

RESULTS

Surgical interventions were performed at a mean of 4.1 years from onset. Histologically, focal necrosis (49%) and mild perilobular fibrosis (54%) predominated, Pseudocysts (n = 41, mostly postnecrotic) occurred in 88% within 6 years from onset. Autopsy specimens were obtained at a mean of 12 years. These pancreata often showed severe perilobular and intralobular fibrosis (85%) and calcifications (74%), but rarely necrosis (4%). Fibrosis correlated with progressive pancreatic dysfunction (P < 0.001), particularly in the 10 patients with two histological assessments (mean interval between biopsy and autopsy, 8 years).

CONCLUSIONS

The data support an evolution from severe alcoholic acute pancreatitis to chronic pancreatitis.

Does acute pancreatitis progress to chronic pancreatitis? A microvascular pancreatitis model in the rat

Ischemia as a causative factor for acute pancreatitis has been discussed for decades but has only recently gained wider acceptance. Chronic pancreatitis, however, has rarely been attributed to ischemic injury. While experimental evidence is available for the ischemic pathogenesis of acute pancreatitis, no studies have been reported about pancreatic ischemia as a single cause of chronic pancreatitis. Also, the progression from acute to chronic pancreatitis has been a very controversial issue. To address both questions we have injected polystyrene microspheres of 20-microns diameter into the pancreatic branches of the splenic artery of 36 rats. Thirteen more rats were sham operated and injected with saline. The animals were killed at 1, 2, 3, and 9 weeks after operation and macroscopically and histologically examined, and serum alpha-amylase and weight gain were determined. For the pancreas the following parameters were assessed using a score from 0 (no change) to 4 (severe change): atrophy, hemorrhage, edema, fat necrosis, acinar necrosis, polymorphonuclear infiltration, mononuclear infiltration, interstitial fibrosis, and ductal changes. While no difference between control and experiment was observed for serum alpha-amylase, weight gain, edema, and hemorrhage, persistent differences were evident for the parameters characteristic of chronic pancreatitis, most significantly for interstitial fibrosis, ductal changes, mononuclear infiltration, acinar necrosis, and atrophy. No spontaneous deaths occurred. The severity of the lesions remained stationary after the first week. Our work shows for the first time that pancreatic ischemia by microvascular hypoperfusion can cause histopathologic changes characteristic of chronic pancreatitis and that these changes follow acute necrotizing pancreatitis.

Prognosis of chronic pancreatitis: an international multicenter study. International Pancreatitis Study Group

OBJECTIVES

The aim of this study was to determine which factors predict mortality in a cohort of patients with chronic alcoholic and nonalcoholic pancreatitis. Patients with chronic pancreatitis are known to have a reduced life expectancy, but the quantitative relationship between various clinical features and survival is unclear.

METHODS

We evaluated survival among 2015 subjects with chronic pancreatitis treated at seven centers located in six countries.

RESULTS

Mean age at diagnosis was 46 +/- 13 yr and mean duration of follow-up was 7.4 +/- 6.2 yr. Overall survival at 10 yr was 70% (95% confidence interval (CI), 68-73%) and at 20 yr was 45% (95% CI, 41-49%). Survival was significantly less than in the background population. There were 559 deaths observed among those with chronic pancreatitis compared with an expected number of 157.4, yielding a standardized mortality ratio (SMR) of 3.6 (95% CI, 3.3-3.9). Older subjects and those with alcoholic pancreatitis had a significant reduction in survival. In a multivariate analysis, mortality of middle-aged and older subjects was 2.3 (95% CI, 1.8-2.8) and 6.3 (95% CI, 4.7-8.3) times greater than subjects less than 40 yr at diagnosis. Smoking (hazard ratio, 1.4; 95% CI, 1.0-1.9), drinking (hazard ratio, 1.6; 95% CI, 1.2-2.2), or development of cirrhosis (hazard ratio, 2.5; 95% CI, 2.0-3.2) increased the risk of death during the observation period, but we observed no survival difference in operated vs. nonoperated patients.

CONCLUSIONS

Age at diagnosis, smoking, and drinking are major predictors of mortality in patients with chronic pancreatitis.

Separation and analysis of pig pancreatic zymogen granules with free flow electrophoresis and lectins

Purified pig pancreatic zymogen granules were subjected to free flow electrophoresis (FFE) in an acetate buffer system (acetic acid/NaOH, pH 5.5) to detect the presence or absence of more than one population or zymogen granules. Pig pancreatic zymogen granules were purified by differential and density gradient centrifugation and subjected to FFE. Fractions were analyzed for protein, alpha-amylase (EC 3.2.1.1) and 5'-nucleotidase (EC 3.1.3.5) as marker enzymes for zymogen granule content and membranes, respectively. Only one distinct peak, with coincident alpha-amylase and 5'-nucleotidase activity, and most protein was detected, which reflects the presence of a single population of intact zymogen granules. This was confirmed by electron microscopy. When the granules were incubated with different lectins before FFE, the one distinct peak representing intact zymogen granules was shifted towards the cathode in the case of concanavalin A (Con A) and Ricinus communis agglutinin 120 (RCA 120). No splitting of the peak occurred. Our results do not support the hypothesis of a coexistence of more than one distinct population of zymogen granules.

Alcoholic nonprogressive chronic pancreatitis: prospective long-term study of a large cohort with alcoholic acute pancreatitis (1976-1992)

140 patients with alcoholic acute (recurrent) pancreatitis were enrolled in a prospective long-term study over the last 16 years. Regular control studies regarding progression to advanced chronic pancreatitis were performed. Based on long-term outcome the patients were classified into two groups: group A (n = 109; 77.8%) with progression to advanced chronic pancreatitis (84% with calcification, 95% with exocrine insufficiency) and group B (n = 31; 22.2%) without progression (no calcification, no exocrine insufficiency). The two groups were comparable in age, sex, and mean duration of disease from onset (13.1 +/- 5.2 vs. 13.8 +/- 4.9 years). Surgery for pseudocysts was performed in 47% of group A and in 29% of group B. In group B, no pancreatic duct dilatation occurred (in 86% > 8 years from onset). However, 4 of 7 patients with adequate histology showed unequivocal chronic pancreatitis. Surprisingly, all patients of group B except two got spontaneous lasting pain relief irrespective of alcohol intake or normal pancreatic function. Our findings indicate that a subgroup of alcoholic acute pancreatitis does not progress to advanced chronic pancreatitis. This subgroup may be identical with "small duct" chronic pancreatitis. The factors responsible for progression (group A) or nonprogression (group B) remain to be elucidated.

Progression of alcoholic acute to chronic pancreatitis

Alcoholic chronic pancreatitis usually progresses from acute attacks to chronic pancreatitis within one to 19 years. The factors responsible for the appreciable variability in progression are unclear. In this study the relation between progression and the incidence and severity of acute episodes in a large cohort of patients with alcoholic chronic pancreatitis was analysed. All patients with at least one documented episode of acute pancreatitis have been studied prospectively over the past 30 years according to our protocol. Patients were classified according to their long term course into (a) calcific (n = 185), (b) non-calcific (n = 30), and (c) non-progressive (n = 39) chronic pancreatitis groups. The yearly incidence of acute attacks of pancreatitis was significantly higher in groups (a) and (b) than in group (c). Furthermore, the progression rate to advanced chronic pancreatitis (groups (a) and (b)) correlated with the incidence of severe pancreatitis (associated with pseudocysts in more than 55%). Pseudocysts were located primarily in the cephalic pancreas in groups (a) and (b) (58-71%) and in the pancreatic tail in group (c) (61%). In conclusion, these data suggest that the progression of acute to chronic pancreatitis is closely related to the incidence and severity of acute attacks. This finding and the primary location of pseudocysts in the cephalic pancreas (groups (a) plus (b)) are compatible with the 'necrosis-fibrosis' pathogenetic hypothesis.

Effect of chemotherapy on the larval mass and the long-term course of alveolar echinococcosis. Swiss Echinococcosis Study Group

The efficacy of long-term chemotherapy in nonresectable alveolar echinococcosis is debated, particularly because of the difficulty in defining therapeutic success. In this study the effect of chemotherapy on the parasitic mass was evaluated in a series of 37 patients. The patients had larval lesions documented by serial computed tomography studies at least 1.5 yr after chemotherapy (mean = 6.4 yr, range = 1.5 to 10.7 yr). The therapeutic regimen consisted of mebendazole (n = 34) or albendazole (n = 3) as previously described. The maximal areas of the parasitic lesions were assessed morphometrically by means of digital image analysis, utilizing the point-integration method, before and after chemotherapy. Marked regression of larval tissue occurred in 18 patients (group A; 48.6%), stationary lesions were noted in 13 patients (group C; 35.1%) and progression was found in 6 patients (group B; 16.2%). The three groups did not differ significantly with regard to age, plasma drug levels, duration of chemotherapy or initial size and composition of lesions (e.g., cystic cavities, degree of calcification). Despite morphologically successful chemotherapy in moist patients (e.g., 84%; groups A and C), late cholestatic complications after 1.5 to 11 yr of chemotherapy occurred in 10 patients (group A, n = 7; group C, n = 3; 4 of them died) and esophageal variceal bleeding occurred in 3 patients (relieved by sclerotherapy). These late complications were probably mainly due to posttherapy fibrosis of hilar structures. In conclusion, our data support the efficacy of chemotherapy. However, chemotherapy is not curative, and severe late complications were observed in patients with hilar (fibrotic) involvement.

Pancreatitis and the risk of pancreatic cancer. International Pancreatitis Study Group

BACKGROUND

The results of case-control studies and anecdotal reports suggest that pancreatitis may be a risk factor for pancreatic cancer, but there have been no studies of sufficient size and power to assess the magnitude of the relation between these two diseases.

METHODS AND RESULTS

We undertook a multicenter historical cohort study of 2015 subjects with chronic pancreatitis who were recruited from clinical centers in six countries. A total of 56 cancers were identified among these patients during a mean (+/-SD) follow-up of 7.4 +/- 6.2 years. The expected number of cases of cancer calculated from country-specific incidence data and adjusted for age and sex was 2.13, yielding a standardized incidence ratio (the ratio of observed to expected cases) of 26.3 (95 percent confidence interval, 19.9 to 34.2). For subjects with a minimum of two or five years of follow-up, the respective standardized incidence ratios were 16.5 (95 percent confidence interval, 11.1 to 23.7) and 14.4 (95 percent confidence interval, 8.5 to 22.8). The cumulative risk of pancreatic cancer in subjects who were followed for at least 2 years increased steadily, and 10 and 20 years after the diagnosis of pancreatitis, it was 1.8 percent (95 percent confidence interval, 1.0 to 2.6 percent) and 4.0 percent (95 percent confidence interval, 2.0 to 5.9 percent), respectively.

CONCLUSIONS

The risk of pancreatic cancer is significantly elevated in subjects with chronic pancreatitis and appears to be independent of sex, country, and type of pancreatitis.