Differential roles of the SPINK1 gene mutations in alcoholic and nonalcoholic chronic pancreatitis

Global trends in pancreas cancer among Asia-Pacific population

The incidence of pancreatic cancer is rising. Understanding trends of pancreatic cancer is crucial prior to putting policies and interventions in place. Countries with a high human development index (HDI) have a higher incidence, prevalence and mortality due to pancreatic cancer. This global trend is replicated in the Asia-Pacific countries with high HDI having higher incidence, prevalence and mortality due to pancreatic cancer. The incidence of pancreatic cancer is rising in the Asia-Pacific population as life expectancy increases with a rising HDI. Lack of good cancer registries has resulted in under reporting of pancreatic cancer in developing countries in the Asia-Pacific region. The mortality still remains high as in the Western world as most pancreatic cancers are diagnosed in an advanced stage of the disease due to non-availability of cost-effective screening tools with few patients receiving definitive care. Smoking, alcohol consumption, poor diet and obesity are significant modifiable risk factors contributing to the development of pancreatic cancer. Population based screening for pancreatic cancer is not cost-effective. Identification of hereditary and genetic factors in the Asia-Pacific population can help in targeted screening of high-risk individuals. Policies and interventions aimed at primary prevention have the greatest potential to be cost-effective yet impactful and reduce the disease burden.

SPINK1 mutations and risk of pancreatic cancer in a Chinese cohort

OBJECTIVE

The relationship between SPINK1 and pancreatic cancer (PC) remains controversial. The current study aimed to determine the effect of SPINK1 mutations on PC development among patients with chronic pancreatitis (CP).

METHODS

This is a prospective observational study including a large cohort of 965 CP patients with 11-year follow-up. Patients' demographic characteristics and clinical CP outcomes were documented in detail. Genetic testing was performed. The effect of SPINK1 mutations on the clinical development of PC was explored using Cox proportional hazards regression. Subgroup analyses conducted included the consideration of gender, onset age of CP (early- and late-onset), etiologies of CP, smoking, and alcoholic drinking status.

RESULTS

PC was diagnosed in 2.5% (24/965) of patients, and the cumulative incidence rates were 0.2%, 0.8%, and 1.5% at 3, 5, and 10 years since the onset of CP, respectively. In this cohort, SPINK1 c.194+2T > C was the most common variant with a proportion of 39.1%. And the risk of PC development varied marginally between patients with and without SPINK1 mutations (Cox HR 0.39(0.14-1.04), P = 0.059). In the subgroup analyses, patients carrying SPINK1 mutations had a significantly lower risk of PC (Cox HR 0.18(0.04-0.80), P = 0.025) in the non-smoking group. SPINK1 mutations showed no significant effect in the other subgroups considered.

CONCLUSIONS

CP patients harboring SPINK1 mutations do not have an elevated risk of PC development compared to mutation-negative CP patients. On the contrary, SPINK1 mutations may be a protective factor in non-smoking patients with CP.

Pancreas divisum: a reemerging risk factor for pancreatic diseases

Pancreas divisum (PD) is the most common developmental anatomic variant of pancreatic duct. The attention towards the PD has grown significantly since there are reports that this condition may cause acute relapsing pancreatitis, chronic pancreatitis and chronic abdominal pain syndrome. Furthermore, over the years, there have been multiple reports of PD associated with different types of tumors. There is evidence that PD can be associated with pancreatic tumors (up to 12.5% of cases). The golden standard for diagnosing PD is endoscopic retrograde cholangiopancreatography, but since it is an invasive procedure magnetic resonance cholangiopancreatography with secretin is a good alternative. In case the patient is symptomatic, endoscopic or surgical treatment should be performed. This review describes the key points of the pathophysiology, diagnostic modalities, risks of pancreatitis and tumors, as well as treatment options of PD.

Genetically Determined Chronic Pancreatitis but not Alcoholic Pancreatitis Is a Strong Risk Factor for Pancreatic Cancer

OBJECTIVE

To study if chronic pancreatitis (CP) is a risk factor for pancreatic cancer.

METHODS

Through a cohort and a case-control study design, CP and other important risk factors including smoking, diabetes, alcohol, obesity, and genetic mutations were studied for their association with pancreatic cancer.

RESULTS

In the cohort study, 402 patients with CP were included. During 3967.74 person-years of exposure, 5 of the 402 patients (4 idiopathic CP, 1 hereditary CP) developed pancreatic cancer after 16.60 ± 3.51 years of CP. The standardized incidence ratio was 121. In the case-control study, 249 pancreatic cancer patients and 1000 healthy controls were included. Of the 249 patients with pancreatic cancer, 24 had underlying idiopathic CP, and none had alcoholic pancreatitis. SPINK1 gene mutation was present in 16 of 26 patients with idiopathic CP who had pancreatic cancer. Multivariable analysis showed CP (odds ratio [OR], 97.67; 95% confidence interval [CI], 12.69-751.36), diabetes (>4 years duration) (OR, 3.05; 95% CI, 1.79-5.18), smoking (OR, 1.93; 95% CI, 1.38-2.69) as significant risk factors for pancreatic cancer. The population attributable risk was 9.41, 9.06, and 9.50 for diabetes, CP, and smoking, respectively.

CONCLUSIONS

Genetically determined CP but not alcoholic CP is a strong risk factor for pancreatic cancer.

Metastatic pancreatic adenocarcinoma associated with chronic calcific pancreatitis and a heterozygous SPINK1 N34S mutation

Contrary to patients with a cationic trypsinogen gene (PRSS1) mutations, Serine protease inhibitor Kazal-type 1 (SPINK1) heterozygote gene mutation carriers have a very low penetrance for acute, acute recurrent and/or chronic pancreatitis. Despite this, heterozygote SPINK 1 gene mutation patients have a similar age of onset of pancreatitis as PRSS 1 gene mutation patients. While the substantially elevated risk of pancreatic cancer in patients with PRSS1 gene mutations with chronic pancreatitis has been well established, little is known about the risk of pancreatic cancer in SPINK 1 gene mutation carriers with pancreatitis. We describe a case of malignant pancreatic cancer diagnosed in a young patient with chronic pancreatitis who is a SPINK 1 heterozygote gene mutation carrier. The risk of pancreatic cancer in gene mutation patients with chronic pancreatitis, in addition to screening options and management options for these patients is discussed.

Functional significance of SPINK1 promoter variants in chronic pancreatitis

Chronic pancreatitis is a progressive inflammatory disorder of the pancreas, which often develops as a result of genetic predisposition. Some of the most frequently identified risk factors affect the serine protease inhibitor Kazal type 1 (SPINK1) gene, which encodes a trypsin inhibitor responsible for protecting the pancreas from premature trypsinogen activation. Recent genetic and functional studies indicated that promoter variants in the SPINK1 gene might contribute to disease risk in carriers. Here, we investigated the functional effects of 17 SPINK1 promoter variants using luciferase reporter gene expression assay in four different cell lines, including three pancreatic acinar cell lines (rat AR42J with or without dexamethasone-induced differentiation and mouse 266-6) and human embryonic kidney 293T cells. We found that most variants caused relatively small changes in promoter activity. Surprisingly, however, we observed significant variations in the effects of the promoter variants in the different cell lines. Only four variants exhibited consistently reduced promoter activity in all acinar cell lines, confirming previous reports that variants c.-108G>T, c.-142T>C, and c.-147A>G are risk factors for chronic pancreatitis and identifying c.-52G>T as a novel risk variant. In contrast, variant c.-215G>A, which is linked with the disease-associated splice-site mutation c.194 + 2T>C, caused increased promoter activity, which may mitigate the overall effect of the pathogenic haplotype. Our study lends further support to the notion that sequence evaluation of the SPINK1 promoter region in patients with chronic pancreatitis is justified as part of the etiological investigation.

Therapeutic step-up strategy for management of hereditary pancreatitis in children

BACKGROUND/PURPOSE

Various different regimes exist for the treatment of hereditary pancreatitis in childhood. Here, we propose a therapeutic pathway with emphasis on endoscopic and surgical procedures.

METHODS

From 2006 to 2013, 12 patients with a diagnosis of hereditary pancreatitis were prospectively included in a therapeutic step-up schema. The treatment outcome was evaluated and correlated to aetiological factors and pathoanatomic findings.

RESULTS

After diagnostic work-up (laboratory data, ultrasound examination, magnetic resonance cholangiopancreatography and genetic testing), all 12 patients underwent early endoscopic retrograde cholangiopancreatography (ERCP), which was successfully performed in ten children. Obstructive pancreatitis was found in eight children, and required sphincterotomy, dilation and stenting for 12 months. In two children with unsuccessful ERCP, open surgical drainage procedures were performed. After a mean follow-up of 32 months all children are free of recurrence of pancreatitis without any impairment of everyday activities.

CONCLUSIONS

For children with hereditary pancreatitis, a therapeutic step plan with early ERCP and open surgical drainage procedures in case of impossible or insufficient endoscopic treatment prevents recurring pancreatitis and offers a normal quality of life without any major complications.

Genetic risk factors for pancreatic disorders

A combination of genetic, environmental, and metabolic factors contribute to the development and recurrence of acute and chronic pancreatitis; information on all of these is required to manage patients effectively. For example, variants that affect regulation of the protease, serine (PRSS)1-PRSS2, and claudin (CLDN)2 loci, rather than their coding sequences, interact with other genetic and environmental factors to affect disease development. New strategies are needed to use these data and determine their contribution to pathogenesis, because these variants differ from previously studied, rare variants in exons (coding regions) of genes such as PRSS1, SPINK1, cystic fibrosis transmembrane conductance regulator (CFTR), chymotrypsin (CTR)C, and calcium-sensing receptor (CASR). Learning how various genetic factors affect pancreatic cells and systems could lead to etiology-based therapies rather than treatment of symptoms.

Is the SPINK1 variant p.N34S overrepresented in patients with acute pancreatitis?

OBJECTIVES

Serine Protease Inhibitor Kazal type 1 (SPINK1) protects against premature intracellular activation of trypsinogen and development of acute pancreatitis. Our aim was to determine the prevalence of SPINK1 mutations (a) in unselected patients with first-time acute pancreatitis and (b) in the Danish background population (c) in a meta-analysis to combine the results with findings in similar investigations worldwide and (d) to evaluate whether patients with SPINK1 mutations had a more severe clinical course.

METHODS

A total of 75 consecutive patients admitted to a surgical department with first-time acute pancreatitis were prospectively included. In addition, 188 healthy controls were tested for the SPINK1 variants: p.N34S, p.P55S, p.R65Q, p.R67C, and IVS3+2 T>C, in order to calculate the prevalence of SPINK1 mutations in the Danish background population. A meta-analysis was conducted on previous studies on acute pancreatitis and SPINK1 mutations.

RESULTS

Two patients (2.7%) and two controls (1.1%) were heterozygous for the p.N34S variant. The meta-analysis confirmed that the p.N34S variant is overrepresented in patients with acute pancreatitis compared with the background population (OR=3.16, P<0.001). But this analysis did not clarify whether this was only true for patients with first-time acute pancreatitis or recurrent pancreatitis as the present studies do not provide this information, and those who do not have enough patients to reach levels of statistic significance, even if data are pooled.

CONCLUSION

The SPINK1 variant p.N34S is overrepresented in patients with acute pancreatitis, but more studies distinguishing between first-time and recurrent acute pancreatitis have to be done to determine whether this is only true for patients with recurrent acute pancreatitis.

Familial pancreatic cancer and hereditary syndromes: screening strategy for high-risk individuals

Globally, and almost evenly across nations, a familial disposition can be found in 4-10% of patients with pancreatic cancer (PC). A family history of PC is a risk for this disease and the risk level changes in correlation with the number of affected relatives. Several hereditary syndromes with potential germline mutation also have a high risk for PC; however, little is yet known regarding the genes responsible for familial pancreatic cancer (FPC). Characteristics of FPC cases are similar to those of other familial tumors, including younger onset than in sporadic cases and an ethnic difference (Ashkenazi Jewish > other Caucasian). Other risks resemble those of sporadic cases and include smoking and diabetes mellitus. People with several genetic syndromes, including Peutz-Jeghers syndrome, hereditary pancreatitis, breast-ovarian cancer syndrome, hereditary nonpolyposis colorectal cancer, and familial adenomatous polyposis also have an increased risk of PC. In many countries, but not yet in Japan, screening of these high-risk individuals is now ongoing for the detection of early PC under established familial pancreatic cancer registries. In addition to the ordinary risk factors, such as smoking, diabetes, pancreatitis, cysts, duct ectasia, and intraductal papillary mucinous neoplasm (IPMN), individuals with a family history of PC and hereditary syndromes are expected to be entered into the screening protocol.

High incidence of PRSS1 and SPINK1 mutations in Korean children with acute recurrent and chronic pancreatitis

OBJECTIVES

We evaluated the frequencies and clinical consequences of mutations in the genes encoding cationic trypsinogen, serine protease 1 (PRSS1), and serine protease inhibitor Kazal type 1 (SPINK1) in children with acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP).

PATIENTS AND METHODS

The study population consisted of 32 children with ARP or CP and 28 healthy controls. We analyzed clinical data and the sequences of the entire coding region and the intron-exon boundaries of the PRSS1 and SPINK1 genes from each patient.

RESULTS

Fifteen (46.9%) of the 32 patients had at least 1 PRSS1 or SPINK1 mutation. Four (12.5%) of the 32 patients carried the p.N29I, p.R122H, or p.N29T mutation or a p.G208A variant of the PRSS1 gene in a heterozygote state. Eleven (34.4%) of the 32 patients carried either the IVS3 + 2T>C or p.N34S mutation of the SPINK1 gene. No PRSS1 or SPINK1 mutations were identified in the control group. In particular, mutations were identified in 4 of our patients who experienced pancreas divisum with CP, whereas the remaining 2 patients with pancreas divisum and ARP did not have mutation.

CONCLUSIONS

The frequencies of the PRSS1 and SPINK1 mutations are relatively high in Korean children with ARP or CP. Mutations in the PRSS1 and SPINK1 genes are highly associated with the development of childhood ARP or CP. Our findings suggest that patients with genetic mutations combined with pancreas divisum tend to develop CP early.

Incidence of pancreatic cancer in chinese patients with chronic pancreatitis

BACKGROUND AND AIM

It is suggested that patients with chronic pancreatitis (CP) have a markedly increased risk of pancreatic cancer compared with the general population. This study was designed to determine the rate of pancreatic cancer in CP patients in China.

METHODS

This was a semiprospective, single-center study including 420 consecutive CP patients (285 males and 135 females, median age at onset 39.5 years), with the median follow-up time being 102.3 months (range 24-419 months). We calculated the standardized incidence ratio (SIR) based on the pancreatic cancer incidence in the general population of China.

RESULTS

Four cases of pancreatic cancer (0.9% of patients) were observed in 3,591 patient-years (expected number of cases 0.15; SIR 27.2, 95% CI 7.4-69.6). Similar results were seen in alcoholics and non-alcoholics, and in smokers and non-smokers. When patients lost to follow-up were considered to be followed up until the end point without having developed pancreatic cancer (4,280 patient-years), SIR was 22.8 (CI 6.2-58.4). Based on the Cox model, with inserting factors being sex, age at the time of CP clinical onset, type of pancreatitis, and presence or absence of diabetes, calcification, alcohol use and smoking status, only age was found to correlate positively with the occurrence of pancreatic cancer (>50 years, hazard ratio, 1.8 ± 0.5; p = 0.044).

CONCLUSION

The risk of pancreatic cancer is markedly increased in CP patients in China compared with the general population, especially in older patients. and IAP.

The prevalence of cationic trypsinogen (PRSS1) and serine protease inhibitor, Kazal type 1 (SPINK1) gene mutations in Polish patients with alcoholic and idiopathic chronic pancreatitis

BACKGROUND

The main cause of chronic pancreatitis (CP) is excessive alcohol consumption. On the other hand, only 5-10% of heavy drinkers develop chronic pancreatitis. We have only limited information regarding the pathogenic mechanism by which alcohol leads to the disease. Mutations of the PRSS1 and SPINK 1 have been mostly implicated in hereditary and idiopathic CP, but their presence in other types of this disease have also been reported.

AIMS

The aim of the study was to determine the frequency of PRSS1 and SPINK1 mutations in patients with chronic alcoholic (ACP) and idiopathic pancreatitis (ICP) as well as to investigate their relation to the clinical course of the disease.

METHODS

The study included 33 ACP and 14 ICP patients as well 46 healthy subjects. The diagnosis of CP was based on clinical data, ultrasound, and computed tomography. After isolation of DNA from peripheral blood two trypsinogen mutations were detected N29I and R122H by allelo-specific amplification polymerase chain reaction (ASA-PCR) and by the PCR-restriction fragment length polymorphism (RFLP). Beside this N34S mutation of SPINK1 was analyzed by PCR restriction fragment length polymorphism (PCR-RFLP).

RESULTS

PRSS1 mutations have been detected in 11 (33%) patients with ACP. The frequency of the PRSS1 mutations was higher in patients with ACP than in controls (4.3%) (p < 0.001). The frequency of PRSS1 mutation was present in 21.4% of ICP patients, which was significantly higher (p < 0.05) than in controls. Overall, six (18%) SPINK1 mutations in ACP group have been detected. Among 14 patients with ICP, in four (28.6%) of them SPINK1 has been detected. The same mutations have also been found in three (6.5%) control subjects. The frequency of the N34S mutation was higher in patients with ICP than in the controls (p < 0.05), but the frequency of N34S mutation did not differ between ACP and the control group. No relations have been detected between PRSS1 and SPINK1 mutations presence and clinical course and complications of CP.

CONCLUSIONS

Those preliminary data suggest the high prevalence of SPINK1 and PRSS1 mutations in the Polish population, generally, as well as in CP patients. It may be speculated that those mutations contribute to the development of chronic pancreatitis, especially in patients with alcohol overindulgence.

-651C/T promoter polymorphism in the CD14 gene is associated with severity of acute pancreatitis in Japan

PURPOSE

This study aimed to clarify the association of the promoter variants in the CD14 gene with pancreatic diseases in Japan.

METHODS

Three hundred forty-six unrelated patients with acute pancreatitis (AP) (107 with severe and 239 with mild), 263 patients with chronic pancreatitis (CP), 264 patients with pancreatic neoplasm, and 319 healthy controls were genotyped for the single nucleotide polymorphisms at positions -260 and -651 from the AUG start codon in the CD14 gene by polymerase chain reaction-restriction enzyme digestion.

RESULTS

The allele and genotype frequencies of the -260C/T and -651C/T polymorphisms did not differ between controls and patients with AP. In subgroup analyses, patients with severe AP had more -651C allele than controls [P = 0.005; odds ratio (OR) 1.71; 95% confidence interval (CI) = 1.18-2.49] or patients with mild AP (P = 0.001; OR 1.95; 95% CI = 1.33-2.85). Genotype -651CC was more common (P = 0.001 vs. controls and P = 0.001 vs. mild AP), and -651CT was less (P = 0.009 vs. controls and P = 0.007 vs. mild AP) in patients with severe AP than in healthy controls or patients with mild AP. The frequencies of pseudocyst development and requirement of surgery were higher in AP patients with -651CC than in those without this genotype. The -260C/T polymorphism was not associated with the severity of AP. The allele and genotype frequencies of both polymorphisms did not differ between controls and patients with CP or pancreatic neoplasm.

CONCLUSION

-651C/T promoter polymorphism in the CD14 gene was associated with severity of AP in Japan.

Microsatellite polymorphism in intron 2 of human Toll-like receptor 2 gene is associated with susceptibility to acute pancreatitis in Japan

This study evaluated the association of the polymorphisms in the Toll-like receptor (TLR)2 and TLR4 genes with acute pancreatitis (AP) in Japan. The numbers of guanine-thymine [(GT)n] repeats in intron 2 of the TLR2 gene were counted in 202 unrelated patients with AP (80 with severe and 122 with mild disease) and in 286 healthy controls, using polymerase chain reaction and Genescan analysis. The alleles were divided into three subclasses: (GT)16 or less as the S allele; between (GT)17 and (GT)22 as the M allele; and (GT)23 or more as the L allele. Asp299Gly and Thr399Ile polymorphisms in the TLR4 gene were examined by polymerase chain reaction-restriction fragment length polymorphism analysis. Patients with AP had more S alleles (p < 0.001; odds ratio = 2.37; 95% confidence interval = 1.78-3.17) and fewer M alleles (p < 0.001; odds ratio = 0.40; 95% confidence interval 0.31-0.52) than did healthy controls. Genotypes SS and SL were more common, whereas MM and ML were less common in patients with AP. In subgroup analyses, the genotypes including S alleles were more common in patients with severe AP than in controls. No Asp299Gly and Thr399Ile polymorphisms were detected. In conclusion, microsatellite polymorphism in intron 2 of the TLR2 gene was associated with susceptibility to AP and its severity in Japan.

Clinical and radiological outcome of patients suffering from chronic pancreatitis associated with gene mutations

OBJECTIVES

Cystic fibrosis transmembrane conductance regulator (CFTR), cationic trypsinogen gene (PRSS1), and serine protease inhibitor kazal type 1 (SPINK1) gene mutations have been associated with chronic pancreatitis (CP). The aim of this study was to compare clinical and radiological findings in sporadic CP with (CPgm) and without (CPwt) gene mutations.

METHODS

Data from patients observed between 2001 and 2006 were collected. All patients were tested for 25 CFTR gene mutations, for R122H and N29I on the PRSS1 gene, and for N34S mutation on the SPINK1 gene.

RESULTS

We found 34 (17.2%) of 198 patients with CPgm, 23 (11.6%) of them on the CFTR gene, 11 (5.6%) on the SPINK1, and none on the PRSS1 gene. The age at clinical onset was younger in CPgm (36.2 +/- 17.2 years) than in CPwt (44 +/- 12.6 years; P = 0.005). There were more heavy drinkers among CPwt (33%) than among CPgm (9%; P = 0.003), and the same applied to smokers (69% vs 33%, respectively; P < 0.0001). In CPgm group, the onset of pancreatic calcifications was observed more frequently in drinkers and/or smokers. Exocrine and endocrine insufficiency occurred less frequently and later in CPgm than in CPwt patients.

CONCLUSIONS

Clinical and radiological outcome differ in CPgm compared with CPwt. Alcohol, even in small quantities, and cigarette smoking influence the onset of pancreatic calcifications.

Pathways to injury in chronic pancreatitis: decoding the role of the high-risk SPINK1 N34S haplotype using meta-analysis

Background

The complex interactions between recurrent trypsin-mediated pancreatic injury, alcohol-associated pancreatic injury and SPINK1 polymorphisms in chronic pancreatitis (CP) are undefined. We hypothesize that CP occurs as a result of multiple pathological mechanisms (pathways) that are initiated by different metabolic or environmental factors (etiologies) and may be influenced differentially by downstream genetic risk factors. We tested this hypothesis by evaluating the differences in effect size of the high risk SPINK1 N34S haplotype on CP from multiple etiologies after combining clinical reports of SPINK1 N34S frequency using meta-analysis.

Methods and Findings

The Pubmed and the Embase databases were reviewed. We studied 24 reports of SPINK1 N34S in CP (2,421 cases, 4,857 controls) using reported etiological factors as surrogates for pathways and multiple meta-analyses to determine the differential effects of SPINK1 N34S between alcoholic and non-alcoholic etiologies. Using estimates of between-study heterogeneity, we sub-classified our 24 studies into four specific clusters. We found that SPINK1 N34S is strongly associated with CP overall (OR 11.00; 95% CI: 7.59–15.93), but the effect of SPINK1 N34S in alcoholic CP (OR 4.98, 95% CI: 3.16–7.85) was significantly smaller than in idiopathic CP (OR 14.97, 95% C.I. = 9.09–24.67) or tropical CP (OR 19.15, 95% C.I. = 8.83–41.56). Studies analyzing familial CP showed very high heterogeneity suggestive of a complex etiology with an I² = 80.95%.

Conclusion

The small effect of SPINK1 N34S in alcoholic subjects suggests that CP is driven through a different pathway that is largely trypsin-independent. The results also suggest that large effect sizes of SPINK1 N34S in small candidate gene studies in CP may be related to a mixture of multiple etiologic pathways leading to the same clinical endpoint.