Combining full-length gene assay and SpliceAI to interpret the splicing impact of all possible SPINK1 coding variants.

BACKGROUND: Single-nucleotide variants (SNVs) within gene coding sequences can significantly impact pre-mRNA splicing, bearing profound implications for pathogenic mechanisms and precision medicine. In this study, we aim to harness the well-established full-length gene splicing assay (FLGSA) in conjunction with SpliceAI to prospectively interpret the splicing effects of all potential coding SNVs within the four-exon SPINK1 gene, a gene associated with chronic pancreatitis. RESULTS: Our study began with a retrospective analysis of 27 SPINK1 coding SNVs previously assessed using FLGSA, proceeded with a prospective analysis of 35 new FLGSA-tested SPINK1 coding SNVs, followed by data extrapolation, and ended with further validation. In total, we analyzed 67 SPINK1 coding SNVs, which account for 9.3% of the 720 possible coding SNVs. Among these 67 FLGSA-analyzed SNVs, 12 were found to impact splicing. Through detailed comparison of FLGSA results and SpliceAI predictions, we inferred that the remaining 653 untested coding SNVs in the SPINK1 gene are unlikely to significantly affect splicing. Of the 12 splice-altering events, nine produced both normally spliced and aberrantly spliced transcripts, while the remaining three only generated aberrantly spliced transcripts. These splice-impacting SNVs were found solely in exons 1 and 2, notably at the first and/or last coding nucleotides of these exons. Among the 12 splice-altering events, 11 were missense variants (2.17% of 506 potential missense variants), and one was synonymous (0.61% of 164 potential synonymous variants). Notably, adjusting the SpliceAI cut-off to 0.30 instead of the conventional 0.20 would improve specificity without reducing sensitivity. CONCLUSIONS: By integrating FLGSA with SpliceAI, we have determined that less than 2% (1.67%) of all possible coding SNVs in SPINK1 significantly influence splicing outcomes. Our findings emphasize the critical importance of conducting splicing analysis within the broader genomic sequence context of the study gene and highlight the inherent uncertainties associated with intermediate SpliceAI scores (0.20 to 0.80). This study contributes to the field by being the first to prospectively interpret all potential coding SNVs in a disease-associated gene with a high degree of accuracy, representing a meaningful attempt at shifting from retrospective to prospective variant analysis in the era of exome and genome sequencing.

Classification of PRSS1 variants responsible for chronic pancreatitis: An expert perspective from the Franco-Chinese GREPAN study group.

BACKGROUND: PRSS1 was the first reported chronic pancreatitis (CP) gene. The existence of both gain-of-function (GoF) and gain-of-proteotoxicity (GoP) pathological PRSS1 variants, together with the fact that PRSS1 variants have been identified in CP subtypes spanning the range from monogenic to multifactorial, has made the classification of PRSS1 variants very challenging. METHODS: All currently reported PRSS1 variants (derived primarily from two databases) were manually reviewed with respect to their clinical genetics, functional analysis and population allele frequency. They were classified by variant type and pathological mechanism within the framework of our recently proposed ACMG/AMP guidelines-based seven-category system. RESULTS: The total number of distinct germline PRSS1 variants included for analysis was 100, comprising 3 copy number variants (CNVs), 12 5' and 3' variants, 19 intronic variants, 5 nonsense variants, 1 frameshift deletion variant, 6 synonymous variants, 1 in-frame duplication, 3 gene conversions and 50 missense variants. Based upon a combination of clinical genetic and functional analysis, population data and in silico analysis, we classified 26 variants (all 3 CNVs, the in-frame duplication, all 3 gene conversions and 19 missense) as "pathogenic", 3 variants (missense) as "likely pathogenic", 5 variants (four missense and one promoter) as "predisposing", 13 variants (all missense) as "unknown significance", 2 variants (missense) as "likely benign", and all remaining 51 variants as "benign". CONCLUSIONS: We describe an expert classification of the 100 PRSS1 variants reported to date. The results have immediate implications for reclassifying many ClinVar-registered PRSS1 variants as well as providing optimal guidelines/standards for reporting PRSS1 variants.

Clinical characteristics of smoking-related chronic pancreatitis.

Objective: The pathogenesis of chronic pancreatitis (CP) is not completely clear. With further studies, smoking is toxic to the pancreas. This study classified smoking-related CP as a new etiology of CP and defined the cutoff of smoking. Design: Patients with CP admitted from January 2000 to December 2013 were included in the study. The characteristics were compared between smoking patients, drinking patients, and a group of patients who never smoke or drink (control group). The cumulative rates of steatorrhea, diabetes mellitus (DM), pancreatic pseudocyst (PPC), pancreatic stone, and biliary stricture after the onset of CP were calculated, respectively. Results: A total of 1,324 patients were included. Among them, 55 were smoking patients, 80 were drinking patients, and 1,189 were controls. The characteristics of smokers are different from the other two groups, especially in age at the onset and diagnosis of CP, initial manifestation, and type of pain. The development of DM (P = 0.011) and PPC (P = 0.033) was significantly more common and earlier in the smokers than in the other two groups. Steatorrhea also developed significantly more in the smokers than in the controls (P = 0.029). Smokers tend to delay the formation of pancreatic stones and steatorrhea. Conclusion: The clinical characteristics of smoking-related CP is different from CP of other etiologies. A new type of CP, smoking-related CP, was put forward. Smoking-related CP should be separated from idiopathic CP and defined as a new independent subtype of CP different from alcoholic CP or idiopathic CP.

Association between sedation and small neoplasm detection during diagnostic esophagogastroduodenoscopy: a propensity score-matched retrospective study.

BACKGROUND: Esophagogastroduodenoscopy (EGD) is fundamental for detecting upper gastrointestinal (GI) neoplasms. However, the impact of sedation on small neoplasm detection during EGD has not been evaluated. The aim of this study was to investigate whether EGD with sedation could improve small upper GI neoplasm detection. METHODS: This propensity score-matched retrospective study analyzed the medical records of outpatients undergoing diagnostic EGD at a large tertiary center between January 2013 and December 2018. The primary outcome was the detection rate of small upper GI neoplasms (≤10 mm). The secondary outcomes were biopsy rate and small neoplasms in different anatomic subsites. RESULTS: After propensity score matching, 20,052 patients undergoing diagnostic EGD with or without propofol sedation were identified. A higher detection rate of small upper GI neoplasms was observed in the sedation group (2.80% vs. 2.02%; p < .001). In particular, the detection rate of small cancers in the sedation group was 3-fold higher than that in the no-sedation group (0.16% vs. 0.05%; p = .023). Small neoplasms were more likely identified at the gastric antrum (1.60% vs. 1.09%; p = .002) and angulus (0.66% vs. 0.45%; p = .044) in the sedation group. In addition, endoscopists were more likely to take biopsies when performing sedated EGD (41.4% vs. 36.4%, p < .001), and a higher biopsy rate was associated with an increased detection rate of small neoplasms. CONCLUSIONS: Sedation was significantly associated with a higher detection rate of small upper GI neoplasms and might be recommended for improving the quality of EGD.

Splicing Outcomes of 5' Splice Site GT>GC Variants That Generate Wild-Type Transcripts Differ Significantly Between Full-Length and Minigene Splicing Assays.

Combining data derived from a meta-analysis of human disease-associated 5' splice site GT>GC (i.e., +2T>C) variants and a cell culture-based full-length gene splicing assay (FLGSA) of forward engineered +2T>C substitutions, we recently estimated that ∼15-18% of +2T>C variants can generate up to 84% wild-type transcripts relative to their wild-type counterparts. Herein, we analyzed the splicing outcomes of 20 +2T>C variants that generate some wild-type transcripts in two minigene assays. We found a high discordance rate in terms of the generation of wild-type transcripts, not only between FLGSA and the minigene assays but also between the different minigene assays. In the pET01 context, all 20 wild-type minigene constructs generated the expected wild-type transcripts; of the 20 corresponding variant minigene constructs, 14 (70%) generated wild-type transcripts. In the pSPL3 context, only 18 of the 20 wild-type minigene constructs generated the expected wild-type transcripts whereas 8 of the 18 (44%) corresponding variant minigene constructs generated wild-type transcripts. Thus, in the context of a particular type of variant, we raise awareness of the limitations of minigene splicing assays and emphasize the importance of sequence context in regulating splicing. Whether or not our findings apply to other types of splice-altering variant remains to be investigated.

The Experimentally Obtained Functional Impact Assessments of 5' Splice Site GT'GC Variants Differ Markedly from Those Predicted.

INTRODUCTION: 5' splice site GT>GC or +2T>C variants have been frequently reported to cause human genetic disease and are routinely scored as pathogenic splicing mutations. However, we have recently demonstrated that such variants in human disease genes may not invariably be pathogenic. Moreover, we found that no splicing prediction tools appear to be capable of reliably distinguishing those +2T>C variants that generate wild-type transcripts from those that do not. METHODOLOGY: Herein, we evaluated the performance of a novel deep learning-based tool, SpliceAI, in the context of three datasets of +2T>C variants, all of which had been characterized functionally in terms of their impact on pre-mRNA splicing. The first two datasets refer to our recently described "in vivo" dataset of 45 known disease-causing +2T>C variants and the "in vitro" dataset of 103 +2T>C substitutions subjected to full-length gene splicing assay. The third dataset comprised 12 BRCA1 +2T>C variants that were recently analyzed by saturation genome editing. RESULTS: Comparison of the SpliceAI-predicted and experimentally obtained functional impact assessments of these variants (and smaller datasets of +2T>A and +2T>G variants) revealed that although SpliceAI performed rather better than other prediction tools, it was still far from perfect. A key issue was that the impact of those +2T>C (and +2T>A) variants that generated wild-type transcripts represents a quantitative change that can vary from barely detectable to an almost full expression of wild-type transcripts, with wild-type transcripts often co-existing with aberrantly spliced transcripts. CONCLUSION: Our findings highlight the challenges that we still face in attempting to accurately identify splice-altering variants.

5' splice site GC>GT and GT>GC variants differ markedly in terms of their functionality and pathogenicity.

In the human genome, most 5' splice sites (~99%) employ the canonical GT dinucleotide whereas a small minority (~1%) use the noncanonical GC dinucleotide. The functionality and pathogenicity of 5' splice site GT>GC (+2T>C) variants have been extensively studied but we know very little about 5' splice site GC>GT (+2C>T) variants. Herein, we have addressed this deficiency by performing a meta-analysis of reported +2C>T "pathogenic" variants together with a functional analysis of engineered +2C>T substitutions using a cell culture-based full-length gene splicing assay. Our results establish proof of concept that +2C>T variants are qualitatively different from +2T>C variants in terms of their functionality and suggest that, in sharp contrast to +2T>C variants, most if not all +2C>T variants have no pathological relevance. Our findings have important implications for interpreting the clinical relevance of +2C>T variants and understanding the evolutionary switching between GT and GC 5' splice sites in mammalian genomes.

Characterization of CEL-DUP2: Complete duplication of the carboxyl ester lipase gene is unlikely to influence risk of chronic pancreatitis.

BACKGROUND/OBJECTIVES: Carboxyl ester lipase is a pancreatic enzyme encoded by CEL, an extremely polymorphic human gene. Pathogenic variants of CEL either increases the risk for chronic pancreatitis (CP) or cause MODY8, a syndrome of pancreatic exocrine and endocrine dysfunction. Here, we aimed to characterize a novel duplication allele of CEL (CEL-DUP2) and to investigate whether it associates with CP or pancreatic cancer. METHODS: The structure of CEL-DUP2 was determined by a combination of Sanger sequencing, DNA fragment analysis, multiplex ligation-dependent probe amplification and whole-genome sequencing. We developed assays for screening of CEL-DUP2 and analyzed cohorts of idiopathic CP, alcoholic CP and pancreatic cancer. CEL protein expression was analyzed by immunohistochemistry. RESULTS: CEL-DUP2 consists of an extra copy of the complete CEL gene. The allele has probably arisen from non-allelic, homologous recombination involving the adjacent pseudogene of CEL. We found no association between CEL-DUP2 carrier frequency and CP in cohorts from France (cases/controls: 2.5%/2.4%; P = 1.0), China (10.3%/8.1%; P = 0.08) or Germany (1.6%/2.3%; P = 0.62). Similarly, no association with disease was observed in alcohol-induced pancreatitis (Germany: 3.2%/2.3%; P = 0.51) or pancreatic cancer (Norway; 2.5%/3.2%; P = 0.77). Notably, the carrier frequency of CEL-DUP2 was more than three-fold higher in Chinese compared with Europeans. CEL protein expression was similar in tissues from CEL-DUP2 carriers and controls. CONCLUSIONS: Our results support the contention that the number of CEL alleles does not influence the risk of pancreatic exocrine disease. Rather, the pathogenic CEL variants identified so far involve exon 11 sequence changes that substantially alter the protein's tail region.

Risk factors and nomogram for diabetes mellitus in idiopathic chronic pancreatitis.

BACKGROUND AND AIM: Diabetes mellitus (DM) is a common complication of idiopathic chronic pancreatitis (ICP), which impairs the quality of life for patients. This study aimed to identify risk factors and develop nomogram for DM in ICP to help early diagnosis. METHODS: Idiopathic chronic pancreatitis patients admitted to our center from January 2000 to December 2013 were included. Cumulative rates of DM were calculated by Kaplan-Meier method. Patients were randomly assigned, in a 2:1 ratio, to the training and validation cohort. Based on training cohort, risk factors for DM were identified through Cox proportional hazards regression model, and nomogram was developed. Internal and external validations were performed based on the training and validation cohort, respectively. RESULTS: Totally, 1633 patients with ICP were finally enrolled. The median follow-up duration was 9.8 years. DM was found in 26.3% (430/1633) of patients after the onset of CP. Adult at onset of ICP, biliary stricture at/before diagnosis of CP, steatorrhea at/before diagnosis of CP, and complex pathologic changes in main pancreatic duct were identified risk factors for DM development. The nomogram achieved good concordance indexes in the training and validation cohorts, respectively, with well-fitted calibration curves. CONCLUSIONS: Risk factors were identified, and nomogram was developed to determine the risk of DM in ICP patients. Patients with one or more of the risk factors including adult at onset of ICP, biliary stricture at/before diagnosis of CP, steatorrhea at/before diagnosis of CP, and complex pathologic changes in main pancreatic duct have higher incidence of DM.

Risk Factors and Nomogram for Pancreatic Stone Formation in Chronic Pancreatitis over a Long-Term Course: A Cohort of 2,153 Patients.

BACKGROUND: Pancreatic stones are pathognomonic of chronic pancreatitis (CP). This study aimed to determine the incidence, identify risk factors, and develop a nomogram for pancreatic stones in CP patients. METHODS: Patients with CP admitted to our center from January 2000 to December 2013 were enrolled. Cumulative rates of pancreatic stones after the onset of CP and after the diagnosis of CP were calculated. Patients were randomly assigned, in a 2:1 ratio, to the training and validation cohort. Based on the training cohort, risk factors were identified through Cox proportional hazards regression model, and nomogram was developed. Internal and external validations were performed based on the training and validation cohort, respectively. RESULTS: With a total of 2,153 CP patients, pancreatic stones were detected in 1,626 (75.5%) patients, with a median follow-up of 7.8 years. Age at the onset of CP, body mass index, smoking, diabetes mellitus, pancreatic pseudocyst, biliary stricture, severe acute pancreatitis, and type of pain were identified risk factors for pancreatic stones development. The nomogram with these 8 factors achieved good accuracy. CONCLUSIONS: The nomogram achieved an individualized prediction of pancreatic stones development in CP. It may help the management of pancreatic stones.

Risk factor for diabetes mellitus in pediatric chronic pancreatitis patients.

Pediatric patients suffer from chronic pancreatitis (CP), especially those with diabetes mellitus (DM). This study aimed to identify the incidence of and risk factors for DM in pediatric CP.CP patients admitted to our center from January 2000 to December 2013 were assigned to the pediatric (<18 years old) and adult group according to their age at onset of CP. Cumulative rates of DM and risk factors for both groups were calculated and identified.The median follow-up duration for the whole cohort was 7.6 years. In these 2153 patients, 13.5% of them were pediatrics. The mean age at the onset and the diagnosis of CP in pediatrics were 11.622 and 19.727, respectively. DM was detected in 13.1% patients and 31.0% patients in the pediatric group and adult group, respectively. Age at the onset of CP, smoking history, body mass index (BMI), and etiology of CP were identified risk factors for DM in pediatrics.DM was detected in 13.1% pediatric patients. Age at the onset of CP, smoking history, BMI, and etiology of CP were identified risk factors for the development of DM in pediatric CP patients. The high-risk populations were suggested to be monitored frequently. They could also benefit from a lifestyle modification.

First estimate of the scale of canonical 5' splice site GT>GC variants capable of generating wild-type transcripts.

It has long been known that canonical 5' splice site (5'SS) GT>GC variants may be compatible with normal splicing. However, to date, the actual scale of canonical 5'SSs capable of generating wild-type transcripts in the case of GT>GC substitutions remains unknown. Herein, combining data derived from a meta-analysis of 45 human disease-causing 5'SS GT>GC variants and a cell culture-based full-length gene splicing assay of 103 5'SS GT>GC substitutions, we estimate that ~15-18% of canonical GT 5'SSs retain their capacity to generate between 1% and 84% normal transcripts when GT is substituted by GC. We further demonstrate that the canonical 5'SSs in which substitution of GT by GC-generated normal transcripts exhibit stronger complementarity to the 5' end of U1 snRNA than those sites whose substitutions of GT by GC did not lead to the generation of normal transcripts. We also observed a correlation between the generation of wild-type transcripts and a milder than expected clinical phenotype but found that none of the available splicing prediction tools were capable of reliably distinguishing 5'SS GT>GC variants that generated wild-type transcripts from those that did not. Our findings imply that 5'SS GT>GC variants in human disease genes may not invariably be pathogenic.

Toward a clinical diagnostic pipeline for SPINK1 intronic variants.

BACKGROUND: The clinical significance of SPINK1 intronic variants in chronic pancreatitis has been previously assessed by various approaches including a cell culture-based full-length gene assay. A close correlation between the results of this assay and in silico splicing prediction was apparent. However, until now, a clinical diagnostic pipeline specifically designed to classify SPINK1 intronic variants accurately and efficiently has been lacking. Herein, we present just such a pipeline and explore its efficacy and potential utility in potentiating the classification of newly described SPINK1 intronic variants. RESULTS: We confirm a close correlation between in silico splicing prediction and results from the cell culture-based full-length gene assay in the context of three recently reported pathogenic SPINK1 intronic variants. We then integrated in silico splicing prediction and the full-length gene assay into a stepwise approach and tested its utility in the classification of two novel datasets of SPINK1 intronic variants. The first dataset comprised 16 deep intronic variants identified in 52 genetically unexplained Chinese chronic pancreatitis patients by sequencing the entire intronic sequence of the SPINK1 gene. The second dataset comprised five novel rare proximal intronic variants identified through the routine analysis of the SPINK1 gene in French pancreatitis patients. Employing a minor allele frequency of > 5% as a population frequency filter, 6 of the 16 deep intronic variants were immediately classified as benign. In silico prediction of the remaining ten deep intronic variants and the five rare proximal intronic variants with respect to their likely impact on splice site selection suggested that only one proximal intronic variant, c.194 + 5G > A, was likely to be of functional significance. Employing the cell culture-based full-length gene assay, we functionally analyzed c.194 + 5G > A, together with seven predicted non-functional variants, thereby validating their predicted effects on splicing in all cases. CONCLUSIONS: We demonstrated the accuracy and efficiency of in silico prediction in combination with the cell culture-based full-length gene assay for the classification of SPINK1 intronic variants. Based upon these findings, we propose an operational pipeline for classifying SPINK1 intronic variants in the clinical diagnostic setting.

Autoantibody detection is not recommended for chronic pancreatitis: a cross-sectional Study of 557 patients.

BACKGROUND: Autoimmune factor was regarded as one of the risk factors in the pathogenesis of chronic pancreatitis (CP), especially for autoimmune pancreatitis (AIP). However, whether autoimmune factor plays a role in non-AIP CP or not was unknown. METHODS: Hospitalized patients with non-AIP CP from January 2010 to October 2016 were detected for 22 autoantibodies at the time of hospital admission. Autoantibodies with frequency > 0.5% were enrolled to calculate the frequency in historial healthy controls through literature search in PubMed. Differentially expressed autoantibodies were determined between patients and historial healthy controls, and related factors were identified by multivariate logistic regression analysis. RESULTS: In a total of 557 patients, 113 cases were detected with 19 kinds of positive autoantibodies, among them anti-ß2-glycoprotein I (ß2-GPI) antibody was most frequent (9.16%). Compared with historial healthy controls, the frequencies of serum ß2-GPI and anti SS-B antibody in patients were significantly higher, while frequencies of anti-smooth muscle antibody and anticardiolipin antibody were significantly lower (all P < 0.05). Multivariate logistic regression analysis result showed that diabetes mellitus (OR = 2.515) and common bile duct stricture (OR = 2.844) were the risk factors of positive ß2-GPI antibody in patients while diabetes mellitus in first-/second-/third-degree relatives (OR = 0.266) was the protective factor. There were no related factors for other three differentially expressed autoantibodies. CONCLUSIONS: Four autoantibodies were expressed differentially between patients with non-AIP CP and historial healthy controls. Due to limited significance for diagnosis and treatment of chronic pancreatitis, autoantibodies detection is not recommended conventionally unless suspected of AIP.

Risk Factors and Nomogram for Common Bile Duct Stricture in Chronic Pancreatitis: A Cohort of 2153 Patients.

GOALS: To identify the risk factors and develop nomograms for common bile duct (CBD) stricture in chronic pancreatitis (CP) patients. BACKGROUND: CBD stricture is a common complication in CP and has a variable clinical presentation ranging from asymptomatic to overt jaundice and cholangitis. STUDY: Patients with CP admitted to Changhai Hospital (Shanghai, China) from January 2000 to December 2013 were enrolled. Cumulative rates of CBD stricture after onset and diagnosis of CP were calculated. Patients were randomly assigned, in a 2:1 ratio, to the training and validation cohort. On the basis of the training cohort, risk factors for CBD stricture and symptomatic CBD stricture were identified through Cox proportional hazards regression model, and nomograms was developed, respectively. Internal and external validations were performed based on the training and validation cohort, respectively. RESULTS: With a total of 2153 patients, the median duration of follow-up was 7.0 years. CBD strictures were detected in 340 (15.8%) patients, whereas 159 of them were symptomatic. Male gender, age at onset of CP, smoking, body mass index, and morphology of main pancreatic duct were identified risk factors for CBD stricture development. Age at onset of CP, body mass index, and type of pain were identified risk factors for symptomatic CBD stricture development. Both nomograms achieved good concordance indexes with well-fitted calibration curves. CONCLUSIONS: The nomogram achieved an individualized prediction of symptomatic CBD stricture development in CP patients. It may help the early diagnosis and intervention of symptomatic CBD stricture and reduce the rates of severe adverse events.

Extracorporeal shock wave lithotripsy is safe and effective for geriatric patients with chronic pancreatitis.

BACKGROUND AND AIM: Pancreatic extracorporeal shock wave lithotripsy (P-ESWL) is a first-line treatment for chronic pancreatitis (CP) patients with pancreatic stones. However, the performance of P-EWSL in geriatric patients remains unclear. We aimed to evaluate the safety and efficacy of P-ESWL for them. METHODS: This prospective study was conducted in painful CP patients who underwent P-ESWL. Patients aged over 65 years were included in geriatric group; patients aged under 65 years were assigned to control group. For the long-term follow-up investigation, geriatric patients were matched with patients from the control group in a 1:1 ratio. Primary outcomes were complications of P-ESWL and pain relief. Secondary outcomes included stone clearance, physical and mental health, quality of life score, changes in exocrine and endocrine pancreatic function, and survival. RESULTS: From March 2011 to March 2016, P-ESWL was performed in 1404 patients (72 in the geriatric group and 1332 in the control group). No significant differences were observed in complications of P-ESWL between the two groups (P = 0.364). Among the 67 (67/72, 93.1%) geriatric patients who underwent follow up for 4.02 years, complete pain relief was achieved in 53 patients, which was not significantly different from that of matched controls (54/70; P = 0.920). The death in the geriatrics was significantly higher (P = 0.007), but none of them were correlated with P-ESWL. CONCLUSIONS: P-ESWL is safe and effective for geriatric CP patients with pancreatic stones. It can promote significant pain relief and stone clearance and improve quality of life and mental and physical health.

Risk factor for steatorrhea in pediatric chronic pancreatitis patients.

BACKGROUND: Pediatric patients always suffer from chronic pancreatitis (CP), especially those with steatorrhea. This study aimed to identify the incidence of and risk factors for steatorrhea in pediatric CP. To our best knowledge, there is no pediatric study to document the natural history of steatorrhea in CP. METHODS: CP patients admitted to our center from January 2000 to December 2013 were enrolled. Patients were assigned to the pediatric (< 18 years old) and adult group according to their age at onset of CP. Cumulative rates of steatorrhea in both groups were calculated. Risk factors for both groups were identified, respectively. RESULTS: The median follow-up duration for the whole cohort was 7.6 years. In a total of 2153 patients, 13.5% of them were pediatrics. The mean age at the onset and the diagnosis of CP in pediatrics were 11.622 and 19.727, respectively. Steatorrhea was detected in 46 patients (46/291, 15.8%) in the pediatric group and in 447 patients (447/1862, 24.0%) in the adult group. Age at the onset of CP (hazard ratio [HR], 1.121), diabetes mellitus (DM, HR, 51.140), and severe acute pancreatitis (SAP, HR, 13.946) was identified risk factor for steatorrhea in the pediatric group. CONCLUSIONS: Age at the onset of CP, DM and SAP were identified risk factors for the development of steatorrhea in pediatric CP patients. The high-risk populations were suggested to be followed up closely. They may benefit from a full adequate pancreatic exocrine replacement therapy.

SPINK1, PRSS1, CTRC, and CFTR Genotypes Influence Disease Onset and Clinical Outcomes in Chronic Pancreatitis.

OBJECTIVES: Rare pathogenic variants in the SPINK1, PRSS1, CTRC, and CFTR genes have been strongly associated with a risk of developing chronic pancreatitis (CP). However, their potential impact on the age of disease onset and clinical outcomes, as well as their potential interactions with environmental risk factors, remain unclear. These issues are addressed here in a large Chinese CP cohort. METHODS: We performed targeted next-generation sequencing of the four CP-associated genes in 1061 Han Chinese CP patients and 1196 controls. To evaluate gene-environment interactions, the patients were divided into three subgroups, idiopathic CP (ICP; n = 715), alcoholic CP (ACP; n = 206), and smoking-associated CP (SCP; n = 140). The potential impact of rare pathogenic variants on the age of onset of CP and clinical outcomes was evaluated using the Kaplan-Meier model. RESULTS: We identified rare pathogenic genotypes involving the SPINK1, PRSS1, CTRC, and/or CFTR genes in 535 (50.42%) CP patients but in only 71 (5.94%) controls (odds ratio = 16.12; P < 0.001). Mutation-positive patients had significantly earlier median ages at disease onset and at diagnosis of pancreatic stones, diabetes mellitus and steatorrhea than mutation-negative ICP patients. Pathogenic genotypes were present in 57.1, 39.8, and 32.1% of the ICP, ACP, and SCP patients, respectively, and influenced age at disease onset and clinical outcomes in all subgroups. CONCLUSIONS: We provide evidence that rare pathogenic variants in the SPINK1, PRSS1, CTRC, and CFTR genes significantly influence the age of onset and clinical outcomes of CP. Extensive gene-environment interactions were also identified.