Sohail Z. Husain

Definitions of pediatric pancreatitis and survey of present clinical practices.

Objectives: There is limited literature on acute pancreatitis (AP), acute recurrent pancreatitis (ARP), and chronic pancreatitis (CP) in children. The International Study Group of Pediatric Pancreatitis: In Search for a Cure (INSPPIRE) consortium was formed to standardize definitions, develop diagnostic algorithms, investigate disease pathophysiology, and design prospective multicenter studies in pediatric pancreatitis. Methods: Subcommittees were formed to delineate definitions of pancreatitis, and a survey was conducted to analyze present practice. Results: AP was defined as requiring 2 of the following: abdominal pain compatible with AP, serum amylase and/or lipase values ≥3 times upper limits of normal, and imaging findings of AP. ARP was defined as ≥2 distinct episodes of AP with intervening return to baseline. CP was diagnosed in the presence of typical abdominal pain plus characteristic imaging findings, or exocrine insufficiency plus imaging findings, or endocrine insufficiency plus imaging findings. We found that children with pancreatitis were primarily managed by pediatric gastroenterologists. Unless the etiology was known, initial investigations included serum liver enzymes, triglycerides, calcium, and abdominal ultrasound. Further investigations (usually for ARP and CP) included magnetic resonance or other imaging, sweat chloride, and genetic testing. Respondents’ future goals for INSPPIRE included determining natural history of pancreatitis, developing algorithms to evaluate and manage pancreatitis, and validating diagnostic criteria. Conclusions: INSPPIRE represents the first initiative to create a multicenter approach to systematically characterize pancreatitis in children. Future aims include creation of patient database and biologic sample repository.

What Have We Learned About Acute Pancreatitis in Children

Pediatric pancreatitis has received much attention during the past few years. Numerous reports have identified an increasing trend in the diagnosis of acute pancreatitis in children and key differences in disease presentation and management between infants and older children. The present review provides a brief, evidence-based focus on the latest progress in the clinical field. It also poses important questions for emerging multicenter registries to answer about the natural history and management of affected children with pancreatitis.

Changing Referral Trends of Acute Pancreatitis in Children: A 12-year Single-center Analysis

Background:Acute pancreatitis is a painful inflammatory disorder known to occur in children. Recent reports, primarily on the basis of adult data, have suggested an increasing incidence. However, pediatric studies are limited. Objective:The study was performed to examine the frequency of acute pancreatitis in a pediatric population from 1994 to 2007 and to characterize etiologies by age subsets. Patients and Methods:In this retrospective study, cases of pancreatitis were identified by ICD-9 codes and subjected to inclusion criteria. Results:Two hundred and seventy-one cases of pancreatitis met inclusion criteria. Mean age of the subjects was 13.1 ± 5.6 years. The recurrence rate was 15.3%. Biliary disease was the most common etiology (32.6%). Acute pancreatitis cases evaluated at a single tertiary care center increased 53% between 1995 to 2000 and 2001 to 2006 (P < 0.02). However, when cases were normalized by all annual pediatric emergency department visits for all medical reasons, the increase was reduced to 22% and lost statistical significance (P = 0.16). The rise was not associated with a change in etiologies or body mass index (BMI). Conclusions:This is the first report demonstrating that an increase in pediatric pancreatitis may in part be due to growing referrals to tertiary care centers. The data on etiologies, particularly with regard to differing ages, may be helpful in managing children who present with acute pancreatitis.

A Comparison of Presentation and Management Trends in Acute Pancreatitis Between Infants/Toddlers and Older Children

Objectives: Acute pancreatitis is a necroinflammatory disease that leads to 210,000 hospitalizations in the United States annually. Recent reports suggest that there may be important differences in clinical features between infants/toddlers and older children. Thus, in this study we make a direct comparison between the pediatric age groups in presentation and management trends of acute pancreatitis. Patients and Methods: We examined all children (ages 0 to 20 years) admitted to Yale-New Haven Childrens Hospital with pancreatitis between 1994 and 2007. Results: Two hundred seventy-one cases met inclusion criteria for acute pancreatitis. Infants and toddlers manifested fewer signs and symptoms of abdominal pain, epigastric tenderness, and nausea compared with older children (43% vs 93%; 57% vs 90%; and 29% vs 76%, respectively; P < 0.05 for all comparisons). They were more likely to be diagnosed by serum lipase than by amylase and to undergo radiographic evaluation (P < 0.05). They had a longer hospital stay (19.5 vs 4 days; P < 0.05) and were less likely to be directly transitioned to oral nutrition (14% vs 71%; P < 0.05). Conclusions: Infants and toddlers with acute pancreatitis present with fewer classical symptoms and are managed differently from older children. We believe these data will be helpful in evaluating and understanding treatment practices in this age group.

PEDIATRIC CHRONIC PANCREATITIS IS ASSOCIATED WITH GENETIC RISK FACTORS AND SUBSTANTIAL DISEASE BURDEN

OBJECTIVE To determine the clinical presentation, diagnostic variables, risk factors, and disease burden in children with chronic pancreatitis. STUDY DESIGN We performed a cross-sectional study of data from the International Study Group of Pediatric Pancreatitis: In Search for a Cure, a registry of children with acute recurrent pancreatitis and chronic pancreatitis. Between-group differences were compared using Wilcoxon rank-sum test. RESULTS Among 170 subjects in the registry, 76 (45%) had chronic pancreatitis; 57% were female, 80% were white; median age at diagnosis was 9.9 years. Pancreatitis-predisposing genetic mutations were identified in 51 (67%) and obstructive risk factors in 25 (33%). Toxic/metabolic and autoimmune factors were uncommon. Imaging demonstrated ductal abnormalities and pancreatic atrophy more commonly than calcifications. Fifty-nine (77%) reported abdominal pain within the past year; pain was reported as constant and receiving narcotics in 28%. Children with chronic pancreatitis reported a median of 3 emergency department visits and 2 hospitalizations in the last year. Forty-seven subjects (70%) missed 1 day of school in the past month as the result of chronic pancreatitis; 26 (34%) missed 3 or more days. Children reporting constant pain were more likely to miss school (P = .002), visit the emergency department (P = .01), and experience hospitalizations (P = .03) compared with children with episodic pain. Thirty-three children (43%) underwent therapeutic endoscopic retrograde pancreatography; one or more pancreatic surgeries were performed in 30 (39%). CONCLUSIONS Chronic pancreatitis occurs at a young age with distinct clinical features. Genetic and obstructive risk factors are common, and disease burden is substantial.

Bile acids induce pancreatic acinar cell injury and pancreatitis by activating calcineurin

Background: Bile acid exposure causes pancreatic acinar cell injury through a sustained rise in cytosolic Ca2+. Results: Pharmacologic and genetic inhibition of the Ca2+-activated phosphatase calcineurin dramatically reduces acinar cell injury and in vivo pancreatitis resulting from bile acid exposure. Conclusion: Acinar cell calcineurin mediates acinar cell injury and pancreatitis resulting from bile acid exposure. Significance: Calcineurin inhibitors may provide an adjunctive therapy for biliary pancreatitis. Biliary pancreatitis is the leading cause of acute pancreatitis in both children and adults. A proposed mechanism is the reflux of bile into the pancreatic duct. Bile acid exposure causes pancreatic acinar cell injury through a sustained rise in cytosolic Ca2+. Thus, it would be clinically relevant to know the targets of this aberrant Ca2+ signal. We hypothesized that the Ca2+-activated phosphatase calcineurin is such a Ca2+ target. To examine calcineurin activation, we infected primary acinar cells from mice with an adenovirus expressing the promoter for a downstream calcineurin effector, nuclear factor of activated T-cells (NFAT). The bile acid taurolithocholic acid-3-sulfate (TLCS) was primarily used to examine bile acid responses. TLCS caused calcineurin activation only at concentrations that cause acinar cell injury. The activation of calcineurin by TLCS was abolished by chelating intracellular Ca2+. Pretreatment with 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (acetoxymethyl ester) (BAPTA-AM) or the three specific calcineurin inhibitors FK506, cyclosporine A, or calcineurin inhibitory peptide prevented bile acid-induced acinar cell injury as measured by lactate dehydrogenase leakage and propidium iodide uptake. The calcineurin inhibitors reduced the intra-acinar activation of chymotrypsinogen within 30 min of TLCS administration, and they also prevented NF-κB activation. In vivo, mice that received FK506 or were deficient in the calcineurin isoform Aβ (CnAβ) subunit had reduced pancreatitis severity after infusion of TLCS or taurocholic acid into the pancreatic duct. In summary, we demonstrate that acinar cell calcineurin is activated in response to Ca2+ generated by bile acid exposure, bile acid-induced pancreatic injury is dependent on calcineurin activation, and calcineurin inhibitors may provide an adjunctive therapy for biliary pancreatitis.

Molecular and cellular mechanisms of pancreatic injury.

Purpose of review This review focuses on studies from the past year that highlight molecular and cellular mechanisms of pancreatic injury arising from acute and chronic pancreatitis. Recent findings Factors that induce or ameliorate injury as well as cellular pathways involved have been examined. Causative or sensitizing factors include refluxed bile acids, hypercalcemia, ethanol, hypertriglyceridemia, and acidosis. In addition, the diabetes drug exendin-4 has been associated with pancreatitis, whereas other drugs may reduce pancreatic injury. The intracellular events that influence disease severity are better understood. Cathepsin-L promotes injury through an antiapoptotic effect, rather than by trypsinogen activation. In addition, specific trypsinogen mutations lead to trypsinogen misfolding, endoplasmic reticulum stress, and injury. Endogenous trypsin inhibitors and upregulation of proteins including Bcl-2, fibroblast growth factor 21, and activated protein C can reduce injury. Immune cells, however, have been shown to increase injury via an antiapoptotic effect. Summary The current findings are critical to understanding how causative factors initiate downstream cellular events resulting in pancreatic injury. Such knowledge will aid in the development of targeted treatments for pancreatitis. This review will first discuss factors influencing pancreatic injury, and then conclude with studies detailing the cellular mechanisms involved.

Risk Factors Associated With Pediatric Acute Recurrent and Chronic Pancreatitis: Lessons From INSPPIRE

IMPORTANCE Pediatric acute recurrent pancreatitis (ARP) and chronic pancreatitis (CP) are poorly understood. OBJECTIVE To characterize and identify risk factors associated with ARP and CP in childhood. DESIGN, SETTING, AND PARTICIPANTS A multinational cross-sectional study of children with ARP or CP at the time of enrollment to the INSPPIRE (International Study Group of Pediatric Pancreatitis: In Search for a Cure) study at participant institutions of the INSPPIRE Consortium. From August 22, 2012, to February 8, 2015, 155 children with ARP and 146 with CP (aged ≤19 years) were enrolled. Their demographic and clinical information was entered into the REDCap (Research Electronic Data Capture) database at the 15 centers. Differences were analyzed using 2-sample t test or Wilcoxon rank sum test for continuous variables and Pearson χ2 test or Fisher exact test for categorical variables. Disease burden variables (pain variables, hospital/emergency department visits, missed school days) were compared using Wilcoxon rank sum test. MAIN OUTCOMES AND MEASURES Demographic characteristics, risk factors, abdominal pain, and disease burden. RESULTS A total of 301 children were enrolled (mean [SD] age, 11.9 [4.5] years; 172 [57%] female); 155 had ARP and 146 had CP. The majority of children with CP (123 of 146 [84%]) reported prior recurrent episodes of acute pancreatitis. Sex distribution was similar between the groups (57% female in both). Hispanic children were less likely to have CP than ARP (17% vs 28%, respectively; odds ratio [OR] = 0.51; 95% CI, 0.29-0.92; P = .02). At least 1 gene mutation in pancreatitis-related genes was found in 48% of patients with ARP vs 73% of patients with CP (P < .001). Children with PRSS1 or SPINK1 mutations were more likely to present with CP compared with ARP (PRSS1: OR = 4.20; 95% CI, 2.14-8.22; P < .001; and SPINK1: OR = 2.30; 95% CI, 1.03-5.13; P = .04). Obstructive risk factors did not differ between children with ARP or CP (33% in both the ARP and CP groups), but toxic/metabolic risk factors were more common in children with ARP (21% overall; 26% in the ARP group and 15% in the CP group; OR = 0.55; 95% CI, 0.31-0.99; P = .046). Pancreatitis-related abdominal pain was a major symptom in 81% of children with ARP or CP within the last year. The disease burden was greater in the CP group compared with the ARP group (more emergency department visits, hospitalizations, and medical, endoscopic, and surgical interventions). CONCLUSIONS AND RELEVANCE Genetic mutations are common in both ARP and CP. Ethnicity and mutations in PRSS1 or SPINK1 may influence the development of CP. The high disease burden in pediatric CP underscores the importance of identifying predisposing factors for progression of ARP to CP in children.

Pancreatic cell tracing, lineage tagging and targeted genetic manipulations in multiple cell types using pancreatic ductal infusion of adeno-associated viral vectors and/or cell-tagging dyes

Genetic manipulations, with or without lineage tracing for specific pancreatic cell types, are very powerful tools for studying diabetes, pancreatitis and pancreatic cancer. Nevertheless, the use of Cre/loxP systems to conditionally activate or inactivate the expression of genes in a cell type– and/or temporal-specific manner is not applicable to cell tracing and/or gene manipulations in more than one lineage at a time. Here we report a technique that allows efficient delivery of dyes for cell tagging into the mouse pancreas through the duct system, and that also delivers viruses carrying transgenes or siRNA under a specific promoter. When this technique is applied in genetically modified mice, it enables the investigator to perform either double lineage tracing or cell lineage tracing combined with gene manipulation in a second lineage. The technique requires <40 min.

Two-day bowel preparation with polyethylene glycol 3350 and bisacodyl: a new, safe, and effective regimen for colonoscopy in children.

Objectives: To assess the safety, efficacy, and acceptance of a 2-day bowel preparation with polyethylene glycol (PEG) 3350 without electrolytes and bisacodyl for colonoscopy in children. Patients and Methods: In a prospective study, 111 children of mean age 11.9 years were given 2 g/kg of PEG and a 5-mg tablet of bisacodyl daily for 2 days before colonoscopy. Stool frequency, consistency, and adverse effects were monitored for the duration of the bowel preparation. Compliance and quality of colonic preparation were assessed on the day of the colonoscopy. Results: The average daily stool frequency increased from a baseline of 2, to 4* on day 1, and 6.5* on day 2 of the bowel preparation (*P < 0.001 for difference vs baseline). The colonic preparations were rated as excellent or good in 92% and 93% of the patients in the right and left colon, respectively. Adverse effects were mild nausea (19%), abdominal pain (11%), and vomiting (4%). The compliance was rated as excellent in 95% of the patients. Conclusions: A 2-day bowel preparation with PEG and bisacodyl is safe, effective, and well accepted for colonoscopy in children without any major adverse effects.