Maisam Abu-El-Haija

Pancreatic Damage in Fetal and Newborn Cystic Fibrosis Pigs Involves the Activation of Inflammatory and Remodeling Pathways

Pancreatic disease has onset in utero in humans with cystic fibrosis (CF), and progresses over time to complete destruction of the organ. The exact mechanisms leading to pancreatic damage in CF are incompletely understood. Inflammatory cells are present in the pancreas of newborn pigs with CF (CF pigs) and humans, which suggests that inflammation may have a role in the destructive process. We wondered whether tissue inflammation and genes associated with inflammatory pathways were increased in the pancreas of fetal CF pigs [83 to 90 days gestation (normal pig gestation is ~114 days)] and newborn pigs. Compared with fetal pigs without CF (non-CF pigs), in fetal CF pigs, the pancreas exhibited patchy inflammation and acinar atrophy, with progression in distribution and severity in neonatal CF pigs. Large-scale transcript profiling revealed that the pancreas in fetal and newborn CF pigs exhibited significantly increased expression of proinflammatory, complement cascade, and profibrotic genes when compared with fetal and newborn non-CF pigs. Acinar cells exhibited increased apoptosis in the pancreas of fetal and newborn CF pigs. α-Smooth muscle actin and transforming growth factor β1 were increased in both fetal and newborn CF pig pancreas, suggesting activation of profibrotic pathways. Cell proliferation and mucous cell metaplasia were detected in newborn, but not fetal, CF pigs, indicating that they were not an initiator of pathogenesis but a response. Proinflammatory, complement cascade, proapoptotic, and profibrotic pathways are activated in CF pig pancreas, and likely contribute to the destructive process.

Glycaemic regulation and insulin secretion are abnormal in cystic fibrosis pigs despite sparing of islet cell mass

Diabetes is a common and significant co-morbidity in cystic fibrosis (CF). The pathogenesis of cystic fibrosis related diabetes (CFRD) is incompletely understood. Because exocrine pancreatic disease is similar between humans and pigs with CF, the CF pig model has the potential to contribute significantly to the understanding of CFRD pathogenesis. We determined the structure of the endocrine pancreas in fetal, newborn and older CF and non-CF pigs and assessed endocrine pancreas function by intravenous glucose tolerance test (IV-GTT). In fetal pigs, pancreatic insulin and glucagon density was similar between CF and non-CF. In newborn and older pigs, the insulin and glucagon density was unchanged between CF and non-CF per total pancreatic area, but increased per remnant lobular tissue in CF reflecting exocrine pancreatic loss. Although fasting glucose levels were not different between CF and non-CF newborns, CF newborns demonstrated impaired glucose tolerance and increased glucose area under the curve during IV-GTT. Second phase insulin secretion responsiveness was impaired in CF newborn pigs and significantly lower than that observed in non-CF newborns. Older CF pigs had elevated random blood glucose levels compared with non-CF. In summary, glycaemic abnormalities and insulin secretion defects were present in newborn CF pigs and spontaneous hyperglycaemia developed over time. Functional changes in CF pig pancreas were not associated with a decline in islet cell mass. Our results suggest that functional islet abnormalities, independent of structural islet loss, contribute to the early pathogenesis of CFRD.

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.

Update to the management of pediatric acute pancreatitis: highlighting areas in need of research.

ABSTRACT Acute pancreatitis is an emerging problem in pediatrics, with an incidence that is rising in the last 2 decades. Data regarding the optimal management and physician practice patterns are lacking. We present a literature review and updates on the management of pediatric pancreatitis. Prospective multicenter studies defining optimal management of pediatric pancreatitis are needed to guide care and improve outcomes for this patient population.

Effects of 70% ethanol locks on rates of central line infection, thrombosis, breakage, and replacement in pediatric intestinal failure.

Objectives: Parenteral nutrition is essential for the growth and nutrition of patients with intestinal failure (IF). Catheter-related bloodstream infections (CRBSI) are a major complication of parenteral nutrition use. Few retrospective studies have shown that 70% ethanol lock (ETL) therapy for central lines can reduce the infection rate. Studies assessing line breakage, thrombosis, and replacement with the use of ETL are lacking in the pediatric literature. Methods: The present study is a retrospective chart review, with a primary outcome of CRBSI rate per 1000 catheter days, and secondary outcomes of line thrombosis, line breakage requiring repair, and line replacement rates with use of ETL compared with heparin locks. Rates were compared using the Wilcoxon signed-rank test for paired nonparametric data. Results: Seven patients satisfied the inclusion criteria that included having a single-lumen silicone central line exposed to both heparin and ETL therapy during the study period. There was a statistically significant decrease in overall and Gram-negative CRBSI rates per 1000 catheter days with a use of ETL therapy (10.3–1.4 per 1000 catheter days for overall CRBSIs, P = 0.02; 6.7–0 per 1000 catheter days for Gram-negative CRBSI, P = 0.03). There was an increasing trend in line thrombosis and repair rates with ETL therapy. Logistic regression analysis evaluating the impact of line luminal size on line repair rate showed a reduced risk of line repair when using larger-diameter central lines. Conclusions: ETL therapy is an effective method for decreasing CRBSI in patients with IF; however, it may have a negative impact on line integrity. Patients should be carefully selected when deciding on ETL therapy use for central line care. Studies are needed on the effect of different ethanol concentrations on infection rate and line integrity to optimize the outcome in this high-risk population.

An Activated Immune and Inflammatory Response Targets the Pancreas of Newborn Pigs with Cystic Fibrosis

Background/Aims: In cystic fibrosis (CF), pancreatic disease begins in utero and progresses over time to complete destruction of the organ. Although inflammatory cells have been detected in the pancreas of humans and pigs with CF, their subtypes have not been characterized. Methods: Using four-color flow cytometry, we analyzed the surface antigens of leukocytes in pancreas, blood, and mesenteric lymph nodes (MLN) of newborn pigs with CF (CFTR^–/– and CFTR^Δ^F508/^Δ^F508) and in those without CF (CFTR^+/–, CFTR^+/^Δ^F508, CFTR^+/+). Pancreatic histopathology was examined with HE stain. Results: CF pig pancreas had patchy distribution of inflammatory cells with neutrophils/macrophages in dilated acini, and lymphocytes in the interstitium compared to non-CF. B cells, effector (MHC-II⁺) and cytotoxic (CD2⁺CD8⁺) γδ T cells, activated (MHC-II⁺ and/or CD25⁺) and effector (CD4⁺CD8⁺) αβ T helper cells, effector natural killer cells (MHC-II⁺CD3^–CD8⁺), and monocytes/macrophages and neutrophils were increased in the CF pig pancreas compared to pigs without CF. Blood and MLN leukocyte populations were not different between CF and non-CF pigs. Conclusions: We discovered an activated immune response that was specific to the pancreas of newborn CF pigs; inflammation was not systemic. The presence of both innate and adaptive immune cells suggests that the disease process is complex and extensive.

Pancreatic and biliary secretion are both altered in cystic fibrosis pigs

The pancreas, liver, and gallbladder are commonly involved in cystic fibrosis (CF), and acidic, dehydrated, and protein-rich secretions are characteristic findings. Pancreatic function studies in humans have been done by sampling the jejunal fluid. However, it has been difficult to separately study the function of pancreatic and biliary systems in humans with CF, because jejunal fluid contains a mixture of bile and pancreatic fluids. In contrast, pancreatic and biliary ducts open separately into the porcine intestine; therefore, biliary and pancreatic fluid can be individually analyzed in CF pigs. We studied newborn wild-type (WT) and CF pigs and found that CFTR was localized to the pancreatic ducts. We collected bile and pancreatic fluid and analyzed pancreatic enzymes with activity assays and immunoblot. Pancreatic enzyme expression was significantly decreased in CF compared with WT pigs. The volume and pH of pancreatic fluid were significantly lower and protein concentration was >5-fold higher in CF pigs. Secretin stimulation increased pancreatic fluid volume and pH in WT, but not CF, pigs. Baseline bile volume did not differ between WT and CF pigs, but volume did not increase in response to secretin in CF pigs. Bile pH was lower and protein concentration was twofold higher in CF pigs. These results indicate that pancreatic and biliary secretions are altered in CF pigs. Abnormal pancreatic and biliary secretion in CF may have important implications in disease pathogenesis.

Early Enteral Nutrition and Aggressive Fluid Resuscitation are Associated with Improved Clinical Outcomes in Acute Pancreatitis

OBJECTIVES To determine whether recommendations for treatment of acute pancreatitis (AP) in adults impact the outcomes of pediatric AP. STUDY DESIGN Adult guidelines regarding early management of AP were implemented through an admission order set at Cincinnati Childrens Hospital Medical Center at the beginning of the year 2014. Recommendations included administering high rates of intravenous fluid (IVF) within 24 hours of admission and enteral nutrition within 48 hours of admission. A retrospective chart review of AP admissions before and after the implementation of the recommendations was undertaken. Outcomes studied were: hospital length of stay, intensive care unit transfer rates, development of severe AP, pulmonary complications, and readmission rates post discharge from the hospital. RESULTS The study included 201 patients. Children who received feeds within the first 48 hours and received greater than maintenance IVF within 24 hours had a shorter length of stay, less intensive care unit admissions and severe AP rates compared with the patients who remained nil per os during the first 48 hours and received lower rates of IVF. CONCLUSION Our data support that early enteral nutrition and early aggressive IVF improve outcomes of pediatric AP.

Simplified and versatile method for isolation of high-quality RNA from pancreas

Isolation of high-quality RNA from pancreas is challenging because the organ contains large quantities of RNases and undergoes autolysis upon harvest. Here we present a simplified perfusion method of the pancreas using an RNase inhibitor. The technique consistently yields high-quality RNA from stored pancreas samples suitable for molecular biology applications, including quantitative RT-PCR. Yields are comparable to RNA isolated from pancreas immediately, but superior to RNA isolated from stored samples that were snap-frozen or immersed in an RNase inhibitor solution. In addition, when compared to the previously reported in situ ductal perfusion technique, our method does not cause histological artifacts.

Toxic-metabolic Risk Factors in Pediatric Pancreatitis: Recommendations for Diagnosis, Management, and Future Research.

ABSTRACT Pancreatitis in children can result from metabolic and toxic risk factors, but the evidence linking these factors is sparse. We review the evidence for association or causality of these risk factors in pancreatitis, discuss management strategies, and their rationale. We conducted a review of the pediatric pancreatitis literature with respect to the following risk factors: hyperlipidemia, hypercalcemia, chronic renal failure, smoking exposure, alcohol, and medications. Areas of additional research were identified. Hypertriglyceridemia of 1000 mg/dL or greater poses an absolute risk for pancreatitis; persistent elevations of calcium are predisposing. Further research is necessary to determine whether end-stage renal disease leads to increased pancreatitis in children similar to adults. It is unknown whether cigarette smoking exposure, which clearly increases risk in adults, also increases risk in children. The role of alcohol in pediatric pancreatitis, whether direct or modifying, needs to be elucidated. The evidence supporting most cases of medication-induced pancreatitis is poor. Drug structure, improper handling of drug by host, and bystander status may be implicated. Other pancreatitis risk factors must be sought in all cases. The quality of evidence supporting causative role of various toxic and metabolic factors in pediatric pancreatitis is variable. Careful phenotyping is essential, including search for other etiologic risk factors. Directed therapy includes correction/removal of any agent identified, and general supportive measures. Further research is necessary to improve our understanding of these pancreatitis risk factors in children.