The Development of the International Intestinal Failure Registry and an Overview of its Results.

Pediatric intestinal failure (IF) is a rare disease that represents an evolving field in pediatric gastroenterology and surgery. With only a limited number of multicenter collaborations, much of the research in pediatric IF is often confined to single-center reports with small sample sizes. This has resulted in challenges in data interpretation and left many knowledge gaps unanswered. Over the past two decades, five large multicenter collaborations, primarily from North America and Europe, have published their findings. Apart from one ongoing European adult and pediatric registry, these relatively large-scale efforts have been concluded.In 2018, the International Intestinal Failure Registry (IIFR) was initiated by the International Intestinal Rehabilitation and Transplant Association to continue these efforts and answer some of the knowledge gaps in pediatric IF. The IIFR goals are to prospectively assess the natural history of children diagnosed with IF and creating a worldwide platform to facilitate benchmarking and evidence-based interventions in pediatric IF. A pilot phase involving 204 enrolled patients was initiated in 2018 to assess the feasibility of an international IF registry and refine the study protocol and data collection forms. Following the successful completion of this phase, the current phase of the IIFR was launched in 2021. As of May 2023, the registry includes 362 prospectively followed children from 26 centers worldwide. This review provides an overview of the development, structure, and challenges of the IIFR, as well as the main findings from both the pilot and current phase.

Predictors of 1-year enteral autonomy in children with intestinal failure: A descriptive retrospective cohort study.

INTRODUCTION: The International Intestinal Failure Registry (IIFR) is an international consortium to study intestinal failure (IF) outcomes in a large contemporary pediatric cohort. We aimed to identify predictors of early (1-year) enteral autonomy. METHODS: We included IIFR pilot phase patients. IF was defined by a parenteral nutrition need for at least 60 days due to a primary gastrointestinal etiology. The primary outcome was time to enteral autonomy achievement. We built a mixed-effects Weibull accelerated failure time model with random effects by center to analyze variables associated with enteral autonomy achievement with a primary outcome of time ratio (TR). RESULTS: We included 189 patients (82% with short bowel syndrome) representing 11 international centers. Cumulative incidence of early enteral autonomy was 51.6%, and death was 6.5%. In multivariable analysis, ostomy presence (TR, 2.63; 95% CI, 1.41-4.90) was associated with increased time to enteral autonomy achievement, and Asian/Indian (TR, 0.28; 95% CI, 0.10-0.81) and Pacific Islander race (TR, 0.34; 95% CI, 0.13-0.90) were associated with decreased time to enteral autonomy achievement. In a second model in the subset with measured percentage of bowel length remaining, ostomy presence (TR, 4.21; 95% CI, 1.90-9.33) was associated with increased time to enteral autonomy achievement, whereas greater percentage of bowel remaining (TR, 0.96; 95% CI, 0.94-0.98) was associated with decreased time to enteral autonomy achievement. CONCLUSIONS: Minimizing bowel resection at initial surgery and establishing bowel continuity by ostomy reversal can effectively decrease the time to early enteral autonomy achievement in children with IF.

Body Composition and Physical Activity in Pediatric Intestinal Failure On and Off Parenteral Nutrition.

OBJECTIVES: Data on the relationship between body composition (BC) and physical activity (PA) in children with intestinal failure (IF) are lacking. The objectives were to collect data on PA and BC in children with IF, both parenterally and enterally fed, and to assess the relationship between PA and BC. METHODS: Cross-sectional study in children 5-18 years with IF including those receiving parenteral nutrition (PN) and those fully enterally fed. PA levels were measured using accelerometry. BC was measured by dual-energy X-ray absorptiometry. Data were compared to age- and sex-matched population norms using t tests. Regression analysis assessed the relationship between BC and PA. RESULTS: Fifty-eight children with IF (38 males), mean (SD) age of 10.0 (3.5) years, 20 dependent on PN were included. Patients with IF had significantly fewer steps per day ( P ≤ 0.001) compared with literature controls, with a mean (SD) of 7,972 (3,008) and 11,749 (1,106), respectively. There were no significant differences between patients receiving PN and those enterally fed, but both groups were significantly less active than literature controls ( P < 0.001). Patients with IF had higher fat mass and lower fat-free mass compared to literature controls ( P = 0.008). PA had a significant effect on BC ( r2 = 0.32, P < 0.001). CONCLUSIONS: Children with IF, those receiving PN and those fully enterally fed, are at risk of decreased PA and altered BC. PA should be part of ongoing rehabilitation and management to optimize outcomes.

Outcome After Intestinal Transplantation From Living Versus Deceased Donors: A Propensity-matched Cohort Analysis of the International Intestinal Transplant Registry.

OBJECTIVE: To describe the worldwide experience with living donation (LD) in intestinal transplantation (ITx) and compare short-term and long-term outcomes to a propensity-matched cohort of deceased donors. BACKGROUND: ITx is a rare life-saving procedure for patients with complicated intestinal failure (IF). Living donation (LD)-ITx has been performed with success, but no direct comparison with deceased donation (DD) has been performed. The Intestinal Transplant Registry (ITR) was created in 1985 by the Intestinal Transplant Association to capture the worldwide activity and promote center's collaborations. METHODS: Based on the ITR, 4156 ITx were performed between January 1987 and April 2019, of which 76 (1.8%) were LD, including 5 combined liver-ITx, 7 ITx-colon, and 64 isolated ITx. They were matched with 186 DD-ITx for recipient age/sex, weight, region, IF-cause, retransplant, pretransplant status, ABO compatibility, immunosuppression, and transplant date. Primary endpoints were acute rejection and 1-/5-year patient/graft survival. RESULTS: Most LDs were performed in North America (61%), followed by Asia (29%). The mean recipient age was: 22 years; body mass index: 19kg/m²; and female/male ratio: 1/1.4. Volvulus (N=17) and ischemia (N=17) were the most frequent IF-causes. Fifty-two percent of patients were at home at the time of transplant. One-/5-year patient survival for LD and DD was 74.2/49.8% versus 80.3/48.1%, respectively ( P =0.826). One-/5-year graft survival was 60.3/40.6% versus 69.2/36.1%, respectively ( P =0.956). Acute rejection was diagnosed in 47% of LD versus 51% of DD ( P =0.723). CONCLUSION: Worldwide, LD-ITx has been rarely performed. This retrospective matched ITR analysis revealed no difference in rejection and in patient/graft survival between LD and DD-ITx.

Immunogenicity of a quadrivalent human papillomavirus vaccine in pediatric kidney and liver transplant recipients.

BACKGROUND: Solid-organ transplant recipients are at increased risk of developing human papillomavirus-related diseases. METHODS: To evaluate the immunogenicity of a quadrivalent vaccine, a prospective observational study included females aged 12-19 years who had received kidney or liver transplants, or were otherwise healthy volunteers. With the three-dose vaccination, serum antibodies were measured. RESULTS: The study included 17 transplant recipients (seven kidney and 10 liver) and 16 healthy participants. Six of seven kidney transplant recipients were on three immunosuppressive medications, whereas 9 of the 10 liver transplant recipients were on one. For the serology within 6 months from the last vaccine dose, the geometric mean titers of human papillomavirus types 6, 11, 16, and 18 were 26.7, 8.6, 35.7, and 42.4 (kidney transplant); 579.2, 569.3, 3097.3, and 835.7 (liver transplant); and 860.5, 638.8, 4391.6, and 902.6 milli-Merck Units/ml (healthy). The seropositivity rates of kidney transplant recipients for the four serotypes ranged from 50% to 75%, while all liver transplant recipients and healthy participants had 100% seropositivity rates for all four types. While there were no statistical differences of titers between liver transplant recipients and healthy participants, the titers of kidney transplant recipients were lower than those of healthy participants for type 6 (p = .034), type 11 (p = .032), and type 16 (p = .032). CONCLUSIONS: The results support the recommendation of human papillomavirus vaccination in pediatric transplant recipients given the significant risk of human papillomavirus-related diseases in this population, though immunogenicity was lower in kidney transplant recipients on multiple immunosuppressive medications.

Use of a combined transient elastography and biochemical strategy to determine liver fibrosis in pediatric intestinal failure.

BACKGROUND & AIMS: Non-invasive monitoring of intestinal failure (IF) associated liver disease is an ongoing challenge in children with IF. Our objective was to develop a combined algorithm of clinical, transient elastography (TE) and biochemical parameters to identify liver fibrosis in this population. METHODS: A retrospective cohort study of IF patients followed by our intestinal rehabilitation program between November 2015 to October 2019. Patients with a liver biopsy and TE were included. Demographic and liver function tests were collected. Fibrosis on liver biopsies was graded using the modified Scheuer score. Decision tree based algorithms classified low (F0-F1) versus high (F2-F4) fibrosis scores based on a combination of TE, biochemical and demographic parameters, using 6-fold classification error, sensitivity and specificity cross-validation (CV) scores. RESULTS: 42 patients (74% male, median age 7.6 (4.6; 42.7) months) were evaluated. Median length of PN therapy was 182 (121; 556) days. High fibrosis was present in 40.5% with a median TE of 12.1 (6.7; 12.9) kPa in high fibrosis children. An algorithm, based on cut-off values for TE of 11.3 kPa and AST of 40 U/L, and grouping of the underlying etiology resulted in a correct classification of 88.1% of the pathology scores; with sensitivity 0.82 (95% CI 0.57; 0.96), specificity 0.92 (95% CI 0.74; 0.99), positive predictive value 0.88 (95% CI 0.64; 0.96) and negative predictive value 0.88 (95% CI 0.73; 0.96). The CV classification error was 28.6%, CV sensitivity 72.2% and CV specificity 75.5%. CONCLUSIONS: This algorithm shows promising results that could simplify non-invasive monitoring of liver fibrosis in children with IF. Validation in additional IF cohorts is needed.

The Diverse Phenotype of Intestinal Dysmotility Secondary to ACTG2-related Disorders.

BACKGROUND AND AIMS: The initial description of a heterozygous dominant ACTG2 variant in familial visceral myopathy was followed by the identification of additional variants in other forms of intestinal dysmotility disorders. we aimed to describe the diverse phenotype of this newly reported and rare disease. METHODS: Report of 4 new patients, and a systematic review of ACTG2-related disorders. we analyzed the population frequency and used in silico gene damaging predictions. Genotype-phenotype correlations were explored. RESULTS: One hundred three patients (52% girls), from 14 publications, were included. Twenty-eight unique variants were analyzed, all exceedingly rare, and 27 predicted to be highly damaging. The median Combined Annotation Dependent Depletion (CADD) score was 29.2 (Interquartile range 26.3-29.4). Most patients underwent abdominal surgery (66%), about half required intermittent bladder catheterization (48.5%), and more than half were parenteral nutrition (PN)-dependent (53%). One-quarter of the patients died (25.7%), and 6 required transplant (5.8%). Girls had a higher rate of microcolon (P  = 0.009), PN dependency (P = 0.003), and death/transplant (P = 0.029) compared with boys, and early disease onset (<2 years of age) was associated with megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) features. There was no statistical association between disease characteristics and CADD scores. CONCLUSIONS: Damaging ACTG2 variants are rare, often associated with MMIHS phenotype, and overall have a wide phenotypic variation. Symptoms usually present in the perinatal period but can also appear at a later age. The course of the disease is marked by frequent need for surgical interventions, PN support, and mortality. Poor outcomes are more common among girls with ACTG2 variants.

Sequential paternal haploidentical donor liver and HSCT in EPP allow discontinuation of immunosuppression post-organ transplant.

BACKGROUND: EPP is characterized by photosensitivity and by liver disease. When LT is performed in EPP, recurrence often occurs in the allograft due to ongoing protoporphyrin production in bone marrow. Therefore, curative treatment requires allogeneic HSCT after LT. Long-term immunosuppression could be spared by using the same donor for both transplants. METHODS: A 2-year-old girl with EPP in liver failure underwent liver transplant from her father. Transfusion and apheresis therapy were used to lower protoporphyrin levels before and after liver transplant. Ten weeks after liver transplant, she underwent HSCT, using the same donor. Conditioning was with treosulfan, fludarabine, cyclophosphamide, and ATG. GVHD prophylaxis was with abatacept, methotrexate, MMF, and tacrolimus. We followed the patient's erythrocyte protoporphyrin and liver and skin health for 2 years after transplant. RESULTS: After hematopoietic stem cell engraftment, a decline in protoporphyrin levels was observed, with clinical resolution of photosensitivity. Liver biopsies showed no evidence of EPP. Mild ACR occurred and responded to steroid pulse. Two years post-HSCT, the patient has been weaned off all immunosuppression and remains GVHD and liver rejection free. CONCLUSIONS: Sequential liver and HSCT from the same haploidentical donor are feasible in EPP. This strategy can allow for discontinuation of immune suppression.

Standardized Feeding Protocol Improves Delivery and Acceptance of Enteral Nutrition in Children Immediately After Liver Transplantation.

Delivery of adequate nutrition after liver transplantation (LT) surgery is an important goal of postoperative care. Existing guidelines recommend early enteral nutrition after abdominal surgery and in the child who is critically ill but data on nutritional interventions after LT in children are sparse. We evaluated the impact of a standardized postoperative feeding protocol on enteral nutrition delivery in children after LT. Data from 49 children (ages 0-18 years) who received a LT prior to feeding protocol implementation were compared with data for 32 children undergoing LT after protocol implementation. The 2 groups did not differ with respect to baseline demographic data. After protocol implementation, enteral nutrition was started earlier (2 versus 3 days after transplant; P = 0.005) and advanced faster when a feeding tube was used (4 versus 8 days; P = 0.03). Protocol implementation was also associated with reduced parenteral nutrition use rates (47% versus 75%; P = 0.01). No adverse events occurred after protocol implementation. Hospital length of stay and readmission rates were not different between the 2 groups. In conclusion, implementation of a postoperative nutrition protocol in children after LT led to optimized nutrient delivery and reduced variability of care.

Physical Activity and Fatigue in Children With Intestinal Failure on Parenteral Nutrition.

OBJECTIVES: With improved survival of children with intestinal failure (IF), it is important to examine the impact on long-term physical function, physical activity (PA), and fatigue and identify clinical factors that may be predictive of impairment. METHODS: Cross-sectional study in children with IF on parenteral nutrition (PN) compared with healthy age- and sex-matched controls (HCs). Assessments included: Paediatric Quality of Life (PedsQL) Physical Function subscale, PedsQL Multi-Dimensional Fatigue Scale, and PA Perceived Benefits and Barriers scale. PA was measured using an accelerometer. Medical data was collected by chart abstraction. RESULTS: Participants included 21 children with IF (14 girls), median age 8.33 (interquartile range [IQR] 6.96-11.04) years and 33 HCs (20 boys), 8.25 (6.67-10.79) years. In those with IF, 13 (62%) were born prematurely with a median of 15 (7.5-24.5) in-patient hospitalizations. There was a significant difference (P = 0.033) in mean steps/day in children with IF (9709 +/- 3975) compared with HCs (13104 +/- 5416), and a correlation between moderate-to-vigorous PA and gestational age (r = 0.642, P = 0.010). Child and parent proxy scores indicate poorer physical function and greater fatigue in the IF group, along with a correlation between greater fatigue (r = -0.538, P = 0.012), poorer physical function (r = -0.0650, P = 0.0001) in children with more hospitalizations. Barriers to PA include "I am tired" and "I am worried about my line." CONCLUSIONS: Children with IF present with lower levels of PA and physical function and greater fatigue compared with their peers. Ongoing development of medical and rehabilitation intervention strategies is vital to optimize outcomes.

Findings encountered in percutaneous cholangiography in a case of post-transplant recurrence of hepatic Langerhans cell histiocytosis with biliary involvement.

This case report describes a four-year-old boy who presented with the diagnosis of LCH with liver involvement. This required a living-related liver transplant one year later. The primary disease recurred in the transplanted liver 6 months post-transplant and led to progressive biliary dilatation. A percutaneous trans-hepatic cholangiogram was performed five years after transplant, showing a pattern of multifocal biliary duct strictures mimicking the pattern of primary sclerosing cholangitis and a stenosis of the biliary-enteric anastomosis. Despite management with an internal-external biliary drain, the stenosis of the biliary-enteric anastomosis evolved to an occlusion one year after drain removal. This was associated with progression of the changes in the biliary tree, this time associated with significant saccular dilatations secondary to the multiple areas of stenosis. Due to these findings and progressive deterioration of the function of the graft, the patient required re-transplantation. This report illustrates the findings in imaging of the biliary tree secondary to the recurrence of LCH after liver transplantation, which may help to recognize this complication to physicians facing a similar clinical scenario.

Percutaneous removal of biliary stones post-liver transplant in a pediatric patient: Case report and review of the literature.

This case report describes an 8-year-old girl who underwent a segmental LT for a primary diagnosis of citrullinemia at the age of 12 months. She presented with cholangitis secondary to stenosis of the biliary-enteric anastomosis. MRI revealed dilatation of intrahepatic bile ducts associated with multiple stones. An endoscopic approach failed to decompress the bile ducts and remove the stones. A percutaneous approach was then undertaken. After placement of a temporary external biliary drain for 12 days, a 26 French sheath was placed to access the bile ducts. Using a 14Fr flexible cystoscope, 80%-90% of the biliary stones were removed. This was followed by antegrade balloon dilatation of the biliary-enteric anastomosis. Two months later, the procedure was repeated, resulting in complete clearance of the biliary stones. An internal-external biliary drain was maintained in placed for 10 months. The patient has been asymptomatic, with no evidence of stone recurrence for 13 months after drain removal. Percutaneous biliary stone removal is commonly performed in adults with non-transplanted livers, especially in complex cases, and has also been shown to be successful in the pediatric population. However, it is rarely reported in transplanted livers in adults, and to the best of our knowledge, no pediatric cases have been reported. This case illustrates that this technique can be successfully utilized in pediatric LT patients.

New Insights Into the Indications for Intestinal Transplantation: Consensus in the Year 2019.

In 2001, a Statement was published that described indications for intestinal transplantation in patients with intestinal failure expected to require parenteral nutrition indefinitely. Since 2001, advances in the management of intestinal failure including transplantation and patient survival, both on extended parenteral nutrition and after transplantation, have improved, leading to a reduction in the number of intestinal transplants worldwide from a peak of 270 per year in 2008 to 149 per year in 2017. These changes suggest that the original 2001 Statement requires reassessment. All patients with permanent intestinal failure should be managed by dedicated multidisciplinary intestinal rehabilitation teams. Under care of these teams, patients should be considered for intestinal transplantation in the event of progressive intestinal failure-associated liver disease, progressive loss of central vein access, and repeated life-threatening central venous catheter-associated infections requiring critical care. Additional indications for transplantation include large desmoid tumors and other intra-abdominal tumors with reasonable expectation of posttransplant cure, extensive mesenteric vein thrombosis and intestinal infarction, total intestinal aganglionosis, and nonrecoverable congenital secretory diarrhea. Quality of life typically improves after successful intestinal transplantation and may support the decision to proceed with transplantation when other indications are present. However, the requirement for life-long immunosuppression and its associated side effects preclude intestinal transplantation if motivated only by an expectation of improved quality of life. Increasing experience with intestinal transplantation and critical appraisal of transplant outcomes including graft survival and patient quality of life together with potential advances in immunosuppression can be expected to influence transplant practices in the future.

Posttransplant Lymphoproliferative Disorder in Pediatric Patients: Characteristics of Disease in EBV-seropositive Recipients.

BACKGROUND: Patients at greatest risk of posttransplant lymphoproliferative disorder (PTLD) are those who acquire primary Epstein-Barr virus (EBV) infection after solid organ transplantation. The incidence of PTLD among patients who are EBV-seropositive before transplant is lower, and little is known about the differences in presentation and outcome of this population. We describe the characteristics of EBV-seropositive transplant recipients (R+) who developed PTLD and compare survival outcomes with EBV-seronegative recipients (R-). METHODS: A hospital-based registry was used to identify all patients with biopsy-proven PTLD for the period 2000-2014. Characteristics and outcomes were compared between R+ and R- patients with PTLD. RESULTS: Sixty-nine patients were included, among which 20 (29.0%) were R+ and 49 (71.0%) were R-. Multiorgan transplant patients accounted for 25% of PTLD cases in R+ patients, while accounting for only 2.1% of all transplants during the study period. There was no difference in PTLD site between R+ and R- patients. PTLD among R+ individuals occurred during the second year after transplant (median: 1.92; range: 0.35-3.09 y) compared with during the first year for R- individuals (median: 0.95; range: 0.48-2.92 y; P = 0.380). There was a trend for a higher overall mortality among R+ individuals (log rank: 0.09). PTLD-related mortality did not differ between R+ and R- individuals (log rank: 0.17). CONCLUSIONS: PTLD among R+ individuals was more likely to occur among multiorgan recipients, and there was a tendency for poorer outcomes at 1 and 5 years after the diagnosis of PTLD.

Kidney disease and organ transplantation in methylmalonic acidaemia.

OBJECTIVES: MMA is associated with chronic tubulointerstitial nephritis and a progressive decline in GFR. Optimal management of these children is uncertain. Our objectives were to document the pre-, peri-, and post-transplant course of all children with MMA who underwent liver or combined liver-kidney transplant in our centers. DESIGN AND METHODS: Retrospective chart review of all cases of MMA who underwent organ transplantation over the last 10 years. RESULTS: Five children with MMA underwent liver transplant (4/5) and combined liver-kidney transplant (1/5). Three were Mut0 and two had a cobalamin B disorder. Four of five were transplanted between ages 3 and 5 years. Renal dysfunction prior to transplant was seen in 2/5 patients. Post-transplant (one liver transplant and one combined transplant) renal function improved slightly when using creatinine-based GFR formula. We noticed in 2 patients a big discrepancy between creatinine- and cystatin C-based GFR calculations. One patient with no renal disease developed renal failure post-liver transplantation. Serum MMA levels have decreased in all to <300 µmol/L. Four patients remain on low protein diet, carnitine, coenzyme Q, and vitamin E post-transplant. CONCLUSIONS: MMA is a complex metabolic disorder. Renal disease can continue to progress post-liver transplant and close follow-up is warranted. More research is needed to clarify best screening GFR method in patients with MMA. Whether liver transplant alone, continued protein restriction, or the addition of antioxidants post-transplant can halt the progression of renal disease remains unclear.

Posttransplant lymphoproliferative disorder in pediatric patients: Survival rates according to primary sites of occurrence and a proposed clinical categorization.

Posttransplant lymphoproliferative disorder (PTLD) is a devastating complication of organ transplant. In a hospital-based registry, we identified biopsy-proven cases of PTLD among children during a 15-year period and reviewed trends in PTLD rates, the sites of involvement, and the associated survival rates. Cases that were included had at least 1 year of follow-up after the diagnosis of PTLD. We studied 82 patients with first-episode PTLD. Median age at diagnosis was 6.4 years (IQR 3.2-12.3 years). The most frequent PTLD sites were tonsillar/adenoidal (T/A [34%]) and gastrointestinal (32%), followed by miscellaneous (defined as less common sites including central nervous system, kidney, lung, and soft tissue [12%]), lymph node (11%), and multisite (11%). Kaplan-Meier survival curves showed that T/A PTLD was associated with decreased all-cause mortality compared with PTLD at other sites (log-rank 0.004), even after adjustment for histological subtype (P = .047). PTLD-related mortality was also decreased among T/A PTLD (log-rank 0.012) but showed a trend toward significance only after adjustment for histological subtype (P = .09). Among first episodes of PTLD, T/A PTLD was associated with a survival advantage compared with PTLD at other sites, even after adjustment for potential confounders. Based on our observations, we propose a clinical categorization of PTLD according to anatomical site of occurrence.

The evolution of the serial transverse enteroplasty for pediatric short bowel syndrome at a single institution.

PURPOSE: The serial transverse enteroplasty (STEP) tapers and lengthens the gut to improve adaptation. Mortality has decreased with multidisciplinary intestinal rehabilitation programs (IRP) allowing more time to reach adaptive potential. We reviewed our STEP experience to compare surgical outcomes between early and late eras of our IRP. METHODS: A retrospective cohort study of all STEP patients managed by our IRP (Jan 2003-Dec 2016; era 1 2003-2005, era 2 2006-2016) was completed. Patient demographics, operative data, complications, and outcome data were collected. Univariate analysis between eras with nonparametric statistics was performed. RESULTS: Thirty-six patients received STEP (Era 1 = 12; Era 2 = 24) [median age 5mo; males 22/36 (61.1%)]. In Era 2 a higher proportion had gastroschisis (8.3% vs 58.3%); p = 0.004) and shorter pre-STEP small bowel remnant (48 vs 111 cm, p = 0.001). The median increase in bowel length post-STEP was 52.9%. Overall, 42% of patients reached enteral autonomy (Era 1 7/12 (58%) vs Era 2 8/24 (33%); p = 0.15). Median time to PN discontinuation was shorter in Era 1 (259 vs 968 days, p = .208). Staple line complications were higher in Era 1 (16.7% vs 0%; p = 0.040). CONCLUSION: Presently, STEP is reserved for a specific subset of IRP patients, allowing 42% to wean off PN. STEP's use should be under the umbrella of a multidisciplinary IRP. TYPE OF STUDY: Retrospective cohort study. LEVEL OF EVIDENCE: III.

Predicting Intestinal Adaptation in Pediatric Intestinal Failure: A Retrospective Cohort Study.

OBJECTIVE: The primary goal in intestinal failure (IF) is adaptation and enteral autonomy (EA). Our goals were to determine the proportion of patients treated for IF by an established intestinal rehabilitation program who achieved EA and to assess the predictors of EA. BACKGROUND: There have been considerable advancements in the management of IF over the last 15 years, children with short bowel syndrome with a reduction in mortality. Several studies have discussed variables that may influence the ability to attain EA; however, majority were written when mortality rates were considerably higher compared with the current contemporary experience. METHODS: A retrospective analysis of infants <12 months with short bowel syndrome referred between 2006 and 2013 (n = 120). Data was collected on IF-related factors and nutritional intake. The cohort was stratified based on achievement of EA. Statistical testing completed using t test, Chi Square, and Cox Proportional Hazards regression (P < 0.05). RESULTS: EA was achieved in 84 (70.0%) patients. Patients who remained parenteral nutrition dependent were more likely to have volvulus (1.2 vs 22.2%, P < 0.001), shorter percent residual small bowel (29.4 vs 68.6%; P < 0.0001) and colon length (64.6 vs 86.0%; P = 0.001), and no ileocecal valve (61.1 vs 29.8%; P = 0.05). Mortality was also decreased in those who achieved EA (4 vs 22%; P = 0.004). Percent residual small bowel (HR = 1.03; 95% CI 1.02-1.03) and colon (HR = 1.01; 95% CI 1.00-1.02) length were positively associated with EA, while number of septic episodes was negatively associated (HR = 0.95; 95% CI 0.91-0.99). CONCLUSION: Seventy percent of infants with IF achieved EA. Residual small and large bowel length were the most important predictors of EA and septic events had a negative impact.

Liver-associated immune abnormalities.

In recent years, the cross talk between the liver and the immune system is being uncovered, in part by studying liver involvement in primary immune deficiencies (PID) and in part by investigating the alterations of the immune system following orthotopic liver transplantation (OLT). Here we review some of the reciprocal interactions between the liver and the immune system. Patients with PID, particularly those involving inherited defects in T and B cells or innate immunity are prone to infections and inflammatory responses that often involve the liver. Omenn's syndrome, familial hemophagocytic lymphohistiocytosis, AIRE, FOXP3 and CD25 deficiencies, common variable immunodeficiency, CD40 ligand deficiency, chronic granulomatous disease and autoimmune lymphoproliferative syndrome are some of the notable PID associated with typical hepatobiliary abnormalities. Knowledge gained from studying these PID together with laboratory and histological evaluations can assist in managing PID-associated liver dysfunction. The liver itself also has important effects on the immune system, as evident from the growing experience with patients surviving OLT. Up to 40% of pediatric patients who receive OLT suffer from post transplantation allergy, autoimmunity, and immune-mediated disorders (PTAA). PTAA is more common after liver and heart transplantations than kidney transplantations. Potential contributing factors for the increased frequency of PTAA after OLT include the age of the patients, the prolonged use of tacrolimus and the reduced regulatory immune function with a shift towards a TH2 immune response. Better understanding of the mechanisms leading to the development of PTAA after OLT will also improve the management of these conditions.

Inflammasome Priming Mediated via Toll-Like Receptors 2 and 4, Induces Th1-Like Regulatory T Cells in De Novo Autoimmune Hepatitis.

De novo autoimmune hepatitis (DAIH) is an important cause of late allograft dysfunction following liver transplantation, but its cause and underlying pathogenesis remains unclear. We sought to identify specific innate and adaptive immune mechanisms driving the pro-inflammatory cytokine secreting regulatory T cell (Treg) phenotype in DAIH and determine if modulation of these pathways could resolve the inflammatory milieu observed in the livers of patients with DAIH. Here, we demonstrate toll-like receptors (TLRs) 2- and 4-mediated inflammasome activation in CD14++ monocytes, a finding that is key to maintaining dysfunctional Tregs in patients with DAIH. Furthermore, silencing of TLR 2 and 4 in CD14++ monocytes prevented activation of the inflammasome and significantly decreased IFN-γ production by FOXP3+ Tregs. We also observed significantly increase in expression of tumor necrosis factor α-induced protein 3 (TNFAIP3), a negative regulator of the NLRP3 Inflammasome, in monocytes/macrophages of liver transplant subjects who have normal allograft function and do not have DAIH. TNFAIP3 expression was virtually absent in monocytes/macrophages of patients with DAIH. Our findings suggest that autoimmunity in DAIH is promoted by CD14++ monocytes predominantly through activation of inflammatory signaling pathways.