Mercedes Martinez

Reversal of intestinal failure–associated liver disease in infants and children on parenteral nutrition: experience with 93 patients at a referral center for intestinal rehabilitation

PURPOSE Intestinal failure (IF)-associated liver disease (IFALD) complicates the treatment of children with IF receiving parenteral nutrition (PN). We hypothesized that prevention or resolution of IFALD was possible in most children and that this would result in improved outcomes. METHODS We reviewed prospectively gathered data on all children referred to the intestinal rehabilitation and transplantation center at our institution. Total bilirubin level (TB) was used as the marker for IFALD. Patients were grouped based on TB at referral and at subsequent inpatient stays and outpatient visits. Standard treatment consisted of cycling of PN, limiting lipid infusion, enteral stimulation, use of ursodeoxycholic acid, and surgical intervention when necessary. Outcomes such as mortality, dependence on PN, and need for transplantation were assessed. Statistical analyses were performed using Fishers exact, Mann-Whitney U, and Wilcoxon signed rank tests. RESULTS Ninety-three patients with intestinal failure and on PN were treated at our center from 2003 to 2009. Median age at referral was 5 months (0.5-264 months). Prematurity was a complicating factor in 63 patients and necrotizing enterocolitis was the most common diagnosis. Eighty-two children had short bowel syndrome, whereas the remaining 11 had extensive motility disorders. 97% of children required significant alteration of their PN administration. At referral, 76 of 93 children had TB 2.0 mg/dL or higher, and 17 had TB below 2.0 mg/dL. TB normalized in 57 of 76 children with elevated TB at referral, and TB remained elevated in 19. Normalization of TB was associated with a mortality of 5.2%, and transplantation was needed in 5.2%. Conversely, when TB remained elevated, mortality was 58% (P = .0002 vs TB normalized), and transplantation occurred in 58% owing to failure of surgical and medical rehabilitation. CONCLUSIONS Most children referred for treatment of IF have IFALD. A dedicated IF rehabilitation program can reverse IFALD in many children, and this is associated with improved outcome.

Multivisceral ex vivo surgery for tumors involving celiac and superior mesenteric arteries.

Abdominal tumors involving both roots of the celiac and superior mesenteric artery are deemed unresectable by conventional surgical methods. We performed three cases of multivisceral ex vivo surgery involving temporary removal of the entire abdominal viscera followed by vascular reconstruction, ex vivo tumor resection and autotransplantation of excised organs. We achieved a complete tumor resection with negative margins in all cases. All patients have survived with no tumor recurrence to date at 17‐, 27‐ and 38‐month follow‐up. Postoperative complications included diarrhea, sphincter of Oddi dysfunction and arterial stenosis; all responded to directed treatments. Multivisceral ex vivo surgery applying techniques of deceased donor multivisceral transplantation is feasible in achieving local control of otherwise unresectable abdominal tumors. This surgery is best suitable for locally invasive tumors unresectable because of location and vascular involvement.

The natural history of primary sclerosing cholangitis in 781 children: A multicenter, international collaboration

There are limited data on the natural history of primary sclerosing cholangitis (PSC) in children. We aimed to describe the disease characteristics and long‐term outcomes of pediatric PSC. We retrospectively collected all pediatric PSC cases from 36 participating institutions and conducted a survival analysis from the date of PSC diagnosis to dates of diagnosis of portal hypertensive or biliary complications, cholangiocarcinoma, liver transplantation, or death. We analyzed patients grouped by disease phenotype and laboratory studies at diagnosis to identify objective predictors of long‐term outcome. We identified 781 patients, median age 12 years, with 4,277 person‐years of follow‐up; 33% with autoimmune hepatitis, 76% with inflammatory bowel disease, and 13% with small duct PSC. Portal hypertensive and biliary complications developed in 38% and 25%, respectively, after 10 years of disease. Once these complications developed, median survival with native liver was 2.8 and 3.5 years, respectively. Cholangiocarcinoma occurred in 1%. Overall event‐free survival was 70% at 5 years and 53% at 10 years. Patient groups with the most elevated total bilirubin, gamma‐glutamyltransferase, and aspartate aminotransferase‐to‐platelet ratio index at diagnosis had the worst outcomes. In multivariate analysis PSC–inflammatory bowel disease and small duct phenotypes were associated with favorable prognosis (hazard ratios 0.6, 95% confidence interval 0.5‐0.9, and 0.7, 95% confidence interval 0.5‐0.96, respectively). Age, gender, and autoimmune hepatitis overlap did not impact long‐term outcome. Conclusion: PSC has a chronic, progressive course in children, and nearly half of patients develop an adverse liver outcome after 10 years of disease; elevations in bilirubin, gamma‐glutamyltransferase, and aspartate aminotransferase‐to‐platelet ratio index at diagnosis can identify patients at highest risk; small duct PSC and PSC–inflammatory bowel disease are more favorable disease phenotypes. (Hepatology 2017;66:518–527).

Small-bowel allograft biopsies in the management of small-intestinal and multivisceral transplant recipients: histopathologic review and clinical correlations.

CONTEXT Intestinal transplant has become a standard treatment option in the management of patients with irreversible intestinal failure. The histologic evaluation of small-bowel allograft biopsy specimens plays a central role in assessing the integrity of the graft. It is essential for the management of acute cellular and chronic rejection; detection of infections, particularly with respect to specific viruses (cytomegalovirus, adenovirus, Epstein-Barr virus); and immunosuppression-related lymphoproliferative disease. OBJECTIVE To provide a comprehensive review of the literature and illustrate key histologic findings in small-bowel biopsy specimen evaluation of patients with small-bowel or multivisceral transplants. DATA SOURCES Literature review using PubMed (US National Library of Medicine) and data obtained from national and international transplant registries in addition to case material at Columbia University, Presbyterian Hospital, and Mount Sinai Medical Center, New York, New York. CONCLUSIONS Key to the success of small-bowel transplantation and multivisceral transplantation are the close monitoring and appropriate clinical management of patients in the posttransplant period, requiring coordinated input from all members of the transplant team with the integration of clinical, laboratory, and histopathologic parameters.

Effect of ex vivo Expanded Recipient Regulatory T Cells on Hematopoietic Chimerism and Kidney Allograft Tolerance Across MHC Barriers in Cynomolgus Macaques

BackgroundInfusion of recipient regulatory T (Treg) cells promotes durable mixed hematopoietic chimerism and allograft tolerance in mice receiving allogeneic bone marrow transplant (BMT) with minimal conditioning. We applied this strategy in a Cynomolgus macaque model. MethodsCD4+ CD25high Treg cells that were polyclonally expanded in culture were highly suppressive in vitro and maintained high expression of FoxP3. Eight monkeys underwent nonmyeloablative conditioning and major histocompatibility complex mismatched BMT with or without Treg cell infusion. Renal transplantation (from the same BMT donor) was performed 4 months post-BMT without immunosuppression to assess for robust donor-specific tolerance. ResultsTransient mixed chimerism, without significant T cell chimerism, was achieved in the animals that received BMT without Treg cells (N = 3). In contrast, 2 of 5 recipients of Treg cell+ BMT that were evaluable displayed chimerism in all lineages, including T cells, for up to 335 days post-BMT. Importantly, in the animal that survived long-term, greater than 90% of donor T cells were CD45RA+ CD31+, suggesting they were new thymic emigrants. In this animal, the delayed (to 4 months) donor kidney graft was accepted more than 294 days without immunosuppression, whereas non–Treg cell BMT recipients rejected delayed donor kidneys within 3 to 4 weeks. Early CMV reactivation and treatment was associated with early failure of chimerism, regardless of Treg cell administration. ConclusionsOur studies provide proof-of-principle that, in the absence of early CMV reactivation (and BM-toxic antiviral therapy), cotransplantation of host Treg cell can promote prolonged and high levels of multilineage allogeneic chimerism and robust tolerance to the donor.

Macrochimerism in Intestinal Transplantation: Association With Lower Rejection Rates and Multivisceral Transplants, Without GVHD.

Blood chimerism has been reported sporadically among visceral transplant recipients, mostly in association with graft‐vs‐host disease (GVHD). We hypothesized that a higher degree of mixed chimerism would be observed in multivisceral (MVTx) than in isolated intestinal (iITx) and isolated liver transplant (iLTx) recipients, regardless of GVHD. We performed a longitudinal prospective study investigating multilineage blood chimerism with flow cytometry in 5 iITx and 4 MVTx recipients up to one year posttransplant. Although only one iITx patient experienced GVHD, T cell mixed chimerism was detected in 8 out of 9 iITx/MVTx recipients. Chimerism was significantly lower in the four subjects who displayed early moderate to severe rejection. Pre‐formed high‐titer donor‐specific antibodies, bound in vivo to the circulating donor cells, were associated with an accelerated decline in chimerism. Blood chimerism was also studied in 10 iLTx controls. Among nonsensitized patients, MVTx recipients exhibited greater T and B cell chimerism than either iITx or iLTx recipients. Myeloid lineage chimerism was present exclusively among iLTx and MVTx (6/13) recipients, suggesting that its presence required the hepatic allograft. Our study demonstrates, for the first time, frequent T cell chimerism without GVHD following visceral transplantation and a possible relationship with reduced rejection rate in MVTx recipients.

Improved tolerance for enteral nutrition after serial transverse enteroplasty (STEP) in infants and children with short bowel syndrome—A seven-year single-center experience

BACKGROUND Serial transverse enteroplasty (STEP) was designed to lengthen and taper the small intestine in patients with short bowel syndrome (SBS) and dilated small bowel. We hypothesized that tolerance for enteral nutrition (EN) improves after STEP. METHODS Patients who underwent STEP between March 2004 and January 2011 were identified. Candidates for STEP had radiographic evidence of dilated small bowel and either failed to advance EN or demonstrated deterioration in tolerance for EN. Clinical and nutritional data were analyzed pre- and post-STEP. EN was defined as the percentage of calories administered enterally. Statistical analysis employed the signed rank test with significance assumed when p<0.05. RESULTS Twenty STEPs were performed at a median age of 13.7 months. Median pre-STEP bowel length was 30 cm with a median increase in bowel length of 42%. Five patients achieved enteral autonomy at a median of 6.5 months post-STEP. EN increased in 75%, while 25% exhibited unchanged or decreased EN post-STEP. In aggregate, median EN tolerance increased from 22% at one month pre-STEP to 61% at six months post-STEP (p=0.003). CONCLUSIONS The STEP is an effective adjunct in the treatment of patients with intestinal failure. While enteral autonomy is eventually possible in some patients, improved enteral tolerance can be achieved in a majority of cases.

Risk Factors Associated with Liver Injury and Impact of Liver Injury on Transplantation-Related Mortality in Pediatric Recipients of Allogeneic Hematopoietic Stem Cell Transplantation

In adults, hepatic complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT) are associated with significant morbidity and transplantation-related mortality (TRM). However, there is a paucity of parallel data on the incidence of, and risk factors for, liver injury (LI) and the impact of LI on TRM in pediatric allo-HSCT recipients. We compared total bilirubin, direct bilirubin, and alanine aminotransferase values before allo-HSCT and at 1 month, day +100, and 12 months after allo-HSCT in 248 patients who received either a myeloablative conditioning (MAC) regimen (n = 109) or a reduced-toxicity/reduced-intensity conditioning (RTC/RIC) regimen (n = 139). LI was defined as grade ≥ 2 hyperbilirubinemia according to the National Cancer Institutes Common Terminology Criteria for Adverse Events 3.0/4.0 (total bilirubin, >1.95 mg/dL, 1.5 times above the upper limit of normal for our laboratory). Univariate and multivariate logistic regression models were used to identify risk factors for LI and TRM. The incidence of LI at 1 month after allo-HSCT was 14.1%. The median bilirubin level was 3.5 mg/dL (range, 1.97 to 32.2 mg/dL). Only LI as defined by total bilirubin level, but not by direct bilirubin or alanine aminotransferase level, was found to be a significant predictor for TRM. The 1-year TRM was 60.7% (95% confidence interval, 42.6% to 78.7%) in patients with LI at 1 month after allo-HSCT, compared with 14.6% (95% confidence interval, 9.9% to 19.4%) (P < .0001) in patients those who did not have liver injury. Multivariate analysis identified age (P = .03), total body irradiation (P = .007), bacterial bloodstream infection (BBSI) (P = .001), and invasive fungal infection (IFI) (P = .002) as significant risk factors for developing LI at 1 month. On multivariate analysis for risk factors for TRM, only LI at 1 month after allo-HSCT (P < .0001), primary graft failure (P = .001), BBSI (P = .003), and systemic viral infection (P = .04) were identified as significant risk factors for TRM. LI before allo-HSCT conditioning was not associated with higher TRM. Although the incidence of LI in pediatric allo-HSCT recipients is low, LI is associated with very high TRM. BBSI and IFI are the primary risk factors for LI.

Production of Proinflammatory Cytokines by Monocytes in Liver-Transplanted Recipients with De Novo Autoimmune Hepatitis Is Enhanced and Induces TH1-like Regulatory T Cells

A subset of human regulatory T cells (Tregs) can secrete IFN-γ or IL-17, and thus share features of TH1 or TH17 effector cells and lose suppressive function. The main factors driving this differentiation of Tregs toward a proinflammatory phenotype include IL-12 for TH1-like and IL-6 for TH17-type Tregs. In this study we show that Tregs of patients with de novo autoimmune hepatitis (dAIH) display increased frequencies of proinflammatory IFN-γ and IL-17 cytokines. Irrespective of a fully demethylated FOXP3 locus, Tregs of subjects with dAIH are functionally impaired. In line with the observed Treg phenotype, we detected the presence of two dominant cytokines (IL-12 and IL-6) clustering with CD68+ monocyte/macrophage cells in livers of subjects with dAIH, and isolated monocytes of subjects with dAIH secrete high levels of proinflammatory IL-12 and IL-6, suggesting that this inflammatory milieu is key for functional impairment of Tregs. Importantly, the blockade of IFN-γ partially restores suppressive function of Tregs of subjects with dAIH, indicating that monocyte/macrophage-derived triggers might play a central role in Treg dysfunction and pathogenesis of dAIH.

Bidirectional intragraft alloreactivity drives the repopulation of human intestinal allografts and correlates with clinical outcome

Clinical transplant outcomes reflect the balance between host-versus-graft and graft-versus-host reactivities. Transplantation stalemate Successful organ transplantation depends on both preventing rejection of the graft by host cells [host versus graft (HvG)] and blocking graft cells that attack the host (GvH). Zuber et al. demonstrated that a balance in this two-way alloreactivity affected clinical outcomes in organ transplant recipients. They examined gut-resident T cell turnover kinetics in human intestinal allografts and found that HvG-reactive cells persisted long-term in the graft, acquiring a tissue-resident phenotype. However, GvH-reactive cells expanded within the graft in the absence of rejection. The GvH-reactive cells may balance out the HvG-reactive cells, preventing rejection. One paradigm in transplantation is that graft-infiltrating T cells are largely nonalloreactive “bystander” cells. However, the origin and specificity of allograft T cells over time have not been investigated in detail in animals or humans. We used polychromatic flow cytometry and high-throughput T cell receptor sequencing of serial biopsies to show that gut-resident T cell turnover kinetics in human intestinal allografts are correlated with the balance between intragraft host-versus-graft (HvG) and graft-versus-host (GvH) reactivities and with clinical outcomes. In the absence of rejection, donor T cells were enriched for GvH-reactive clones that persisted in the long term in the graft. Early expansion of GvH clones in the graft correlated with the rapid replacement of donor antigen-presenting cells by the recipient. Rejection was associated with transient infiltration by blood-like recipient CD28+ NKG2DHi CD8+ αβ T cells, marked predominance of HvG clones, and accelerated T cell turnover in the graft. Ultimately, these recipient T cells acquired a steady-state tissue-resident phenotype but regained CD28 expression during rejections. Increased ratios of GvH to HvG clones were seen in nonrejectors, potentially mitigating the constant threat of rejection posed by HvG clones persisting within the tissue-resident graft T cell population.