Maria H. Alonso

Genetic induction of proinflammatory immunity in children with biliary atresia

BACKGROUND Biliary atresia is the commonest cause of pathological jaundice in infants and the leading indication for liver transplantation in children worldwide. The cause and pathogenesis remain largely unknown. Because of clinical heterogeneity and experimental difficulties in addressing molecular mechanisms underlying multifactorial disorders in human beings, we searched for genomic signatures of biliary atresia in affected infants. METHODS We generated pools of biotinylated cRNA from livers of 14 infants with biliary atresia and six with neonatal intrahepatic cholestasis (diseased controls) and hybridised the cRNA against oligonucleotide-based gene chips. Immunohistochemistry and reverse transcriptase (RT)-PCR were used to assess the specificity of the findings and functional commitment of lymphocytes in affected livers. FINDINGS Data filtering, to identify genes that are differentially expressed, and cluster analysis revealed a predominant and coordinated activation of immunity/inflammation genes within the livers of infants with biliary atresia. Most of the genes showed differential lymphocyte function, with activation of osteopontin, a regulator of cell-mediated (T-helper 1 [Th-1]) immunity in T-helper lymphocytes, and suppression of immunoglobulin genes in early stages of disease. These findings were associated with production of interferon gamma in 65% of infants with biliary atresia and no diseased control. However, histologically similar inflammatory infiltrates were present in livers of both groups, implying differential activation states of similar cell types. INTERPRETATION Livers of infants with biliary atresia have a coordinated activation of genes involved in lymphocyte differentiation. Among these genes, the overexpression of osteopontin and interferon gamma points to a potential role of Th-1-like cytokines in disease pathogenesis.

Late hepatic artery thrombosis in liver allograft recipients is associated with intrahepatic biliary necrosis.

Hepatic artery thrombosis (HAT) after liver transplantation is a potentially life-threatening complication that occurs in 2-25% of patients, depending on several risk factors and the patient population studied. Arterial thrombosis occurring early after liver transplantation is associated with acute fulminant hepatic failure, biliary tract necrosis and leaks, or relapsing bacteremia and is associated with a high rate of graft loss and patient mortality. The onset of late posttransplant HAT (after 6 months) has been thought to have a more benign and often asymptomatic course. The reasons for the differences between the manifestations of early and late HAT are not well understood. We reviewed the adult liver transplant experience at the University of Cincinnati and found four patients with late HAT, three of whom developed severe intrahepatic biliary necrosis. Two patients were successfully retransplanted and 1 patient who refused retransplantation died. One patient had mild, transient graft damage due to gradual arterial stenosis and the development of arterial collaterals prior to thrombosis. Late HAT has a significant potential for irreversible graft damage requiring retransplantation. Screening for the development of hepatic artery stenosis prior to late thrombosis may be worthwhile.

Determination of risk factors for Epstein-Barr virus-associated posttransplant lymphoproliferative disorder in pediatric liver transplant recipients using objective case ascertainment

Background. Previous studies have suggested an increased risk of Epstein-Barr virus-associated posttransplant lymphoproliferative disorder (EBV-PTLD) in patients receiving tacrolimus for immunosuppression. We hypothesized that after correction for confounding variables, immunosuppression with tacrolimus is not associated with an increased risk of EBV-PTLD. Methods. Potential cases of EBV-PTLD, identified by chart review, were independently ascertained by three clinicians and defined using published criteria. Agreement in diagnosing EBV-PTLD was measured using Kappa coefficients. Unadjusted and adjusted relative risk estimates were determined using proportional hazards regression. Results. Twenty-three cases of EBV-PTLD were identified in 221 patients, a proportion of 10.4% (95% confidence interval [CI]: 6.4%–14.4%). Multivariable analysis revealed that immunosuppression with tacrolimus was associated with an increased risk of EBV-PTLD (relative risk 3.10: 95% CI: 1.21–7.92), as was age at transplantation as a continuous variable (parameter estimate −0.15, P =0.03). Kappa coefficients in diagnosing EBV-PTLD and subclassifying as neoplastic and non-neoplastic EBV-PTLD were 0.73 (95% CI: 0.54–0.93) and 0.54 (95% CI: 0.40–0.68), respectively. Patients with neoplastic PTLD demonstrated a lower probability of survival than patients with non-neoplastic PTLD and non-cases. Conclusions. Immunosuppression with tacrolimus and young age at transplantation are associated with an increased risk of EBV-PTLD in children undergoing liver transplantation, although we cannot exclude detection bias as an explanation for this observed increase. Good agreement between observers can be achieved using previously published criteria for defining EBV-PTLD. Patients with neoplastic EBV-PTLD may have a worse prognosis, and thus identification of risk factors for the development of this subtype of the disorder may be more important.

Spectrum of hepatic hemangiomas: management and outcome.

PURPOSE Infants with multiple cutaneous hemangiomas often present with hepatic hemangiomas. They can follow a benign clinical course or require complex management. We reviewed our experience in the management of hepatic hemangiomas. METHODS We performed a retrospective review of patients (1996-2007) with hepatic hemangiomas treated in our institution. RESULTS Twenty-six patients were diagnosed with hepatic hemangiomas as follows: 8 focal, 12 multiple, and 6 diffuse lesions. Nineteen (73%) patients had associated cutaneous hemangiomas. Sixteen patients had multiple and 3 patients had single cutaneous hemangiomas. All patients with multiple or diffuse liver lesions were screened for heart failure and hypothyroidism. Congestive heart failure developed in 4 patients, 3/4 of these patients had diffuse lesions. Two patients required thyroid replacement because of elevated thyroid-stimulating hormone. Because of progression of disease, 9 patients required steroid treatment. Two patients were treated with vincristine and 3 patients received alpha-interferon because of poor response to steroid treatment. Two patients went on to surgical resection for failed response to medical management and worsening heart failure (left lobectomy, liver transplant). Both patients had uncomplicated postoperative courses. Five patients had a previously undescribed constellation of rapidly involuting cutaneous hemangiomas (gone by 3 months, glut-1-negative) with associated liver lesions also resolving at a faster pace (mean resolution of cutaneous hemangiomas, 1.9 vs 7.9 months; P = .001; liver, 5.8 vs 25.3 months; P = .004). All patients in our series survived. CONCLUSION Patients with multiple cutaneous hemangiomas should be screened for hepatic lesions. Patients with diffuse or multifocal liver hemangiomas should be screened for congestive heart failure and hypothyroidism. A subgroup of rapidly involuting cutaneous hemangiomas have a significantly shorter time for involution of hepatic lesions. The status of cutaneous lesions can be used as indicators for the liver hemangiomas.

LONG-TERM SURVIVAL AFTER LIVER TRANSPLANTATION

BACKGROUND Liver transplantation (LT) remains a high-risk operation, especially during the first months after LT when technical complications and preexisting illness exert their influence on survival. However, there are late deaths. The authors have reviewed their experience to identify factors impacting on long-term survival. METHODS A total of 150 patients who had undergone liver transplantation over an 11-year period were reviewed. Thirty-three patients died after LT (22%). Of these, 18 of 33 (55%) died in the first 3 postoperative months. One hundred thirty-two patients survived beyond 3 months, and 15 patients (11%) suffered late deaths. This review concentrates on the latter group. RESULTS The primary cause of death was sepsis in 11 of 15 (73%). In two, sepsis complicated retransplantation in chronically debilitated patients. Two additional patients had late-presenting postoperative complications (bile leak or abscess, intestinal obstruction with perforation). In two cases, pneumocystis carinii pneumonia occurred; noncompliance or unplanned discontinuation of prophylaxis was directly responsible. Multiple organ system failure from presumed immunoincompetence developed in four patients; one had undergone bone marrow transplantation for aplastic anemia (AA) after fulminant hepatic failure (FHF). Lymphoproliferative disease (LPD) was the cause of death in 3 of 15 cases (20%). In only three cases was the cause of death related to the patients primary disease (chronic hepatitis, Alpers syndrome or seizures, and AA with FHF). Pretransplant diagnosis, and UNOS status at the time of LT did not influence the long-term survival. CONCLUSIONS Long-term survival in patients who have undergone LT was compromised by immunosuppressive complications and sepsis. Early mortality factors, such as UNOS status, age at LT, primary diagnosis, and technical complications do not predict late deaths. In children who adhere to their medical regimen and have good initial allograft function, late postoperative infection, especially with Ebstein-Barr virus, accounts for most of the late mortality. Improved and decreased immunosuppression may further improve these long-term results.

High prevalence of α-1-antitrypsin heterozygosity in children with chronic liver disease

Objective: α-1-antitrypsin (A1AT) deficiency is the most common genetic cause of liver disease in children; however, the role of polymorphic heterogeneity in the A1AT gene as a modifier of other forms of pediatric liver disease is not clear. We hypothesized that non-M A1AT allele variants are more common in children with chronic liver disease than in the general population. Methods: A retrospective, single-center study was performed in which A1AT phenotypes were obtained by reviewing charts of children with chronic liver disease. Chi-square analysis was used to compare allele frequencies in the population of children with liver disease with published epidemiologic data and to compare allele frequencies among disease subgroups. Results: The frequency of A1AT Z and other alleles was increased in children with chronic liver disease (n = 241) when compared with the published reference database (P < 0.001). This increase remained significant when the population was divided into disease subsets: biliary atresia (n = 67) and other liver disease (n = 174) (P < 0.001 for both). Among children with biliary atresia referred for liver transplant evaluation, the presence of a non-M allele was associated with a lower mean age at transplant listing than the MM phenotype (235 vs 779 days, P = 0.036) and more frequent loss of native liver by 24 months of age (90% vs 65%, P = 0.04). Conclusions: A1AT non-M alleles are more frequent in children with chronic liver disease than in the general population. We speculate that these non-M alleles may act as genetic modifiers in pediatric liver disease in general and modulate disease progression in children with biliary atresia in particular.

CAUSES AND MANAGEMENT OF PORTAL HYPERTENSION IN THE PEDIATRIC POPULATION

Therapeutic options for children with portal hypertension now include a broad range of pharmacologic, endoscopic, and surgical procedures. Thoughtful application of all of these options can improve quality of life by decreasing the complications of portal hypertension and can decrease mortality by preventing the consequences of variceal hemorrhage. The development of portal hypertensive gastropathy following palliative procedures such as endoscopic sclerotherapy and band ligation may limit their long-term success in children. The excellent results now obtained with selective portosystemic shunts and liver transplantation assure that definitive surgical treatments will continue to be important components in the treatment of children with portal hypertensive complications or progressive liver disease. Evolving procedures, such as TIPS, represent excellent short-term life-preserving techniques to stabilize critically ill patients while awaiting liver transplantation. Their role in the future, long-term management of children is yet to be defined.

Liver transplant for relapsed undifferentiated embryonal sarcoma in a young child

Undifferentiated embryonal sarcoma of the liver is a rare hepatic malignancy of childhood with a historically poor prognosis. Recent improvements in outcomes have been reported in small numbers of cases with the use of combination therapy involving aggressive surgical resection and chemotherapy. Complete surgical resection is frequently difficult to achieve when the location of the tumor is along the margins of the major hepatic vessels (portal vein, hepatic vein, and hepatic artery). Here we report a case of undifferentiated embryonal sarcoma of the liver that recurred along surgical hepatic vein margins in a 9-year-old boy who subsequently underwent orthotopic liver transplantation from a cadaveric donor. The patient has been in continuous clinical remission for the last 5 years.

Outcomes following liver transplantation

As the field of Liver Transplantation has matured, survival alone is no longer an acceptable single metric of success. This chapter explores the impact of the PELD system for donor organ allocation, surgical modification of donor organs, living donation, and long-term transplant-related complications on overall quality of life and outcome. Strategies to improve survival, overall outcome, and health-related quality of life in long-term recipients are outlined.

Management and long‐term consequences of portal vein thrombosis after liver transplantation in children

Portal vein thrombosis (PVT) occurs in ≤12% of pediatric recipients of liver transplantation (LT). Known complications of PVT include portal hypertension, allograft loss, and mortality. The management of PVT is varied. A single‐center, case‐control study of pediatric LT recipients with portal vein (PV) changes after LT was performed. Cases were categorized as early PVT (if PVT was detected within 30 days of transplantation) or late PVT (if PVT was detected more than 30 days after transplantation or if early PVT persisted beyond 30 days). Two non‐PVT control patients were matched on the basis of the recipient weight, transplant indication, and allograft type to each patient with PVT. Thirty‐two of the 415 LT recipients (7.7%) received 37 allografts and developed PVT. In comparison with control patients, a higher proportion of patients with PVT had PVT present before LT (13.3% versus 0%, P = 0.01). Patients with early PVT usually returned to the operating room, and 9 of 15 patients (60%) had PV flow restored. Patients with late PVT had lower white blood cell (4.9 [1000/μL] versus 6.8 [1000/μL], P < 0.01) and platelet counts (140 [1000/μL] versus 259 [1000/μL], P < 0.01), an elevated international normalized ratio (1.2 versus 1.0, P < 0.001), and more gastrointestinal bleeding (25% versus 8.3%, P = 0.03) compared to controls. Patients with PVT were also less frequently at the expected grade level (52% versus 88%, P < 0.001). The patient survival rates were 84%, 78%, and 78% and 91%, 84%, and 79% for cases and controls at 1, 5, and 10 years, respectively. The allograft survival rates were 90%, 80%, and 80% for cases and 94%, 89%, and 87% for controls at 1, 5, and 10 years, respectively. In conclusion, patients with early and late PVT had preserved allograft function, and there was no impact on mortality. Patients diagnosed with early PVT often underwent operative interventions with successful restoration of flow. Patients diagnosed with late PVT experienced variceal bleeding, and some required portosystemic shunting procedures. Academic delays were also more common. In late PVT, the clinical presentation dictates care because the optimal management algorithm has not yet been determined. Multi‐institutional studies are needed to confirm these findings and improve patient outcomes. Liver Transpl 19:315–321, 2013.