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J B Otte

Publications and source records attributed to J B Otte.

At least 19 recordsLinked to original sources

Liver transplantation for hepatoblastoma: results from the International Society of Pediatric Oncology (SIOP) study SIOPEL-1 and review of the world experience.

BACKGROUND: For hepatoblastoma (HB) that remains unresectable by partial hepatectomy after chemotherapy, total hepatectomy with orthotopic liver transplantation (LTX) has been advocated as the best treatment option. The role of LTX in the overall management of HB is still, however, unclear. PROCEDURE: The results of LTX from the first study of HB by the International Society of Pediatric Oncology, SIOPEL-1, were analyzed. In addition, the world experience of LTX for HB was extensively reviewed. Twelve patients in the SIOPEL-1 study underwent a LTX. Median (range) follow-up at Dec. 31, 2001 was 117 months (52-125) since LTX. RESULTS: Overall survival at 10 years post-LTX was 85% for the seven children who received a "primary LTX" and 40% for the 5 children who underwent a "rescue LTX" after previous partial hepatectomy. In the world experience (147 cases), the overall survival rate at 6 year post-LTX was 82% for 106 patients who received a "primary LTX" and 30% for 41 patients who underwent a "rescue LTX." Multivariate analysis of patients undergoing primary LTX showed that only macroscopic venous invasion had a significant impact (P-value: 0.045 with a hazard ratio of 2.96) on overall survival. CONCLUSIONS: Orthotopic LTX has added a new dimension to the treatment of HB unresectable by partial hepatectomy. Because of the rarity of the disease and to optimize results, children with extensive HB should be treated in centers with surgical expertise in pediatric major liver resection and LTX, in close collaboration with pediatric oncologists, radiologists, and histopathologists.

Child↗

Risk-adapted treatment for childhood hepatoblastoma. final report of the second study of the International Society of Paediatric Oncology--SIOPEL 2.

SIOPEL 2 was a pilot study designed to test the efficacy and toxicity of two chemotherapy (CT) regimens, one for patients with hepatoblastoma (HB) confined to the liver and involving no more than three hepatic sectors ('standard-risk (SR) HB'), and one for those with HB extending into all four sectors and/or with lung metastases or intra-abdominal extra hepatic spread 'high-risk (HR) HB'. SR-HB patients were treated with four courses of cisplatin (CDDP), at a dose of 80 mg/m(2) every 14 days, delayed surgery, and then two more similar CDDP courses. HR-HB patients were given CDDP alternating every 14 days with carboplatin (CARBO), 500 mg/m(2), and doxorubicin (DOXO), 60 mg/m(2). Two courses of CARBO/DOXO and one of CDDP were given postoperatively. Between October 1995 and May 1998, 77 SR-HB (10 of whom were actually treated with the HR protocol) and 58 HR-HB patients were registered and all 135 could be evaluated. Response rates for the entire SR-HB and HR-HB groups were 90% (95% CI 80-96%) and 78% (95% CI 65-87%), and resection rates were 97% (95% CI 87-99%) and 67% (95% CI 54-79%) including several children undergoing liver transplantation. For SR-HB patients, 3-year overall and progression-free survivals were 91% (+/-7%) and 89% (+/-7%) and for the HR-HB group 53% (+/-13%) and 48% (+/-13%), respectively. The short-term toxicity of these regimens was acceptable, with no toxic deaths. A treatment strategy based on CDDP monotherapy and surgery thus appears effective in SR-HB but, despite CT intensification, only half of the HR-HB patients are long-term survivors. For SR-HB patients, the efficacy of CDDP monotherapy and the CDDP/DOXO ('PLADO') combination are now being compared in a prospective randomised trial (SIOPEL 3).

Adolescent↗

Pediatric liver transplantation for biliary atresia: results of primary grafts in 328 recipients.

PURPOSE: The purpose of this study was to assess the overall results of recipients undergoing transplantation for biliary atresia (BA), according to age, surgical techniques, and transplant eras, and to identify the prognostic factors affecting outcome. METHODS: Between 1984 and 2000, 328 pediatric recipients with BA who underwent orthotopic liver transplantation (OLT) were reviewed. Median age at OLT was 1.5 years (range, 0.4-14.5 years). Kasai hepatoportoenterostomy (KHPE) had been previously performed in 285 (87%) children. Regarding surgical techniques, 125 (38%) children received a whole-liver graft, 128 (39%) received a reduced-size graft, 16 (5%) received a split-liver graft, and 59 (18%) received a living-related (LR) donor graft. RESULTS: Overall actuarial patient survivals were 87%, 83%, and 81% at 1, 5, and 10 years, respectively. One-year patient survivals in children undergoing transplantation at the different age ranges were 85% (under 1 year), 86% (1-3 years), 83% (3-6 years), 100% (6-10 years), and 100% (beyond 10 years) (not significant). One-year patient survivals for the different transplant eras were 75% (1984-1988), 85% (1989-1992), 93% (1993-1996), and 98% (1997-2000) (P=0.0001). Multivariate analysis demonstrated that pretransplant recipient weight (P=0.004), indication for OLT (P=0.083), and age at OLT (P=0.024) predicted patient survival. The type of baseline calcineurin inhibitor (tacrolimus) and the age at OLT (beyond 6 years) were significantly associated with a better graft survival. CONCLUSIONS: Best results in children undergoing transplantation beyond 6 years indicate the importance of performing a KHPE as the first therapeutic step in BA; innovative surgical techniques, particularly LR donor graft, allowed successful transplantation in infants with early failure of KHPE.

Adolescent↗

Hepatocellular carcinoma in children: results of the first prospective study of the International Society of Pediatric Oncology group.

PURPOSE: To improve survival and reduce operative morbidity and mortality in children with primary epithelial liver tumors by using preoperative chemotherapy, as well as to collect information on the epidemiology, natural history, and prognostic factors. PATIENTS AND METHODS: Forty children with hepatocellular carcinoma (HCC) were registered onto the Group for Epithelial Liver Tumors International Society of Pediatric Oncology's first study from January 1990 to February 1994. The outcome could be analyzed in 39 of those patients. Disease was often advanced at the time of diagnosis; metastases were identified in 31% of the children and extrahepatic tumor extension, vascular invasion, or both in 39%. Multifocal tumors were common (56%). Thirty-three percent of tumors were associated with hepatic cirrhosis. All but two patients received preoperative chemotherapy (cisplatin and doxorubicin). RESULTS: Partial response was observed in 18 (49%) of 37 patients; there was no response or progression in the remainder. Complete tumor resection was achieved in 14 patients (36%). Twenty patients (51%) never became operable. Overall survival at 5 years was 28%, and event-free survival was 17%. Most deaths resulted from tumor progression (26 of 28). Presence of metastases and pretreatment extent of disease system grouping at diagnosis had an adverse influence on overall survival in multivariate analysis. CONCLUSION: Survival for pediatric HCC patients is significantly inferior to that for children with hepatoblastoma. Complete tumor excision remains the only realistic chance of cure, although it is often prevented by advanced disease. The presence of metastases is the most potent predictor of poor prognosis. A prospective worldwide cooperation in the field of pediatric HCC should be encouraged to look for novel therapeutic concepts.

Adolescent↗

History of pediatric liver transplantation. Where are we coming from? Where do we stand?

The history of pediatric liver transplantation cannot be dissociated from one man, Thomas E. Starzl, whose pioneer efforts contributed more than anyone else to what has become a routinely successful clinical procedure. During the pre-cyclosporine era, the pediatric experience was confined nearly exclusively in Denver: first attempt in 1963, first success with survival beyond one year in 1967, cumulative experience with 84 pediatric cases in the pre-cyclosporine era (1967-1979) with a 2-year patient survival rate of 30%. The stampede for the development of other liver transplant centers came with the introduction of cyclosporine in the early eighties. Besides Pittsburgh, seven centers (Brussels, Cambridge and Hanover in Europe; Boston, Dallas, UCLA, Minneapolis in USA) had performed up to 1986 at least 20 pediatric liver transplants each with a long-term (>1 year) patient survival rate ranging between 57% and 83%. At the moment, a long-term patient survival rate in excess of 90% in elective patients -including infants - is commonly obtained in experienced centers. The shortage of size matched liver donors which was responsible for a high death rate on the cadaveric waiting list stimulated the development or technical innovations based on the segmental anatomy of the liver: reduced ('cutdown') liver graft, split graft and living liver transplantation. Challenging technical aspects in the recipient have been solved in order to reduce the incidence of surgical complications like outflow obstruction, arterial and portal thrombosis, and biliary problems. The indications of liver transplantation have been refined; regarding biliary atresia, which is the most frequent indication, a consensus has developed to propose a sequential strategy with a single attempt at hepatoportoenterostomy followed, when it fails, by liver transplantation. Some contra-indications accepted in the past are not currently valid with better understanding of the pathophysiology and/or increased clinical experience; such is the case of the hepatopulmonary syndrome. A major progress in preoperative management has been achieved through a multidisciplinary approach, particularly regarding nutrition and control of portal hypertension-related bleeding and ascites. Perioperatively, liver transplantation has derived benefit from the expertise of anesthetists managing babies with serious conditions and increased experience of the transplant surgeons regarding the knowledge of all the technical modalities, good strategy, technical skills and meticulous control of bleeding. It is well-recognized that children require more immunosuppression than adults. As in adults, the first breakthrough came with the introduction of cyclosporine which more than doubled the one-year patient survival rate. The next advance during the last decade was afforded by FK 506 - Tacrolimus which allows steroid withdrawal with the first year post-transplant in most patients. Besides its efficacy in reducing the incidence of rejection and absence of cosmetic side-effects, the steroid-sparing effect of Tacrolimus is of utmost importance to preserve the growth potential of children. The use of OKT-3 both for induction and treatment of rejection has been abandoned nearly universally because its use, cumulated with other immunosuppressants, resulted in a high incidence of lymphoproliferative disorder. In contrast, anti-IL2-receptor monoclonal antibodies, will most likely gain an increasing place in induction, with the availability of chimeric or humanized preparations. The side-effects of immunosuppression can endanger both the quality of life and the life expectancy; they are a special source of concern in pediatric recipients whose survival can be expected to be more than a few decades. Children would benefit most from the development of a marker able to identify the patients who have developed graft acceptance, allowing complete wearing of immunosuppression. Also they would benefit most from research protocols of tolerance induction. Since the vast majority of liver-transplanted children will have a reasonably normal life expectancy, the focus should be switched to their long-term rehabilitation and the assessment of their quality of life when they reach adulthood.

Child↗

Elevated right ventricular pressures are not a contraindication to liver transplantation in Alagille syndrome.

BACKGROUND: Elevated right ventricle pressure resulting from pulmonary artery stenoses may affect outcome and survival after liver transplantation in patients with Alagille syndrome. METHODS AND RESULTS: Between 1984 and 1997, among 444 pediatric liver transplant recipients, 17 had liver transplantation for Alagille syndrome (mean age 3.5 years, range 1.2-13 years), mainly because of poor quality of life with intractable pruritus, and failure to thrive. All patients had pulmonary artery stenosis. In 10 patients considered to have elevated RV pressure on ECG and/or Doppler-echocardiography, a cardiac catheterization was performed before liver transplantation. Mean RV systolic pressure was 55 mmHg (median 49.5 mmHg, range 35-98 mm Hg), mean RV to left ventricular systolic pressure ratio 0.53 (median 0.53, range 0.29-0.78) with a ratio above 0.5 in 6 patients (median 0.66, range 0.5-0.8). All patients underwent successful liver transplantation. Five patients died 1 to 9 months after transplantation from noncardiac causes. In two of them, cardiac catheterization before transplantation showed a RV to left ventricular pressure ratio of 0.51 in one and 0.37 in the second. In the three others, echocardiography before transplantation estimated RV pressures below 0.5 systemic pressures. At follow-up (median 6 years, range 1.5-15 years), liver tests were normal in all, none complained of pruritus and body weight was normalized in 70%. None of the patients presented cardiac symptoms, arrhythmias, or worsening of their cardiac status. CONCLUSIONS: Liver transplantation can be performed safely in children with Alagille syndrome, even in the presence of elevated right ventricular pressure.

Adolescent↗

Posttransplant lymphoproliferative disorder after liver transplantation in miniature swine.

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) is a well-known, life-threatening complication of immunosuppressive therapy, occurring in both adult and pediatric transplant recipients. METHODS: To study the effect of major histocompatibility complex on tolerance induction to primarily vascularized liver allograft, a semi-identical miniature swine model was developed to mimic the clinical situation of parent-into-infant liver transplantation. Long-term acceptance of semi-identical liver allograft was obtained by a transient course of FK506. In a subgroup of six animals, three developed a lethal PTLD. These animals were studied by histology and immunohistochemistry and the anti-donor cellular immune response was assessed. In addition, the possible viral origin of the proliferative process was evoked. RESULTS: Histology and immunohistochemistry revealed an abnormal B-cell proliferation in many organs of swine suffering from PTLD. Evidence of human Epstein-Barr virus, cytomegalovirus, and adenovirus was not evidenced, but a porcine virus responsible for a respiratory and reproductive syndrome (PRRS) was identified in the lymphoid tissue of these animals. In mixed lymphocyte reaction, a significant antiself immune response confirmed an infection by a virus. CONCLUSIONS: This is the first report suggesting that PRRS virus might provoke PTLD in immunosuppressed miniature swine after orthotopic liver transplantation. Whether PTLD could be induced by injection of the PRRS virus in immunosuppressed animals, a pig model of PTLD might be developed and would represent an interesting preclinical model for testing anti-PTLD therapies.

Animals↗

Use of mycophenolate mofetil as rescue therapy after pediatric liver transplantation.

BACKGROUND: Mycophenolate mofetil (MMF) has been increasingly used after liver transplantation (LT) in adults. We report our preliminary experience with MMF as rescue therapy after pediatric LT. METHODS: A total of 19 children received MMF for 21 indications. Median age at LT was 30 months (range 7-149). The median initial oral dose of MMF was 23 mg/kg/day (range 12-43) orally. Median follow-up after initiation of MMF therapy was 642 days (range 229-1606). RESULTS: 1) EFFICACY: MMF was indicated for rejection or insufficient immunosuppression in 16 cases, with normalization of both liver function tests and liver histology in 10 (62%). MMF was successfully used in one patient with post-LT immmune hepatitis and one patient with corticodependence. In three patients with renal function impairment, MMF allowed reduction of cyclosporine A or tacrolimus blood levels, without subsequent rejection. 2) Tolerance: Six patients (32%) experienced eight side effects, mainly gastrointestinal and hematological, which resolved after cessation of MMF in five cases and dose reduction in three. One case of posttransplant lymphoproliferative disease (PTLD) occurred under MMF therapy (5.2%). Four patients had EBV primary infection, while under MMF therapy, without subsequent PTLD. Three patients had CMV primary infection, and five CMV reactivation, under MMF therapy. Seven remained asymptomatic, and one presented with CMV enteritis. CONCLUSIONS: These preliminary results suggest that MMF is an effective and safe immunosuppressant in pediatric LT recipients. Its use is hampered by frequent gastrointestinal and hematological side-effects. MMF does not seem to increase the risk of PTLD nor CMV disease.

Burkitt Lymphoma↗

Simplified technique of orthotopic liver transplantation in pigs.

BACKGROUND: Pig models have become common in transplantation immunological research. However, in pigs, clamping of the venous splanchnic system during orthotopic liver transplantation (OLT) is responsible for high morbidity and mortality rates; therefore, the use of venovenous bypass (VVB) is advocated. Because venous bypass can also cause specific complications, a simplified method for OLT in pigs has been developed and evaluated in terms of morbidity and mortality. METHODS: Twenty-three OLTs were performed between pairs of inbred miniature swine. Donor and recipient pairs (weighing 20-35 kg) were selected at 3-6 months of age. In the donor, the portal vein, infrahepatic vena cava, and suprahepatic vena cava were dissected, whereas the hepatic artery was preserved in continuity with the coeliac trunk and the abdominal aorta up to the iliac bifurcation. In situ cold perfusion was then performed. The recipient was prepared simultaneously by another surgical team. After total hepatectomy and complete portal and caval clamping, the suprahepatic vena cava and portal vein were sutured; VVB was not used. After completion of both venous sutures, the liver graft was reperfused. The infrahepatic vena cava was then anastomosed and unclamped. The donor aorta conduit was implanted end-to-side to the recipient infrarenal aorta, and the biliary reconstruction consisted of a cholecystojejunostomy with a Roux-Y loop. RESULTS: Twenty of 23 (87%) animals survived more than 1 week (7-483 days). The mean anhepatic time was 29.6+/-4.12 min. Although severe hypotension was noted during the anhepatic phase, the hemodynamic status rapidly recovered and stabilized after graft reperfusion. CONCLUSION: Simplified technique without VVB is appropriate for successfully achieving OLT in pigs.

Animals↗

Adult liver transplantation and steroid-azathioprine withdrawal in cyclosporine (Sandimmun)-based immunosuppression - 5 year results of a prospective study.

New immunosuppressants are said to be superior to cyclosporine due to their higher incidence of steroid sparing and to the reduced incidence of side-effects. From May 1992 to February 1995, 79 adults underwent primary liver transplantation using cyclosporine A (Sandimmun)-based triple drug immunosuppression. Nine patients who died early after liver transplantation due to reasons unrelated to immunological problems were excluded from this analysis. The long-term outcome of the remaining 70 patients was prospectively studied in relation to steroid and azathioprine withdrawal. They were re-evaluated 6-monthly in relation to liver and kidney function; cholesterolemia, infection, de novo diabetes mellitus and arterial hypertension, malignancy, ophthalmological and osteomuscular diseases. In case of rejection occurring during or after steroid tapering, patients were switched, by protocol, to tacrolimus therapy. Median follow-up was 81 months (range 60-96). Forty-four patients (62.8 %) were biopsied 5 years after transplant; 20 patients (28.6 %) were biopsied at a median follow-up of 32 months (range 7.8-47). Six patients (8.6 %) who refused biopsies more than 1 year after liver transplantation had normal liver values throughout the whole follow-up period. Five-year actual patient and graft survivals were 75 % and 65.8 %, respectively, for the whole group (n = 79) and 85.7 % and 74.3 % for the studied group (n = 70). Steroids could be withdrawn in all but two patients (97.1 %) at a median time of 7 months (range 3-42). Steroids were restarted in six patients (8.6 %) for extrahepatic reasons. Freedom from steroids was thus observed in 62 patients (88.6 %). Seven patients (10 %) had rejection after steroid tapering; six were switched to tacrolimus. Two patients (2.9 %) needed retransplantation because of acute and chronic rejection whilst still being on full immunosuppression. In total, three patients (4.3 %) had histological signs of chronic rejection during follow-up. At 5 years post-transplant, 66.6 % and 13.3 % of the 60 patients at risk were on cyclosporine and tacrolimus monotherapy, respectively; 93.3 % were steroid-free. Mean creatinine and cholesterol levels were 1.56 +/- 1.3 mg/dl and 193.5 +/- 56.6 mg/dl; incidences of de novo arterial hypertension, insulin dependent diabetes mellitus were 26.6 % and 13.3 %. Two patients (2.8 %) developed post-transplant lymphoproliferative disease, two (2.8 %) had skin cancer. Cyclosporine-based immunosuppression allows safe steroid withdrawal in most patients and cyclosporine monotherapy can be achieved in two-thirds without compromising graft and patient survival. Results of new immunosuppressive strategies should be approached with caution, especially when considering steroid sparing and the incidence of side-effects.

Adolescent↗

Unusual evolution of an Epstein-Barr virus-associated leiomyosarcoma occurring after liver transplantation.

We report the case of a child who developed, 2 yr after orthotopic liver transplantation (OLTx) for biliary atresia, a multi-focal hepatic tumor with lymphonodular metastases, identified as an Epstein-Barr virus (EBV)-associated leiomyosarcoma. Chemotherapy was given without tumor response. Subsequently, slow growth of the tumor was observed. Immunosuppression was tapered and stopped 9 yr after transplantation. At the present time, 12 yr after the discovery of the first hepatic lesions, the patient is alive and completely symptom-free, the abdominal masses are stable, and liver function tests are completely normal. Smooth muscle tumors are increasingly recognized in children with various immunodeficiencies occurring after organ transplantation. This unusual evolution of a clinically aggressive tumor into a stable disease after restoration of immunity confirms that the immune status of the patient is a crucial factor.

Biliary Atresia↗

Sacrococcygeal teratoma: results of a retrospective multicentric study in Belgium and Luxembourg.

Eighteen patients, operated upon for sacrococcygeal teratoma in 7 different centres in Belgium and Luxembourg between 1992 and 1996, were reviewed. From an epidemiological point of view, this series compares very well to others. Although excellent results were obtained, with all patients surviving, some imperfection in diagnosis, timing of delivery and of operation, and in operative technique was observed. Therefore, it is stated that for optimal treatment of sacrococcygeal teratoma to be achieved, these cases should be treated in just a very few centres of neonatal surgery.

Adult↗

Skeletonizing en bloc esophagectomy for cancer.

OBJECTIVE: To evaluate the long-term outcome of patients with esophageal cancer after resection of the extraesophageal component of the neoplastic process en bloc with the esophageal tube. SUMMARY BACKGROUND DATA: Opinions are conflicting about the addition of extended resection of locoregional lymph nodes and soft tissue to removal of the esophageal tube. METHODS: Esophagectomy performed en bloc with locoregional lymph nodes and resulting in a real skeletonization of the nonresectable anatomical structures adjacent to the esophagus was attempted in 324 patients. The esophagus was removed using a right thoracic (n = 208), transdiaphragmatic (n = 39), or left thoracic (n = 77) approach. Lymphadenectomy was performed in the upper abdomen and lower mediastinum in all patients. It was extended over the upper mediastinum when a right thoracic approach was used and up to the neck in 17 patients. Esophagectomy was carried out flush with the esophageal wall as soon as it became obvious that a macroscopically complete resection was not feasible. Neoplastic processes were classified according to completeness of the resection, depth of wall penetration, and lymph node involvement. RESULTS: Skeletonizing en bloc esophagectomy was feasible in 235 of the 324 patients (73%). The 5-year survival rate, including in-hospital deaths (5%), was 35% (324 patients); it was 64% in the 117 patients with an intramural neoplastic process versus 19% in the 207 patients having neoplastic tissue outside the esophageal wall or surgical margins (P <.0001). The latter 19% represented 12% of the whole series. The 5-year survival rate after skeletonizing en bloc esophagectomy was 49% (235 patients), 49% for squamous cell versus 47% for glandular carcinomas (P =.4599), 64% for patients with an intramural tumor versus 34% for those with extraesophageal neoplastic tissue (P <.0001), and 43% for patients with fewer than five metastatic nodes versus 11% for those with involvement of five or more lymph nodes (P =.0001). CONCLUSIONS: The strategy of attempting skeletonizing en bloc esophagectomy in all patients offers long-term survival to one third of the patients with resectable extraesophageal neoplastic tissues. These patients represent 12% of the patients with esophageal cancer suitable for esophagectomy and 19% of those having neoplastic tissue outside the esophageal wall or surgical margins.

Adenocarcinoma↗

Smooth muscle tumor developing in an immunocompromised child after therapy for leukemia.

We report a 5.5-year-old boy who underwent autologous peripheral blood stem cell transplantation for high-risk acute lymphoblastic leukemia and who had two abdominal masses develop 6 months later. Macroscopically complete resection of the abdominal tumors was performed and revealed a well-differentiated leiomyosarcoma. Smooth muscle tumors, benign or malignant, are increasingly recognized in children with various immunodeficiencies; the association with acute lymphoblastic leukemia is rarely described.

Abdominal Neoplasms↗

Normalised intrinsic mortality risk in liver transplantation: European Liver Transplant Registry study.

BACKGROUND: No model exists for liver transplantation to estimate the mortality risk in a given patient, and no standard by which to assess performance in different centres. We investigated the intrinsic mortality risk in the absence of known mortality risk factors. METHODS: We identified mortality risk factors and risk ratios quantified in data from the European Liver Transplant Registry (22,089 patients at 102 centres in 18 countries) registered from 1988 to 1997. To develop a model of the intrinsic risk and the risk ratios for specific factors, univariate and multivariate analyses were done separately for the overall population, for adults, and for children younger than 15 years, and the number of deaths were estimated. We validated the model by comparing mortality in patients without risk factors with the model-adjusted mortality in patients with risk factors. FINDINGS: Overall 5-year and 8-year actuarial survival was 66% (95% CI 65-66) and 61% (60-62). 65% of deaths occurred within 6 months. Retransplantation, transplantation for cancer, acute liver failure, fewer than 20 split-liver grafts per year, and a centre workload of fewer than 25 transplants per year were the main risk factors of 12 identified factors. 1-year and 5-year death rates among adults with no risk factors were similar to model estimates (15 [13-16] vs 14% [13-15], and 22 (20-24) vs 23% [21-24]). Corresponding data for paediatric transplants were 9% (7-12) compared with 11% (9-12) and 13% (10-17) compared with 14% (11-16). The reduction of mortality risk in high-volume centres was even greater in patients without risk factors (48 vs 23%, p<0.001). INTERPRETATION: The normalised intrinsic mortality risk can be combined with the relative risk ratios of known risk factors to better estimate the mortality risk of a given procedure in a given patient. Centres can assess performance by removing potential bias of donor and recipient selection.

Adolescent↗

A 12-day course of FK506 allows long-term acceptance of semi-identical liver allograft in inbred miniature swine.

BACKGROUND: Spontaneous tolerance to liver allograft has been reported previously in outbred pig models, but the lack of genetic background did not allow to analyze the impact of the major histocompatibility complex (MHC) on tolerance induction. A model of semi-identical liver allograft was therefore developed in inbred miniature swine in order to mimic the clinical situation of living related liver transplant (parent into infant) and to study a protocol for inducing tolerance to liver allograft. METHODS: SLAdd (class Id/d, class IId/d) pigs received orthotopic liver allograft from heterozygous SLAcd (class Ic/d, class IIc/d) miniature swine. Eight animals did not receive immunosuppression. Fourteen SLAdd animals had a 12-day course of FK506 and were divided in two subgroups. In subgroup FK-1, six pigs received a daily intramuscular injection of FK506 at 0.1-0.4 mg/kg, in order to reach daily trough levels between 7 and 20 ng/ml; in subgroup FK-2, eight additional animals received two daily injections of FK506 at 0.05 mg/kg regardless of the daily trough levels. Graft survival, liver biological tests, histology, cellular and humoral immune responses, as well as detection of microchimerism were assessed in all groups. RESULTS: All untreated animals rejected their allograft and died within 28.1 +/- 9.5 days. These rejector animals developed a significant anti-donor cellular and humoral immune response. No peripheral or lymphoid tissue microchimerism was detected in this group. In contrast, long-term survival was obtained in five FK-treated animals (112, 154, 406, 413, and 440 days), whereas several pigs died with a normal allograft function from either overimmunosuppression or intercurrent causes. All FK-treated pigs developed a specific anti-donor unresponsiveness in both cell mediated lymphocytotoxicity and mixed lymphocyte reaction and did not develop anti-donor alloantibodies. The study of the anti-donor immune response by mixed lymphocyte reaction, during the first postoperative week, demonstrated a specific anti-donor unresponsiveness in the peripheral blood from the first posttransplant day. Although microchimerism was detectable in the peripheral blood for several postoperative weeks (maximum 10 weeks) in FK-treated animals, donor cells or DNA were not detected during the long-term follow-up in peripheral blood or lymphoid tissues. CONCLUSIONS: Spontaneous tolerance to semi-identical orthotopic liver allograft did not occur, whereas a 12-day course of FK506 allowed long-term graft acceptance. All FK-treated animals developed in vitro signs of specific immune unresponsiveness and transient peripheral microchimerism. The specific anti-donor cellular unresponsiveness occurred on the first postoperative day after surgery and was of long-term duration. The study of the early immunological events in this model could be of major importance regarding clinical living related liver transplantation.

Animals↗