Prediction of key milk biomarkers in dairy cows through milk mid-infrared spectra and international collaborations.

At the individual cow level, suboptimum fertility, mastitis, negative energy balance, and ketosis are major issues in dairy farming. These problems are widespread on dairy farms and have an important economic impact. The objectives of this study were (1) to assess the potential of milk mid-infrared (MIR) spectra to predict key biomarkers of energy deficit (citrate, isocitrate, glucose-6 phosphate [glucose-6P], free glucose), ketosis (ß-hydroxybutyrate [BHB] and acetone), mastitis (N-acetyl-ß-d-glucosaminidase activity [NAGase] and lactate dehydrogenase), and fertility (progesterone); (2) to test alternative methodologies to partial least squares (PLS) regression to better account for the specific asymmetric distribution of the biomarkers; and (3) to create robust models by merging large datasets from 5 international or national projects. Benefiting from this international collaboration, the dataset comprised a total of 9,143 milk samples from 3,758 cows located in 589 herds across 10 countries and represented 7 breeds. The samples were analyzed by reference chemistry for biomarker contents, whereas the MIR analyses were performed on 30 instruments from different models and brands, with spectra harmonized into a common format. Four quantitative methodologies were evaluated to address the strongly skewed distribution of some biomarkers. Partial least squares regression was used as the reference basis, and compared with a random modification of distribution associated with PLS (random-downsampling-PLS), an optimized modification of distribution associated with PLS (KennardStone-downsampling-PLS), and support vector machine (SVM). When the ability of MIR to predict biomarkers was too low for quantification, different qualitative methodologies were tested to discriminate low versus high values of biomarkers. For each biomarker, 20% of the herds were randomly removed within all countries to be used as the validation dataset. The remaining 80% of herds were used as the calibration dataset. In calibration, the 3 alternative methodologies outperform the PLS performances for the majority of biomarkers. However, in the external herd validation, PLS provided the best results for isocitrate, glucose-6P, free glucose, and lactate dehydrogenase (coefficient of determination in external herd validation [R2v] = 0.48, 0.58, 0.28, and 0.24, respectively). For other molecules, PLS-random-downsampling and PLS-KennardStone-downsampling outperformed PLS in the majority of cases, but the best results were provided by SVM for citrate, BHB, acetone, NAGase, and progesterone (R2v = 0.94, 0.58, 0.76, 0.68, and 0.15, respectively). Hence, PLS and SVM based on the entire dataset provided the best results for normal and skewed distributions, respectively. Complementary to the quantitative methods, the qualitative discriminant models enabled the discrimination of high and low values for BHB, acetone, and NAGase with a global accuracy around 90%, and glucose-6P with an accuracy of 83%. In conclusion, MIR spectra of milk can enable quantitative screening of citrate as a biomarker of energy deficit and discrimination of low and high values of BHB, acetone, and NAGase, as biomarkers of ketosis and mastitis. Finally, progesterone could not be predicted with sufficient accuracy from milk MIR spectra to be further considered. Consequently, MIR spectrometry can bring valuable information regarding the occurrence of energy deficit, ketosis, and mastitis in dairy cows, which in turn have major influences on their fertility and survival.

Teaching humanitarian surgery: Filling the gap between NGO needs and subspecialized surgery through a novel inter-university certificate.

Background: Access to surgical care is a global health burden. A broad spectrum of surgical competences is required in the humanitarian context whereas current occidental surgical training is oriented towards subspecialties. We proposed to design a course addressing the specificities of surgery in the humanitarian setting and austere environment.Method: The novelty of the course lies in the implication of academic medical doctors alongside with surgeons working for humanitarian non-governmental organizations (NGO). The medical component of the National Defense participated regarding particular topics of war surgery. The course is aimed at trained surgeons and senior residents interested in participating to humanitarian missions.Results: The program includes theoretical teaching on surgical knowledge and skills applied to the austere context. The course also covers non-medical aspects of humanitarian action such as international humanitarian law, logistics, disaster management and psychological support. It comprises a large-scale mass casualty exercise and a practical skills lab on surgical techniques, ultrasonography and resuscitation. Attendance to the four teaching modules, ATLS certification and succeeding final examinations provide an interuniversity certificate.30 participants originating from 11 different countries joined the course. Various surgical backgrounds, training levels as well as humanitarian experience were represented.Feedback from the participants was solicited after each teaching module and remarks were applied to the following session. Overall participant evaluations of the first course session are presented.Conclusion: Teaching humanitarian surgery joining academic and field actors seems to allow filling the gap between high-income country surgical practice and the needs of the humanitarian context.

Progressive Fibrosis Is Driven by Genetic Predisposition, Allo-immunity, and Inflammation in Pediatric Liver Transplant Recipients.

AIM: To determine predisposing factors of idiopathic allograft fibrosis among pediatric liver transplant recipients. BACKGROUND: Protocol biopsies (PB) from stable liver transplant (LT) recipient children frequently exhibit idiopathic fibrosis. The relation between allograft inflammation, humoral immune response and fibrosis is uncertain. Also the role of HLA-DRB1 genotype has not been evaluated, though it's associated with fibrosis in autoimmune hepatitis. PATIENTS AND METHODS: This observational study, included 89 stable LT recipient transplanted between 2004-2012 with mean follow-up of 4.3years, 281 serial PBs (3.1 biopsy/child) and human leukocyte antigen (HLA) antibody data. PBs were taken 1-2, 2-3, 3-5, 5-7, and 7-10years post-LT, and evaluated for inflammation and fibrosis using liver allograft fibrosis score (LAFSc). The evolution of fibrosis, inflammation and related predisposing factors were analysed. FINDINGS: HLA-DRB1*03/04 allele and Class II DSA were significantly associated with portal fibrosis (p=0.03; p=0.03, respectively). Portal inflammation was predisposed by Class II DSA (p=0.02) and non-HLA antibody presence (p=0.01). Non-portal fibrosis wasn't predisposed by inflammation. Lobular inflammation was associated with non-HLA antibodies. INTERPRETATION: We conclusively demonstrated that allograft inflammation results in fibrosis and is associated with post-LT Class II DSA and non-HLA antibodies. The HLA-DRB1*03/04 allele caused genetic predisposition for fibrosis. FUNDING: None.

Development of Fourier transform mid-infrared calibrations to predict acetone, ß-hydroxybutyrate, and citrate contents in bovine milk through a European dairy network.

To manage negative energy balance and ketosis in dairy farms, rapid and cost-effective detection is needed. Among the milk biomarkers that could be useful for this purpose, acetone and ß-hydroxybutyrate (BHB) have been proved as molecules of interest regarding ketosis and citrate was recently identified as an early indicator of negative energy balance. Because Fourier transform mid-infrared spectrometry can provide rapid and cost-effective predictions of milk composition, the objective of this study was to evaluate the ability of this technology to predict these biomarkers in milk. Milk samples were collected in commercial and experimental farms in Luxembourg, France, and Germany. Acetone, BHB, and citrate contents were determined by flow injection analysis. Milk mid-infrared spectra were recorded and standardized for all samples. After edits, a total of 548 samples were used in the calibration and validation data sets for acetone, 558 for BHB, and 506 for citrate. Acetone content ranged from 0.020 to 3.355mmol/L with an average of 0.103mmol/L; BHB content ranged from 0.045 to 1.596mmol/L with an average of 0.215mmol/L; and citrate content ranged from 3.88 to 16.12mmol/L with an average of 9.04mmol/L. Acetone and BHB contents were log-transformed and a part of the samples with low values was randomly excluded to approach a normal distribution. The 3 edited data sets were then randomly divided into a calibration data set (3/4 of the samples) and a validation data set (1/4 of the samples). Prediction equations were developed using partial least square regression. The coefficient of determination (R(2)) of cross-validation was 0.73 for acetone, 0.71 for BHB, and 0.90 for citrate with root mean square error of 0.248, 0.109, and 0.70mmol/L, respectively. Finally, the external validation was performed and R(2) obtained were 0.67 for acetone, 0.63 for BHB, and 0.86 for citrate, with respective root mean square error of validation of 0.196, 0.083, and 0.76mmol/L. Although the practical usefulness of the equations developed should be further verified with other field data, results from this study demonstrated the potential of Fourier transform mid-infrared spectrometry to predict citrate content with good accuracy and to supply indicative contents of BHB and acetone in milk, thereby providing rapid and cost-effective tools to manage ketosis and negative energy balance in dairy farms.

Dynamics of allograft fibrosis in pediatric liver transplantation.

Progressive liver allograft fibrosis (LAF) is well known to occur long term, as shown by its high prevalence in late posttransplant liver biopsies (LBs). To evaluate the influence of clinical variables and immunosuppression on LAF progression, LAF dynamic was assessed in 54 pediatric liver transplantation (LT) recipients at 6 months, 3 and 7 years post-LT, reviewing clinical, biochemical data and protocol LBs using METAVIR and the liver allograft fibrosis score, previously designed and validated specifically for LAF assessment. Scoring evaluations were correlated with fibrosis quantification by morphometric analysis. Progressive LAF was found in 74% of long-term patients, 70% of whom had unaltered liver enzymes. Deceased grafts showed more fibrosis than living-related grafts (p = 0.0001). Portal fibrosis was observed in correlation with prolonged ischemia time, deceased grafts and lymphoproliferative disease (p = 0.001, 0.006 and 0.012, respectively). Sinusoidal fibrosis was correlated with biliary complications (p = 0.01). Centrilobular fibrosis was associated with vascular complications (p = 0.044), positive autoantibodies (p = 0.017) and high gamma-globulins levels (p = 0.028). Steroid therapy was not associated with reduced fibrosis (p = 0.83). LAF could be viewed as a dynamic process with mostly progression along the time. Peri- and post-LT-associated factors may condition fibrosis development in a specific area of the liver parenchyma.

Population pharmacokinetic analysis of tacrolimus in the first year after pediatric liver transplantation.

PURPOSES: Tacrolimus (TAC) is the most widely used immunosuppressant for the prevention of acute rejection after solid organ transplantation. Its pharmacokinetics (PK) show considerable variability, making TAC a good candidate for therapeutic drug monitoring (TDM). The principal aim of the study was to describe the PK of TAC in pediatric patients during the first year after transplantation. METHODS: Routine TDM trough levels of TAC were obtained from 42 pediatric liver allograft recipients during the first year after transplantation. A population PK model was developed using nonlinear mixed-effects modeling to describe TAC PK during this period and to explain the observed variability by means of patients' demographics, biochemical test results and physiological characteristics. RESULTS: The PK of TAC were best described by a two-compartment model with first-order elimination. Apparent volumes of the central compartment, intercomparmental clearance and maximum blood clearance estimates were 253 L, 115 L/day and 314 L/day, respectively. The absorption first-order rate and volume of peripheral compartment were fixed to 4.5 h(-1) and 100 L, respectively. While hematocrit levels, time after transplantation and bodyweight influenced TAC clearance, bodyweight was the only covariate retained on volume of distribution. CONCLUSIONS: We developed a TAC population PK model in pediatrics covering the first year after liver transplantation that may serve as a tool for TAC dose individualization as part of TDM.

Histological and immunohistochemical revision of hepatocellular adenomas: a learning experience.

Light has been shed on the genotype/phenotype correlation in hepatocellular adenoma (HCA) recognizing HNF1 α -inactivated HCA (H-HCA), inflammatory HCA (IHCA), and ß -catenin-activated HCA (b-HCA). We reviewed retrospectively our surgical HCA series to learn how to recognize the different subtypes histopathologically and how to interpret adequately their immunohistochemical staining. From January 1992 to January 2012, 37 patients underwent surgical resection for HCA in our institution. Nine had H-HCA (25%) characterized by steatosis and loss of L-FABP expression; 20 had IHCA (55.5%) showing CRP and/or SAA expression, sinusoidal dilatation, and variable inflammation; and 1 patient had both H-HCA and IHCA. In 5 patients (14%), b-HCA with GS and ß -catenin nuclear positivity was diagnosed, two already with hepatocellular carcinoma. Two cases (5.5%) remained unclassified. One of the b-HCA showed also the H-HCA histological and immunohistochemical characteristics suggesting a subgroup of ß -catenin-activated/HNF1 α -inactivated HCA, another b-HCA exhibited the IHCA histological and immunohistochemical characteristics suggesting a subgroup of ß -catenin-activated/inflammatory HCA. Interestingly, three patients had underlying vascular abnormalities. Using the recently published criteria enabled us to classify histopathologically our retrospective HCA surgical series with accurate recognition of b-HCA for which we confirm the higher risk of malignant transformation. We also underlined the association between HCA and vascular abnormalities.

[Postoperative pain trajectories to identify risk of chronic postsurgical pain in living donors for liver transplantation]. / Identification du risque de douleur chronique après hépatectomie pour don de foie par les trajectoires de douleur.

OBJECTIVES: To assess pain trajectories in predicting risk of chronic postoperative pain (CPP) after liver resection for living donor transplantation. STUDY DESIGN: Retrospective analysis of patients undergoing liver resection for living donor transplantation during 3years. PATIENTS AND METHODS: After recording perioperative data, patients presenting CPP at 3months were separated from patients without postsurgical pain problem in order to build a pain trajectory for liver donor patients without CPP. Postoperative course of liver donors with CPP was then compared to that standard pain trajectory. RESULTS: Sixty-five patients (30 females, 35 males) were included. Epidural analgesia was used in 66%; others received autocontrolled analgesia by morphine. Severe acute pain was expressed by 11% and 37% at rest and movement respectively on the first day. Chronic pain involved six patients without any link with gender or type of analgesia. Analysis of pain trajectories shown that these patients presented either higher initial pain at day 1 or positive slopes with worsening of pain. CONCLUSION: Acute postoperative pain is a risk factor of developing CPP. Identification of those people by pain trajectories can be useful to treat them early.

Novel histologic scoring system for long-term allograft fibrosis after liver transplantation in children.

The existing systems for scoring fibrosis were not developed to evaluate transplanted livers. Our aim was to design and validate a novel fibrosis scoring system specifically adapted to assess liver allograft fibrosis (LAF). Clinical data, histology, transient elastography (TE) and AST/platelet ratio index (APRI) were reviewed in 38 pediatric liver transplant (LT) recipients. Protocol liver biopsies performed at 6 months and 7 years post-LT were reviewed by three pathologists who assessed LAF using the METAVIR and Ishak systems. LAF was also scored separately in portal (0-3), sinusoidal (0-3) and centrolobular areas (0-3). Scoring evaluations were correlated with fibrosis quantification using morphometry, and also with TE and APRI. Statistical correlations between morphometry and METAVIR were 0.571 (p < 0.000) and 0.566 (p < 0.000) for the Ishak system. The novel score (0-9) for separate assessment of portal, sinusoidal and centrolobular fibrosis showed a better correlation with morphometry (0.731; p < 0.000) and high intra-/interobserver agreement (0.966; p < 0.000 and 0.794; p < 0.000, respectively). No correlation was found between TE or APRI and morphometry or the three histologic scores. In conclusion, this novel semiquantitative fibrosis scoring system seems to more accurately reflect LAF than the existing scoring system and may become a practical tool for staging fibrosis in LT.

Acquired antithrombin type IIb deficiency after liver transplantation: a case report.

A 3-year-old girl with multifocal hepatoblastoma was referred to our clinic for living-donor liver transplantation, the patient's father being the donor. Pretransplant evaluation revealed that the father presented partial asymptomatic antithrombin (AT) deficiency, with no inherited AT deficiency found in the girl. The genetic testing showed an AT type IIb deficiency responsible for a defect in the heparin-binding region of AT which is less thrombogenic but more common than the other AT qualitative defects. Her mother was ABO incompatible. Despite the thrombophilia on the father's side, transplantation was successfully performed under replacement therapy with intravenous AT concentrate and low-molecular-weight heparin thromboprophylaxis given to both the recipient and the donor. No thrombotic complications occurred. In the posttransplantation course, acquired partial AT deficiency was detected in the recipient, who received adjuvant chemotherapy without thrombotic complications. This case report highlights the relevance of full thrombophilic work-up before liver transplantation from a living donor, while illustrating that the procedure can be successfully performed in the case of AT deficiency on the donor's side provided that appropriate AT supplementation and thromboprophylaxis are administered to both the recipient and the donor.

Living related liver transplant following bone marrow transplantation from same donor: long-term survival without immunosuppression.

We report long-term (seven yr) immunological tolerance in a 16-yr-old boy, to a liver allograft donated by his father following a bone marrow transplant at age 2.5 yr from the same donor. The bone marrow transplant was complicated by severe GVHD leading to liver failure and the ensuing need for a liver transplant, performed under planned avoidance of immunosuppression. At one wk post-transplant, although a liver biopsy was histologically compatible with acute rejection, favorable clinical and biochemical evolution precluded initiating immunosuppressive therapy, thus highlighting the need for caution when interpreting early histological changes so that administration of unnecessary immunosuppression can be avoided. Induction of tolerance in transplant recipients remains an elusive goal. In those patients who had received conventional bone marrow transplants and had endured the consequences of GVHD, development of macrochimerism may allow immunosuppression-free solid organ transplantation from the same donor.

[A ten year university cooperation program in pediatric surgery in Saigon, Vietnam. Lessons and perspectives]. / Dix ans de coopération universitaire en chirurgie pédiatrique a Saigon, Viêt-nam. Des leçons et des perspectives.

A university cooperation in the field of the medico-surgical management of pediatric digestive pathology was set up since 1999 at Children's Hospital no 2 in Saigon, Vietnam. Supported by the Belgian Commission for University Development (CUD), this program focused on postgraduate teaching and research regarding the early detection of neonatal malformations. Replying to a request of Vietnamese health authorities, a pediatric liver transplant program with parental living donors was also launched. Six children were successfully transplanted since 2005, an achievement which required the elaboration of new standards of clinical care in this eight hundred beds pediatric hospital. The direct and indirect improvements promoted through this program should contribute to enhance the overall medico-surgical management of children in this major Southern institution.

Liver transplantation using non-heart-beating donors: Belgian experience.

UNLABELLED: Mortality on liver transplantation (OLT) waiting lists has increased dramatically. Until recently, non-heart-beating donors (NHBD) were not considered suitable for OLT, because of a higher risk of primary graft nonfunction (PNF) and biliary strictures. However, recent experimental/clinical evidence has indicated that NHBD-OLT is feasible when the period of warm ischemia is short. PURPOSE: To characterize the results of NHBD-OLT in Belgium, a survey was sent to all Belgian OLT centers. RESULTS: Between January 2003 and November 2005, 16 livers originating from NHBD were procured and transplanted. The mean donor age was 48.8 years, including 9 males and 7 females with mean time of stop-therapy to cardiac arrest being 18 minutes and from cardiac arrest to liver cold perfusion, 10.5 minutes. Mean recipient age was 52.2 years including 12 males and 4 females. Mean cold ischemia time was 7 hours 15 minutes. No PNF requiring re-OLT was observed. Mean post-OLT peak transaminase was 2209 IU/L, which was higher among imported versus locally procured grafts. Biliary complications occurred in 6 patients requiring re-OLT (n = 2), endoscopic treatment (n = 2), surgical treatment (n = 1), or left untreated (n = 1). These tended to be more frequent after prolonged warm ischemia. Graft and patient survivals were 62.5% and 81.3%, respectively, with a follow-up of 3 to 36 months. CONCLUSION: This survey showed acceptable graft/patient survivals after NHBD-LT. The NHBD-liver grafts suffered a high rate of ischemic injury and biliary complications and therefore should be used carefully, namely with no additional donor risk factors, lower risk recipients, and short cold/warm ischemia.

Living-related versus deceased donor pediatric liver transplantation: a multivariate analysis of technical and immunological complications in 235 recipients.

Timely access to a living donor (LD) reduced pretransplant mortality in pediatric liver transplantation (LT). We hypothesized that this strategy may provide better posttransplant outcome. Between July 1993 and April 2002, 235 children received a primary LT from a LD (n = 100) or a deceased donor (DD) (n = 135). Demographic, surgical and immunological variables were compared, and respective impact on posttransplant complications was studied using a multivariate analysis. Five-year patient survival rates were 92% and 85% for groups LD and DD, respectively (p = 0.181), the corresponding graft survival rates being 89% and 77% (p = 0.033). At multivariate analysis: (1) type of donor (DD) was correlated with higher rate of artery thrombosis (p < 0.012); (2) biliary complication rate at 5 years was 29% and 23% for groups LD and DD, respectively (p = 0.451); (3) lower acute rejection incidence could be correlated with type of donor (DD) (p = 0.001), and immunosuppressive therapy (tacrolimus) (p < 0.001). We conclude that (1) according to the multivariate analysis, LT with LD provided similar patient and graft outcome, when compared to DD; (2) a higher rate of artery thrombosis and a lower rate of rejection were observed in group DD; (3) this study confirms the efficacy of tacrolimus for immunoprophylaxis, whatever the type of organ donor is.

Evaluation of a new immunoassay to measure sirolimus blood concentrations compared to a tandem mass-spectrometric chromatographic analysis.

A new immunoassay of sirolimus based on the microparticle enzyme immunoassay (MEIA) principle has been developed with collaboration of Abbott Diagnostics. Laboratories and Axis-Shield. Our laboratory evaluated this new assay on 153 whole blood samples (EDTA) drawn from a population of renal (n = 141) and hepatic (n = 12) transplant patients. Each blood sample was analyzed simultaneously by MEIA (Y) and by a reference method (X) used routinely in our laboratory, namely, liquid chromatography tandem mass spectrometry (LC-MS/MS). The statistical analysis of Passing-Bablok produced the following results: Spearman r value = 0.95, slope = 1.15 and intercept with the Y axis = +0.2 ng/mL. The observed global overestimation of 15% compared to the reference method could be explained by the cross-reactivity of sirolimus metabolites with the antibody. A complementary analysis taking into account the transplanted organ (kidney versus hepatic) did not show any significant difference between the populations, most likely owing to the low number of hepatic transplantation samples. The analytical performance of the MEIA method showed CV < or =10% and a limit of quantification of 1.5 ng/mL, which were acceptable for routine clinical monitoring. In conclusion, the MEIA method has shown robust, stable, reproducible, features with an excellent correlation with the reference LC-MS/MS method.

Orthotopic liver transplantation from a living-related donor in an infant with a peroxisome biogenesis defect of the infantile Refsum disease type.

Peroxisomal biogenesis defects include a number of severe neurodevelopmental disorders, among which infantile Refsum disease (IRD) occupies the mildest end of the spectrum. Although high docosahexaenoic acid (DHA) and low phytanic acid diets can correct some of the biochemical defects, they have not consistently altered the progressive course of the disease. We carried out orthotopic liver transplantation (OLT) in a mildly symptomatic 6-month-old infant who was a sibling of a severely neurologically impaired older sister. After transplantation the clinical course of this young child appeared much improved by comparison to her older sister. She walked alone at 4 years, had acceptable social interaction and had a noticeable recovery of audition. After transplantation her biochemical parameters were significantly improved: phytanic acid and very long-chain fatty acid (VLCFA) serum concentrations decreased. Abnormal bile acids disappeared from plasma. Although the OLT did not result in a cure of the disorder, the clinical and biochemical results suggest that OLT should be considered in mildly symptomatic patients.

Long-term complications of immunosuppression in pediatric liver recipients.

Liver transplantation (LT) today constitutes a well-standardized and efficient therapy for children with acute and chronic hepatic failure. Appropriate pre-transplant management, organ preservation, adequate surgical techniques, and the progressive introduction of new immunosuppressive regimens have contributed to significantly improve, over the years, the general outcome after LT. Consequently, these good overall results has allowed the constitution of a growing cohort of children, adolescents and young adults submitted to chronic immunosuppression. The long-term complications of immunosuppression administered to transplant recipients include the adverse effects secondary to the depression of the immune system, the toxicities specifically related to the individual immunosuppressive drugs, and the sense of lack of rehabilitation for the transplant patient, with, secondarily, the question of non-adherence to the medications. This review will essentially focus on these three issues in the particular context of pediatric liver transplantation.

[Contribution to the study of mechanisms of rejection and tolerance in organ transplantation: minimizing immunosuppression as a strategy for graft tolerance in pediatric liver transplantation]]. / Contributions a l'étude des mécanismes de rejet et de tolérance en transplantation d'organes: la minimisation de l'immunosuppression comme stratégie tolérogénique en greffe hépatique pédiatrique.

Basic concepts in transplantation immunology have been recently revisited. Accordingly, the immune response towards an allograft is not anymore considered as necessarily harmful, but could participate, under certain conditions, to graft acceptation through active mechanisms. This novel paradigm was progressively evaluated in clinical liver transplantation, with the aim to minimize the immunosuppressive regimens and, as a first step, to completely withdraw steroids from the immunoprophylactic regimen. The development of laboratory tests to reproducibly assess the immune reactivity of a recipient towards his/her transplanted organ should allow the identification of operationally tolerant patients, and the elective withdrawal of maintenance immunosuppression in this subgroup.

The paediatric liver transplantation program at the Université catholique de Louvain.

The Paediatric Liver Transplant Program at Saint-Luc University Clinics constitutes a substantial single centre experience, including 667 transplantations performed between March 1984 and April 2003, and the history of this program reflects the tremendous progress in this field since twenty years. Liver transplantation in children constitutes a considerable undertaking and its results depend on multiple, intermingled risk factors. An analysis of the respective impact of several surgical and immunological parameters on patient/graft outcome and allograft rejection after paediatric liver transplantation showed a significant learning curve effect as well as the respective impact of pre-transplant diagnosis on survival and of primary immunosuppression on the rejection incidence. The introduction of living related liver transplantation in 1993 not only permitted to provide access to liver replacement in as many as 74% more candidate recipients, but also resulted in better graft survival and reduced retransplantation rate. The results of a recent pilot study suggest that steroid avoidance is not harmful, and could even be beneficial for paediatric liver recipients, particularly regarding growth, and that combining tacrolimus with basiliximab (anti-CD25 chimeric monoclonal antibody) for steroid substitution appears to constitute a safe alternative in this context. The long-term issues represent the main future challenges in the field, including the possibility of a full rehabilitation through immunosuppression withdrawal and tolerance induction, the development of adolescence transplant medicine, and the risk of early atherogenesis in the adulthood.