After the implementation of universal hepatitis A virus vaccination inArgentina, the outcome of pediatric acute liver failure (PALF) remains unknown. We aimed to identify variables associated with the risk of liver transplantation (LT) or death and to determine the causes and short-term outcomes of PALF in Argentina. We retrospectively included 135 patients with PALF listed for LT between 2007 and 2016. Patients with autoimmune hepatitis (AIH), Wilson's disease (WD), or inborn errors of metabolism (IEM) were classified as PALF-chronic liver disease (CLD), and others were classified as "pure" PALF. A logistic regression model was developed to identify factors independently associated with death or need of LT and risk stratification. The most common etiologies were indeterminate (52%), AIH (23%), WD (6%), and IEM (6%). Overall, transplant-free survival was 35%, whereas 50% of the patients underwent LT and 15% died on the waiting list. The 3-month risk of LT or death was significantly higher among patients with pure PALF compared with PALF-CLD (76.5% versus 42.5%; relative risk, 1.8 [1.3-2.5]; P < 0.001), and 3 risk factors were independently associated with worse outcome: international normalized ratio (INR) ≥3.5 (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.3-7.2]), bilirubin ≥17 mg/dL (OR, 4.4; 95% CI, 1.9-10.3]), and pure PALF (OR, 3.8; 95% CI, 1.6-8.9). Patients were identified by the number of risk factors: Patients with 0, 1, or ≥2 risk factors presented a 3-month risk of worse outcome of 17.6%, 36.6%, and 82%, respectively. In conclusion, although lacking external validation, this simple risk-staging model might help stratify patients with different transplant-free survival rates and may contribute to establishing the optimal timing for LT. Liver Transplantation 26 268-275 2020 AASLD.

Tacrolimus C0 values, its variability, and CYP3A5 polymorphisms were identified as risk factors of AR and tacrolimus ADR. This knowledge may help to control and reduce their incidence in pediatric liver transplant patients. Prospective studies are important to validate these results.

Grafts from split livers (SLs) constitute an accepted approach to expand the donor pool. Over the last 5 years, most Argentinean centers have shown significant interest in increasing the use of this technique. The purpose of this article is to describe and analyze the outcomes of right-side grafts (RSGs) and left-side grafts (LSGs) from a multicenter study. The multicenter retrospective study included data from 111 recipients of SL grafts from between January 1, 2009 and December 31, 2013. Incidence of surgical complications, patient and graft survival, and factors that affected RSG and LSG survival were analyzed. Grafts types were 57 LSG and 54 RSG. Median follow-up times for LSG and RSG were 46 and 42 months, respectively. The 36-month patient and graft survivals for LSG were 83% and 79%, respectively, and for RSG were 78% and 69%, respectively. Retransplantation rates for LSG and RSG were 3.5% and 11%, respectively. Arterial complications were the most common cause of early retransplantation (less than 12 months). Cold ischemia time (CIT) longer than 10 hours and the use of high-risk donors (age 40 years or body mass index 30 kg/m 2 or 5 days intensive care unit stay) were independent factors for diminished graft survival in RSG. None of the analyzed variables were associated with worse graft survival in LSG. Biliary complications were the most frequent complications in both groups (57% in LSG and 33% in RSG). Partial grafts obtained from liver splitting are an excellent option for patients in need of liver transplantation and have the potential to alleviate the organ shortage. Adequate donor selection and reducing CIT are crucial for optimizing results. Liver transplantation (LT) performed with split liver (SL) grafts may currently be considered a safe and effective resource to alleviate the organ shortage. Over the past years, multiple review articles have shown results that are similar to those obtained in transplantations performed with whole organs. [1][2][3][4] Nevertheless, in the majority of countries, the strategy remains underused, despite its known potential to decrease mortality on the pediatric waiting list without harming adults waiting for LT, resulting in a net benefit for health care systems by providing the possibility to optimize the use of a scarce resource. [5][6][7] Over the last 5 years in most Argentinean centers, there has been significant interest in increasing the use of this technique.The aim of this study was to report the results of SL transplantations over the past 5 years in Argentina

The evidence available in the pediatric population is limited for making clinical decisions regarding the optimization of tacrolimus (TAC) in pharmacotherapy. The objective of this study was to estimate the frequency of CYP3A5 genetic polymorphisms and their relationship with tacrolimus requirements in the pediatric population. This was a longitudinal cohort study with a two-year follow-up of 77 patients under 18 years old who underwent a liver transplant during the period 2009–2012 at the J.P. Garrahan Pediatric Hospital. Tacrolimus levels from day five up to two years after the transplant were obtained from hospital records of routine therapeutic drug monitoring. The genotyping of CYP3A5 (CYP3A5*1/*3 or *3/*3) was performed in liver biopsies from both the donor and the recipient. The frequency of CYP3A5*1 expression for recipients was 37.1% and 32.2% for donors. Patients who received an expresser organ showed lower Co/dose, especially following 90 days after the surgery. The role of each polymorphism is different according to the number of days after the transplant, and it must be taken into account to optimize the benefits of TAC therapy during the post-transplant induction and maintenance phases.

The most common indications for early liver retransplantation (eRe‐LT) are vascular complications and primary nonfunction (PNF). These patients are usually in a critical clinical condition that can affect their chances of survival. In fact, the survival of these patients is usually lower compared with the patients undergoing a first transplant. To the best of our knowledge, no specific series of pediatric patients undergoing eRe‐LT has been published to date. Therefore, the aim of this study is to report the results of eRe‐LT and to analyze factors potentially related to success or failure. Our work is of a retrospective cohort study of patients who underwent eRe‐LT at the Juan P. Garrahan Pediatric Hospital of Buenos Aires, Argentina, between May 1995 and December 2018 (n = 60). Re‐LT was considered early when performed ≤30 days after the previous LT. A total of 40 (66.7%) patients were enrolled due to vascular causes and 20 (33.3%) were enrolled because of PNF. Of all the relisted patients, 36 underwent eRe‐LT, 14 died on the waiting list, and 10 recovered without eRe‐LT. A total of 23 (63.9%) patients died after eRe‐LT, most of them due to infection‐related complications. Survival rates at 1 and 5 years were 42.4% and 33.9%, respectively. On univariate logistic regression analysis, Pediatric End‐Stage Liver Disease (PELD)/Model for End‐Stage Liver Disease (MELD) scores, transplant era, and advanced life support at eRe‐LT were found to be related to 60‐day mortality. However, on multivariate analysis, era (odds ratio [OR], 9.3; 95% confidence interval [CI], 1.19‐72.35; P = 0.033) and PELD/MELD scores (OR, 1.07; 95% CI, 1‐1.14; P = 0.036) were significantly associated with 60‐day patient mortality. This study found that the level of acuity before retransplant, measured by the requirement of advanced life support and the PELD/MELD score at eRe‐LT, was significantly associated with the chances of post–eRe‐LT patient survival.