Erratum: Measuring disparate outcomes of content recommendation algorithms with distributional inequality metrics.

[This corrects the article DOI: 10.1016/j.patter.2022.100568.].

The Italian data on SARS-CoV-2 infection in transplanted patients support an organ specific immune response in liver recipients.

Introduction: The study of immune response to SARSCoV-2 infection in different solid organ transplant settings represents an opportunity for clarifying the interplay between SARS-CoV-2 and the immune system. In our nationwide registry study from Italy, we specifically evaluated, during the first wave pandemic, i.e., in non-vaccinated patients, COVID-19 prevalence of infection, mortality, and lethality in liver transplant recipients (LTRs), using non-liver solid transplant recipients (NL-SOTRs) and the Italian general population (GP) as comparators. Methods: Case collection started from February 21 to June 22, 2020, using the data from the National Institute of Health and National Transplant Center, whereas the data analysis was performed on September 30, 2020.To compare the sex- and age-adjusted distribution of infection, mortality, and lethality in LTRs, NL-SOTRs, and Italian GP we applied an indirect standardization method to determine the standardized rate. Results: Among the 43,983 Italian SOTRs with a functioning graft, LTRs accounted for 14,168 patients, of whom 89 were SARS-CoV-2 infected. In the 29,815 NL-SOTRs, 361 cases of SARS-CoV-2 infection were observed. The geographical distribution of the disease was highly variable across the different Italian regions. The standardized rate of infection, mortality, and lethality rates in LTRs resulted lower compared to NL-SOTRs [1.02 (95%CI 0.81-1.23) vs. 2.01 (95%CI 1.8-2.2); 1.0 (95%CI 0.5-1.5) vs. 4.5 (95%CI 3.6-5.3); 1.6 (95%CI 0.7-2.4) vs. 2.8 (95%CI 2.2-3.3), respectively] and comparable to the Italian GP. Discussion: According to the most recent studies on SOTRs and SARS-CoV-2 infection, our data strongly suggest that, in contrast to what was observed in NL-SOTRs receiving a similar immunosuppressive therapy, LTRs have the same risk of SARS-CoV-2 infection, mortality, and lethality observed in the general population. These results suggest an immune response to SARS-CoV-2 infection in LTRS that is different from NL-SOTRs, probably related to the ability of the grafted liver to induce immunotolerance.

Economic Impact of European Liver and Intestine Transplantation Association (ELITA) Recommendations for Hepatitis B Prophylaxis After Liver Transplantation.

The European Liver and Intestine Transplant Association, ELITA, promoted a Consensus Conference involving 20 experts across the world which generated updated guidelines on HBV prophylaxis in liver transplant candidates and recipients. This study explores the economic impact associated with the implementation of the new ELITA guidelines. To this aim, a condition-specific cohort simulation model has been developed to compare new and historical prophylaxis, including only pharmaceutical cost and using the European perspective. The target population simulated in the model included both prevalent and incident cases, and consisted of 6,133 patients after the first year, that increased to 7,442 and 8,743 patents after 5 and 10 years from its implementation. The ELITA protocols allowed a cost saving of around € 235.65 million after 5 years and € 540.73 million after 10 years; which was mainly due to early HIBG withdrawal either after the first 4 weeks or after the first year post Liver Transplantation (LT) depending on the virological risk at transplantation. Results were confirmed by sensitivity analyses. The money saved by the implementation of the ELITA guidelines would allow healthcare decision makers and budget holders to understand where costs could be reduced and resources re-allocated to different needs.

Similar survival but higher and delayed hepatocellular carcinoma recurrence in HIV-positive compared to negative cirrhotics undergoing liver transplantation.

BACKGROUND: Liver transplantation (LT) represents the best therapeutic option for hepatocellular carcinoma (HCC) and end-stage liver disease (ESLD). Although HIV infection does not seem to lower survival rates, HCV and HCC recurrence appear more harmful. AIMS: To compare the overall survival after LT; evaluate the impact of anti-HCV direct-acting agents (DAA); assess the rate of HCC recurrence in HIV-positive and negative patients. METHODS: Subjects with HCV/HBV infection who underwent LT for HCC or ESLD from 2012 to 2019 were retrospectively evaluated. RESULTS: Study population included 299 individuals, 31 (10.4%) were HIV-positive. Overall mortality was similar (16.1% versus 19.0%, p = 0.695). HCC recurrence was observed in 6 HIV-positive (19.4%) and in 17 negative subjects (6.3%, p = 0.022). Time to relapse was 831 days in HIV-positive and 315 days in negative patients (p = 0.046). Cox model found a significant role for HIV in univariate analysis but, after adjusting for variables, extra-hepatic tumor was the only factor associated to recurrence (aHR 56.379, p < 0.001). CONCLUSIONS: Post-LT survival improved after DAA availability and HIV has no impact on mortality. A higher and delayed rate of HCC recurrence was observed in co-infected individuals: surveillance protocols should be strengthened along time in this population.

ESOT Consensus Platform for Organ Transplantation: Setting the Stage for a Rigorous, Regularly Updated Development Process.

The European Society for Organ Transplantation (ESOT) has created a platform for the development of rigorous and regularly updated evidence based guidelines for clinical practice in the transplantation field. A dedicated Guideline Taskforce, including ESOT-council members, a representative from the Centre for Evidence in Transplantation, editors of the journal Transplant International has developed transparent procedures to guide the development of guidelines, recommendations, and consensus statements. During ESOT's first Consensus Conference in November 2022, leading experts will present in-depth evidence based reviews of nine themes and will propose recommendations aimed at reaching a consensus after public discussion and assessment by an independent jury. All recommendations and consensus statements produced for the nine selected topics will be published including the entire evidence-based consensus-finding process. An extensive literature review of each topic was conducted to provide final evidence and/or expert opinion.

Measuring disparate outcomes of content recommendation algorithms with distributional inequality metrics.

The harmful impacts of algorithmic decision systems have recently come into focus, with many examples of machine learning (ML) models amplifying societal biases. In this paper, we propose adapting income inequality metrics from economics to complement existing model-level fairness metrics, which focus on intergroup differences of model performance. In particular, we evaluate their ability to measure disparities between exposures that individuals receive in a production recommendation system, the Twitter algorithmic timeline. We define desirable criteria for metrics to be used in an operational setting by ML practitioners. We characterize engagements with content on Twitter using these metrics and use the results to evaluate the metrics with respect to our criteria. We also show that we can use these metrics to identify content suggestion algorithms that contribute more strongly to skewed outcomes between users. Overall, we conclude that these metrics can be a useful tool for auditing algorithms in production settings.

Impact of COVID-19 on the liver and on the care of patients with chronic liver disease, hepatobiliary cancer, and liver transplantation: An updated EASL position paper.

The COVID-19 pandemic has presented a serious challenge to the hepatology community, particularly healthcare professionals and patients. While the rapid development of safe and effective vaccines and treatments has improved the clinical landscape, the emergence of the omicron variant has presented new challenges. Thus, it is timely that the European Association for the Study of the Liver provides a summary of the latest data on the impact of COVID-19 on the liver and issues guidance on the care of patients with chronic liver disease, hepatobiliary cancer, and previous liver transplantation, as the world continues to deal with the consequences of the COVID-19 pandemic.

Location and allocation: Inequity of access to liver transplantation for patients with severe acute-on-chronic liver failure in Europe.

There is growing evidence that liver transplantation (LT) is the most effective treatment for acute-on-chronic liver failure grade-3 (ACLF-3). This study examines whether and how this evidence translates into practice by analyzing the variability in intensive care unit (ICU) admissions, listing strategies, and LT activity for patients with ACLF-3 across transplantation centers in Europe. Consecutive patients who were admitted to the ICU with ACLF-3, whether or not they were listed and/or transplanted with ACLF-3, between 2018 and 2019 were included across 20 transplantation centers. A total of 351 patients with ACLF-3 were included: 33 had been listed prior to developing ACLF-3 and 318 had not been listed at the time of admission to the ICU. There was no correlation between the number of unlisted patients with ACLF-3 admitted to the ICU and the number listed or transplanted while in ACLF-3 across centers. By contrast, there was a correlation between the number of patients listed and the number transplanted while in ACLF-3. About 21% of patients who were listed while in ACLF-3 died on the waiting list or were delisted. The percentage of LT for patients with ACLF-3 varied from 0% to 29% for those transplanted with decompensated cirrhosis across centers (average = 8%), with an I2 index of 68% (95% confidence interval, 49%-80%), showing substantial heterogeneity among centers. The 1-year survival for all patients with ACLF-3 was significantly higher in centers that listed and transplanted more patients with ACLF-3 (>10 patients) than in centers that listed and transplanted fewer: 36% versus 20%, respectively (p = 0.012). Patients with ACLF-3 face inequity of access to LT across Europe. Waitlisting strategies for patients with ACLF-3 influence their access to LT and, ultimately, their survival.

Implementation of the frailty assessment to improve liver transplant outcomes.

The majority of patients undergoing Orthotopic Liver Transplantation (OLT) have increased in age, therefore chronological age may have become an unreliable parameter for supporting clinical decisions. The age-related deficit accumulation model measuring frailty proposed by Rockwood et al., may propose an alternative in providing an estimate of an individual's biological age. No Frailty Index (FI) tailored specifically for OLT patients exists to date. Forty-three consecutive OLT patients with ≥ 20 years of survival with a functioning graft were included in our study. The FI was computed taking to account 39 items (FI-39), meeting the standard criteria for internal validation. Endpoints were polypharmacy, and recent Emergency Room admission. The mean age of our population was 69 (sd 9) years. The mean FI-39 was 0.23 (sd 0.1). The FI-39 was associated with polypharmacy [odds ratio (OR) 1.13; Confidence interval (95%CI) 1.03-1.24; p = 0.01], and recent Emergency Room admission [beta coefficient + 1.98; 95%CI + 0.26, + 3.70; p = 0.03], independent for age and sex. This study demonstrates that an FI can be derived from data collected during routine clinical follow-up and allows for improved differentiation related to the OLT clinical complexity in OLT patients, independent of chronological age. This may lead to the adoption of FI-39 to improve personalized OLT patient care.

Global impact of the first wave of COVID-19 on liver transplant centers: A multi-society survey (EASL-ESOT/ELITA-ILTS).

BACKGROUND AND AIMS: The global impact of SARS-CoV-2 on liver transplantation (LT) practices across the world is unknown. The goal of this survey was to assess the impact of the pandemic on global LT practices. METHOD: A prospective web-based survey (available online from 7th September 2020 to 31st December 2020) was proposed to the active members of the EASL-ESOT/ELITA-ILTS in the Americas (including North, Central, and South America) (R1), Europe (R2), and the rest of the world (R3). The survey comprised 4 parts concerning transplant processes, therapy, living donors, and organ procurement. RESULTS: Of the 470 transplant centers reached, 128 answered each part of the survey, 29 centers (23%), 64 centers (50%), and 35 centers (27%) from R1, R2, and R3, respectively. When we compared the practices during the first 6 months of the pandemic in 2020 with those a year earlier in 2019, statistically significant differences were found in the number of patients added to the waiting list (WL), WL mortality, and the number of LTs performed. At the regional level, we found that in R2 the number of LTs was significantly higher in 2019 (p <0.01), while R3 had more patients listed, higher WL mortality, and more LTs performed before the pandemic. Countries severely affected by the pandemic ("hit" countries) had a lower number of WL patients (p = 0.009) and LTs (p = 0.002) during the pandemic. Interestingly, WL mortality was still higher in the "non-hit" countries in 2020 compared to 2019 (p = 0.022). CONCLUSION: The first wave of the pandemic differentially impacted LT practices across the world, especially with detrimental effects on the "hit" countries. Modifications to the policies of recipient and donor selection, organ retrieval, and postoperative recipient management were adopted at a regional or national level. LAY SUMMARY: The health emergency caused by the coronavirus pandemic has dramatically changed clinical practice during the pandemic. The first wave of the pandemic impacted liver transplantation differently across the world, with particularly detrimental effects on the countries badly hit by the virus. The resilience of the entire transplant network has enabled continued organ donation and transplantation, ultimately improving the lives of patients with end-stage liver disease.

Algorithmic amplification of politics on Twitter.

Content on Twitter's home timeline is selected and ordered by personalization algorithms. By consistently ranking certain content higher, these algorithms may amplify some messages while reducing the visibility of others. There's been intense public and scholarly debate about the possibility that some political groups benefit more from algorithmic amplification than others. We provide quantitative evidence from a long-running, massive-scale randomized experiment on the Twitter platform that committed a randomized control group including nearly 2 million daily active accounts to a reverse-chronological content feed free of algorithmic personalization. We present two sets of findings. First, we studied tweets by elected legislators from major political parties in seven countries. Our results reveal a remarkably consistent trend: In six out of seven countries studied, the mainstream political right enjoys higher algorithmic amplification than the mainstream political left. Consistent with this overall trend, our second set of findings studying the US media landscape revealed that algorithmic amplification favors right-leaning news sources. We further looked at whether algorithms amplify far-left and far-right political groups more than moderate ones; contrary to prevailing public belief, we did not find evidence to support this hypothesis. We hope our findings will contribute to an evidence-based debate on the role personalization algorithms play in shaping political content consumption.

Liver transplantation for severe alcoholic hepatitis: A multicenter Italian study.

There is increasing evidence that early liver transplantation (eLT), performed within standardized protocols can improve survival in severe alcoholic hepatitis (sAH). The aim of the study was to assess outcomes after eLT for sAH in four Italian LT centers and to compare them with non-responders to medical therapy excluded from eLT. Patients admitted for sAH (2013-2019), according to NIAAA criteria, were included. Patients not responding to medical therapy were placed on the waiting list for eLT after a strict selection. Histological features of explanted livers were evaluated. Posttransplant survival and alcohol relapse were evaluated. Ninety-three patients with severe AH were evaluated (65.6% male, median [IQR] age: 47 [42-56] years). Forty-five of 93 patients received corticosteroids, 52 of 93 were non-responders and among these, 20 patients were waitlisted. Sixteen patients underwent LT. Overall, 6-, 12-, and 24-month survival rates were 100% significantly higher compared with non-responders to medical therapy who were denied LT (45%, 45%, and 36%; p < .001). 2/16 patients resumed alcohol intake, one at 164 days and one at 184 days. Early LT significantly improves survival in sAH non-responding to medical therapy, when a strict selection process is applied. Further studies are needed to properly assess alcohol relapse rates.

Performance of the model for end-stage liver disease score for mortality prediction and the potential role of etiology.

BACKGROUND & AIMS: Although the discriminative ability of the model for end-stage liver disease (MELD) score is generally considered acceptable, its calibration is still unclear. In a validation study, we assessed the discriminative performance and calibration of 3 versions of the model: original MELD-TIPS, used to predict survival after transjugular intrahepatic portosystemic shunt (TIPS); classic MELD-Mayo; and MELD-UNOS, used by the United Network for Organ Sharing (UNOS). We also explored recalibrating and updating the model. METHODS: In total, 776 patients who underwent elective TIPS (TIPS cohort) and 445 unselected patients (non-TIPS cohort) were included. Three, 6 and 12-month mortality predictions were calculated by the 3 MELD versions: discrimination was assessed by c-statistics and calibration by comparing deciles of predicted and observed risks. Cox and Fine and Grey models were used for recalibration and prognostic analyses. RESULTS: In the TIPS/non-TIPS cohorts, the etiology of liver disease was viral in 402/188, alcoholic in 185/130, and non-alcoholic steatohepatitis in 65/33; mean follow-up±SD was 25±9/19±21 months; and the number of deaths at 3-6-12 months was 57-102-142/31-47-99, respectively. C-statistics ranged from 0.66 to 0.72 in TIPS and 0.66 to 0.76 in non-TIPS cohorts across prediction times and scores. A post hoc analysis revealed worse c-statistics in non-viral cirrhosis with more pronounced and significant worsening in the non-TIPS cohort. Calibration was acceptable with MELD-TIPS but largely unsatisfactory with MELD-Mayo and -UNOS whose performance improved much after recalibration. A prognostic analysis showed that age, albumin, and TIPS indication might be used to update the MELD. CONCLUSIONS: In this validation study, the performance of the MELD score was largely unsatisfactory, particularly in non-viral cirrhosis. MELD recalibration and candidate variables for an update to the MELD score are proposed. LAY SUMMARY: While the discriminative performance of the model for end-stage liver disease (MELD) score is credited to be fair to good, its calibration, the correspondence of observed to predicted mortality, is still unsettled. We found that application of 3 different versions of the MELD in 2 independent cirrhosis cohorts yielded largely imprecise mortality predictions particularly in non-viral cirrhosis. Thus, we propose a recalibration and suggest candidate variables for an update to the model.

2020 position statement and recommendations of the European Liver and Intestine Transplantation Association (ELITA): management of hepatitis B virus-related infection before and after liver transplantation.

BACKGROUND: Prophylaxis of HBV recurrence is critical after liver transplantation in HBV patients. Despite new prophylactic schemes, most European LT centres persist on a conservative approach combining hepatitis B immunoglobulin (HBIG) and nucleos(t)ides analogues (NA). AIM: This setting prompted the European Liver Intestine Transplantation Association (ELITA) to look for a consensus on the prevention of HBV recurrence. METHODS: Based on a 4-round Delphi process, ELITA investigated 16 research questions and established 50 recommendations. RESULTS: Prophylaxis should be driven according to 3 simplified risk groups: Low and high virological risk patients, with undetectable and detectable HBV DNA pre-LT, respectively, and special populations (HDV, HCC, poorly adherent patients). In low-risk patients, short-term (4 weeks) combination of third-generation NA+ HBIG, or third generation NA monotherapy can be considered as prophylactic options. In high-risk patients, HBIG can be discontinued once HBV DNA undetectable. Combined therapy for 1 year is advised. HBV-HCC patients should be treated according to their virological risk. In HDV/HBV patients, indefinite dual prophylaxis remains the gold standard. Full withdrawal of HBV prophylaxis following or not HBV vaccination should only be attempted in the setting of clinical trials. Organs from HBsAg+ve donors may be considered after assessment of risks, benefits, and patient consent. They should not be used if HDV is present. In poorly adherent patients, dual long-term prophylaxis is recommended. Budget impact analysis should be taken into account to drive prophylactic regimen. CONCLUSIONS: These ELITA recommendations should stimulate a more rational and homogeneous approach to HBV prophylaxis across LT programs.

Nutritional Properties of Rice Varieties Commonly Consumed in Italy and Applicability in Gluten Free Diet.

Gluten-free diets are often characterized by an inadequate intake of nutrients and are generally monotonous for the limited number of products celiac patients can use. As rice is the most used cereal by celiac consumers, studying rice varieties nutritional characteristics is of interest to manage diet quality and variety. Proteins, total carbohydrates and amylose content of six rice varieties (Ribe, Vialone Nano, Carnaroli, Arborio, Basmati, and Fragrance) were analyzed. Analyses were performed in raw products and after boiling, stewing, and microwaving. A decrease of proteins and total carbohydrates amount was observed in cooked rice. The same was reported for amylose content with boiling showing the highest loss (average retained amylose 53%). Considering amylose percentage with respect to total carbohydrates, each variety showed either an increase or a decrease depending on cooking method. The highest values were obtained with stewing above all for Basmati rice and Arborio rice. However, exceptions can be underlined as Carnaroli rice, showing the highest percentage when boiled. In this context, nutritional characteristics of cooked rice varieties appear to be of great importance to increase specific nutritional knowledge to better manage gluten-free diets.

COVID-19 in liver transplant candidates: pretransplant and post-transplant outcomes - an ELITA/ELTR multicentre cohort study.

OBJECTIVE: Explore the impact of COVID-19 on patients on the waiting list for liver transplantation (LT) and on their post-LT course. DESIGN: Data from consecutive adult LT candidates with COVID-19 were collected across Europe in a dedicated registry and were analysed. RESULTS: From 21 February to 20 November 2020, 136 adult cases with laboratory-confirmed SARS-CoV-2 infection from 33 centres in 11 European countries were collected, with 113 having COVID-19. Thirty-seven (37/113, 32.7%) patients died after a median of 18 (10-30) days, with respiratory failure being the major cause (33/37, 89.2%). The 60-day mortality risk did not significantly change between first (35.3%, 95% CI 23.9% to 50.0%) and second (26.0%, 95% CI 16.2% to 40.2%) waves. Multivariable Cox regression analysis showed Laboratory Model for End-stage Liver Disease (Lab-MELD) score of ≥15 (Model for End-stage Liver Disease (MELD) score 15-19, HR 5.46, 95% CI 1.81 to 16.50; MELD score≥20, HR 5.24, 95% CI 1.77 to 15.55) and dyspnoea on presentation (HR 3.89, 95% CI 2.02 to 7.51) being the two negative independent factors for mortality. Twenty-six patients underwent an LT after a median time of 78.5 (IQR 44-102) days, and 25 (96%) were alive after a median follow-up of 118 days (IQR 31-170). CONCLUSIONS: Increased mortality in LT candidates with COVID-19 (32.7%), reaching 45% in those with decompensated cirrhosis (DC) and Lab-MELD score of ≥15, was observed, with no significant difference between first and second waves of the pandemic. Respiratory failure was the major cause of death. The dismal prognosis of patients with DC supports the adoption of strict preventative measures and the urgent testing of vaccination efficacy in this population. Prior SARS-CoV-2 symptomatic infection did not affect early post-transplant survival (96%).