Evaluation of the Kinetics of Antibody Response to COVID-19 Vaccine in Solid Organ Transplant Recipients: The Prospective Multicenter ORCHESTRA Cohort

Previous studies assessing the antibody response (AbR) to mRNA COVID-19 vaccines in solid organ transplant (SOT) recipients are limited by short follow-up, hampering the analysis of AbR kinetics. We present the ORCHESTRA SOT recipients cohort assessed for AbR at first dose (t0), second dose (t1), and within 3 ± 1 month (t2) after the first dose. We analyzed 1062 SOT patients (kidney, 63.7%; liver, 17.4%; heart, 16.7%; and lung, 2.5%) and 5045 health care workers (HCWs). The AbR rates in the SOTs and HCWs were 52.3% and 99.4%. The antibody levels were significantly higher in the HCWs than in the SOTs (p < 0.001). The kinetics showed an increase (p < 0.001) in antibody levels up to 76 days and a non-significant decrease after 118 days in the SOT recipients versus a decrease up to 76 days (p = 0.02) and a less pronounced decrease between 76 and 118 days (p = 0.04) in the HCWs. Upon multivariable analysis, liver transplant, ≥3 years from SOT, mRNA-1273, azathioprine, and longer time from t0 were associated with a positive AbR at t2. Older age, other comorbidities, mycophenolate, steroids, and impaired graft function were associated with lower AbR probability. Our results may be useful to optimize strategies of immune monitoring after COVID-19 vaccination and indications regarding timing for booster dosages calibrated on SOT patients’ characteristics.The ORCHESTRA project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 101016167Peer reviewe

Using machine learning to predict antibody response to SARS-CoV-2 vaccination in solid organ transplant recipients: the multicentre ORCHESTRA cohort

Objectives: Study aim is to assess predictors of negative antibody response (AbR) in solid organ transplant (SOT) recipients after the first booster of SARS-CoV-2 vaccination. Methods: SOT recipients receiving SARS-CoV-2 vaccination were prospectively enrolled (March 2021-January 2022) at six hospitals in Italy and Spain. AbR was assessed at first dose (t0), second dose (t1), 3±1&nbsp;month (t2), and 1&nbsp;month after third dose (t3). Negative AbR at t3 was defined as anti-receptor binding domain titre &lt;45 BAU/mL. Machine Learning models were developed to predict the individual risk of negative (vs. positive) AbR using as covariates age, type of transplant, time between transplant and vaccination, immunosuppressive drugs, type of vaccine, and graft function, and subsequently assessed using a validation cohort. Results: Overall, 1615 SOT recipients (1072 [66.3%] males, mean±standard deviation (SD) age 57.85±13.77) were enrolled and 1211 received three vaccination doses. Negative AbR rate decreased from (886/946) 93.66% to (202/923) 21.90% from t0 to t3. Univariate analysis showed that older patients (mean age 60.21±11.51 vs. 58.11±13.08), anti-metabolites (57.9% vs. 35.1%) steroids (52.9% vs. 38.5%), recent transplantation (&lt;3&nbsp;years) (17.8% vs. 2.3%), and kidney, heart, or lung compared to liver transplantation (25%, 31.8%, 30.4% vs. 5.5%) had a higher likelihood of negative AbR. Machine learning algorithms showing best prediction performance were logistic regression (precision recall curve-PRAUC mean 0.37 [95%CI 0.36-0.39]) and k-Nearest Neighbors (PRAUC 0.36 [0.35-0.37]). Conclusions: Almost a quarter of SOT recipients showed negative AbR after first booster dosage. Unfortunately, clinical information cannot efficiently predict negative AbR even with ML algorithms

Evaluation of the kinetics of antibody response to COVID-19 vaccine in solid organ transplant recipients: the prospective, multicentre ORCHESTRA cohort

Previous studies assessing the antibody response (AbR) to mRNA COVID-19 vaccines in solid organ transplant (SOT) recipients are limited by short follow-up, hampering the analysis of AbR kinetics. We present the ORCHESTRA SOT recipients cohort assessed for AbR at first dose (t0), second dose (t1), and within 3 ± 1 month (t2) after the first dose. We analyzed 1062 SOT patients (kidney, 63.7%; liver, 17.4%; heart, 16.7%; and lung, 2.5%) and 5045 health care workers (HCWs). The AbR rates in the SOTs and HCWs were 52.3% and 99.4%. The antibody levels were significantly higher in the HCWs than in the SOTs (p &lt; 0.001). The kinetics showed an increase (p &lt; 0.001) in antibody levels up to 76 days and a non-significant decrease after 118 days in the SOT recipients versus a decrease up to 76 days (p = 0.02) and a less pronounced decrease between 76 and 118 days (p = 0.04) in the HCWs. Upon multivariable analysis, liver transplant, ≥3 years from SOT, mRNA-1273, azathioprine, and longer time from t0 were associated with a positive AbR at t2. Older age, other comorbidities, mycophenolate, steroids, and impaired graft function were associated with lower AbR probability. Our results may be useful to optimize strategies of immune monitoring after COVID-19 vaccination and indications regarding timing for booster dosages calibrated on SOT patients’ characteristic

The Italian compassionate use of sofosbuvir in HCV patients waitlisted for liver transplantation: A national real-life experience

Background &amp; Aims: This study aimed to assess the real-life clinical and virological outcomes of HCV waitlisted patients for liver transplantation (LT) who received sofosbuvir/ribavirin (SOF/R) within the Italian compassionate use program. Methods: Clinical and virological data were collected in 224 patients with decompensated cirrhosis and/or hepatocellular carcinoma (HCC) receiving daily SOF/R until LT or up a maximum of 48&nbsp;weeks. Results: Of 100 transplanted patients, 51 were HCV-RNA negative for &gt;4&nbsp;weeks before LT (SVR12: 88%) and 49 negative for &lt;4&nbsp;weeks or still viraemic at transplant: 34 patients continued treatment after LT (bridging therapy) (SVR12: 88%), while 15 stopped treatment (SVR12: 53%). 98 patients completed SOF/R without LT (SVR12: 73%). In patients with advanced decompensated cirrhosis (basal MELD 6515 and/or C-P 65B8), a marked improvement of the scores occurred in about 50% of cases and almost 20% of decompensated patients without HCC reached a condition suitable for inactivation and delisting. Conclusions: These real-life data indicate that in waitlisted patients: (i) bridging antiviral therapy can be an option for patients still viraemic or negative &lt;4&nbsp;weeks at LT; and (ii) clinical improvement to a condition suitable for delisting can occur even in patients with advanced decompensated cirrhosis

Evaluation of the Kinetics of Antibody Response to {COVID}-19 Vaccine in Solid Organ Transplant Recipients: The Prospective Multicenter {ORCHESTRA} Cohort

Previous studies assessing the antibody response (AbR) to mRNA COVID-19 vaccines in solid organ transplant (SOT) recipients are limited by short follow-up, hampering the analysis of AbR kinetics. We present the ORCHESTRA SOT recipients cohort assessed for AbR at first dose (t0), second dose (t1), and within 3   1 month (t2) after the first dose. We analyzed 1062 SOT patients (kidney, 63.7%; liver, 17.4%; heart, 16.7%; and lung, 2.5%) and 5045 health care workers (HCWs). The AbR rates in the SOTs and HCWs were 52.3% and 99.4%. The antibody levels were significantly higher in the HCWs than in the SOTs (p &lt; 0.001). The kinetics showed an increase (p &lt; 0.001) in antibody levels up to 76 days and a non-significant decrease after 118 days in the SOT recipients versus a decrease up to 76 days (p = 0.02) and a less pronounced decrease between 76 and 118 days (p = 0.04) in the HCWs. Upon multivariable analysis, liver transplant,  3 years from SOT, mRNA-1273, azathioprine, and longer time from t0 were associated with a positive AbR at t2. Older age, other comorbidities, mycophenolate, steroids, and impaired graft function were associated with lower AbR probability. Our results may be useful to optimize strategies of immune monitoring after COVID-19 vaccination and indications regarding timing for booster dosages calibrated on SOT patients’ characteristic