Minimization of immunosuppression and administration of antiretrovirals have been recommended for kidney transplant recipients (KTRs) with coronavirus disease 2019 (COVID‐19). However, outcomes remain poor. Given the likely benefit of cyclosporine because of its antiviral and immunomodulatory effect, we have been using it as a strategy in KTRs diagnosed with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). We studied 29 kidney transplant recipients (KTRs) who were admitted to our institution with COVID‐19 between March 15and April, 24, 2020. Mycophenolate and/or mammalian target of rapamycin inhibitors (mTORi) were discontinued in all patients. Two therapeutic strategies were compared: Group 1, minimization of calcineurin inhibitors (N = 6); and Group 2, cyclosporine‐based therapy (N = 23), with 15 patients switched from tacrolimus. Hydroxychloroquine was considered in both strategies but antivirals in none. Six patients died after respiratory distress (20.6%). Five required mechanical ventilation (17.2%), and 3 could be weaned. Nineteen patients had an uneventful recovery (65.5%). In group 1, 3 of 6 patients died (50%) and 1 of 6 required invasive mechanical ventilation (16.7%). In group 2, 3 of 23 patients died (12.5%). Renal function did not deteriorate and signs of rejection were not observed in any patient on the second treatment regime. In conclusion, immunosuppressant treatment based on cyclosporine could be safe and effective for KTRs diagnosed with COVID‐19.

We investigated the impact of acute kidney failure after a heart valve procedure among patients with or without chronic kidney disease (CKD). All patients who had undergone a surgical valve procedure between 2005 and 2017 at our institution were divided into 2 groups depending on whether they had previous history of CKD (estimated glomerular filtration rate <60 ml/min/1.73 m2) or not. Homogeneous groups were obtained by propensity score matching. Long-term mortality was compared between the 2 groups and according to the occurrence of postoperative acute kidney failure. Level of significance was set at P-value <0.008 for multiple comparison tests. From the 3907 patients included to this study, 1476 (37.78%) had previous history of CKD. After adjusting for propensity score 1:1, patients with preoperative impaired renal function were at a higher risk of acute kidney failure (26.83% vs 10.16%, P < 0.001) and postoperative mortality (8.48% vs 5.17%, P = 0.001). In the follow-up, they had a poorer survival at 1, 5 and 10 years as compared to patients with normal renal function (88% vs 91.95%, 78.29% vs 81.11% and 56.13% vs 66.29%, respectively; P < 0.001). Patients without postoperative kidney failure had similar survival whether they had preoperative CKD or not [hazard ratio (HR) 1.16, 99.2% confidence interval (CI) 0.87-2.52; P = 0.142]. As compared to patients with postoperative preserved renal function, those with postoperative kidney failure had a higher long-term mortality either if they had previous kidney disease or not [(HR 2.18, 99.2% CI 1.75-2.72; P < 0.001) and (HR 1.48, 99.2% CI 1.33-1.65; P < 0.001), respectively]. Preoperative CKD was the strongest predictor of acute kidney failure (odds ratio 4.45; 95% CI 3.59-5.53; P < 0.001). Patients with CKD are at higher risk of postoperative adverse events and have poorer long-term outcomes. Postoperative acute kidney failure increases long-term mortality.

Background.: Few studies have described the clinical impact of anti–severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in renal transplant recipients (RTRs) in the context of omicron variant and the third vaccine dose. Antibody titer has been tried to relate to the prediction of outcomes related to SARS-CoV-2, but it results controversially in these populations. Methods.: All patients with positive SARS-CoV-2 polymerase chain reaction followed at a RTRs reference center from March 15, 2020, to March 15, 2022, were considered for analysis. Cases were analyzed by vaccination status. Breakthrough cases were then analyzed by nonantibodies (100 AU/mL) against SARS-CoV-2 spike protein. Outcomes included pneumonia and mortality. We used logistic regression multivariable to assess for confounders. Results.: Among 186 RTRs with coronavirus disease 2019, 50.5% (n = 94) were vaccinated versus 49.5% (n = 92) unvaccinated. Of the vaccinated patients, 67.02% developed a high antibody titer (>100 AU/mL) but 14.89% achieved a low antibody titer and 18.08%. Pneumonia-free survival (day 20) was 95% in high antibody titer but 40% in unvaccinated RTRs. Survival in RTRs at day 60 was similar in the unvaccinated group compared with nonantibodies breakthrough cases (82%) but 92% in the low antibody titer group (relative risk, 0.027; 95% confidence interval, 0.002-0.479; P = 0.014). Only patients with >100 AU/mL showed a 100% survival on day 60 postinfection. Conclusions.: Vaccinated RTRs who achieve at least a low antibody titer (>20 AU/mL) had better results in terms of pneumonia and mortality than unvaccinated RTRs. Antibody titer >100 AU/mL associate with even better results than patients with lower antibody titers.

Background: IgG4 is the least immunogenic subclass of IgG. Immunization with mRNA vaccines against SARS-CoV-2, unlike other vaccines, induces an increase in IgG4 against the spike protein in healthy populations. This study investigated whether immunosuppressive therapy affects the immune response, focusing on IgG subclass changes, to four doses of mRNA vaccine in kidney transplant recipients (KTRs). Methods: This study includes 146 KTRs and 23 dialysis patients (DPs) who received three mRNA-1273 vaccine doses and a BNT162b2 booster. We evaluated anti-spike IgG titers and subclasses, T-CD4+ and T-CD8+ cellular responses, and serum neutralizing activity (SNA). Results: At the fourth dose, 75.8% of COVID-19 naïve KTRs developed humoral and cellular responses (vs. 95.7% in DPs). There was a correlation between anti-spike IgG titers/subclasses and SNA (p < 0.001). IgG subclass kinetics after the third/fourth dose differed between COVID-19 naïve KTRs and DPs. Immunosuppressive therapy influenced IgG subclasses: mTOR inhibitors (mTORi) positively influenced IgG1 and IgG3 (p < 0.05), while mycophenolic acid negatively affected IgG1, IgG3, and IgG4 (p < 0.05). SNA is correlated with breakthrough infections after four doses of vaccine in KTRs. mTORi was the only factor associated with SNA > 65% in naïve KTRs [4.29 (1.21–15.17), p = 0.024]. Conclusions: KTRs show weaker cellular and humoral immune responses to mRNA vaccines and a class shift towards non-inflammatory anti-S IgG4 upon booster doses. IgG subclasses show a positive correlation with SNA and are influenced by immunosuppression. Increased SNA after four doses of vaccine is protective against infection. mTORi may benefit non-responding KTRs.