Objectives We aimed to evaluate rates of antibody response to mRNA SARS-CoV-2 vaccine among kidney transplant recipients, and to identify factors associated with reduced immunogenicity. Methods A prospective cohort study including consecutive kidney transplant recipients in a single referral transplant center. Participants were tested for anti-spike (anti-S) antibodies 2-4 weeks following second vaccine dose. Primary outcome was rate of seropositivity. Univariate and multivariate analyses were conducted to identify factors associated with seropositivity. Results Of 308 kidney transplant recipients included, only 112 (36.4%) tested positive for anti-S antibodies 2-4 weeks after receiving the second dose of BNT162b2 vaccine. Median antibody titer was 15.5 AU/mL (interquartile range [IQR] 3.5-163.6). Factors associated with antibody response were higher estimated glomerular filtration rate (eGFR) (odds ratio [OR] 1.025 per ml/min/1.73m 2 , 95% confidence interval [CI] 1.014 - 1.037, p<0.001), lower mycophenolic acid dose (OR 2.347 per 360 mg decrease, 95% CI 1.782 - 3.089, p<0.001), younger age (OR 1.032 per year decrease, 95% CI 1.015 - 1.05, p<0.001) and lower calcineurin inhibitors (CNI) blood level (OR 1.987, 95% CI 1.146 - 3.443, p=0.014). No serious adverse events to the vaccine were reported. Conclusions Kidney transplant recipients demonstrated inadequate antibody response to mRNA SARS-CoV-2 vaccination. Immunosuppression level was a significant factor in this response. Strategies to improve immunogenicity should be examined in future studies.

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BackgroundThe effectiveness of mechanical thrombectomy (MT) in acute ischemic stroke due to large vessel occlusion is time-dependent. While only stroke centers with endovascular capabilities perform MT, many patients who had a stroke initially present to the closest primary stroke centers capable of administering earlier intravenous thrombolysis, and then require to be transferred to a comprehensive stroke center for MT.PurposeTo compare the outcomes of this care pathway (drip and ship (DS)) with that whereby patients are directly transferred to a comprehensive stroke center (mothership (MS)).MethodsWe performed a systematic review and meta-analysis of published studies using several electronic databases to determine whether successful reperfusion (modified Thrombolysis In Cerebral Infarction ≥2b), functional independence at 90 days (modified Rankin Scale score ≤2), symptomatic intracranial hemorrhage, and 90-day mortality differed between those who underwent MT with the DS or the MS treatment pathway. Outcomes were meta-analyzed and the results expressed as adjusted relative risk (aRR) for the primary analysis and unadjusted relative risk (uRR) for secondary analysis.ResultsEight studies including 2068 patients were selected, including one study reporting results fully adjusted for baseline characteristics. Patients undergoing MS had better functional independence than those undergoing DS (uRR=0.87, 95% CI 0.81 to 0.93; aRR=0.87, 95% CI 0.77 to 0.98). No difference was found between the treatment pathways in successful reperfusion (uRR=1.05, 95% CI 0.95 to 1.15; aRR=1.00, 95% CI 0.92 to 1.10), symptomatic intracranial hemorrhage (uRR=1.37, 95% CI 0.91 to 2.06; aRR, 1.53, 95% CI 0.79 to 2.98), and 90-day mortality (uRR=1.00, 95% CI 0.84 to 1.19; aRR=1.21, 95% CI 0.89 to 1.64).ConclusionsPatients who had an acute ischemic stroke admitted directly to a comprehensive stroke center (MS patients) with endovascular capacities may have better 90-day outcomes than those receiving DS treatment. However, major limitations of current evidence (ie, retrospective studies and selection bias) suggest a need for adequately powered studies. Multicenter randomized controlled trials are expected to answer this question.