SARS-CoV-2 Vaccination in Kidney Transplant Recipients-Stratified Analysis of the Humoral Immune Response.

Kidney transplant recipients are at increased risk of SARS-CoV-2 infection and a more severe course of COVID-19. Methods: We conducted a quantitative serologic testing of antibodies specific for the wild type of SARS-CoV-2 and the Omicron variant of concern before and after a third-dose vaccination, either mRNA-1273 (Moderna) or BNT162b2 (Pfizer-BioNTech) in a cohort of 103 stable kidney transplant recipients (median [range] age, 58 [22-84] y, 57 men [55.3%]). Results: Third-dose vaccination increased the seroconversion rate from 57.3% to 71.8%. However, despite a marked rise of the antibody concentrations after the booster, 55.4% and 11.6% only formed neutralizing antibodies against the SARS-CoV-2 wild type and Omicron, respectively. Treatment with mycophenolic acid/mycophenolate mofetil (in strata of the dose quartiles), advanced age, and' above all' impaired renal function (eGFR <60 mL/min) adversely influenced the humoral immunity regarding seroconversion and inhibition of the wild type of SARS-CoV-2. Conclusions: Apart from immunosuppressive therapy, the humoral vaccination response is largely affected by nonmodifiable factors in kidney transplant recipients. With the currently leading and clinically easier Omicron variant, this puts into perspective the strategy to significantly enhance the protective efficacy of the available vaccines by reducing or temporarily stopping proliferation inhibitors, not least considering the inherent rejection risk with a possible deterioration of graft function.

Heterologous immunization with BNT162b2 followed by mRNA-1273 in dialysis patients: seroconversion and presence of neutralizing antibodies.

INTRODUCTION: The vital renal replacement therapy makes it impossible for dialysis patients to distance themselves socially. This results in a high risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and developing coronavuris disease 2019, with excess mortality due to disease burden and immunosuppression. We determined the efficacy of a 100-µg booster of mRNA-1273 (Moderna, Cambridge, MA, USA) 6 months after two doses of BNT162b2 (BioNTech/Pfizer, Mainz, Germany/New York, USA) in 194 SARS-CoV-2-naïve dialysis patients. METHODS: Anti-SARS-CoV-2 spike antibodies were measured with the Elecsys Anti-SARS-CoV-2 S assay (Roche Diagnostics, Mannheim, Germany) 4 and 10-12 weeks after two doses of BNT162b2 as well as 4 weeks after the mRNA-1273 booster. The presence of neutralizing antibodies was measured by the SARS-CoV-2 Surrogate Virus Neutralization Test (GenScript Biotech, Piscataway, NJ, USA). Two different cut-offs for positivity were used, one according to the manufacturer's specifications and one correlating with positivity in a plaque reduction neutralization test (PRNT). Receiver operating characteristics analyses were performed to match the anti-SARS-CoV-2 spike antibody cut-offs with the cut-offs in the surrogate neutralization assay accordingly. RESULTS: Any level of immunoreactivity determined by the anti-SARS-CoV-2 spike antibody assay was found in 87.3% (n = 144/165) and 90.6% (n = 164/181) of patients 4 and 10-12 weeks, respectively, after two doses of BNT162b2. This was reduced to 68.5% or 60.6% 4 weeks and 51.7% or 35.4% 10-12 weeks, respectively, when using the ROC cut-offs for neutralizing antibodies in the surrogate neutralization test (manufacturer's cut-off ≥103 U/mL and cut-off correlating with PRNT ≥196 U/mL). Four weeks after the mRNA-1273 booster, the concentration of anti-SARS-CoV-2 spike antibodies increased to 23 119.9 U/mL and to 97.3% for both cut-offs of neutralizing antibodies. CONCLUSION: Two doses of BNT162b2 followed by one dose of mRNA-1273 within 6 months in patients receiving maintenance dialysis resulted in significant titres of SARS-CoV-2 spike antibodies. While two doses of mRNA vaccine achieved adequate humoral immunity in a minority, the third vaccination boosts the development of virus-neutralizing quantities of SARS-CoV-2 spike antibodies (against wild-type SARS-CoV-2) in almost all patients.

Acute effects of calcineurin inhibitors on kidney allograft microperfusion visualized by contrast-enhanced sonography.

BACKGROUND: Calcineurin inhibitors induce detrimental vascular remodeling, which may be one cause of chronic allograft failure. Real-time contrast-enhanced sonography (CES) is a relatively new technique in providing quantitative information on microvascular tissue perfusion in kidney allografts in more detail. The purpose of the study was to explore whether acute changes of kidney allograft microperfusion due to the administration of cyclosporine A (CsA) and tacrolimus (Tac) can be evidenced using real-time CES. METHODS: In an explorative single-center clinical trial, renal parenchymal tissue perfusion of 32 stable kidney allograft recipients was evaluated with CES before and 2 hr after the intake of CsA or Tac. In addition to laboratory and clinical parameters, Doppler indices and estimated glomerular filtration rate were measured. RESULTS: Although systolic and diastolic blood pressure and color Doppler indices did not significantly differ, there was a significant decrease of renal blood flow 2 hr after the intake of CsA compared with baseline (4.78±2.31 dB/s, 49%, respectively). In contrast, kidney allograft microperfusion was neither significantly reduced in patients receiving CsA paralleled by calcium channel blockers nor significantly reduced in patients receiving Tac. Furthermore, there was a significant correlation between renal blood flow obtained before drug administration and kidney function. CONCLUSIONS: CES revealed a 49% reduction of kidney allograft microperfusion 2 hr after the intake of CsA, which might be abrogated by calcium channel blockers. In comparison to CsA, Tac did not result in a significant decrease of kidney blood flow.

Value of functional capacity evaluation information in a clinical setting for predicting return to work.

OBJECTIVE: To evaluate the quality of Functional Capacity Evaluation (FCE) information in predicting return to work (RTW). DESIGN: Prospective cohort study. SETTING: Inpatient rehabilitation clinic. PARTICIPANTS: Patients (N=220) with chronic musculoskeletal disorders (MSD) conducting a medical rehabilitation. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patients filled in questionnaires at admission and 1-year follow-up. An FCE was performed on admission. RTW was defined as a combination of employment at 1-year follow-up with a maximum of 6 weeks sick leave because of MSD in the postrehabilitation year. As predictive FCE information, the physical capacity (Dictionary of Occupational Titles categories 1-5), the number of test results not meeting work demands (0-25), and the tester's recommendation of work ability in the actual job (> or =6h/d) were analyzed. Logistic regression models (crude and adjusted for the concurrent predictors employment, preadmission sick leave, and patient's prognosis of RTW) were created to predict RTW. RESULTS: Complete data were obtained for 145 patients. The sample showed a non-RTW at 1-year follow-up for 37.9%. All FCE information showed significant relations to RTW (r=.28-.43; P<.05). In the crude as well as in the adjusted regression models, all FCE information predicted RTW, but the models' quality was low. The integration of FCE information led to an increase of 5%. The predictive efficiency was poor. The adjusted model for failed tests showed a substantial improvement compared with the reference model (concurrent predictors only). CONCLUSIONS: There was a significant relation between FCE information and RTW with and without concurrent predictors, but the predictive efficiency is poor. Primarily, the number of failed tests seemed to be of significance for patients with ambiguous RTW prognosis. A first proposal for a prediction rule was discussed.