Humoral Response after SARS-CoV-2 mRNA Vaccination in a Cohort of Hemodialysis Patients and Kidney Transplant Recipients.

BACKGROUND: Kidney transplant recipients and patients receiving hemodialysis are immunocompromised populations that are prioritized for COVID-19 vaccination but were excluded from clinical trials of SARS-CoV-2 mRNA vaccines. Antibody titers and rates of seroconversion after vaccination are lower among patients with CKD and those taking immunosuppressants compared with controls. Data are lacking regarding their humoral response to vaccination to prevent COVID-19. METHODS: This investigation of early serological response after COVID-19 vaccination with the Pfizer/BioNTech (BNT162b2) mRNA vaccine included 78 patients undergoing hemodialysis, 74 kidney transplant recipients, and seven healthy controls. We recorded data from the medical file for various clinical parameters, including response to hepatitis B vaccination, and measured antibody titers against SARS-CoV-2 at 0, 14, 28, 36, and 58 days after the first injection. RESULTS: In controls, we detected antibodies at a positive level (>13 arbitrary units per ml; AU/ml) at day 14 postinjection, which increased progressively to peak at day 36 (1082 AU/ml; interquartile range [IQR], 735.0-1662.0). Patients undergoing hemodialysis had lower titers that peaked at day 58 (276 AU/ml; IQR, 83.4-526.0). We detected a positive antibody level in only three transplant recipients at day 36. In patients on hemodialysis, those aged <75 years had a higher antibody response versus those aged >75 years, and serum albumin and Kt/V were positively correlated with serological response (P<0.04 and P<0.0, respectively); nonresponders to HBV vaccine had the lowest anti-SARS-CoV-2 antibody titers. CONCLUSIONS: Our results suggest that the postvaccination humoral response is strongly inhibited by immunosuppressant therapy in kidney transplant recipients, and is reduced by the uremic condition in patients undergoing hemodialysis.

How to handle missed or delayed doses of tacrolimus in renal transplant recipients? A pharmacokinetic investigation.

Every transplant patient will, at least occasionally, miss immunosuppressive drug doses or take them outside the prescribed times. This study aims at quantifying the impact of poor execution on tacrolimus exposure in renal transplant patients. Validated pharmacokinetic tools applied in clinical setting were used to simulate the steady-state pharmacokinetic profiles of the drug when given as the immediate-release formulation to renal transplant patients, being CYP3A5 expressors or not, and who have reached either a standard or a minimized exposure. Situations of interruption due to a missed or delayed dose were simulated and the impact on drug exposure was explored. In case of a missed dose, it was observed that: (i) a single forgotten dose can greatly impact exposure: up to 49% decrease for tacrolimus trough concentration and 70% for AUC0-12 h in patients with the highest clearance values; (ii) patients with a minimized exposure are the most affected by a missed dose; and (iii) a dose of 1.5 times the usual dose may be recommended after a total dose oversight. Considering that intra-patient exposure variability is a predictive factor of poor graft outcome, these modeling results may serve as recommendations for patients, both preventively and in response to their questions.

The clinical status and survival in elderly dialysis: example of the oldest region of France.

BACKGROUND: The number of elderly (≥75 years) patients with end-stage renal disease (ESRD) has increased markedly, including in the Limousin region, which has the oldest population in France. We retrospectively compared outcomes in elderly and non-elderly ESRD patients who started dialysis during two time periods. METHODS: Baseline clinical characteristics, care, and survival rates were assessed in 557 ESRD patients aged ≥75 and <75 years who started dialysis in 2002-2004 and 2005-2007. Survival curves and Cox proportional hazards model were used to assess survival and factors associated with survival. RESULTS: Of the 557 patients, 343 and 214 were <75 years and ≥75 years, respectively. Dialysis was started in 2002-2004 and 2005-2007 by 197 and 146 patients <75 years, respectively, and by 96 and 118 patients ≥75 years, respectively. Median age (73.4 years [interquartile range [IQR] 61.7-79.5 years] vs 69.5 years [IQR 57.4-77.4 years] p = 0.001) and the proportion aged ≥75 years (44.7% vs 32.8%, p = 0.004) were significantly higher in 2005-2007 than in 2002-2004. Improved initial status during 2005-2007 was observed only in patients ≥75 years, with a decrease in some co-morbidities, improved walking and better preparation for dialysis. Mortality rates were significantly lower in 2005-2007 than in 2002-2004 (hazard ratio 0.81, 95% confidence interval 0.69-0.95; p = 0.008), with the difference due to factors associated with clinical status and care. CONCLUSIONS: Improved initial clinical status and better preparation for dialysis, accompanied by increased survival, were observed for patients ≥75 years who started dialysis more recently, perhaps because of early referral to a nephrologist.

Severe sirolimus-induced acute hepatitis in a renal transplant recipient.

Sirolimus is currently used as an immunosuppressive agent in kidney transplantation due to its lack of nephrotoxicity and antiproliferative properties. However, a large number of side effects has been described with the use of m-Tor inhibitors. Most are reversible when treatment is withdrawn. Hepatotoxicity is one of these side effects, considered as a benign condition and resulting generally in a transitory and small increase in transaminase levels. We report here, to the best of our knowledge, the first case of severe sirolimus-induced acute hepatitis confirmed by liver biopsy, in a renal transplant recipient. This condition was completely cured in few weeks after sirolimus withdrawal.