Monitoring strategy of COVID-19 vaccination in dialysis patients based on a multiplex immunodot method: The CovidDial study.

INTRODUCTION: COVID-19 vaccine was demonstrated to be effective in dialysis patients, but boosters are mandatory due to a rapid waning of anti-spike antibodies. A vaccination strategy based on immunologic response might be useful to maintain a favorable risk-benefit balance in this vulnerable population. METHODS: CoviDial is an observational prospective study enrolling 121 dialysis patients to receive a 3-dose mRNA-1273 vaccine according to a uniform schedule. At baseline, months 1, 3, 6, 9, and 12, anti-spike antibodies against four epitopes (S1, S2, ECD-S1 + S2, RBD) were monitored with a multiplex immunodot enzymatic assay. Potential correlation between initial serologic response and subsequent COVID-19 infection was then assessed. RESULTS: Overall, 96.2% and 96.8% of patients had anti-RBD antibodies at 3 and 12 months, respectively. All antibodies titers significantly decreased at month 6 compared to month 3. Booster vaccine induced a robust serologic response at month 9, but with a waning 3 months later, particularly for anti-S2 (37.2 ± 3.3 vs. 61.3 ± 3.0, p < 0.0001) and anti-S1 + S2 antibodies (68.4 ± 3.3 vs. 88.4 ± 2.3, p = 0.0015). Fifteen patients were later tested positive for SARS-CoV-2. At month 3, mean titers of anti-RBD, anti-S1 + S2, and anti-S2 antibodies were lower in the subsequent SARS-CoV-2 infected cohort (71.57 ± 9.01 vs. 85.79 ± 2.61, p = 0.0131; 41.07 ± 7.96 vs. 61.68 ± 3.56, p = 0.0237; 13.79 ± 5.03 vs. 39.70 ± 3.86, p = 0.0096; respectively). CONCLUSION: Three doses of mRNA-1273 vaccine induce a robust but time-limited immunologic response in dialysis patients. Lower anti-spike antibodies titers after initial vaccination are associated with a higher risk to subsequently contract SARS-CoV-2, even beyond 6 months.

Forty years of peritoneal dialysis Listeria peritonitis: Case and review.

Infections with Listeria monocytogenes (LM) are very uncommon and severe especially in immunocompromised people. We report a continuous cycling peritoneal dialysis (CCPD) patient who presented initially disseminated listeriosis with peritonitis. He was successfully treated with intraperitoneal and intravenous ampicillin but died unfortunately from a cardiorespiratory arrest due to food inhalation. It is the 20th case of such peritonitis mentioned among PD patients and the first reported in Belgium. This case illustrates the importance of a systematic approach to get quick diagnosis and effective antibiotic readjustment. Empiric therapy is not effective on Listeria which is naturally resistant to cephalosporins and poorly sensitive to vancomycin. Ampicillin is the first-line antibiotic. In case of penicillin allergy, trimethoprim-sulfamethoxazole or erythromycin can be used successfully. Identification of LM serotype has a prognostic value. PD educative programmes should recommend to avoid unpasteurized dairy products to prevent listeriosis.