Immune Responses after a Third Dose of mRNA Vaccine Differ in Virus-Naive versus SARS-CoV-2- Recovered Dialysis Patients.

BACKGROUND AND OBJECTIVES: After two doses of mRNA vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), patients on dialysis show a defective humoral response, but a third dose could increase anti-SARS-CoV-2 spike IgG titers. Responses could be different in virus-naive and SARS-CoV-2-recovered patients on dialysis. However, characterization of memory B cell response after three doses is lacking. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We evaluated the dynamics of antireceptor binding domain IgG titers and antireceptor binding domain memory B cells until 6 months after two and three doses (administered within 6 months after the second dose) of mRNA vaccine in SARS-CoV-2-recovered and virus-naive dialysis populations. Results were analyzed by ordinary one-way ANOVA, the Kruskal-Wallis test, or the Wilcoxon matched-pairs test as appropriate. RESULTS: In total, 108 individuals (59 patients on dialysis and 49 controls) were included. In virus-naive patients on dialysis, antireceptor binding domain IgG response was quantitatively lower after two doses compared with healthy controls, but IgG titers increased by three-fold after three doses (P=0.008). In SARS-CoV-2-recovered patients on dialysis, antireceptor binding domain IgG titers after two doses were significantly higher compared with virus-naive patients on dialysis but did not significantly increase after a third dose. Regarding memory B cell response, we detected receptor binding domain-specific memory B cells at similar proportions in virus-naive patients on dialysis and vaccinated controls after two doses. Moreover, a strong receptor binding domain-specific memory B cell expansion was observed after the third dose in virus-naive patients on dialysis (5.5-fold; P<0.001). However, in SARS-CoV-2-recovered patients on dialysis, antireceptor binding domain memory B cells remained unchanged after the third dose. CONCLUSIONS: The third dose of mRNA vaccine given within 6 months after the second dose boosts serologic and memory response in virus-naive patients but not in SARS-CoV-2-recovered patients on dialysis. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: COVID-19: SARS-CoV-2 Specific Memory B and T-CD4+ Cells (MEMO-COV2), NCT04402892.

Long-term impact of COVID-19 among maintenance haemodialysis patients.

BACKGROUND: Maintenance haemodialysis (MHD) patients have a high risk of initial mortality from coronavirus disease 2019 (COVID-19). However, long-term consequences of this disease in the MHD population are poorly described. We report the clinical presentation, outcome and long-term follow-up of MHD patients affected by COVID-19 in a multicentric cohort from the Paris, France area. METHODS: We conducted a retrospective analysis of clinical presentation and long-term follow-up of MHD patients affected by COVID-19 in 19 MHD centres in the Paris, France area. RESULTS: In this cohort of 248 patients with an initial mortality rate of 18%, age, comorbidities, dyspnoea and previous immunosuppressive treatment were associated with death at <30 days. Among the 203 surviving patients following the acute phase, long-term follow-up (median 180 days) was available for 189 (93%) patients. Major adverse events occurred in 30 (16%) patients during follow-up, including 12 deaths (6%) after a median of 78 days from onset of symptoms. Overall, cardiovascular events, infections and gastrointestinal bleeding were the main major adverse events. Post-COVID-19 cachexia was observed in 25/189 (13%) patients. Lower initial albuminaemia was significantly associated with this cachexia. No reinfection with severe acute respiratory syndrome coronavirus 2 was observed. CONCLUSIONS: This work demonstrates the long-term consequences of COVID-19 in MHD patients, highlighting both initial and long-term severity of the disease, including severe cachexia.

Kinetics of Anti-SARS-CoV-2 IgG Antibodies in Hemodialysis Patients Six Months after Infection.

BACKGROUND: The humoral response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the hemodialysis population, including its dynamics over time, remains poorly understood. METHODS: To analyze initial and long-term humoral responses against SARS-CoV-2 in a hemodialysis population, we retrospectively evaluated findings from SARS-CoV-2 IgG serologic assays targeting the nucleocapsid antigen or spike antigen up to 6 months of follow-up in patients on hemodialysis in the Paris, France, region who had recovered from coronavirus disease 2019 (COVID-19). RESULTS: Our analysis included 83 patients (median age 65 years); 59 (71%) were male and 28 (34%) had presented with severe COVID-19. We observed positive initial SARS-CoV-2 IgG antinucleocapsid serology in 74 patients (89%) at a median of 67 days postdiagnosis. By multivariable analysis, immunocompromised status was the only factor significantly associated with lack of an IgG antinucleocapsid antibody response. Follow-up data were available at 6 months postdiagnosis for 60 of 74 patients (81%) with positive initial antinucleocapsid serology, and 15 (25%) of them had negative antinucleocapsid serology at month 6. In total, 14 of 15 sera were tested for antispike antibodies, 3 of 14 (21%) of which were also negative. Overall, 97% of antinucleocapsid-antibody-positive specimens were also antispike-antibody positive. Female sex, age >70 years, and nonsevere clinical presentation were independently associated with faster IgG antinucleocapsid titer decay in multivariable analysis. After adjustment for sex and age >70 years, nonsevere clinical presentation was the only factor associated with faster decay of IgG antispike antibodies. CONCLUSIONS: This study characterizes evolution of the SARS-CoV-2 antibody response in patients on hemodialysis and identifies factors that are associated with lack of seroconversion and with IgG titer decay.