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.

Morbidity and mortality of sickle cell disease patients starting intermittent haemodialysis: a comparative cohort study with non- Sickle dialysis patients.

We performed a retrospective study to assess the changes in clinical, biological and heart echocardiographic parameters in 32 sickle cell disease (SCD) patients beginning haemodialysis. Acute SCD-related complications were similar at 6 months before and 6 months after the initiation of haemodialysis. Median haemoglobin level did not change significantly, but the need for blood transfusions increased (P < 0·001). The 5-year incidence of death was higher in SCD patients (P < 0·0001). The 5-year likelihood of receiving a renal graft was lower in SCD patients (P = 0·022). Our findings suggest that SCD patients have poorer survival and a lower likelihood of receiving a renal graft.

Paradoxical embolism following thromboaspiration of an arteriovenous fistula thrombosis: a case report.

INTRODUCTION: Paradoxical embolism is an increasingly reported cause of arterial embolism. Several embolic sources have been described, but thrombosis of an arteriovenous fistula as a paradoxical emboligenic source has not, to the best of our knowledge, been reported. CASE PRESENTATION: A 50-year-old Caucasian woman received a renal graft for primary hyperoxaluria. After transplantation, she was maintained on daily hemodialysis. Thrombosis of her arteriovenous fistula occurred two weeks post-transplantation and was treated by thromboaspiration, which was partially successful. During a hemodialysis session immediately following thromboaspiration, she developed a coma with tetraplegia requiring intensive cardiorespiratory resuscitation. Brain magnetic resonance imaging revealed various hyperdense areas in the vertebrobasilar territory resulting from bilateral occlusion of posterior cerebral arteries. Transesophageal echocardiographic examination showed a patent foramen ovale, while pulse echography of the arteriovenous fistula revealed the persistence of extensive clots that were probably the embolic source. A paradoxical embolus through a patent foramen ovale was suggested because of the proximity of the neurological event to the thrombectomy procedure. CONCLUSIONS: The risk of paradoxical embolism in a hemodialyzed patient with a patent foramen ovale deserves consideration and requires careful evaluation in situations of arteriovenous fistula thrombosis.