Diminished Short- and Long-Term Antibody Response after SARS-CoV-2 Vaccination in Hemodialysis Patients.

Short-term studies have shown an attenuated immune response in hemodialysis patients after COVID-19-vaccination. The present study examines how antibody response is maintained after vaccination against SARS-CoV-2 in a large population of hemodialysis patients from six outpatient dialysis centers. We retrospectively assessed serum antibody levels against SARS-CoV-2 spike protein and nucleocapsid protein (electrochemiluminescence immunoassays, Roche Diagnostics) after COVID-19-vaccination in 298 hemodialysis and 103 non-dialysis patients (controls), comparing early and late antibody response. Compared to a non-dialysis cohort hemodialysis patients showed a favorable but profoundly lower early antibody response, which decreased substantially during follow-up measurement (median 6 months after vaccination). Significantly more hemodialysis patients had anti-SARS-CoV-2-S antibody titers below 100 U/mL (p < 0.001), which increased during follow-up from 23% to 45% but remained low in the control group (3% vs. 7%). In multivariate analysis, previous COVID-19 infections (p < 0.001) and female gender (p < 0.05) were significantly associated with higher early as well as late antibody vaccine response in hemodialysis patients, while there was a significant inverse correlation between patient age and systemic immunosuppression (p < 0.001). The early and late antibody responses were significantly higher in patients receiving vaccination after a SARS-CoV-2 infection compared to uninfected patients in both groups (p < 0.05). We also note that a higher titer after complete immunization positively affected late antibody response. The observation, that hemodialysis patients showed a significantly stronger decline of SARS-CoV-2 vaccination antibody titers within 6 months, compared to controls, supports the need for booster vaccinations to foster a stronger and more persistent antibody response.

Perspective on COVID-19 vaccination in patients with immune-mediated kidney diseases: consensus statements from the ERA-IWG and EUVAS.

Patients with immune-mediated kidney diseases are at increased risk of severe coronavirus disease 2019 (COVID-19). The international rollout of COVID-19 vaccines has provided varying degrees of protection and enabled the understanding of vaccine efficacy and safety. The immune response to COVID-19 vaccines is lower in most patients with immune-mediated kidney diseases; either related to immunosuppression or comorbidities and complications caused by the underlying disease. Humoral vaccine response, measured by the presence of antibodies, is impaired or absent in patients receiving rituximab, mycophenolate mofetil (MMF), higher doses of glucocorticoids and likely other immunosuppressants, such as cyclophosphamide. The timing between the use of these agents and administration of vaccines is associated with the level of immune response: with rituximab, vaccine response can only be expected once B cells start to recover and patients with transient discontinuation of MMF mount a humoral response more frequently. The emergence of new COVID-19 variants and waning of vaccine-induced immunity highlight the value of a booster dose and the need to develop mutant-proof vaccines. COVID-19 vaccines are safe, exhibiting a very low risk of de novo or relapsing immune-mediated kidney disease. Population-based studies will determine whether this is causal or coincidental. Such cases respond to standard management, including the use of immunosuppression. The Immunonephrology Working Group and European Vasculitis Society recommend that patients with immune-mediated kidney diseases follow national guidance on vaccination. Booster doses based on antibody measurements could be considered.

The COVID-19 pandemic and ANCA-associated vasculitis - reports from the EUVAS meeting and EUVAS education forum.

The Coronavirus Disease 2019 (COVID-19) pandemic influenced the management of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. A paucity of data exists on outcome of patients with vasculitis following COVID-19, but mortality is higher than in the general population and comparable to patients undergoing haemodialysis or kidney transplant recipients (reported mortality rates of 20-25%). Delays in diagnosis have been reported, which are associated with sequelae such as dialysis-dependency. Management of ANCA-associated vasculitis has not changed with the aim to suppress disease activity and reduce burden of disease. The use of rituximab, an important and widely used agent, is associated with a more severe hospital course of COVID-19 and absence of antibodies following severe acute respiratory syndrome (SARS)-CoV-2 infections, which prone patients to re-infection. Reports on vaccine antibody response are scarce at the moment, but preliminary findings point towards an impaired immune response, especially when patients receive rituximab as part of their treatment. Seropositivity was reported in less than 20% of patients when rituximab was administered within the prior six months, and the antibody response correlated with CD19+ B-cell repopulation. A delay in maintenance doses, if disease activity allows, has been suggested using a CD19+ B-cell guided strategy. Other immunosuppressive measures, which are used in ANCA-associated vasculitis, also impair humoral and cellular vaccine responses. Regular measurements of vaccine response or a healthcare-policy time-based strategy are indicated to provide additional doses ("booster") of COVID-19 vaccines. This review summarizes a recent educational forum and a recent virtual meeting of the European Vasculitis Society (EUVAS) focusing on COVID-19.

Antibody response to mRNA SARS-CoV-2 vaccines in haemodialysis patients.

BACKGROUND: Some studies have shown an attenuated immune response in haemodialysis patients after vaccination. The present study examines the humoral response after mRNA vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a large population of haemodialysis patients from different outpatient dialysis centres. METHODS: We retrospectively assessed antibodies against SARS-CoV-2 spike protein and nucleocapsid protein (chemiluminescence immunoassays, Roche diagnostics) 3-6 weeks after the second mRNA vaccine dose in 179 maintenance haemodialysis and 70 non-dialysis patients (control cohort). Differences in anti-SARS-CoV-2 spike protein titers were statistically analysed with respect to patient-relevant factors, including age, gender, previous coronavirus disease 2019 (COVID-19) infection, systemic immunosuppressive therapy and time on dialysis. RESULTS: We found a favourable, but profoundly lower SARS-CoV-2 spike protein antibody response in comparison with a non-dialysis cohort (median 253.5 versus 1756 U/mL, P < 0.001). In multivariate analysis, previous COVID-19 infection (P < 0.001) and female gender were associated with a significantly higher vaccine response (P = 0.006) in haemodialysis patients, while there was a significant inverse correlation with increasing patient age and systemic immunosuppression (P < 0.001). There was no statistically significant correlation between the antibody titer and time on dialysis. Immune response in haemodialysis patients with a previous COVID-19 infection led to substantially higher antibody titers that were equal to those of vaccinated non-dialysis individuals with previous infection. CONCLUSION: We strongly argue in favour of regular antibody testing after COVID-19 vaccination in haemodialysis patients. Further studies should elucidate the utility of booster vaccinations to foster a stronger and persistent antibody response.

Simultaneous quantification of seven repurposed COVID-19 drugs remdesivir (plus metabolite GS-441524), chloroquine, hydroxychloroquine, lopinavir, ritonavir, favipiravir and azithromycin by a two-dimensional isotope dilution LC-MS/MS method in human serum.

BACKGROUND: The present COVID-19 pandemic has prompted worldwide repurposing of drugs. The aim of the present work was to develop and validate a two-dimensional isotope-dilution liquid chromatrography tandem mass spectrometry (ID-LC-MS/MS) method for accurate quantification of remdesivir and its active metabolite GS-441524, chloroquine, hydroxychloroquine, lopinavir, ritonavir, favipiravir and azithromycin in serum; drugs that have gained attention for repurposing in the treatment of COVID-19. METHODS: Following protein precipitation, samples were separated with a two-dimensional ultra-high performance liquid chromatography (2D-UHPLC) setup, consisting of an online solid phase extraction (SPE) coupled to an analytical column. For quantification, stable isotope-labelled analogues were used as internal standards for all analytes. The method was validated on the basis of the European Medicines Agency bioanalytical method validation protocol. RESULTS: Detuning of lopinavir and ritonavir allowed simultaneous quantification of all analytes with different concentration ranges and sensitivity with a uniform injection volume of 5 µL. The method provided robust validation results with inaccuracy and imprecision values of ≤ 9.59 % and ≤ 11.1 % for all quality controls. CONCLUSION: The presented method is suitable for accurate and simultaneous quantification of remdesivir, its metabolite GS-441525, chloroquine, hydroxychloroquine, lopinavir, ritonavir, favipiravir and azithromycin in human serum. The quantitative assay may be an efficient tool for the therapeutic drug monitoring of these potential drug candidates in COVID-19 patients in order to increase treatment efficacy and safety.