Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 3 de 3
Filter
Add filters

Language
Document Type
Year range
2.
medrxiv; 2022.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2022.06.11.22276272

ABSTRACT

ABSTRACT Objective To determine the immediate need for a fourth COVID-19 vaccination based on the neutralizing capacity in patients on methotrexate (MTX) therapy after mRNA booster immunization. Methods In this observational cohort study, neutralizing serum activity against SARS-CoV-2 wildtype (Wu01) and variant of concern (VOC) Omicron BA.1 and BA.2 were assessed by pseudovirus neutralization assay before, 4 and 12 weeks after mRNA booster immunization in 50 rheumatic patients on MTX, 26 of whom paused the medication. 44 non-immunosuppressed persons (NIP) served as control group. Results While the neutralizing serum activity against SARS-CoV-2 Wu01 and Omicron variants increased 67-to 73-fold in the NIP after booster vaccination, the serum activity in patients receiving MTX increased only 20-to 23-fold. As a result, significantly lower neutralizing capacities were measured in patients on MTX compared to the NIP at week 4. Patients who continued MTX treatment during vaccination had significantly lower neutralizing serum titres against all three virus strains at week 4 and 12 compared to patients who paused MTX and the control group, except for BA.2 at week 12. Patients who paused MTX reached comparably high neutralization titres as the NIP, except for Wu01 at week 12. Neutralization of omicron variants was significantly lower in comparison to wildtype in both groups. Conclusion Patients pausing MTX showed a similar vaccine response to NIP. Patients who continued MTX demonstrated an impaired booster response indicating a potential benefit of a second booster vaccination.


Subject(s)
COVID-19
3.
medrxiv; 2021.
Preprint in English | medRxiv | ID: ppzbmed-10.1101.2021.07.19.21260803

ABSTRACT

Objectives Patients with autoimmune inflammatory rheumatic diseases receiving rituximab (RTX) therapy show substantially impaired anti-SARS-CoV-2 vaccine humoral but partly inducible cellular immune responses. However, the complex relationship between antigen-specific B and T cells and the level of B cell repopulation necessary to achieve anti-vaccine responses remain largely unknown. Methods Antibody responses to SARS-CoV-2 vaccines and induction of antigen-specific B and CD4/CD8 T cell subsets were studied in 19 rheumatoid arthritis (RA) and ANCA-associated vasculitis (AAV) patients receiving RTX, 12 RA patients on other therapies and 30 healthy controls after SARS-CoV-2 vaccination with either mRNA or vector based vaccines. Results A minimum of 10 B cells/µL in the peripheral circulation was necessary in RTX patients to mount seroconversion to anti-S1 IgG upon SARS-CoV-2 vaccination. RTX patients lacking IgG seroconversion showed reduced antigen-specific B cells, lower frequency of TfH-like cells as well as less activated CD4 and CD8 T cells compared to IgG seroconverted RTX patients. Functionally relevant B cell depletion resulted in impaired IFNγ secretion by spike-specific CD4 T cells. In contrast, antigen-specific CD8 T cells were reduced in patients independently of IgG formation. Conclusions Patients receiving rituximab with B cell numbers above 10 B cells/µl were able to mount humoral and more robust cellular responses after SARS-CoV-2 vaccination that may permit optimization of vaccination in these patients. Mechanistically, the data emphasize the crucial role of co-stimulatory B cell functions for the proper induction of CD4 responses propagating vaccine-specific B and plasma cell differentiation.


Subject(s)
Vasculitis , Arthritis, Rheumatoid , Rheumatic Fever
SELECTION OF CITATIONS
SEARCH DETAIL