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1.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-21260124

RESUMO

ObjectivesOur aims were to evaluate Systemic Lupus Erythematosus (SLE) disease activity and SARS-CoV-2 specific immune responses after BNT162b2 vaccination. MethodsIn this prospective study, disease activity and clinical assessments were recorded from the first dose of vaccine, until day 15 after the second dose in 126 SLE patients. SARS-CoV-2 antibody responses were measured against wild-type spike antigen while serum-neutralizing activity was assessed against the SARS-CoV-2 historical strain and variants of concerns (VOCs). Vaccine-specific T-cell responses were quantified by Interferon (IFN)-{gamma} release assay after the second dose. ResultsBNT162b2 was well tolerated and no statistically significant variations of BILAG and SLEDAI scores were observed throughout the study in SLE patients with active and inactive disease at baseline. Mycophenolate Mofetil (MMF) and Methotrexate (MTX) treatments were associated with drastically reduced BNT162b2 antibody-response ({beta}=-78; p=0.007, {beta}=-122; p<0.001, respectively). Anti-spike antibody response was positively associated with baseline total IgG serum levels, naive B cell frequencies ({beta}=2; p=0.018, {beta}=2.5; p=0.003) and SARS-CoV-2-specific T cell response (r=0.462; p=0.003). In responders, serum neutralization activity decreased against VOCs bearing the E484K mutation but remained detectable in a majority of patients. ConclusionMMF, MTX and poor baseline humoral immune status, particularly: low naive B cell frequencies, are independently associated with impaired BNT162b2 mRNA antibody response, delineating SLE patients who might need adapted vaccine regimens and follow-up. KEY MESSAGESO_ST_ABSWhat is already known about this subject?C_ST_ABSO_LIBNT162b2 efficacy and safety has been described in studies mixing different RMDs C_LI What does this study add?O_LINo serious adverse effects, nor SLE flares have been documented after BNT162b2 in SLE patients. C_LIO_LINot only MMF and MTX, but also a poor humoral immune status at baseline impair vaccine antibody response C_LIO_LIAlbeit decreased, serum neutralizing activity against VOCs is conferred to vaccine-responders. C_LI How might this impact on clinical practice or future developments?O_LIThese parameters could be helpful for physicians to delineate which patients should have antibody measurement after full BNT162b2 vaccination and should be proposed a third injection of BNT162b2 vaccine. C_LI

2.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-20173393

RESUMO

It is currently unknown whether acquired immunity to common alpha- and beta-coronaviruses provides cross-protection against SARS-CoV-2. In this study, we found that certain patient sera and intravenous immunoglobulins (IVIG) collected prior to the COVID-19 outbreak were cross-reactive to SARS-CoV-2 full-length Spike, S2 domain, and Nucleocapsid. However, their presence did not translate into neutralizing activity against SARS-CoV-2 in vitro. Importantly, we detected serum IgG reactivity to common coronaviruses in the early sera of patients with severe COVID-19 before the appearance of anti-SARS-CoV-2 antibodies. Collectively, the results of our study indicate that pre-existing immunity to common coronaviruses does not confer cross-protection against SARS-CoV-2 in vivo.

3.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-20126532

RESUMO

A major dogma in immunology has it that the IgM antibody response precedes secondary memory responses built on the production of IgG, IgA and, occasionaly, IgE. Here, we measured acute humoral responses to SARS-CoV-2, including the frequency of antibody-secreting cells and the presence of specific, neutralizing, antibodies in serum and broncho-alveolar fluid of 145 patients with COVID-19. Surprisingly, early SARS-CoV-2-specific humoral responses were found to be typically dominated by antibodies of the IgA isotype. Peripheral expansion of IgA-plasmablasts with mucosal-homing potential was detected shortly after the onset of symptoms and peaked during the third week of the disease. While the specific antibody response included IgG, IgM and IgA, the latter contributed to a much larger extent to virus neutralization, as compared to IgG. However, specific IgA serum levels notably decrease after one month of evolution. These results represent a challenging observation given the present uncertainty as to which kind of humoral response would optimally protect against re-infection, and whether vaccine regimens should consider boosting a potent, although, at least in blood, fading IgA response. One sentence SummaryWhile early specific antibody response included IgG, IgM and IgA, the latter contributed to a much larger extent to virus neutralization.

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