PT  - JOURNAL ARTICLE
AU  - Chiara Tani
AU  - Federico Pratesi
AU  - Rosaria Talarico
AU  - Chiara Cardelli
AU  - Teresita Caruso
AU  - Federica Di Cianni
AU  - Elenia Laurino
AU  - Nazzareno Italiano
AU  - Michele Moretti
AU  - Maria Laura Manca
AU  - Paola Migliorini
AU  - Marta Mosca
TI  - Efficacy of anti-SARS-CoV-2 mRNA vaccine in systemic autoimmune disorders: induction of high avidity and neutralising anti-RBD antibodies
AID  - 10.1136/rmdopen-2021-001914
DP  - 2021 Dec 01
TA  - RMD Open
PG  - e001914
VI  - 7
IP  - 3
4099  - http://rmdopen.bmj.com/content/7/3/e001914.short
4100  - http://rmdopen.bmj.com/content/7/3/e001914.full
SO  - RMD Open2021 Dec 01; 7
AB  - Objectives In patients with systemic autoimmune rheumatic disorders (SARDs), vaccination with SARS-CoV-2 mRNA vaccines has been proposed. The aim of this study is to evaluate the immune response elicited by vaccination with mRNA vaccine, testing IgM, IgA and IgG antibodies to SARS-CoV-2 receptor-binding domain (RBD) and measuring neutralising antibodies.Methods IgG, IgM and IgA anti-RBD antibodies were measured in 101 patients with SARDs. Antibodies inhibiting the interaction between RBD and ACE2 were evaluated. Antibody avidity was tested in a chaotropic ELISA using urea. Twenty-one healthcare workers vaccinated with mRNA vaccine served as control group.Results Anti-RBD IgG and IgA were produced after the first dose (69% and 64% of the patients) and after the boost (93% and 83%). Antibodies inhibiting the interaction of RBD with ACE2 were detectable in 40% of the patients after the first dose and 87% after boost, compared with 100% in healthy controls (p<0.01). Abatacept and mycophenolate had an impact on the titre of IgG anti-RBD antibodies (p<0.05 and p<0.005, respectively) and on the amount of neutralising antibodies. No effect of other therapies was observed. Vaccinated patients produce high avidity antibodies, as healthy controls.Conclusions These data show that double-dose vaccination induced in patients with SARDs anti-RBD IgG and IgA antibodies in amounts not significantly different from controls, and, most interestingly, characterised by high avidity and endowed with neutralising activity.