Induction of cross-reactive, mucosal anti-SARS-CoV-2 antibody responses in rheumatoid arthritis patients after 3rd dose of COVID-19 vaccination.

Systemic vaccination against SARS-CoV-2 elicited high titers of specific antibodies in the blood and in the oral cavity. Preexisting autoimmune diseases, such as rheumatoid arthritis, and biological treatments, like B cell depletion, are known to exhibit higher risk of severe COVID-19 manifestation and increased frequency of breakthrough infections after vaccination. We hypothesized that such increased risk is associated with an aberrant induction of secreted antibodies in the oral cavity. Here we evaluated the levels of secreted antibodies in the oral cavity against the SARS-CoV-2 Spike protein during the course of vaccination in RA patients with or without B cell depletion. We found that total salivary IgG levels were correlated with number of B cells in the blood. Anti-Spike IgG responses 7 days after second vaccination were induced in the oral cavity of all healthy individuals, while only 6 out 23 RA patients exhibited anti-Spike IgG in their saliva regardless of B cell depleting therapy. Importantly, both salivary and serologic anti-Spike IgG and IgA responses towards WT and omicron Spike variants were efficiently induced by third vaccination in RA patients with or without B cell depletion to the levels that were similar to healthy individuals. Altogether, these data advocate for the necessity of three dose vaccination for RA patients to mount anti-Spike antibody responses at the mucosal surfaces and annotate the reduction of secreted salivary IgG by B cell depletion.

[Analysis of the Specificity of IgA Antibodies Produced in the Mouse Small Intestine].

Intestinal microbiota controls multiple aspects of body homeostasis. The microbiota composition changes easily in response to internal or external factors, which may result in dysbiosis and associated inflammatory reactions. Thus, maintaining the microbiota composition by the host immune system is crucial, and one of the main mechanisms for microbiota control is production of immunoglobulin A (IgA) at mucosal surfaces. The molecular mechanisms regulating the interactions between the immune system and microbiota remain obscure. A panel of hybridoma cell lines was constructed to produce monoclonal IgA antibodies specific to various commensal bacteria present in intestinal microbiota. The panel can be used to further understand the mechanisms whereby the adaptive immune system controls the microbiota composition.

[Hygienic assessment of working conditions and health of the workers of mining and processing enterprises].

In the article there are presented results of studies on the hygienic assessment of working conditions and health status of 1200 workers of mining and processing enterprises (MPE) developing deposits of iron ores of the Kursk Magnetic Anomaly: Lebedinskiy MPE, Mikhaylovskiy MPE, Stoylenskiy MPE. There were revealed the differences in the character and intensity of adverse occupational factors, there was made the quantitation of the occupational risk level to the health workers of MPE both factories and quarries. The structure of occupational diseases in MPE factories is formed by dust lung diseases and the occupational pathology of the organ of hearing. In the structure of professional pathology in quarries workers vibration disease (61.5%) prevails. The obtained results indicate to the need of the development of the system of measures for the reduction in general and occupational morbidity rate of workers, the creation of safe working conditions, improving the early diagnosis of occupational and common diseases at the stage of preliminary and periodic medical examinations.