i mmunoglobulins, produced by plasma cells, are the effector arm of the humoral immune system [1]. Each immunoglobulin consists of two identical heavy chains (α, β, γ, δ or ε – all encoded by chromosome 14) and two identical light chains (either κ or λ, encoded by chromosome 2 and 22, respectively) [2]. The immunoglobulins have constant (C) regions (similar within the same isotype) and variable...

Background: Understanding key mechanisms of flare development and sustained remission is one the acute goals in modern rheumatology. Anti-citrullinated protein antibodies (ACPA) are most abundant specific autoantibodies rheumatoid arthritis (RA) patients. However, impact ACPA IgA isotype poorly defined. were previously shown to have a higher percentage IgA2 comparison total IgA; correlation bet...

The ongoing outbreak of coronavirus disease 2019 (COVID-19), which impairs the functionality several organs, represents a major threat to human health. One hardest challenges in fight against COVID-19 is development wide-scale, effective, and rapid laboratory tests control severity, progression, possible sudden worsening. Monitoring patients real-time highly demanded this pandemic era when phys...

Patients who develop reactive arthritis after yersinia enteritis are characterised by high and persisting IgA-anti-yersinia antibodies. We have further analysed the humoral immune response to yersinia in this condition. Total concentrations of IgM, IgG, IgA, and secretory IgA in the serum and specific anti-yersinia antibodies belonging to IgA1, IgA2, or secretory IgA were compared in patients w...

In these studies, we characterize an Fc receptor (FcR) for IgA that is present on human granulocytes, monocyte/macrophages, and their corresponding cell lines. Receptor expression appears to be constitutive but can be selectively upregulated on monocyte cell lines by stimulation with a phorbol ester and polymeric IgA. Both the induction requirements and ligand specificity of the IgA receptor di...