Different classes of anti-modified protein antibodies are induced on exposure to antigens expressing only one type of modification.

Objectives: Autoantibodies against post-translationally modified proteins (anti-modified protein antibodies or AMPAs) are a hallmark of rheumatoid arthritis (RA). A variety of classes of AMPAs against different modifications on proteins, such as citrullination, carbamylation and acetylation, have now been described in RA. At present, there is no conceptual framework explaining the concurrent presence or mutual relationship of different AMPA responses in RA.

Autoantibody status is not associated with early treatment response to first-line methotrexate in patients with early rheumatoid arthritis.

Objectives: In RA, the relationship between autoantibody status and treatment response to MTX remains unclear. We investigated the association between autoantibody status and early remission in newly diagnosed RA patients treated with MTX using real-world data.

Methods: RA-patients initially treated with MTX were selected from an international observational database (METEOR).

Breach of autoreactive B cell tolerance by post-translationally modified proteins.

Objectives: Over 50% of patients with rheumatoid arthritis (RA) harbour a variety of anti-modified protein antibodies (AMPA) against different post-translationally modified (PTM) proteins, including anti-carbamylated protein (anti-CarP) antibodies. At present, it is unknown how AMPA are generated and how autoreactive B cell responses against PTM proteins are induced. Here we studied whether PTM foreign antigens can breach B cell tolerance towards PTM self-proteins.