Rheumatoid arthritis specific autoimmunity in the lung before and at the onset of disease.

We conclude that T cell driven B cell differentiation, resulting in local class switching and somatic hypermutation are evident in lungs before, as well as in, early stages of ACPA-positive RA. Our findings add to the notion of lung mucosa being a site for initiation of the citrulline autoimmunity preceding seropositive RA. This article is protected by copyright. All rights reserved.