Genetics can explain why infections trigger onset of different types of rheumatoid arthritis

(Medical Xpress)—A new international study has revealed how genetics
could explain why different environmental exposures can trigger the
onset of different forms of rheumatoid arthritis.

It was already known that a proportion of rheumatoid arthritis
patients test positive for autoantibodies, whilst about 30% remain
sero-negative. In this study, the researchers have better defined the
genetic distinction between these two disease subtypes: sero-positive
and sero-negative rheumatoid arthritis.


They have now established that different genetic variants of a
protein that plays a vital role in how the body's immune system fights
infection are associated with the two forms of rheumatoid arthritis.
This provides clues to the theory that exposure to different infectious
agents, such as bacteria or viruses, trigger the different forms of
rheumatoid arthritis in susceptible individuals. Sero-negative
rheumatoid is less well understood than sero-positive, and patients who
have this type of arthritis can be misdiagnosed, leading to
inappropriate treatment.