In a nutshell
This study investigated whether specific blood markers can predict if patients will be affected by rheumatoid arthritis-associated interstitial lung disease (RA-IDL).
Some background
Interstitial lung disease is a condition involving inflammation and scarring in the lungs. Patients with rheumatoid arthritis are at higher risk of developing interstitial lung disease (7-10% of patients will be affected). Therefore, it would be valuable if blood markers could predict which patients will be affected by RA-IDL.
Two potential markers are anti-cyclic citrullinated peptide antibody (anti-CCP2) and rheumatoid factor. Increases in both of these proteins can indicate more severe disease. Anti-CCP2 has also been linked to other conditions, including heart disease and type-1 diabetes, which can affect patients with rheumatoid arthritis.
Methods & findings
285 Chinese patients with rheumatoid arthritis were included in the study. Patients were examined for the presence of RA-IDL and blood samples were collected to measure anti-CCP2 and rheumatoid factor. Overall 24.9% of patients had RA-IDL. Patients with RA-IDL were significantly older and had longer disease duration than patients without RA-IDL.
Statistical analysis revealed that low, medium and high levels of anti-CCP2 were linked to the presence of RA-IDL. Low levels of blood anti-CCP2 increased the odds of having RA-IDL by 3.5 times compared to patients with no anti-CCP2. Moderate levels of anti-CCP2 increased the odds of having RA-IDL by 4.22 times and high levels of anti-CCP2 increased the odds of having RA-IDL by 2.96 times compared to patients with no anti-CCP2 in their blood samples.
After taking gender, age, disease duration, smoking, medication and other complications into account rheumatoid factor was not associated with RA-IDL.
The bottom line
The authors concluded that increased anti-CCP2 may be a good marker for diagnosing or predicting RA-IDL in patients with rheumatoid arthritis.
The fine print
As this study was undertaken in Chinese patients, genetic factors may have played a part.
Published By :
PLOS ONE
Date :
Apr 17, 2014
