RA can affect joints and also other tissues. Which organ system is NOT listed as a potential non-joint involvement in RA within the provided material?

• A. Vessels
• B. Lungs
• C. Heart
• D. Kidneys

Answer: (D)

Rheumatoid arthritis is a systemic inflammatory condition, so it can involve organs beyond the joints. The organ systems commonly described as non-joint targets include the vascular system (rheumatoid vasculitis), the lungs (pleuritis, interstitial lung disease), and the heart (pericarditis, myocarditis). The kidneys are not typically listed as a potential non-joint involvement in the material provided. While kidney problems can occur in RA patients—often from secondary AA amyloidosis or drug-related nephrotoxicity—they are not treated as a direct, primary extrarticular manifestation in the standard listings. So, the kidneys stand out as the organ system not listed in that material.