An inverse relationship was found between the inflammatory marker C-reactive protein and plasma PLP status91,92, the acute-phase protein alpha1-acid glycoprotein, tumor necrosis factor-α, and the proinflammatory cytokine interleukin-6 in rheumatoid arthritis and rheumatoid arthritis and inflammatory bowel disease15,87,93. Here, TNF is linked to rheumatoid arthritis.