Pregnancy-associated a2-glycoprotein in rheumatoid arthritis

Pregnancy-associated alpha2-glycoprotein (PAG) was found to be increased in sera and synovial fluids of patients suffering from rheumatoid arthritis tested in the single radial immunodiffusion. The PAG levels in rheumatoid sera correlated well with the activity of arthritis in the patients. The purified PAG inhibited clearly the 3H-thymidine uptake of normal lymphocytes stimulated with phytohemagglutinin and also the spontaneous attachment of sheep erythrocytes to normal lymphocytes. 17 of 19 rheumatoid plasmas inhibited the 3H-thymidine uptake of normal lymphocytes and intensity of their inhibitory effects correlated with serum PAG levels.