CD38 and rheumatoid arthritis: In particular, CD+3 T cells in late OA lymphocytic nodular aggregates were stained for the activation antigens (CD69, CD25, HLA class II, CD38, CD43, and CD45RO); according to some researchers, they were localized around blood vessels as in RA, and in some instances, were indistinguishable from those found in RA, though in OA, the number of these cells and expression of activation molecules were expressed to a lesser extent than in RA synovia [380].