Gangliosides from normal and osteoarthritic joints.

A decrease in all major gangliosides, contrasting with a marked increase in the GM3 third band (3B-GM3), has been demonstrated in osteoarthritic fibrillated cartilage. We found the 3B-GM3 in osteoarthritic fibrillated, grossly intact and osteophytic human cartilage, but it was undetectable in pig and bovine cartilage, bone, synovium, synovial fluid white cells, erythrocytes, and various extracellular tissues. We made a similar finding with lactosyl ceramide, the GM3 neutral glycolipid precursor. The search for an antibody against the 3B-GM3, as a possible specific antigenic marker of osteoarthritis (OA), was unsuccessful. However, an antibody against a molecule very close to 3B-GM3 on high performance thin layer chromatography, which will probably be identified as a glycosylphosphatidylinositol, was found in the serum of some patients with OA.