GANGLIOSIDES FROM NORMAL AND OSTEOARTHRITIC JOINTS

A decrease in all major gangliosides, contrasting with a marked increa se in the GM3 third band (3B-GM3), has been demonstrated in osteoarthr itic fibrillated cartilage, We found the 3B-GM3 in osteoarthritic fibr illated, grossly intact and osteophytic human cartilage, but it was un detectable 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 possibl e specific antigenic marker of osteoarthritis (OA), was unsuccessful, However, an antibody against a molecule very close to 3B-GM3 on high p erformance thin layer chromatography, which will probably be identifie d as a glycosylphosphatidylinositol, was found in the serum of some pa tients with OA.