Increased content of type-VI collagen epitopes in human osteoarthritic cartilage: quantitation by inhibition ELISA.
Type-VI collagen is an integral part of the extracellular cartilage matrix. However, the exact amounts of type-VI collagen in normal and osteoarthritic human cartilage still are not known. In this study, we describe an inhibition enzyme-linked immunosorbent assay that was developed to quantitate type-VI collagen epitopes found in guanidinium chloride extracts from normal and osteoarthritic human cartilage. In 31 cartilage samples from various localizations of healthy adult human knees, type-VI collagen epitopes accounted for approximately 0.40% of the total collagen content. Interestingly, type-VI collagen epitopes increased about 4-fold in osteoarthritic cartilage. A statistically significant increase of type-VI collagen epitopes was found during early stages of the disease, with only a superficial roughening of the cartilage surface and a loss of proteoglycans. Thus, these findings indicate that type-VI collagen is a minor component of normal human articular cartilage and that the amount of type-VI collagen epitopes increases significantly during early stages of osteoarthritis.
Swoboda
B
B
Department of Orthopaedic Surgery, University of Erlangen-Nürnberg, Erlangen, Germany.
Pullig
O
O
Kirsch
T
T
Kladny
B
B
Steinhäuser
B
B
Weseloh
G
G
D000328:Adult; D002356:Cartilage / Q000737:chemistry*; D003094:Collagen / Q000032:analysis* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006801:Humans; D008875:Middle Aged; D010003:Osteoarthritis / Q000378:metabolism*
D000939:Epitopes; D003094:Collagen