MONOCLONAL-ANTIBODIES THAT DETECT BIOCHEMICAL MARKERS OF ARTHRITIS INHUMANS

Objective. To evaluate the potential of using monoclonal antibodies (M Ab) 3-B-3(-) and 7-D-4 to detect biochemical markers of altered cartil age metabolism in human arthritides, Methods. Fifty-five samples of no rmal articular cartilage (subjects' age range 18 weeks of gestation to 83 years of age) and 89 samples of arthritic cartilage (patients' age range 20-81 years) were collected, and their proteoglycans were extra cted and analyzed for the presence of the epitopes recognized by MAb 3 -B-3 and 7-D-4, Results. Native 3-B-3(-) mimotope was expressed at a h igh incidence in proteoglycans extracted from the cartilage of patient s with most of the arthritic diseases examined (osteoarthritis, juveni le rheumatoid arthritis, rheumatoid arthritis, avascular necrosis, and degenerative meniscal tears), Its expression in normal cartilage spec imens was very low or absent, occurring mainly in the young, skeletall y immature individuals, In contrast, expression of the 7-D-4 epitope w as more variable in patients with different arthritides and was also f requently found in normal cartilage specimens, Immunohistochemical ana lyses with both 3-B-3(-) and 7-D-4 showed strong focal positive staini ng in superficial areas, where cartilage degeneration, remodeling, and repair were greatest, Conclusion. The biochemical markers recognized by MAb 3-B-3(-) and 7-D-4 are indicative of altered proteoglycan synth esis and metabolism in human articular cartilage. The data suggest tha t in human cartilage, the 3-B-3(-) epitope might be a better marker of biochemical changes than the 7-D-4 epitope.