Monocyte-macrophage antigen expression on chondrocytes.
OBJECTIVE
To characterize chondrocytes in normal and arthritic joints and compare their phenotype to that of synovial macrophages present in rheumatoid joints.


METHODS
Using an immunoperoxidase staining technique, we examined the presence and distribution of a number of leukocyte activation and differentiation antigens on samples of cartilage obtained from resected joints of normal controls and subjects with rheumatoid arthritis or osteoarthritis.


RESULTS
Chondrocytes in each group were CD14+, CD68+, Thy-1+, CD11a+, CD18+, MAX.3-, and MAX.24-. Staining was variable for MAX.1 and CD45. HLA-DR and CD71 were expressed only on cells located in the superficial layer of rheumatoid cartilage. We found lower levels of expression of CD14 on chondrocytes in arthritic joints, whereas CD58 was expressed at higher levels. Surface expression of CD14 was confirmed on normal chondrocytes using flow cytometry and further supported by the detection of CD14 mRNA by polymerase chain reaction.


CONCLUSIONS
Our findings demonstrate that chondrocytes express several antigens that are also found on monocytes and macrophages.
Summers
K L
KL
Haematology/Immunology Research Group, Christchurch School of Medicine, New Zealand.
O'Donnell
J L
JL
Hoy
M S
MS
Peart
M
M
Dekker
J
J
Rothwell
A
A
Hart
D N
DN
D001172:Arthritis, Rheumatoid / Q000276:immunology*; D001483:Base Sequence; D018968:CD58 Antigens / Q000032:analysis* / Q000378:metabolism; D002358:Cartilage, Articular / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D018950:Lipopolysaccharide Receptors / Q000032:analysis* / Q000378:metabolism; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D008969:Molecular Sequence Data; D009000:Monocytes / Q000276:immunology* / Q000378:metabolism; D010003:Osteoarthritis / Q000276:immunology*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis
D018968:CD58 Antigens; D018950:Lipopolysaccharide Receptors; D012333:RNA, Messenger