PT  - JOURNAL ARTICLE
AU  - Edwards, J C
AU  - Wilkinson, L S
AU  - Pitsillides, A A
TI  - Palisading cells of rheumatoid nodules: comparison with synovial intimal cells.
AID  - 10.1136/ard.52.11.801
DP  - 1993 Nov 01
TA  - Annals of the Rheumatic Diseases
PG  - 801--805
VI  - 52
IP  - 11
4099  - http://ard.bmj.com/content/52/11/801.short
4100  - http://ard.bmj.com/content/52/11/801.full
SO  - Ann Rheum Dis1993 Nov 01; 52
AB  - OBJECTIVES--The palisading cells of rheumatoid nodules share certain features with synovial intimal cells. The similarities between the two cell populations have been reassessed using new cytochemical markers. METHODS--Cell populations in cryostat sections of non-inflamed, rheumatoid and osteoarthritic synovial tissues, and rheumatoid nodules were assessed for the presence of CD68, prolyl hydroxylase, vascular cell adhesion molecule 1 (VCAM-1), and the alpha 4 and beta 1 integrin chains, and the activity of uridine diphosphoglucose dehydrogenase (UDPGD) and nonspecific esterase. RESULTS--Synovial intimal cells formed a dual population of macrophages (nonspecific esterase positive, strongly positive for CD68) and fibroblastic cells (prolyl hydroxylase positive). The latter showed prominent VCAM-1 expression and high UDPGD activity as previously reported and also prominent beta 1 integrin chain expression. Palisading cells similarly proved to be a dual population of macrophages and fibroblastic cells. In contrast with synovial intima, however, the fibroblastic cells lacked UDPGD activity and expression of VCAM-1 and showed no preferential expression of the beta 1 integrin chain. The exception to this rule was where nodules contained central clefts, which were lined with cells showing all the features associated with synovial intimal cells. CONCLUSION--Palisading cells are a mixture of macrophages and fibroblasts, but the latter show no evidence of synoviocyte differentiation. Cells with features of synoviocytes may occur lining clefts within areas of necrobiosis.