Rheumatoid arthritis and pigmented villonodular synovitis: comparative analysis of cell polyploidy, cell cycle phases and expression of macrophage and fibroblast markers in proliferating synovial cells.
OBJECTIVE
Rheumatoid arthritis (RA) and pigmented villonodular synovitis (PVNS) are aggressive diseases with progressive joint destruction. The present study aims to define cell cycle phases, polyploidy and the immunophenotype of proliferating synovial cells in both diseases.


RESULTS
Synovial tissues from patients with proliferative-active RA, localized and diffuse PVNS were analysed by DNA flow cytometry, immunohistochemistry and double immunofluorescence with confocal laser scan microscopy. Expression of macrophage markers (CD68/CD163), fibroblast markers (h4Ph/CD55) and Ki67 antigen was examined. Synovial cells positive for either macrophage or fibroblast markers as well as double-labelled cells were found in both RA and PVNS. In RA, CD68/CD163+ synoviocytes were preferentially located in the vicinity of the synovial lining layer, while they were more randomly distributed in PVNS. Of cases with diffuse PVNS, 20% showed an aneuploid cell pattern. All samples of localized PVNS and RA were diploid. Proliferative activity was significantly higher in aneuploid PVNS.


CONCLUSIONS
In spite of their histologically homogeneous appearance, proliferating synovial cells display a heterogeneous immunophenotype in both RA and PVNS, indicating functional properties of both macrophages and fibroblasts. Aneuploidy seems to be a special feature of diffuse PVNS.
Berger
I
I
Institute of Pathology, University of Heidelberg, Germany. irina_berger@med.uni-heidelberg.de
Weckauf
H
H
Helmchen
B
B
Ehemann
V
V
Penzel
R
R
Fink
B
B
Bernd
L
L
Autschbach
F
F
D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D001172:Arthritis, Rheumatoid / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D015415:Biomarkers / Q000032:analysis; D018958:CD55 Antigens / Q000032:analysis; D049109:Cell Proliferation; D004247:DNA / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000737:chemistry / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D019394:Ki-67 Antigen / Q000032:analysis; D008264:Macrophages / Q000737:chemistry / Q000473:pathology; D011393:Procollagen-Proline Dioxygenase / Q000032:analysis; D011956:Receptors, Cell Surface / Q000032:analysis; D013583:Synovial Membrane / Q000737:chemistry / Q000473:pathology; D013586:Synovitis, Pigmented Villonodular / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000098902:CD163 Antigen; D000097382:CD68 Molecule
D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015415:Biomarkers; D018958:CD55 Antigens; D004247:DNA; D019394:Ki-67 Antigen; D011393:Procollagen-Proline Dioxygenase; D011956:Receptors, Cell Surface; D000098902:CD163 Antigen; C067980:CD68 antigen, human; D000097382:CD68 Molecule