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Intense Lubricin Expression Defines Synoviocyte Differentiation and Detects Cells in Synovium‐Related and Myxoid Tumors
Author(s) -
Solka Kathryn,
Schmid Tom,
Miller Ira
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.lb458
Subject(s) - pathology , tendon sheath , immunohistochemistry , staining , cd68 , peripheral blood mononuclear cell , synovial membrane , monoclonal antibody , cd163 , medicine , antibody , macrophage , chemistry , immunology , tendon , inflammation , in vitro , biochemistry
Immunoprofiles of synovium‐related tumors, such as Giant Cell Tumor of Tendon Sheath (GCTTS), are incompletely explored, partly due to lack of lineage defining synoviocyte markers. Synovial lining is comprised of intimal macrophages and fibroblast‐like synoviocytes (FLS). FLS produce lubricin, a mucin‐like glycoprotein in synovial fluid. Lubricin expression in synovium, GCTTS and myxomas was assessed by immunohistochemistry using two anti‐lubricin antibodies: S6.79, monoclonal antibody, raised against purified, native lubricin, and Ab28484, an affinity purified polyclonal antibody made against a C‐terminal peptide. In synovium, lubricin reactivity was limited to intimal synoviocytes with cytoplasmic and surface lining stainingDouble staining using Ab28484 and anti‐CD163, a marker of synovial intimal macrophages, showed non‐overlap between the two synoviocyte types. In GCTTS, lubricin cytoplasmic expression was limited to large, plump cells, but not giant cells or smaller mononuclear cellsDouble staining showed lubricin positive cells were CD163 negative. Scattered mononuclear cells negative for both lubricin and CD163were present. A case of juxta‐articular myxoma with extensive ganglion cyst‐like areas showed moderate staining of myxoid stroma and intense staining of cyst lining using S6.79. A tumor of uncertain lineage showed reactivity, suggesting relatedness to FLS. Thus, lubricin expression defines cells within synovium‐related and myxoid tumors.