Adhesion of T cells to extracellular matrix (ECM) proteins through VLA integrin receptors is crucial for lymphocyte trafficking, tissue localization and inflammatory function. We have investigated the expression of different VLA integrins (VLA-1-5) on peripheral blood (PB) and synovial fluid (SF) T lymphocytes from patients with rheumatoid arthritis (RA). Their expression on different cell types from synovial membrane (SM) is also reported. The role of VLA-4 fibronectin (FN) receptors in the interaction of activated SF T cells from RA patients with a 38-kD fragment of FN has been previously demonstrated. Here we have focused functional studies on VLA-5 as an alternative FN receptor for RA T cells. A significant higher proportion of SF T cells were able to bind to an 80-kD fragment of FN, containing the Arg-Gly-Asp (RGD) cell binding site, compared with PB T cells. This attachment was almost completely inhibited by anti-VLA-5 MoAbs as well as by RGD peptides. This enhanced capability by SF T cells appears to be independent of the level of the surface expression of the receptor and correlates better with their activation state as determined by the expression of the activation molecule AIM (CD69). The evidence for the expression of VLA heterodimers on both SF and SM cells from RA patients suggests the possible implication of ECM proteins in mediating and perpetuating inflammation in vivo.
Introduction: Multinucleated giant cells (MGC) are a rare finding when evaluating axillary sentinel lymph nodes. Some are described as foreign body-type MGC accompanied by foamy macrophages. They have been rarely reported in nodes from patients in which a previous breast biopsy was performed. The tissue damage induced by biopsy results in secondary changes including fat necrosis and hemorrhage that can migrate to axillary nodes. In this report, we illustrate a lipogranulomatous reaction in cytologic samples obtained during a sentinel lymph node examination of a woman previously biopsied because of breast carcinoma. We have found no previous cytologic descriptions and consider it an interesting finding that should be known to avoid diagnostic misinterpretations. Case: A 51-year-old woman underwent mastectomy of the right breast with a sentinel lymph node biopsy at our medical center. One month before, a control mammography revealed suspicious microcalcifications and a vacuum-assisted breast biopsy resulted in a diagnosis of high-grade intraductal carcinoma with comedonecrosis. Surgery with a sentinel lymph node biopsy was performed. The sentinel node was processed as an intraoperative consultation. Frozen sections and air-dried Diff-Quik stained samples were obtained. They showed abundant lymphocytes with MGC and tumoral cells. MGC showed ample cytoplasm with evident vacuoles of variable size. Occasional hemosiderin-laden macrophages were also present. The complete histologic analysis and immunohistochemical studies revealed no malignant cells. Histologic analysis showed, in subcapsular location, occasional MGC phagocyting lipid droplets. Hemosiderin-laden macrophages were a common finding. Conclusion: Lipogranulomas may appear at axillary sentinel lymph nodes because of fat necrosis induced by previous breast biopsy. The most important consideration is not confounding MGC with epithelial cell clusters. This can occur with not well-processed samples, especially if unmounted.
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