title: The role of follicular and interdigitating dendritic cells in HIV-related lymphoid hyperplasia: localization of fascin.
abstract: Fascin is a 55-kDa, actin-bundling protein expressed in follicular and interdigitating dendritic cells (DCs). Because these cells play a pivotal role in the pathogenesis of human immunodeficiency virus-related lymphoid hyperplasias (HLP), we evaluated them in 49 cases by immunohistochemical localization of fascin, and we related the findings to the histologic stage of disease. Fifteen cases of early HLP revealed strong localization of fascin within DCs of hyperplastic follicles and intense staining in interdigitating DCs and their processes in the interfollicular zones. Some follicles revealed focal disruption of the fascin-positive dendritic framework. DCs were also aligned beneath the peripheral sinuses of the node. In 15 cases of progressive HLP with partial follicular involution, 3 cases revealed findings similar to those described above. Twelve cases revealed loss of follicular dendritic staining, which was moderate in five cases and marked in seven. Residual clusters of DCs remained after partial dissolution. Interfollicular dendritic staining was reduced in 13 cases, and perisinusoidal staining was reduced in 7. In late-stage HLP, staining of both follicular and interdigitating DCs was reduced or absent. Nine cases of diffuse immunoblastic or angioimmunoblastic lymphadenopathy-like proliferation had markedly reduced or absent follicular DCs, but prominent staining was present in interfollicular DCs, which formed a meshwork throughout the node in eight cases. Two cases of hyaline-vascular lymphoid hyperplasia had increased follicular DCs forming a tight syncytial network. In most cases, there was reduction of dendritic fascin-expressing cells with advanced disease and destruction of the dendritic framework of the node. Diffuse hyperplasia of fascin-positive interdigitating cells occurred in cases with angioimmunoblastic morphologic features, and cases of hyaline-vascular lymphoid hyperplasia had increased follicular dendritic histiocytes forming a tight syncytial network. Destruction of DCs and, in some cases, interdigitating cell hyperplasia might be associated with the variable clinical course of HLP.
authors.affiliation: Department of Pathology, University of California School of Medicine, Los Angeles 90095, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Said
authors.forename: J L
authors.initials: JL
authors.lastname: Pinkus
authors.forename: J
authors.initials: J
authors.lastname: Yamashita
authors.forename: S
authors.initials: S
authors.lastname: Mishalani
authors.forename: F
authors.initials: F
authors.lastname: Matsumura
authors.forename: S
authors.initials: S
authors.lastname: Yamashiro
authors.forename: G S
authors.initials: GS
authors.lastname: Pinkus
mesh_terms: D001706:Biopsy; D002352:Carrier Proteins / Q000378:metabolism*; D003713:Dendritic Cells / Q000378:metabolism* / Q000502:physiology; D015658:HIV Infections / Q000473:pathology*; D006801:Humans; D006965:Hyperplasia / Q000473:pathology; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology*; D008840:Microfilament Proteins / Q000378:metabolism; D017463:Receptors, Complement 3b / Q000378:metabolism; D017464:Receptors, Complement 3d / Q000378:metabolism; D012189:Retrospective Studies
chemical_list: D002352:Carrier Proteins; D008840:Microfilament Proteins; D017463:Receptors, Complement 3b; D017464:Receptors, Complement 3d; C020324:fascin