title: Peripolesis in alveolar sarcoidosis.
abstract: We observed that in bronchoalveolar lavages (BAL) of patients with active sarcoidosis (SARC) a mononuclear cell infiltrate is present that often contains clusters consisting of lymphocytes adhering to a macrophage. In order to investigate what kind of cellular interactions are involved in such a process, cell suspensions obtained from BAL of patients with SARC or extrinsic allergic alveolitis (EAA) were cultured for 1 to 2 days, during which time lapse cinematography was applied. We were able to show that such clusters consist of lymphocytes gathered around a macrophage. This is known as peripolesis. Peripolesis, as observed in our BAL, could last for some minutes or for some hours during which time a number of lymphocytes were moving around a single alveolar macrophage, without losing contact with the macrophage. Short interactions were mostly observed in EAA, whereas SARC was characterized by long periods of lymphocyte-macrophage cooperation. We also found a correlation between the time-dependent peripolesis t > 30 min/t < 30 min and the CD4/CD8 ratio. Although the precise mechanisms of peripolesis are not well understood, some interactions between lymphocytes and macrophages have now become more comprehensive.
authors: Department of Pathology, Academical Hospital, Free University, Amsterdam, The Netherlands.
authors: T C
authors: TC
authors: Van Maarsseveen
authors: J
authors: J
authors: De Groot
authors: J
authors: J
authors: Stam
authors: P J
authors: PJ
authors: Van Diest
mesh_terms: D000542:Alveolitis, Extrinsic Allergic / Q000473:pathology; D001992:Bronchoalveolar Lavage Fluid / Q000473:pathology; D002449:Cell Aggregation; D002465:Cell Movement; D006801:Humans; D008171:Lung Diseases / Q000473:pathology*; D008214:Lymphocytes / Q000473:pathology* / Q000502:physiology; D016676:Macrophages, Alveolar / Q000473:pathology* / Q000502:physiology; D012507:Sarcoidosis / Q000473:pathology*