title: Immunohistochemistry of the inflammatory response in Propionibacterium acnes endophthalmitis.
abstract: Specimens were obtained from two patients with culture-proven Propionibacterium acnes endophthalmitis who had undergone vitrectomy. Wright's and Giemsa stains were performed using cytospin preparations of the dilute vitreous and revealed a predominance of polymorphonuclear leukocytes (80% to 90%). The remaining inflammatory cells in the vitreous were mostly macrophages (10% to 15%); very few lymphocytes were present (less than 5%). Immunohistochemical studies using monoclonal antibodies confirmed the paucity of lymphocytes. Most lymphocytes were CD4+ helper/inducer T cells. Almost no CD8+ suppressor/cytotoxic T lymphocytes or B lymphocytes were found. The inflammatory response in these two patients is most characteristic of acute inflammation and consistent with an underlying bacterial infection, despite a clinical picture of persistent, low-grade inflammation. Infection with P acnes has been shown to inhibit CD8+ T cells and may play a role in the persistent inflammation in cases of P acnes endophthalmitis.
authors.affiliation: Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Md. 20892.
authors.forename: S M
authors.initials: SM
authors.lastname: Whitcup
authors.forename: R
authors.initials: R
authors.lastname: Belfort
authors.forename: M D
authors.initials: MD
authors.lastname: de Smet
authors.forename: A G
authors.initials: AG
authors.lastname: Palestine
authors.forename: R B
authors.initials: RB
authors.lastname: Nussenblatt
authors.forename: C C
authors.initials: CC
authors.lastname: Chan
mesh_terms: D000368:Aged; D009877:Endophthalmitis / Q000382:microbiology / Q000473:pathology*; D015818:Eye Infections, Bacterial / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D008214:Lymphocytes; D008264:Macrophages; D008297:Male; D011425:Propionibacterium acnes; D014822:Vitreous Body / Q000473:pathology