title: A cryptic cause of cryptococcal meningitis.
abstract: Cryptococcus neoformans commonly causes opportunistic infection in immunocompromised patients, especially in patients with AIDS. The CD4+ T-lymphocyte count is measured in patients with HIV infection, because it signals an increased risk of opportunistic infection and a decline in immunological function. We report a case of cryptococcal meningitis in a patient with persistently low CD4+ cell counts without evidence of HIV infection. The patient's underlying immunocompromised state was attributed to idiopathic CD4+ T-lymphocytopenia (ICL), a recently described syndrome characterized by depletions in the CD4+ T-cell subsets without evidence of HIV infection. Immunodeficiency can exist in the absence of laboratory evidence of HIV infection, highlighting the importance of evaluating T-cell subsets in patients who present with unusual infections.
authors.affiliation: Division of General Internal Medicine, Department of Medicine, Sunnybrook & Women's College Health Sciences Centre, University of Toronto, Toronto, ON.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Cheung
authors.forename: Anita R
authors.initials: AR
authors.lastname: Rachlis
authors.forename: Steven L
authors.initials: SL
authors.lastname: Shumak
mesh_terms: D000328:Adult; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000276:immunology; D008297:Male; D016919:Meningitis, Cryptococcal / Q000209:etiology* / Q000276:immunology; D013577:Syndrome; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D018344:T-Lymphocytopenia, Idiopathic CD4-Positive / Q000276:immunology