title: Evaluation of a rapid lateral flow immunoassay for the detection of cryptococcal antigen for the early diagnosis of cryptococcosis in HIV patients in Colombia.
abstract: A previous study carried out in a tertiary care hospital in Colombia demonstrated the usefulness of the Cryptococcus capsular antigen detection by latex (CrAg Latex) in the early diagnosis of cryptococcosis in HIV-infected patients with low CD4 + levels. The aim of this study was to establish the performance of a new rapid lateral flow assay (CrAg LFA) in preserved sera of those HIV-infected patients collected between 2001 and 2006. A total of 421 sera from 297 patients with a confirmed diagnosis of HIV were tested with CrAg LFA and results compared with those obtained with CrAg Latex. All patients provided informed consent for specimen collection. A concordance of 100% was found between positive results obtained by both methods. However, 13 sera that were negative by CrAg Latex, were positive by CrAg LFA (3.1%). In these positive patients, median of CD4 + levels was 67 cells/μl (8-608 cells/μl), while median of viral load was 118,965 copies/ml (50-500,000 copies/ml). Patients who were negative for cryptococcosis had a median of 177 cells/μl in CD4 + levels (4-2516 cells/μl) and a median of 62,318 copies/ml in viral loads (25-50,000 copies/ml). A significant statistical difference was found when comparing CD4 + levels and viral load in patients positive for cryptococcosis and those that were proven to be negative (P < 0.0001). The use of Point-of-Care Tests (POCT) like CrAg LFA play an important role in the diagnosis of infectious diseases, especially in resource limited settings, where it will be a useful means to diagnose cryptococcosis early in HIV patients.
authors.affiliation: * Grupo de Microbiologia, Instituto Nacional de Salud , Bogotá , Colombia.
authors.forename: Patricia
authors.initials: P
authors.lastname: Escandón
authors.forename: Jairo
authors.initials: J
authors.lastname: Lizarazo
authors.forename: Clara Ines
authors.initials: CI
authors.lastname: Agudelo
authors.forename: Tom
authors.initials: T
authors.lastname: Chiller
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Castañeda
mesh_terms: D000293:Adolescent; D000328:Adult; D000946:Antigens, Fungal / Q000097:blood*; D002648:Child; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003453:Cryptococcosis / Q000175:diagnosis*; D003454:Cryptococcus / Q000276:immunology*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D042241:Early Diagnosis; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D055815:Young Adult
chemical_list: D000946:Antigens, Fungal