Validation of clinic-based cryptococcal antigen lateral flow assay screening in HIV-infected adults in South Africa.
Sci Rep
; 9(1): 2687, 2019 02 25.
Article
em En
| MEDLINE
| ID: mdl-30804356
ABSTRACT
Since rapid cryptococcal antigen lateral flow assays (CrAg LFA) may expedite treatment of HIV-associated cryptococcal infections, we sought to validate clinic-based CrAg LFA testing. Among newly-diagnosed HIV-infected adults in South Africa, a trained nurse performed clinic-based testing of urine, fingerprick capillary and venous whole blood with rapid CrAg LFA (Immy Diagnostics, Norman, USA). We performed matched laboratory-based serum cryptococcal antigen testing with an enzyme immunoassay (EIA). We assessed diagnostic accuracy using EIA as the gold-standard, and performed additional validation testing on serum and among hospitalized adults with cryptococcal meningitis. Among 5,618 participants enrolled, 1,296 were HIV-infected and screened for cryptococcal antigenemia. Overall CrAg prevalence by serum EIA was 3.6% (95% CI 2.0-6.0%) for adults with CD4 < 200 cells/mm3, and 5.7% (95% CI 2.8-10.2%) for adults with CD4 < 100 cells/mm3. Using expanded screening guidelines (CD4 < 200 cells/mm3), CrAg LFA testing of venous whole blood, fingerprick capillary blood, and urine had diagnostic sensitivities of 46% (95% CI 19-75%), 38% (95% CI 14-68%), and 54% (95% CI 25-81%), and specificities of 97%, 97%, and 86%, respectively. When tested on serum samples, CrAg LFA had sensitivity of 93% (95% CI 66-100%) and specificity of 100% (95% CI 88-100%). All venous and fingerprick whole blood CrAg LFA tests were positive among 30 hospitalized adults with cryptococcal meningitis. Two independent readers had strong agreement for all LFA results (p < 0.0001). When performed at the point-of-care by trained nurses, CrAg LFA testing was feasible, had the highest accuracy on serum specimens, and may accelerate treatment of HIV-associated cryptococcal infections.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Testes Imunológicos
/
Infecções por HIV
/
Cryptococcus
/
Antígenos de Fungos
Tipo de estudo:
Diagnostic_studies
/
Guideline
/
Risk_factors_studies
/
Screening_studies
Limite:
Adult
/
Female
/
Humans
/
Male
País/Região como assunto:
Africa
Idioma:
En
Revista:
Sci Rep
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Estados Unidos