Low Cryptococcus Antigen Titers as Determined by Lateral Flow Assay Should Be Interpreted Cautiously in Patients without Prior Diagnosis of Cryptococcal Infection.
J Clin Microbiol
; 55(8): 2472-2479, 2017 08.
Article
em En
| MEDLINE
| ID: mdl-28566315
ABSTRACT
Detection of Cryptococcus antigen (CrAg) is invaluable for establishing cryptococcal disease. Multiple different methods for CrAg detection are available, including a lateral flow assay (LFA). Despite excellent performance of the CrAg LFA, we have observed multiple cases of low-titer (≤15) positive CrAg LFA results in patients for whom cryptococcosis was ultimately excluded. To investigate the accuracy of low-titer positive CrAg LFA results, we performed chart reviews for all patients with positive CrAg LFA results between June 2014 and December 2016. During this period, serum and/or cerebrospinal fluid (CSF) samples from 3,969 patients were tested with the CrAg LFA, and 55 patients (1.5%) tested positive. Thirty-eight of those patients lacked a history of cryptococcal disease and were the focus of this study. Fungal culture or histopathology confirmed Cryptococcus infection for 20 patients (52.6%), and CrAg LFA titers in serum and CSF samples ranged from 15 to ≥12,560. For the 18 patients (47.4%) without culture or histopathological confirmation, the CrAg LFA results were considered true-positive results for 5 patients (titer range, 110 to ≥12,560), due to clinical improvement with targeted therapy and decreasing CrAg LFA titers. The remaining 13 patients had CrAg LFA titers of 12 (n = 11) or 15 (n = 2) and were ultimately diagnosed with an alternative condition (n = 11) or began therapy for possible cryptococcosis without improvement (n = 2), leading to an overall CrAg LFA false-positive rate of 34%. We recommend careful clinical correlation prior to establishing a diagnosis of cryptococcal infection for patients with first-time positive CrAg LFA titers of 12.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cromatografia de Afinidade
/
Criptococose
/
Cryptococcus
/
Testes Diagnósticos de Rotina
/
Antígenos de Fungos
Tipo de estudo:
Diagnostic_studies
/
Observational_studies
Limite:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article