Diagnostic performance of the Dynamiker cryptococcal antigen lateral flow assay on serum and cerebrospinal fluid samples

The incidence of cryptococcosis is rising, particularly among immunocompetent individuals. Cryptococcal antigen (CrAg) testing is increasingly used in the diagnosis of cryptococcal infections. However, the diagnostic performance of the Dynamiker CrAg lateral flow assay has been evaluated in only a few studies. This study included patients with suspected cryptococcosis who were admitted to the First Affiliated Hospital of Yangtze University between February 1, 2020 and January 31, 2025. A total of 43 confirmed cases were enrolled, including 13 with cryptococcal meningoencephalitis (CM), 26 with pulmonary cryptococcosis (PC), and 4 with asymptomatic cryptococcal antigenemia (ACA), as defined by the revised EORTC/MSG criteria. The CrAg positivity rate was significantly higher in HIV-positive individuals (12.4%, 12/97) than in HIV-negative individuals (2.1%, 22/1058). Notably, 30.8% (8/26) of PC patients were asymptomatic at diagnosis. Additionally, 3 PC cases and 1 CM case tested negative for serum CrAg but were ultimately confirmed by NGS. In serum, the Dynamiker CrAg LFA demonstrated a sensitivity of 88.2%, specificity of 100%, positive predictive value (PPV) of 100%, and negative predictive value (NPV) of 99.6%. In cerebrospinal fluid (CSF), the assay achieved perfect performance (100% for all metrics). NGS demonstrated a positivity rate of 87.6% (14/16). The Dynamiker CrAg ® LFA shows good diagnostic sensitivity and specificity for cryptococcosis in HIV-negative and HIV-positive patients, with considerably better performance in CSF specimens. The shifting epidemiology toward HIV-negative, immunocompetent individuals further underscores the necessity of integrating CrAg testing into routine diagnostic workflows for pulmonary infections.