Abstract
Background: Early diagnosis of pulmonary cryptococcosis (PC) without human immunodeficiency virus (HIV) infection may be challenging. The aim of this study was to investigate the diagnostic value of cryptococcal antigen-lateral flow immunochromatographic assay (CrAg-LFA) in bronchoalveolar lavage fluid (BALF) of patients with PC. Methods: A total pf 308 patients who were admitted to the departments of pulmonary and critical care medicine and thoracic surgery between March 2015 and October 2018, were divided into the PC group (n=72) and the non-PC group (n=236). PC was confirmed by 1) lung biopsy; 2) a positive culture of Cryptococcus neoformans (C. neoformans) from blood culture or biopsy specimen; 3) clinical data, pathogen detection, radiological imaging and the detection of the cryptococcal antigen in blood and BALF samples.Results: The sensitivity, specificity, positive and negative predicted values of CrAg-LFA in the serum were 75.0%, 99.6%, 98.2%, and 92.9%, respectively, while those in the BALF were 93.1%, 100.0%, 100.0%, and 97.9%, respectively. The sensitivity of the CrAg-LFA in BALF was significantly higher than that in the serum of the patients in the PC group (P<0.05). Conclusion: CrAg-LFA is a rapid, simple, and safe experimental method. CrAg-LFA has a higher diagnostic value for PC when analyzing BALF samples compared to serum samples. Furthermore, the BALF positive results are equivalent to the microbiological culture-positive results in terms of diagnostic value.
Detection of Legionella pneumophila Serogroup 1 Antigen in Bronchoalveolar Lavage Fluid by an Immunochromatographic Assay