Development of a Quantitative Antigen Assay to Detect Coccidioidal Chitinase-1 (CTS1) in Human Serum. (28th June 2021)

• Record Type: Journal Article
• Authors: Grill, Francisca J; Grys, Thomas E; Grill, Marie F; Roeder, Alexa; Blair, Janis E; Lake, Douglas F
• Is Part Of: Open forum infectious diseases. Volume 8:Number 7(2021)
• Publication Date: 2021-06-28
• Subjects: coccidioidomycosis -- diagnostic -- ELISA -- Valley fever; Communicable diseases -- Periodicals; Medical microbiology -- Periodicals; Infection -- Periodicals; 616.9
• DOI: 10.1093/ofid/ofab344
• Languages: English
• ISSNs: 2328-8957

Abstract

Abstract: Background: Coccidioidomycosis is often diagnosed with a collection of tests that rely on the patient's ability to mount an immune response to the fungus (antibody-based diagnostics), making diagnosis of this infection challenging. Here we present an antigen-based assay that detects and quantifies coccidioidal chitinase-1 (CTS1) in human serum. Methods: An inhibition-based enzyme-linked immunoassay (ELISA) was developed that utilizes a monoclonal antibody specific for coccidioidal CTS1. CTS1 was quantified in commercial antigen preparations using recombinant CTS1 as a standard. Sera from 192 individuals from an endemic area were tested, which included 78 patients (40.6%) with proven or probable coccidioidomycosis. Results: The quantity of CTS1 in diagnostic commercial antigen preparations from different suppliers varied. CTS1 antigenemia was detected in 87.2% of patients with proven or probable coccidioidomycosis. Specificity was determined to be 96.94% using serum from individuals who reside in the Phoenix, Arizona area who did not have coccidioidomycosis. Levels of CTS1 correlated with low- and high-titer serology from patients with a coccidioidomycosis diagnosis. Conclusions: Since the CTS1 inhibition ELISA described in this report does not depend on the host immune response, it is a promising diagnostic tool to aid in diagnosis and disease monitoring of coccidioidomycosis. Abstract : Diagnosis of coccidioidomycosis often relies on the host's ability to mount an immune response. Here we present an antigen-based assay that detects and quantifies coccidioidal chitinase-1 in human serum to diagnose coccidioidomycosis independent of host immune status.