Journal Article

Identification and validation of diagnostic cut-offs of the ELISpot assay for the diagnosis of invasive aspergillosis in high-risk patients

Giusti, Davide, Bettelli, Francesca, Morselli, Monica, Viale, Pierluigi, Candoni, Anna, Comoli, Patrizia, Nasillo, Vincenzo, Vallerini, Daniela, Potenza, Leonardo, Pagano, Livio, Barozzi, Patrizia, Eccher, Albino, Paolini, Ambra, Maertens, Johan, Luppi, Mario, D’Amico, Roberto, Forghieri, Fabio, Bresciani, Paola, Tagliafico, Enrico, Lewis, Russell, Trenti, Tommaso, Pioli, Valeria, Manfredini, Rossella, Lagreca, Ivana, Marasca, Roberto, Riva, Giovanni, Messerotti, Andrea, Gilioli, Andrea, Colaci, Elisabetta, Cuoghi, Angela, Sarti, Mario, Mussini, Cristina

2024

Overview

We investigated the performance of enzyme linked immunospot (ELISpot) assay for the diagnosis of invasive aspergillosis (IA) in high-risk patients with hematologic malignancies. We prospectively enrolled two cohorts of patients undergoing intensive myelosuppressive or immunosuppressive treatments at high risk for IA. ELISpot was performed to detect Aspergillus-specific T cells producing Interleukin-10. In the discovery cohort, a derived cut-off of 40 spot forming cells (SFCs)/106 PBMCs has shown to correctly classify IA cases with a sensitivity and specificity of 89.5% and 88.6%, respectively. This cut-off is lowered to 25 SFC when considering the subset of possible IA patients, with sensitivity and specificity of 76% and 93%, respectively. The application of the 40 SFCs cut-off to the validation cohort resulted in a positivity rate of 83.3% in proven/probable cases and a negativity rate of 92.5% in possible/non-IA cases. Adopting the 25 SCFs cut-off, the assay resulted positive in 83.3% of proven/probable cases while it resulted negative in 66.7% of possible/non-IA cases. ELISpot shows promises in the diagnosis of IA and the possibility to use two distinct cut-offs with similar diagnostic performances according to patients' different pre-test probability of infection can widen its use in patients at risk.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Adult / Aged / Antifungal agents / Antigens / Aspergillosis / Aspergillosis - diagnosis / Aspergillosis - immunology / Assaying / Automation / Biology and Life Sciences / Blood cancer / Culture / Cytokines / Diagnosis / Enzyme-linked immunosorbent assay / Enzyme-Linked Immunospot Assay - methods / Enzymes / Female / Fungal infections / Hematologic Neoplasms - diagnosis / Hematologic Neoplasms - immunology / Humans / Immune response / Interleukin 10 / Interleukin-10 - immunology / Interleukins / Lymphocytes / Lymphocytes T / Male / Malignancy / Medical diagnosis / Medicine and Health Sciences / Middle Aged / Pathogens / Prospective Studies / Research and Analysis Methods / Risk / Risk groups / Sensitivity / Sensitivity and Specificity / T cells / T-Lymphocytes - immunology