PLoS ONE (Jan 2024)

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

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

DOI
https://doi.org/10.1371/journal.pone.0306728
Journal volume & issue
Vol. 19, no. 7
p. e0306728

Abstract

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ObjectiveWe investigated the performance of enzyme linked immunospot (ELISpot) assay for the diagnosis of invasive aspergillosis (IA) in high-risk patients with hematologic malignancies.MethodsWe 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.ResultsIn 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.ConclusionsELISpot 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.