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

OBJECTIVE: We investigated the performance of enzyme linked immunospot (ELISpot) assay for the diagnosis of invasive aspergillosis (IA) in high-risk patients with hematologic malignancies. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Severe acute respiratory syndrome coronavirus 2 infection in patients with hematological malignancies in the Omicron era: Respiratory failure, need for mechanical ventilation and mortality in seronegative and seropositive patients.

Background: Patients with hematological malignancies (HM) have a high risk of severe coronavirus disease 2019 (COVID-19), also in the Omicron period. Material and methods: Retrospective single-center study including HM patients with severe acute respiratory syndrome Coronavirus 2 (SARS-CoV2) infection from January 2022 to March 2023. Study outcomes were respiratory failure (RF), mechanical ventilation (MV), and COVID-related mortality, comparing patients according to SARS-CoV2 serology. Results: Note that, 112 patients were included: 39% had negative SARS-CoV2 serology. Seronegative were older (71.5 vs. 65.0 years, p = 0.04), had more often a lymphoid neoplasm (88.6% vs. 69.1%, p = 0.02), underwent anti-CD20 therapy (50.0% vs. 30.9% p = 0.04) and had more frequently a severe disease (23.0% vs. 3.0%, p = 0.02) than seropositive.Kaplan-Meier showed a higher risk for seronegative patients for RF (p = 0.014), MV (p = 0.044), and COVID-related mortality (p = 0.021). Negative SARS-CoV2 serostatus resulted in a risk factor for RF (hazards ratio [HR] 2.19, 95% confidence interval [CI] 1.03-4.67, p = 0.04), MV (HR 3.37, 95% CI 1.06-10.68, p = 0.04), and COVID-related mortality (HR 4.26, 95% CI 1.09-16.71, p = 0.04). Conclusions: : HM patients with negative SARS-CoV2 serology, despite vaccinations and previous infections, have worse clinical outcomes compared to seropositive patients in the Omicron era. The use of serology for SARS-CoV2 diagnosis could be an easy tool to identify patients prone to developing complications.