A Novel Strategy to Identify Haematology Patients at High Risk of Developing Aspergillosis

Invasive Aspergillosis (IA), typically caused by the fungus Aspergillus fumigatus, is a leading cause of morbidity and mortality in immunocompromised patients. IA remains a significant burden in haematology patients, despite improvements in the diagnosis and treatment of Aspergillus infection. Diagnosing IA is challenging, requiring multiple factors to classify patients into possible, probable and proven IA cohorts. Given the low incidence of IA, using negative results as exclusion criteria is optimal. However, frequent false positives and severe IA mortality rates in haematology patients have led to the empirical use of toxic, drug-interactive and often ineffective anti-fungal therapeutics. Improvements in IA diagnosis are needed to reduce unnecessary anti-fungal therapy. Early IA diagnosis is vital for positive patient outcomes; therefore, a pre-emptive approach is required. In this study, we examined the sequence and expression of four C-type Lectin-like receptors (Dectin-1, Dectin-2, Mincle, Mcl) from 42 haematology patients and investigated each patient’s anti-Aspergillus immune response (IL-6, TNF). Correlation analysis revealed novel IA disease risk factors which we used to develop a pre-emptive patient stratification protocol to identify haematopoietic stem cell transplant patients at high and low risk of developing IA. This stratification protocol has the potential to enhance the identification of high-risk patients whilst reducing unnecessary treatment, minimizing the development of anti-fungal resistance, and prioritising primary disease treatment for low-risk patients.

Beta-D-Glucan in Patients with Haematological Malignancies

(1-3)-beta-D-glucan (BDG) is an almost panfungal marker (absent in zygomycetes and most cryptococci), which can be successfully used in screening and diagnostic testing in patients with haematological malignancies if its advantages and limitations are known. The aim of this review is to report the data, particularly from the last 5 years, on the use of BDG in haematological population. Published data report mainly on the performance of the Fungitell™ assay, although several others are currently available, and they vary in method and cut-off of positivity. The sensitivity of BDG for invasive fungal disease (IFD) in haematology patients seems lower than in other populations, possibly because of the type of IFD (lower sensitivity was found in case of aspergillosis compared to candidiasis and pneumocystosis) or the use of prophylaxis. The specificity of the test can be improved by using two consecutive positive assays and avoiding testing in the case of the concomitant presence of factors associated with false positive results. BDG should be used in combination with clinical assessment and other diagnostic tests, both radiological and mycological, to provide maximum information. Good performance of BDG in cerebrospinal fluid (CSF) has been reported. BDG is a useful diagnostic method in haematology patients, particularly for pneumocystosis or initial diagnosis of invasive fungal infections.

Vaccine Efficacy after Rituximab Exposure: First Interim Analysis of Virtue Project on Behalf of West Midlands Research Consortium, UK

Background: Anti-CD20 B cell depleting agents are amongst the most commonly used immunotherapeutics employed in the treatment of haematological malignancy and autoimmune diseases. By inducing peripheral B cell aplasia, anti-CD20 depleting agents are hypothesised to significantly impair serological responses to neoantigens, including the SARS-CoV-2 spike glycoprotein within SARS-CoV-2 vaccines. Seropositivity following SARS-CoV-2 is the strongest, measurable correlate of protection from severe COVID-19. Understanding the kinetics of B cell reconstitution and vaccine responsiveness following exposure to B cell depleting agents is essential to maximise vaccine efficacy in patients vulnerable to severe COVID-19. Methods: 80 patients with underlying haematological malignancy and 38 patients with underlying rheumatological disease previously treated with anti-CD20 B cell depleting agents were studied following their second dose of a SARS-CoV-2 vaccine (median time to sampling: 46.5d, IQR: 33.8-63.3). Lymphocyte subset (CD4, CD8, CD19, CD56/16) enumeration was performed using 6 colour flow cytometry (BD Trucount). Total anti-SARS-CoV-2 spike glycoprotein antibodies were measured by enzyme-linked immunosorbent assay (The Binding Site, Human Anti-IgG/A/M SARS-CoV-2-ELISA). The relationship between immune reconstitution following B cell depletion and vaccine responsiveness was explored. Results: In the haematology cohort (median age 70y, IQR 60.3-76.0, 62.5% male), overall seropositivity following vaccination was 60.0%. Individuals on active chemotherapy had significantly lower seroprevalence than those vaccinated following the completion of chemotherapy (22.7% vs 74.1%, p<0.0001). In the rheumatology cohort (median age 65y, IQR 58.3-70.8, 39.9% male), overall seropositivity was 69.4%. In both cohorts, vaccine non-responders had significantly smaller populations of peripheral CD19+ B cells (haematology: 0.20 vs 0.02 x10 9/L, p=0.004, rheumatology: 0.07 vs 0.01 x10 9/L, p=0.03). The magnitude of the antibody response following vaccination did not differ between recipients of Tozinameran and Vaxzeveria in either cohort. Vaccine responsiveness was lower in the first 6 months following B cell depletion therapy; 42.9% in the haematology cohort and 33.3% in the rheumatology cohort, increasing to 100% and 75% respectively in individuals receiving their second dose 6-12 months following B cell depletion (Figure 1). B cell reconstitution in the 7-12 month window following B cell depletion was faster in haematology compared to rheumatology patients (77.8% v 22.2% achieving normal B cell count, p=0.005) and associated with improved vaccine responsiveness. However, persistent immunodeficiency occurred in some haematology patients following completion of treatment: 25% of patients who had completed therapy at least 36 months previously failed to respond to vaccination. In this cohort of vaccine non-responders, 83.3% of individuals had B cell numbers within the normal range. These patients had all previously been treated for follicular lymphoma suggesting a specific mechanism for long-range secondary immunodeficiency in these patients. Conclusions: Serological responsiveness to SARS-CoV-2 vaccines is poor during active chemotherapy for haematological malignancy and in the first 6 months following B cell depletion, regardless of underlying disease. Vaccine responsiveness significantly improves in the 7-12 month window following B cell depletion. Compared to haematology patients, B cell reconstitution is slower in rheumatology patients and associated with reduced vaccine responsiveness, possibly due to the use of additional concurrent disease-modifying anti-rheumatic therapies. Furthermore, long-term secondary immunodeficiency occurs in a minority of haematology patients. To maximise the efficacy from SARS-CoV-2 booster vaccination and optimal utilisation of available vaccine doses, immunisations should be delivered at least 6 months following the administration of anti-CD20 depleting drugs. Figure 1: Kinetics of return of vaccine responsiveness following B cell depletion in haematology and rheumatology patients. Figure 1 Figure 1. Disclosures Paneesha: Roche: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Bristol Myers Squibb: Honoraria; AbbVie: Honoraria; Celgene: Honoraria. Drayson: Abingdon Health: Current holder of individual stocks in a privately-held company.

Retrospective analysis of mortality within 30 days of systemic anticancer therapy and comparison with a previous audit at an Australian Regional Cancer Centre

Purpose To retrospectively determine the rate of death occurring within 14 and 30 days of systemic anticancer therapy (SACT), compare this against a previous audit and benchmark results against other cancer centres. Secondly, to determine if the introduction of immune checkpoint inhibitors (ICI), not available at the time of the initial audit, impacted mortality rates. Method All adult solid tumour and haematology patients receiving SACT at an Australian Regional Cancer Centre (RCC) between January 2016 and July 2020 were included. Results Over a 55-month period, 1709 patients received SACT. Patients dying within 14 and 30 days of SACT were 3.3% and 7.0% respectively and is slightly higher than our previous study which was 1.89% and 5.6%. Mean time to death was 15.5 days. Males accounted for 63.9% of patients and the mean age was 66.8 years. 46.2% of the 119 patients dying in the 30 days post SACT started a new line of treatment during that time. Of 98 patients receiving ICI, 22.5% died within 30 days of commencement. Disease progression was the most common cause of death (79%). The most common place of death was the RCC (38.7%). Conclusion The rate of death observed in our re-audit compares favourably with our previous audit and is still at the lower end of that seen in published studies in Australia and internationally. Cases of patients dying within 30 days of SACT should be regularly reviewed to maintain awareness of this benchmark of quality assurance and provide a feedback process for clinicians.