Retrospective analysis of 300 microbial cell-free DNA sequencing results in routine blood stream infection diagnostics

Introduction

Bloodstream infections are a critical challenge worldwide due to the slow turnaround time of conventional microbiological tests for detecting bacteremia in septic patients. Noscendo GmbH (Duisburg, Germany) has developed the CE/IVD pipeline DISQVER for clinical metagenomics testing based on cell-free DNA (cfDNA) from blood samples to address this issue.

Methods

We conducted a retrospective study to evaluate the diagnostic utility of this methodological setup in improving treatment decisions since it was introduced into our clinical setting. Between January 2021 and June 2022, the first 300 cases in which DISQVER was applied at our university hospital were collected and analyzed. The results were compared with routine microbiology test results, clinical picture, associated treatment decisions, and clinical course.

Results

Our findings demonstrate that DISQVER results where no pathogen was reported effectively ruled out bacterial bloodstream infections, whereas positive results varied in their usefulness. While the metagenomic approach proved highly valuable for detecting non-culturable and rare pathogens, its utility was limited in cases where detected microorganisms were commonly associated with the microbiota.

Discussion

Performing on-site analysis might mitigate delays resulting from logistical challenges and might help optimizing antibiotic stewardship. Once prompt results can be obtained, the relevance of incorporating molecular resistograms will become more pronounced. Further, the specific patient subgroups that most benefit from this analysis must be worked out. Guiding clinicians in identifying the infection focus based on the detected bacteria would significantly improve patient care. Lastly, evidence of filamentous fungi must be diligently followed up.

2024 update of the AGIHO guideline on diagnosis and empirical treatment of fever of unknown origin (FUO) in adult neutropenic patients with solid tumours and hematological malignancies

Febrile Neutropenia is an emergency in the treatment of cancer patients. It requires prompt and evidence-based clinical and antimicrobial management. The implementation of standard operating procedures (SOP) across hospitals and outpatient cancer departments can improve the outcome of FN patients by reducing FN-related morbidity and mortality and by the continuation of cancer treatment. This guideline describes an evidence-based approach to risk stratification, epidemiology, diagnosis, and treatment. It is provided by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) and is an update of the 2017 version. Emerging aspects in epidemiology, diagnostic procedures, risk stratification, first-line antimicrobial treatment, empiric antifungal treatment and the duration of antimicrobial treatment are discussed and rated on evidence-based strength of recommendation and quality of evidence as described by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID). By this, the aim of this guideline is to provide evidence-based recommendations on the management of febrile neutropenia in cancer patients for the practicing clinician.

Case report: Ipilimumab and nivolumab in metastatic adrenocortical cancer with high tumor mutational burden

In the setting of metastatic adrenocortical cancer, there are limited therapy options such as mitotane and platinum-based chemotherapy with only low response rates. Ipilimumab and nivolumab are approved for several solid cancer types. Tumor mutational burden is one established marker to predict treatment success of immunotherapy and has been associated with improved response rates to immune checkpoint inhibitors. We here present the case of a 68-year-old woman with metastatic adrenocortical cancer and high tumor mutational burden treated with ipilimumab and nivolumab in a fourth-line setting. She showed a stable disease for at least 48 weeks, which is significantly longer than the treatment response to mitotane or platinum-based chemotherapy. To the best of our knowledge, this is the first successful use of a long-term two-drug immunotherapy (48 weeks) in a patient with metastatic adrenocortical cancer and high mutational burden. Ipilimumab and nivolumab should be considered as a new therapy option in this patient group.

Respiratory syncytial virus infection in patients with haematological diseases: a retrospective multicentre study

PURPOSE

This study aims to evaluate the burden of respiratory syncytial virus (RSV) infections in patients with haematological diseases. It seeks to analyse the relevance of prevention, diagnosis and treatment of RSV infections.

METHODS

A multi-centre, retrospective study was conducted across University Hospitals in Cologne, Düsseldorf, Bonn, and the University Medical Centre Hamburg-Eppendorf between Jan 2016 and Aug 2023. All haematological patients with diagnosed RSV infection were included. The study focused on the incidence of RSV, underlying conditions, comorbidities, coinfections and clinical outcomes such as hospitalization, intensive care unit (ICU) admission and mortality.

RESULTS

Of 166 patients, 89 (53.6%) had signs of pneumonia and 37 (22.3%) were admitted to ICU due to RSV infection, while 20 (54%) of those were mechanically ventilated with median duration of 11 days (1,33; IQR:18). Mean age was 60 years (range 14-88). Sixteen patients (9.6%) were treated as outpatients, while 52 (31.3%) were hospitalized due to RSV infection; the median hospital stay was 16 days (IQR 25.25, range 0-97). 79 (47.6%) of patients presented with leukopenia and 57 (34.3%) with neutropenia. In total, 22 patients (13.3%) died within 30 days and 29 (17.5%) died within 90 days. Highest mortality rates were seen in patients with aggressive lymphoma (23.5%) and acute leukaemia (18%).

CONCLUSION

RSV significantly impacts patients with haematological diseases, leading to high rates of hospitalization, ICU admission, and mortality. Preventive measures, such as vaccination, alongside early diagnosis and individualized management, are essential to reduce RSV-associated morbidity and mortality in this high-risk population.

Safety and efficacy of helical tomotherapy following lung-sparing surgery in locally advanced malignant pleural mesothelioma

PURPOSE

To assess the value of radiation therapy (RT) with helical tomotherapy (HT) in the management of locally advanced malignant pleural mesothelioma (MPM) receiving no or lung-sparing surgery.

METHODS

Consecutive MPM cases not undergoing extrapleural pneumonectomy and receiving intensity-modulated (IM) HT were retrospectively evaluated for local control, distant control, progression-free survival (PFS), and overall survival (OS). Impact of age, systemic treatment, RT dose, and recurrence patterns was analyzed by univariate and multivariate analysis. As a secondary endpoint, reported toxicity was assessed.

RESULTS

A total of 34 localized MPM cases undergoing IMHT were identified, of which follow-up data were available for 31 patients. Grade 3 side effects were experienced by 26.7% of patients and there were no grade 4 or 5 events observed. Median PFS was 19 months. Median OS was 20 months and the rates for 1‑ and 2‑year OS were 86.2 and 41.4%, respectively. OS was significantly superior for patients receiving adjuvant chemotherapy (p = 0.008).

CONCLUSION

IMHT of locally advanced MPM after lung-sparing surgery is safe and feasible, resulting in satisfactory local control and survival. Adjuvant chemotherapy significantly improves OS. Randomized clinical trials incorporating modern RT techniques as a component of trimodal treatment are warranted to establish an evidence-based standard of care pattern for locally advanced MPM.

Early combination therapy of COVID-19 in high-risk patients

PURPOSE

Prolonged shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been observed in immunocompromised hosts. Early monotherapy with direct-acting antivirals or monoclonal antibodies, as recommended by the international guidelines, does not prevent this with certainty. Dual therapies may therefore have a synergistic effect.

METHODS

This retrospective, multicentre study compared treatment strategies for corona virus disease-19 (COVID-19) with combinations of nirmatrelvir/ritonavir, remdesivir, molnupiravir, and/ or mABs during the Omicron surge. Co-primary endpoints were prolonged viral shedding (≥ 106 copies/ml at day 21 after treatment initiation) and days with SARS-CoV-2 viral load ≥ 106 copies/ml. Therapeutic strategies and risk groups were compared using odds ratios and Fisher's tests or Kaplan-Meier analysis and long-rank tests. Multivariable regression analysis was performed.

RESULTS

144 patients were included with a median duration of SARS-CoV-2 viral load ≥ 106 copies/ml of 8.0 days (IQR 6.0-15.3). Underlying haematological malignancies (HM) (p = 0.03) and treatment initiation later than five days after diagnosis (p < 0.01) were significantly associated with longer viral shedding. Prolonged viral shedding was observed in 14.6% (n = 21/144), particularly in patients with underlying HM (OR 3.5; 95% CI 1.2-9.9; p = 0.02). Clinical courses of COVID-19 were mild to moderate with only few adverse effects potentially related to combination treatment.

CONCLUSION

Early combination treatment of COVID-19 effectively prevented prolonged viral shedding in 85.6% of cases. Considering the rapid viral clearance rates and low toxicity, individualized dual therapy approaches may be beneficial in high-risk patients.