Diagnostic work up to assess early response indicators in invasive pulmonary aspergillosis in adult patients with haematologic malignancies

A peek behind the curtain in the diagnosis and management of COVID‑19‑Associated Mucormycosis (CAM)

Coronavirus disease 2019 (COVID-19)-associated mucormycosis (CAM) is responsible for a high mortality rate due to its unique and severe host-pathogen interactions. Critically ill or immunocompromised COVID-19 patients are more prone to suffer from aggressive mycoses. Probable victims include those with uncontrolled diabetes mellitus (DM), metabolic acidosis, prolonged neutropenia, increased ferritin levels, hypoxia, and prolonged hospitalization with/without mechanical ventilators and corticosteroids administration. The current review aims to outline the journey of patients with CAM as well as the advantages and disadvantages of the currently available diagnostic techniques. It also discussed the current status of treatment options and caveats in the management of mucormycosis. Multidisciplinary team, early diagnosis, controlling the predisposing condition(s), complete surgical debridement, effective antifungal therapies (e.g., amphotericin B, isavuconazole, and posaconazole), and implementing antifungal stewardship programs are imperative in CAM cases.

Sequential low-dose CT thorax scans to determine invasive pulmonary fungal infection incidence after allogeneic hematopoietic cell transplantation

Invasive fungal disease (IFD) during neutropenia goes along with a high mortality for patients after allogeneic hematopoietic cell transplantation (alloHCT). Low-dose computed tomography (CT) thorax shows good sensitivity for the diagnosis of IFD with low radiation exposure. The aim of our study was to evaluate sequential CT thorax scans at two time points as a new reliable method to detect IFD during neutropenia after alloHCT. We performed a retrospective single-center observational study in 265/354 screened patients admitted for alloHCT from June 2015 to August 2019. All were examined by a low-dose CT thorax scan at admission (CT t₀) and after stable neutrophil recovery (CT t₁) to determine the incidences of IFD. Furthermore, antifungal prophylaxis medications were recorded and cohorts were analyzed for statistical differences in IFD incidence using the sequential CT scans. In addition, IFD cases were classified according to EORTC 2008. At CT t₀ in 9.6% of the patients, an IFD was detected and antifungal therapy initiated. The cumulative incidence of IFD in CT t₁ in our department was 14%. The use of Aspergillus-effective prophylaxis through voriconazole or posaconazole decreased CT thorax t₁ suggesting IFD is statistically significant compared to prophylaxis with fluconazole (5.6% asp-azol group vs 16.3% fluconazole group, p = 0.048). In 86%, CT t₁ was negative for IFD. Low-dose sequential CT thorax scans are a valuable tool to detect pulmonary IFDs and guide antifungal prophylaxis and therapies. Furthermore, a negative CT t₁ scan shows a benefit by allowing discontinuation of antifungal medication sparing patients from drug interactions and side effects.

Aspergillosis: Emerging risk groups in critically ill patients

Information on invasive aspergillosis (IA) and other invasive filamentous fungal infections is limited in non-neutropenic patients admitted to the intensive care unit (ICU) and presenting with no classic IA risk factors. This review is based on the critical appraisal of relevant literature, on the authors' own experience and on discussions that took place at a consensus conference. It aims to review risk factors favoring aspergillosis in ICU patients, with a special emphasis on often overlooked or neglected conditions. In the ICU patients, corticosteroid use to treat underlying conditions such as chronic obstructive pulmonary disease (COPD), sepsis, or severe COVID-19, represents a cardinal risk factor for IA. Important additional host risk factors are COPD, decompensated cirrhosis, liver failure, and severe viral pneumonia (influenza, COVID-19). Clinical observations indicate that patients admitted to the ICU because of sepsis or acute respiratory distress syndrome are more likely to develop probable or proven IA, suggesting that sepsis could also be a possible direct risk factor for IA, as could small molecule inhibitors used in oncology. There are no recommendations for prophylaxis in ICU patients; posaconazole mold-active primary prophylaxis is used in some centers according to guidelines for other patient populations and IA treatment in critically ill patients is basically the same as in other patient populations. A combined evaluation of clinical signs and imaging, classical biomarkers such as the GM assay, and fungal cultures examination, remain the best option to assess response to treatment.

LAY SUMMARY

The use of corticosteroids and the presence of co-morbidities such as chronic obstructive pulmonary disease, acute or chronic advanced liver disease, or severe viral pneumonia caused by influenza or Covid-19, may increase the risk of invasive aspergillosis in intensive care unit patients.

Future challenges and chances in the diagnosis and management of invasive mould infections in cancer patients

Diagnosis, treatment, and management of invasive mould infections (IMI) are challenged by several risk factors, including local epidemiological characteristics, the emergence of fungal resistance and the innate resistance of emerging pathogens, the use of new immunosuppressants, as well as off-target effects of new oncological drugs. The presence of specific host genetic variants and the patient's immune system status may also influence the establishment of an IMI and the outcome of its therapy. Immunological components can thus be expected to play a pivotal role not only in the risk assessment and diagnosis, but also in the treatment of IMI. Cytokines could improve the reliability of an invasive aspergillosis diagnosis by serving as biomarkers as do serological and molecular assays, since they can be easily measured, and the turnaround time is short. The use of immunological markers in the assessment of treatment response could be helpful to reduce overtreatment in high risk patients and allow prompt escalation of antifungal treatment. Mould-active prophylaxis could be better targeted to individual host needs, leading to a targeted prophylaxis in patients with known immunological profiles associated with high susceptibility for IMI, in particular invasive aspergillosis. The alteration of cellular antifungal immune response through oncological drugs and immunosuppressants heavily influences the outcome and may be even more important than the choice of the antifungal treatment. There is a need for the development of new antifungal strategies, including individualized approaches for prevention and treatment of IMI that consider genetic traits of the patients.

Lay Abstract

Anticancer and immunosuppressive drugs may alter the ability of the immune system to fight invasive mould infections and may be more important than the choice of the antifungal treatment. Individualized approaches for prevention and treatment of invasive mold infections are needed.

Invasive aspergillosis in solid organ transplant patients: diagnosis, prophylaxis, treatment, and assessment of response

BACKGROUND

Invasive aspergillosis (IA) is a rare complication in solid organ transplant (SOT) recipients. Although IA has significant implications on graft and patient survival, data on diagnosis and management of this infection in SOT recipients are still limited.

METHODS

Discussion of current practices and limitations in the diagnosis, prophylaxis, and treatment of IA and proposal of means of assessing treatment response in SOT recipients.

RESULTS

Liver, lung, heart or kidney transplant recipients have common as well as different risk factors to the development of IA, thus each category needs a separate evaluation. Diagnosis of IA in SOT recipients requires a high degree of awareness, because established diagnostic tools may not provide the same sensitivity and specificity observed in the neutropenic population. IA treatment relies primarily on mold-active triazoles, but potential interactions with immunosuppressants and other concomitant therapies need special attention.

CONCLUSIONS

Criteria to assess response have not been sufficiently evaluated in the SOT population and CT lesion dynamics, and serologic markers may be influenced by the underlying disease and type and severity of immunosuppression. There is a need for well-orchestrated efforts to study IA diagnosis and management in SOT recipients and to develop comprehensive guidelines for this population.

Allicin reduces inflammation by regulating ROS/NLRP3 and autophagy in the context of A. fumigatus infection in mice

OBJECTIVES

Inhibitory effect of allicin with broad-spectrum antimicrobial activity on A. fumigatus and the regulation mechanism of inflammation and autophagy in vitro and in vivo.

METHODS

The corresponding concentration of allicin was prepared according to the needs of the experiment. In vitro, 2 ml 5 × 10⁴ of fungal spores suspension was added to the 6-well plate per hole, and different final concentrations of allicin (1 μl/ml, 2.5 μl/ml, 5 μl/ml, 10 μl/ml, 20 μl/ml, 30 μl/ml) were added. The fungal spores were stained by fluorescent dye SYTO 9 (green) every day, and the spore germination inhibition was detected by flow cytometry in different PH. RAW264.7 cells were cultured and stimulated by A. fumigatus spores for 3 h, then allicin solution was added. Then some cells were stained with ROS probe (green) and hochest33342 (blue). The effect of allicin on ROS was observed by fluorescence microscope. The other part of cells extracted protein from cell lysate and detected the effect of allicin on inflammatory factors and autophagy by Western-blotting. The green and red spots of RAW264.7 cells stably transfected with GFP-RFP-LC3 were observed by fluorescence microscopy. In vivo, A. fumigatus spore was injected intratracheally into mice, then allicin was injected intravenously at a concentration of 5 mg/kg/day for 7 consecutive days. The survival status, pulmonary fungal load and weight of mice was recorded continuously for 30 days and detected the changes of lung by pathological examination and immunohistochemistry.

RESULTS

In vitro, allicin significantly inhibited the spore germination of A. fumigatus within 24 h in a dose-dependent manner and it had a stable inhibition on the spore germination of A. fumigatus in acidic environment. Cell experiments showed that allicin inhibited intracellular spore germination by inhibiting ROS production, inflammation and autophagy. In the animal experiment, the survival rate and body weight of allicin injection group were higher than that of non injection group, while the spore load of lung was lower than that of non injection group (P < 0.05).

CONCLUSIONS

These results support that allicin reduces inflammation and autophagy resistance to A. fumigatus infection, It also provides a possible treatment for Aspergillus infectious diseases, i.e. early anti-inflammation, antibiotics or drugs that inhibit excessive autophagy.

Usefulness of serum galactomannan in initiating and modifying antifungal therapy in children with cancer and persistent high-risk febrile neutropenia

BACKGROUND

Invasive fungal disease is a major cause of morbidity and mortality in children with cancer and high-risk febrile neutropenia (HRFN). Repeated serum galactomannan (sGM) measurements have been described as an effective tool to guide therapy in adults under suspicion of invasive aspergillosis. However, the utility of this approach has not been reported in paediatric population.

OBJECTIVES

To evaluate the usefulness of sGM measurements in initiating and modifying antifungal therapy (AFT) in children with cancer and persistent HRFN.

PATIENTS/METHODS

Nested case-control study in children with cancer and persistent HRFN episodes, between July 2013 and January 2019. Patients were classified as cases and controls depending on if they received AFT or not, respectively. Through odds ratio analysis, we assessed the role of sGM positivity in the AFT initiation decision. Then, we analysed the group of patients that initiated AFT, and compared those who had AFT modifications and those who did not, analysing different sGM kinetics thresholds.

RESULTS

A total of 191 episodes from children with persistent HRFN were enrolled, of which 107 received AFT and 84 did not. The median age was 7 years (IQR 4-12), 52% were male and 89% had a haematologic malignancy as underlying disease. Positive sGM was not associated with AFT initiation (OR 0.99, 95% CI 0.43-2.33, P = .99). A difference threshold in sGM Δ ≥ 0.3 sGM was significantly associated with AFT modification (OR 5.07, 95% CI 1.02- 25.70, P = .04).

CONCLUSIONS

Our results suggest the utility of serial sGM sampling during AFT in children with persistent HRFN.

CAR T Cells Beyond Cancer: Hope for Immunomodulatory Therapy of Infectious Diseases

Infectious diseases are still a significant cause of morbidity and mortality worldwide. Despite the progress in drug development, the occurrence of microbial resistance is still a significant concern. Alternative therapeutic strategies are required for non-responding or relapsing patients. Chimeric antigen receptor (CAR) T cells has revolutionized cancer immunotherapy, providing a potential therapeutic option for patients who are unresponsive to standard treatments. Recently two CAR T cell therapies, Yescarta® (Kite Pharma/Gilead) and Kymriah® (Novartis) were approved by the FDA for the treatments of certain types of non-Hodgkin lymphoma and B-cell precursor acute lymphoblastic leukemia, respectively. The success of adoptive CAR T cell therapy for cancer has inspired researchers to develop CARs for the treatment of infectious diseases. Here, we review the main achievements in CAR T cell therapy targeting viral infections, including Human Immunodeficiency Virus, Hepatitis C Virus, Hepatitis B Virus, Human Cytomegalovirus, and opportunistic fungal infections such as invasive aspergillosis.

Invasive mould infections in solid organ transplant patients: modifiers and indicators of disease and treatment response

PURPOSE

Invasive mould infections, in particular invasive aspergillosis (IA), are comparatively frequent complications of immunosuppression in patients undergoing solid organ transplantation (SOT). Guidelines provide recommendations as to the procedures to be carried out to diagnose and treat IA, but only limited advice for SOT recipients.

METHODS

Literature review and expert consensus summarising the existing evidence related to prophylaxis, diagnosis, treatment and assessment of response to IA and infections by Mucorales in SOT patients RESULTS: Response to therapy should be assessed early and at regular intervals. No indications of improvement should lead to a prompt change of the antifungal treatment, to account for possible infections by Mucorales or other moulds such as Scedosporium. Imaging techniques, especially CT scan and possibly angiography carried out at regular intervals during early and long-term follow-up and coupled with a careful clinical diagnostic workout, should be evaluated as diagnostic tools and outcome predictors, and standardised to improve therapy monitoring. The role of biomarkers such as the galactomannan test and PCR, as well as selected inflammation parameters, has not yet been definitively assessed in the SOT population and needs to be studied further. The therapeutic workup should consider a reduction of immunosuppressive therapy.

CONCLUSIONS

The role of immunosuppression and immune tolerance mechanisms in the response to invasive fungal infection treatment is an important factor in the SOT population and should not be underestimated. The choice of the antifungal should consider not only their toxicity but also their effects on the immune system, two features that are intertwined.

Video-assisted thoracoscopic surgery for invasive pulmonary fungal infection in haematology patients

Background

Invasive pulmonary fungal infection in haematological patients sometimes was a difficult problem in diagnosis and treatments. This retrospective study was intended to assess the outcomes of video-assisted thoracoscopic surgery (VATS) in the treatments of this problem.

Methods

From January 2011 to December 2017, a total of 51 haematological patients underwent VATS for invasive pulmonary fungal infection. We collected and then analyzed potential factors including general conditions, types of haematological diseases, preoperative clinical symptoms, surgical procedures, length of postoperative hospital stay, incidence of postoperative complications and postoperative follow-ups.

Results

Of the 51 patients, 32 patients underwent video-assisted thoracoscopic wedge resection (62.7%), 6 patients underwent video-assisted thoracoscopic segmentectomy (11.8%) and 13 patients underwent video-assisted thoracoscopic lobectomy (25.5%). The mean operative time was 110.24±38.12 min. The average intraoperative blood loss was 112.35±87.85 mL. The mean postoperative hospital stay was 7.75±3.27 days. Prolonged air leak was found in 6 patients (11.8%), followed by excessive effusion which was found in 4 patients (7.8%). No life-threatening complications or resurgence of fungal infection occurred after surgery. Twenty-seven patients (52.9%) received postoperative antifungal therapies. No 30-day mortality and pulmonary fungal infection recurrence occurred in 6 to 24 months follow-ups.

Conclusions

VATS is an effective and safe option in management of invasive pulmonary fungal infection among patients with haematological diseases.

Immunomodulation as a Therapy for Aspergillus Infection: Current Status and Future Perspectives

Invasive aspergillosis (IA) is the most serious life-threatening infectious complication of intensive remission induction chemotherapy and allogeneic stem cell transplantation in patients with a variety of hematological malignancies. Aspergillus fumigatus is the most commonly isolated species from cases of IA. Despite the various improvements that have been made with preventative strategies and the development of antifungal drugs, there is an urgent need for new therapeutic approaches that focus on strategies to boost the host’s immune response, since immunological recovery is recognized as being the major determinant of the outcome of IA. Here, we aim to summarize current knowledge about a broad variety of immunotherapeutic approaches against IA, including therapies based on the transfer of distinct immune cell populations, and the administration of cytokines and antibodies.