Role of pre-transplant chest high-resolution computed tomography and serum galactomannan index in predicting post-transplant invasive pulmonary aspergillosis in allogeneic hematopoietic cell transplant recipients

Adoption value of support vector machine algorithm-based computed tomography imaging in the diagnosis of secondary pulmonary fungal infections in patients with malignant hematological disorders

This study aimed to assess the feasibility of diagnosing secondary pulmonary fungal infections (PFIs) in patients with hematological malignancies (HM) using computerized tomography (CT) imaging and a support vector machine (SVM) algorithm. A total of 100 patients with HM complicated by secondary PFI underwent CT scans, and they were included in the training group. Concurrently, 80 patients with the same underlying disease who were treated at our institution were included in the test group. The types of pathogens among different PFI patients and the CT imaging features were compared. Radiomic features were extracted from the CT imaging data of patients, and a diagnostic SVM model was constructed by integrating these features with clinical characteristics. Aspergillus was the most common pathogen responsible for PFIs, followed by Candida, Pneumocystis jirovecii, Mucor, and Cryptococcus, in descending order of occurrence. Patients typically exhibited bilateral diffuse lung lesions. Within the SVM algorithm model, six radiomic features, namely the square root of the inverse covariance of the gray-level co-occurrence matrix (square root IV), the square root of the inverse covariance of the gray-level co-occurrence matrix, and small dependency low gray-level emphasis, significantly influenced the diagnosis of secondary PFIs in patients with HM. The area under the curve values for the training and test sets were 0.902 and 0.891, respectively. Therefore, CT images based on the SVM algorithm demonstrated robust predictive capability in diagnosing secondary PFIs in conjunction with HM.

Diagnostic Utility of Galactomannan Enzyme Immunoassay in Invasive Aspergillosis in Pediatric patients with Hematological Malignancy

OBJECTIVE

This study aims to determine the diagnostic utility of galactomannan enzyme immunoassay (GM EIA) in invasive aspergillosis (IA) in children with hematological malignancy (high risk population) in terms of sensitivity, specificity, negative predictive value (NPV) and positive predictive values (PPV) at various cut offs while validating the revised EORTC/MSG 2019 criteria in order to obtain the best cut-off.

MATERIAL AND METHODS

For 100 pediatric patients, serum and respiratory samples were collected. Clinical, mycological workup (potassium-hydroxide mount, fungal culture) and GM EIA was done to classify proven, probable, and possible IA as per EORTC-MSG guidelines,2019. Sensitivity, specificity, PPV and NPV were calculated of GM indices at cut-off 0.5, 0.7 and 1, and validated with revised EORTC -MSG, 2019.

RESULTS

Of 100 patients enrolled, 75 were diagnosed with ALL, 14 with AML, two with Hodgkin's, three had non-Hodgkin lymphoma, and six had undifferentiated leukemia. With routine mycological findings, 51 were classified as probable IA, 11 as possible IA, and 38 as no IA. Aspergillus flavus was the most prevalent on culture (56.9%, 29/51) followed by A. fumigatus (29%, 15/51) A. niger (7.8%, 4/51), A. terreus (3.9%, 2/51) and A. nidulans (2%, 1/51). GM EIA demonstrated sensitivity 82.3%, specificity 97.4%, PPV 98.1%, and NPV 77.1% at cut-off 0.67 when comparing probable/possible IA v/s no IA groups. The GM EIA had the best sensitivity (82.4%), specificity (81.8%), PPV (95.5%), and NPV (50%) at cut off 0.78 when the probable IA group was compared to the possible IA. Seven patients succumbed of whom 5 had GMI ≥ 2.

CONCLUSION

This study deduces the optimal cut-off for serum GM EIA to be 0.67 obtained by ROC analysis when comparing possible and probable IA versus no IA and reinforces the definition of probable category of EORTC-MSG criteria, 2019. At 0.5 ODI the sensitivity (87.1%) and NPV (80.5%) are high, thus making it the most suitable cut-off for detecting true positive and ruling out IA respectively, in pediatric patients with hematological malignancy. GM EIA when performed adjunctive to clinico-radiological findings can prove to be screening, diagnostic and prognostic test for IA in pediatric hematological malignancy patients.

Approach to diagnostic evaluation and prevention of invasive fungal disease in patients prior to allogeneic hematopoietic stem cell transplant

In recent years, advancements in the treatment landscape for hematological malignancies, such as acute myeloid leukemia and acute lymphoblastic leukemia, have significantly improved disease prognosis and overall survival. However, the treatment landscape is changing and the emergence of targeted oral therapies and immune-based treatments has brought forth new challenges in evaluating and preventing invasive fungal diseases (IFDs). IFD disproportionately affects immunocompromised hosts, particularly those undergoing therapy for acute leukemia and allogeneic hematopoietic stem cell transplant. This review aims to provide a comprehensive overview of the pretransplant workup, identification, and prevention of IFD in patients with hematological malignancy. The pretransplant period offers a critical window to assess each patient's risk factors and implement appropriate prophylactic measures. Risk assessment includes evaluation of disease, host, prior treatments, and environmental factors, allowing a dynamic evaluation that considers disease progression and treatment course. Diagnostic screening, involving various biomarkers and radiological modalities, plays a crucial role in early detection of IFD. Antifungal prophylaxis choice is based on available evidence as well as individual risk assessment, potential for drug-drug interactions, toxicity, and patient adherence. Therapeutic drug monitoring ensures effective antifungal stewardship and optimal treatment. Patient education and counselling are vital in minimizing environmental exposures to fungal pathogens and promoting medication adherence. A well-structured and individualized approach, encompassing risk assessment, prophylaxis, surveillance, and patient education, is essential for effectively preventing IFD in hematological malignancies, ultimately leading to improved patient outcomes and overall survival.