Distinguishing the Causes of Pulmonary Infiltrates in Patients With Acute Leukemia

The Differential Diagnostic Value of Chest Computed Tomography for the Identification of Pathogens Causing Pulmonary Infections in Patients with Hematological Malignancies

Objective

The role of chest computed tomography (CT) in distinguishing the causative pathogens of pulmonary infections in patients with hematological malignancies (HM) is unclear. The aim of our study was to compare and assess the clinical characteristics, radiologic features and potential differential diagnostic value of CT in HM patients and other different immune statuses patients with pulmonary infections.

Methods

Patients were divided into immunocompetent (105 cases) and immunocompromised groups (99 cases) according to immune status. Immunocompromised patients included the HM group (63 cases) and the non-HM group (42 cases). The basic clinical data and CT findings were collected and statistically analyzed.

Results

Regarding the pathogen distribution, viral, Pneumocystis jirovecii and mixed infections were more common in the immunocompromised group than the immunocompetent (p < 0.01), but viral infections were more common in the HM group than in the non-HM group (p=0.013). Immunocompromised patients had more diverse CT findings and more serious lesions (mostly graded 2-4) than immunocompetent patients. The most common CT findings in HM patients were consolidation and ground-glass opacities (GGO), which were also found in the non-HM group. The overall diagnostic accuracy of CT was lower in immunocompromised patients than in immunocompetent patients (25.7% vs 50.5%, p< 0.01). CT had better diagnostic efficacy for fungi and Pneumocystis jirovecii in HM patients.

Conclusion

CT diagnosis is less efficient in distinguishing the causative pathogens of HM patients. However, CT can help distinguish fungal pneumonia and Pneumocystis jirovecii pneumonia in HM patients.

Clinical Relevance Statement

Our study might facilitate clinical decision-making in fungal pneumonia and Pneumocystis jirovecii pneumonia in HM patients.

BALF metagenomic next-generation sequencing analysis in hematological malignancy patients with suspected pulmonary infection: clinical significance of negative results

Purpose

Metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) is gradually being used in hematological malignancy (HM) patients with suspected pulmonary infections. However, negative results are common and the clinical value and interpretation of such results in this patient population require further analysis.

Methods

Retrospective analysis of 112 HM patients with suspected pulmonary infection who underwent BALF mNGS and conventional microbiological tests. The final diagnosis, imaging findings, laboratory results and treatment regimen of 29 mNGS-negative patients were mainly analyzed.

Results

A total of 83 mNGS positive and 29 negative patients (15 true-negatives and 14 false-negatives) were included in the study. Compared to false-negative patients, true-negative patients showed more thickening of interlobular septa on imaging (p < 0.05); fewer true-negative patients had acute respiratory symptoms such as coughing or sputum production (p < 0.05) clinically; On the aspect of etiology, drug-related interstitial pneumonia (6/15, 40%) was the most common type of lung lesion in true-negative patients; on the aspect of pathogenesis, false-negative patients mainly missed atypical pathogens such as fungi and tuberculosis (8/14, 57.1%). Regarding treatment, delayed anti-infection treatment occurred after pathogen missing in mNGS false-negative patients, with the longest median time delay observed for anti-tuberculosis therapy (13 days), followed by antifungal therapy (7 days), and antibacterial therapy (1.5 days); the delay in anti-tuberculosis therapy was significantly longer than that in antibacterial therapy (p < 0.05).

Conclusion

For HMs patients with imaging showing thickening of interlobular septa and no obvious acute respiratory symptoms, lung lesions are more likely caused by drug treatment or the underlying disease, so caution should be exercised when performing BALF mNGS. If BALF mNGS is negative but infection is still suspected, atypical pathogenic infections should be considered.

Precision Therapy for Invasive Fungal Diseases

Invasive fungal infections (IFI) are a common infection-related cause of death in immunocompromised patients. Approximately 10 million people are at risk of developing invasive aspergillosis annually. Detailed study of the pharmacokinetics (PK) and pharmacodynamics (PD) of antifungal drugs has resulted in a better understanding of optimal regimens for populations, drug exposure targets for therapeutic drug monitoring, and establishing in vitro susceptibility breakpoints. Importantly, however, each is an example of a “one size fits all strategy”, where complex systems are reduced to a singularity that ensures antifungal therapy is administered safely and effectively at the level of a population. Clearly, such a notion serves most patients adequately but is completely counter to the covenant at the centre of the clinician–patient relationship, where each patient should know whether they are well-positioned to maximally benefit from an antifungal drug. This review discusses the current therapy of fungal infections and areas of future research to maximise the effectiveness of antifungal therapy at an individual level.

Two autopsy cases of pulmonary leukemic infiltration mimicking severe pneumonia in patients with acute myeloid leukemia

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Diverse pulmonary complications are often observed in acute myeloid leukemia.

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Clinically significant leukemic infiltration is rarely recognized antemortem.

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Autopsy revealed leukemic infiltration in patient mimicking severe pneumonia.

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It may be difficult to achieved accurate diagnosis without pathological examination.

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Non-invasive examinations for leukemic infiltration diagnosis are required.

Although a previous autopsy series demonstrated that pulmonary leukemic infiltration (PLI) is a major pulmonary complication in patients with acute myeloid leukemia (AML), an antemortem diagnosis of PLI is rare. Diverse pulmonary complications cause acute respiratory failure (ARF) in patients with AML undergoing chemotherapy. This article reports two elderly patients with AML who presented with ARF due to PLI mimicking severe pneumonia during induction chemotherapy. Accurate antemortem diagnosis of PLI was almost impossible without pathological examination since the clinical course was not typical of PLI. We recommend considering PLI in patients with AML who have an unknown etiology of ARF.

Progressive Dyspnea and Hypoxemia With Diffuse Pulmonary Infiltrates in a Previously Healthy Woman

CASE PRESENTATION

A 50-year-old woman presented with 3 months of cough, dyspnea, and fatigue. She also reported new fevers, night sweats, and a rash on her face and torso. On presentation she was tachycardic and tachypneic, with oxygen saturation of 81% on 2 L/min of oxygen. She was in mild respiratory distress. Results of the physical examination were remarkable for tender left cervical and axillary adenopathy and bibasilar pulmonary crackles. She had an acneiform rash on her face, chest, and back, consisting of multiple nonblanching erythematous or violaceous macules and papules (Fig 1) and had conjunctival edema. Admission laboratory test results were significant for a WBC count of 56,000, of which 79.5% were lymphocytes. Hemoglobin and platelet levels were normal. She was admitted for further management.

Shock and Early Death in Hematologic Patients with Febrile Neutropenia

Empirical antibiotic therapy with a beta-lactam is the standard of care in febrile neutropenia (FN) and is given to prevent early death. The addition of vancomycin is recommended in certain circumstances, but the quality of evidence is low, reflecting the lack of clinical data. In order to characterize the epidemiology of early death and shock in FN, we reviewed all episodes of FN from 2003 to 2017 at University Hospital, Federal University of Rio de Janeiro, and looked at factors associated with shock at first fever and early death (within 3 days from first fever) by univariate and multivariate analyses. Among 1,305 episodes of FN, shock occurred in 42 episodes (3.2%) and early death in 15 (1.1%). Predictors of shock were bacteremia due to Escherichia coli (odds ratio [OR], 8.47; 95% confidence interval [95% CI], 4.08 to 17.55; P < 0.001), Enterobacter sp. (OR, 7.53; 95% CI, 1.60 to 35.33; P = 0.01), and Acinetobacter sp. (OR, 6.95; 95% CI, 1.49 to 32.36; P = 0.01). Factors associated with early death were non-Hodgkin's lymphoma (OR, 3.57; 95% CI, 1.18 to 10.73; P = 0.02), pneumonia (OR, 21.36; 95% CI, 5.72 to 79.72; P < 0.001), shock (OR, 11.64: 95% CI, 2.77 to 48.86; P = 0.01), and bacteremia due to Klebsiella pneumoniae (OR, 5.91; 95% CI, 1.11 to 31.47; P = 0.03). Adequate empirical antibiotic therapy was protective (OR, 0.23; 95% CI, 0.07 to 0.81; P = 0.02). Shock or early death was not associated with Gram-positive bacteremia; catheter-related, skin, or soft tissue infection; or inadequate Gram-positive coverage. These data challenge guideline recommendations for the empirical use of vancomycin at first fever in neutropenic patients.

A 74-Year-Old Man Presenting With Cough, Malaise, and Mediastinal Lymphadenopathy

CASE PRESENTATION

A 74-year-old white male farmer was admitted from his primary care physician's office after he presented with symptoms of cough productive of clear sputum, malaise, weakness, fatigue, and shortness of breath on exertion for 3 weeks. He was an ex-smoker with a history of hypertension, hyperlipidemia, and coronary artery bypass graft surgery. He did not report any chills, night sweats, or fevers during this presentation.

High cortactin expression in B-cell acute lymphoblastic leukemia is associated with increased transendothelial migration and bone marrow relapse

Cancer is a major cause of death in children worldwide, with B-lineage cell acute lymphoblastic leukemia (B-ALL) being the most frequent childhood malignancy. Relapse, treatment failure and organ infiltration worsen the prognosis, warranting a better understanding of the implicated mechanisms. Cortactin is an actin-binding protein involved in cell adhesion and migration that is overexpressed in many solid tumors and in adult B-cell chronic lymphocytic leukemia. Here, we investigated cortactin expression and potential impact on infiltration and disease prognosis in childhood B-ALL. B-ALL cell lines and precursor cells from bone marrow (BM) and cerebrospinal fluid (CSF) of B-ALL patients indeed overexpressed cortactin. In CXCL12-induced transendothelial migration assays, transmigrated B-ALL cells had highest cortactin expression. In xenotransplantation models, only cortactinhigh-leukemic cells infiltrated lungs, brain, and testis; and they colonized more easily hypoxic BM organoids. Importantly, cortactin-depleted B-ALL cells were significantly less efficient in transendothelial migration, organ infiltration and BM colonization. Clinical data highlighted a significant correlation between high cortactin levels and BM relapse in drug-resistant high-risk B-ALL patients. Our results emphasize the importance of cortactin in B-ALL organ infiltration and BM relapse and its potential as diagnostic tool to identify high-risk patients and optimize their treatments.

Analysis of Clinical Profile and Outcome of Tuberculosis in Patients with Acute Leukemia

Patients with acute leukemia (AL) are predisposed to develop infections including tuberculosis (TB). The risk is specifically higher in patients from TB endemic areas. Patients (≥12 years) with AL treated between January-2014 to January-2017 who developed TB were reviewed. Patients were classified into three groups: acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML) and acute promyelocytic leukemia (APML) and a systematic analysis of clinical features and outcomes was conducted. Over the study period, 26 patients of AL developed TB. The median time to diagnosis of TB was 8 weeks (0-432 weeks) following the diagnosis of AL and it was comparable between the three leukemia groups. The diagnosis of TB required alteration of anti-leukemia therapy in 26.9% patients and rescheduling in another 42.3% patients. Therapy alteration/rescheduling were more frequent in patients with AML as compared to ALL and APML (p < 0.03, <0.04). Disseminated TB was more common in AML patients (p < 0.016). ATT could be successfully administered in 86.9% patients with improvement of TB. The incidence of ATT induced hepatitis was 34.9%. Mortality was directly attributable to TB in 10% patients. Managing tuberculosis remains a challenge during treatment of acute leukemia. With this analysis, we advocate for a need of early suspicion and evaluation for TB in patients receiving treatment for acute leukemia. Rescheduling and or alteration of anticancer therapy due to TB is associated with significantly higher mortality. Therefore, in carefully selected cases, antileukemia therapy should continue after starting ATT as early as possible.

Fungal infections of the lung in children

Fungal infections of the lungs are relatively common and potentially life-threatening conditions in immunocompromised children. The role of imaging in children with lung mycosis is to delineate the extension of pulmonary involvement, to assess response to therapy, and to monitor for adverse sequelae such as bronchiectasis and cavitation. The aim of this paper is to show imaging findings in a series of patients with fungal pneumonia from two tertiary children's hospitals, to discuss differential diagnoses and to show how imaging findings can vary depending on the host immune response.