Comparison of CT features of Aspergillus and bacterial pneumonia in severely neutropenic patients

Diagnosis by metagenomic next-generation sequencing of invasive pulmonary aspergillosis in an infant with chronic granulomatous disease

Invasive pulmonary aspergillosis (IPA) is a serious fungal infection, with a high degree of mortality in immunocompromised individuals. Diagnosis of IPA is challenging in that clinical manifestations are not specific, with sensitivity of traditional detection procedures low. We report a case of IPA in a chronic granulomatous disease (CGD) infant who was initially suspected to have a lung tumor. Aspergillus fumigatus was identified as the pathogen in bronchoalveolar lavage fluid (BALF) by next-generation sequencing (mNGS). The patient recovered rapidly following a change of appropriate antifungal treatment and was discharged. This case highlights the additional value of BALF-mNGS for the diagnosis of pediatric invasive pulmonary fungal infection in immune-deficient children.

A CT-based nomogram for differentiating invasive fungal disease of the lung from bacterial pneumonia

Background

There is an annual increase in the incidence of invasive fungal disease (IFD) of the lung worldwide, but it is always a challenge for physicians to make an early diagnosis of IFD of the lung. Computed tomography (CT) may play a certain role in the diagnosis of IFD of the lung, however, there are no specific imaging signs for differentiating IFD of lung from bacterial pneumonia (BP).

Methods

A total of 214 patients with IFD of the lung or clinically confirmed BP were retrospectively enrolled from two institutions (171 patients from one institution in the training set and 43 patients from another institution in the test set). The features of thoracic CT images of the 214 patients were analyzed on the picture archiving and communication system by two radiologists, and these CT images were imported into RadCloud to perform radiomics analysis. A clinical model from radiologic analysis, a radiomics model from radiomics analysis and a combined model from integrating radiologic and radiomics analysis were constructed in the training set, and a nomogram based on the combined model was further developed. The area under the ROC curve (AUC) of the receiver operating characteristic (ROC) curve was calculated to assess the diagnostic performance of the three models. Decision curve analysis (DCA) was conducted to evaluate the clinical utility of the three models by estimating the net benefit at a range of threshold probabilities.

Results

The AUCs of the clinical model for differentiating IFD of lung from BP in the training set and test sets were 0.820 and 0.827. The AUCs of the radiomics model in the training set and test sets were 0.895 and 0.857. The AUCs of the combined model in the training set and test setswere 0.944 and 0.911. The combined model for differentiating IFD of lung from BP obtained the greatest net benefit among the three models by DCA.

Conclusion

Our proposed nomogram, based on a combined model integrating radiologic and radiomics analysis, has a powerful predictive capability for differentiating IFD from BP. A good clinical outcome could be obtained using our nomogram.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-022-00903-5.

Two Monoclonal Antibodies That Specifically Recognize Aspergillus Cell Wall Antigens and Can Detect Circulating Antigens in Infected Mice

Invasive aspergillosis (IA) is a life-threatening disease mainly caused by Aspergillus fumigatus and Aspergillus flavus. Early diagnosis of this condition is crucial for patient treatment and survival. As current diagnostic techniques for IA lack sufficient accuracy, we have raised two monoclonal antibodies (1D2 and 4E4) against A. fumigatus cell wall fragments that may provide a platform for a new diagnostic approach. The immunoreactivity of these antibodies was tested by immunofluorescence and ELISA against various Aspergillus and Candida species in vitro and by immunohistochemistry in A. fumigatus infected mouse tissues. Both monoclonal antibodies (mAbs) showed intensive fluorescence with the hyphae wall of A. fumigatus and A. flavus, but there was no staining with other Aspergillus species or Candida species. Both mAbs also showed strong immunoreactivity to the cell wall of A. fumigatus hyphae in the infected liver, spleen and kidney of mice with IA. The antigens identified by 1D2 and 4E4 might be glycoproteins and the epitopes are most likely a protein or peptide rather than a carbohydrate. An antibody-based antigen capture ELISA detected the extracellular antigens released by A. fumigatus, A. flavus, A. niger and A. terreus, but not in Candida species. The antigen could be detected in the plasma of mice after 48 h of infection by double-sandwich ELISA. In conclusion, both 1D2 and 4E4 mAbs are potentially promising diagnostic tools to investigate invasive aspergillosis.

Radiological CT Patterns and Distribution of Invasive Pulmonary Aspergillus, Non-Aspergillus, Cryptococcus and Pneumocystis Jirovecii Mold Infections - A Multicenter Study

PURPOSE

 Clinical signs and symptoms related to invasive fungal disease are nonspecific and need to be followed up by appropriate diagnostic procedures. The goal of this study was to analyze CT imaging patterns in invasive fungal infections and their correlation with the immune status and clinical outcome.

MATERIALS AND METHODS

 We performed a retrospective multicenter study including 85 consecutive patients with invasive pulmonary fungal infection (2011-2014). Lung patterns on computed tomography (CT) scans were classified according to the Fleischner Society glossary. The patients were grouped according to immune status (neutropenia, steroid therapy, organ transplant recipient, and other cause) and outcome (positive outcome, progressive disease, and death). The Chi square test or Fisher exact test was used. Bonferroni correction was applied.

RESULTS

 The total number of patients with invasive Aspergillus and non-Aspergillus infection (IANA), Pneumocystis jirovecii pneumonia (PCP), and Cryptococcus (CRY) was 60, 22, and 3, respectively. Patients with IANA demonstrated significantly more nodules (93 % vs. 59 %, p = 0.001), significantly fewer ground glass opacities (58 % vs. 96 %, p = 0.005), and significantly fewer positive lymph nodes (5 % vs. 41 %, p < 0.001) than patients with PCP. All patients with PCP and CRY had a favorable outcome. Patients with IANA and an adverse outcome demonstrated significantly more nodules with halo sign than patients with IANA and a favorable outcome (42.5 % vs. 15.9 %, p < 0.0001). Interestingly, patients with IANA and a favorable outcome had a higher prevalence of pulmonary infarction than patients with an adverse outcome (8 % vs. 1 %, p = 0.047). Patients with neutropenia showed significantly more consolidations (66 %) than organ transplant recipients (27 %, p = 0.045).

CONCLUSION

 Patients with IANA showed a higher prevalence of nodules and a lower prevalence of ground glass opacities than patients with PCP. In patients with IANA, nodules with halo sign were associated with an adverse outcome. Patients with neutropenia showed generally more consolidations, but the consolidations were not associated with an adverse outcome.

KEY POINTS

  · Nodules, ground glass opacities, and consolidations are common CT findings in all invasive pulmonary fungal infections.. · There is no pattern that is unique for one specific pathogen, although nodules are more predominant in IANA and Cryptococcus, and ground glass opacities are more predominant in PCP patients.. · Immune status had an impact on CT findings in fungal pneumonia with less consolidation in patients after organ transplantation compared to patients with neutropenia.. · Nodules with a halo sign are associated with a worse outcome..

CITATION FORMAT

· Obmann VC, Bickel F, Hosek N et al. Radiological CT Patterns and Distribution of Invasive Pulmonary Aspergillus, Non-Aspergillus, Cryptococcus and Pneumocystis Jirovecii Mold Infections - A Multicenter Study. Fortschr Röntgenstr 2021; DOI: 10.1055/a-1482-8336.

Guidance on Imaging for Invasive Pulmonary Aspergillosis and Mucormycosis: From the Imaging Working Group for the Revision and Update of the Consensus Definitions of Fungal Disease from the EORTC/MSGERC

BACKGROUND

Clinical imaging in suspected invasive fungal disease (IFD) has a significant role in early detection of disease and helps direct further testing and treatment. Revised definitions of IFD from the EORTC/MSGERC were recently published and provide clarity on the role of imaging for the definition of IFD. Here, we provide evidence to support these revised diagnostic guidelines.

METHODS

We reviewed data on imaging modalities and techniques used to characterize IFDs.

RESULTS

Volumetric high-resolution computed tomography (CT) is the method of choice for lung imaging. Although no CT radiologic pattern is pathognomonic of IFD, the halo sign, in the appropriate clinical setting, is highly suggestive of invasive pulmonary aspergillosis (IPA) and associated with specific stages of the disease. The ACS is not specific for IFD and occurs in the later stages of infection. By contrast, the reversed halo sign and the hypodense sign are typical of pulmonary mucormycosis but occur less frequently. In noncancer populations, both invasive pulmonary aspergillosis and mucormycosis are associated with "atypical" nonnodular presentations, including consolidation and ground-glass opacities.

CONCLUSIONS

A uniform definition of IFD could improve the quality of clinical studies and aid in differentiating IFD from other pathology in clinical practice. Radiologic assessment of the lung is an important component of the diagnostic work-up and management of IFD. Periodic review of imaging studies that characterize findings in patients with IFD will inform future diagnostic guidelines.

Johnson E, Littlechild J, Winlove CP, Vollmer F, Gow NAR. Biosensors and Diagnostics for Fungal Detection

Early detection is critical to the successful treatment of life-threatening infections caused by fungal pathogens, as late diagnosis of systemic infection almost always equates with a poor prognosis. The field of fungal diagnostics has some tests that are relatively simple, rapid to perform and are potentially suitable at the point of care. However, there are also more complex high-technology methodologies that offer new opportunities regarding the scale and precision of fungal diagnosis, but may be more limited in their portability and affordability. Future developments in this field are increasingly incorporating new technologies provided by the use of new format biosensors. This overview provides a critical review of current fungal diagnostics and the development of new biophysical technologies that are being applied for selective new sensitive fungal biosensors to augment traditional diagnostic methodologies.

Diagnosis and treatment of invasive fungal infections: looking ahead

Improved standards of care depend on the development of new laboratory diagnostic and imaging procedures and the development of new antifungal compounds. Immunochromatography technologies have led to the development of lateral flow devices for the diagnosis of cryptococcal meningitis and invasive aspergillosis (IA). Similar devices are being developed for the detection of histoplasmosis that meet the requirements for speed (∼15 min assay time) and ease of use for point-of-care diagnostics. The evolution of molecular tools for the detection of fungal pathogens has been slow but the introduction of new nucleic acid amplification techniques appears to be helpful, for example T2Candida. An Aspergillus proximity ligation assay has been developed for a rapid near-patient bedside diagnosis of IA. CT remains the cornerstone for radiological diagnosis of invasive pulmonary fungal infections. MRI of the lungs may be performed to avoid radiation exposure. MRI with T2-weighted turbo-spin-echo sequences exhibits sensitivity and specificity approaching that of CT for the diagnosis of invasive pulmonary aspergillosis. The final part of this review looks at new approaches to drug discovery that have yielded new classes with novel mechanisms of action. There are currently two new classes of antifungal drugs in Phase 2 study for systemic invasive fungal disease and one in Phase 1. These new antifungal drugs show promise in meeting unmet needs with oral and intravenous formulations available and some with decreased potential for drug-drug interactions. Novel mechanisms of action mean these agents are not susceptible to the common resistance mechanisms seen in Candida or Aspergillus. Modification of existing antifungal susceptibility testing techniques may be required to incorporate these new compounds.

CT Halo sign: A systematic review

PURPOSE

The CT Halo sign or Halo sign (HS) refers to ground-glass opacity surrounding a nodule or mass in the lung parenchyma. We conducted a systematic review to find the etiological associations of HS. We also evaluated the diagnostic performances of HS for invasive fungal infections (IFI) in immunosuppressed patients.

METHOD

The systematic review was conducted as per PRISMA guidelines. We searched the PubMed and EMBASE database till June 2018 without any restrictions. Only case reports, case series and original articles published in English language were included. A database created from the electronic searches was compiled and subsequent analysis was done. [PROSPERO registration: CRD42018094739] RESULTS: 168 studies were eligible, which included 51 case reports, 15 prospective studies, 102 retrospective studies. A total of 1977 patients (out of 6371) with HS were identified with age range between <1year-94years. The most common diagnosis in the immunosuppressed, mixed, immunocompetent and not specified groups were IFI (86.9 %, n = 1194), Cryptococcosis (51.6 %, n = 124), Cryptococcosis (40 %, n = 20) and lung neoplasms (81.8 %, n = 36) respectively. 14 studies (11 retrospective, 3 prospective) were included in quantitative analysis. The pooled sensitivity(sn), specificity(sp) and odd's ratio (OR) of HS for diagnosing IFI were 50.4 %, 91 % and 6.61 respectively. Also, HS could not reliably differentiate IPA from mucormycosis in the pooled analysis.

CONCLUSIONS

HS can be seen in a large number of diverse conditions both in immunosuppressed and immunocompetent population. In immunosuppressed patients HS is specific for IFI but cannot rule it out. Additionally, it cannot reliably distinguish between IPA and mucormycosis.

Clinical and computed tomographic (CT) images characteristics in the patients with COVID-19 infection: What should radiologists need to know?

OBJECTIVE

To evaluate the clinical and computed tomographic (CT) features in the patients with COVID-19 pneumonia confirmed by the real-time reverse transcriptase polymerase chain reaction (rRT-PCR) amplification of the viral DNA from a sputum sample.

MATERIAL AND METHODS

Clinical information and CT findings of a total of 14 patients with COVID-19 infection (age range, 12-83 years; females 6) were analyzed retrospectively. The clinical information includes the history of exposure, laboratory results, and the symptoms (such as fever, cough, headache, etc.); CT findings of chest include the extension and distribution of lesion, the ground-glass opacity (GGO), consolidation, bronchovascular enlarged, irregular linear appearances, pleural effusion, and lymphadenopathy.

RESULTS

Eight patients had the exposure history for recent travel to Wuhan of Hubei province (8/14, 57%), 6 had the exposure to patients with COVID-19 infection. Significant statistical differences were observed in lymphocyte percentage decreased and C-reactive protein elevated (p = 0.015). Seven patients had fever, 7 had cough, 2 had headache, 3 had fatigue, 1 had body soreness, 3 had diarrhea, and 2 had no obvious symptoms. In chest CT examination, 10 patients were positive (10/14, 71.43%). Among these patients, 9 had lesions involving both lungs (9/10, 90%), 8 had lesions involving 4 to 5 lobes (8/10, 80%). Most of lesions were distributed peripherally and the most significant lesions were observed in the right lower lobe in 9 patients (9/10, 90%). Nodules were observed in 5 patients (5/10, 50%); GGO, consolidation, and bronchovascular enlarged were shown in 9 patients (9/10, 90%); irregular linear appearances were revealed in 7 patients (7/10, 70%); and pleural effusions were exhibited in 2 patients (2/10, 20%). Last, no patients showed lymphadenopathy.

CONCLUSION

There were some typical CT features for diagnosis of COVID-19 pneumonia. The radiologists should know these CT findings and clinical information, which could help for accurate analysis in the patients with 2019 novel coronavirus infection.

Cost-effectiveness of antifungal prophylaxis, preemptive therapy, or empiric treatment following allogeneic hematopoietic stem cell transplant

BACKGROUND

Invasive fungal infection (IFI) is a life-threatening complication of allogeneic hematopoietic stem cell transplantation (HSCT) that is also associated with excess healthcare costs. Current approaches include universal antifungal prophylaxis, preemptive therapy based on biomarker surveillance, and empiric treatment initiated in response to clinical signs/symptoms. However, no study has directly compared the cost-effectiveness of these treatment strategies for an allogeneic HSCT patient population.

METHODS

We developed a state transition model to study the impact of treatment strategies on outcomes associated with IFIs in the first 100 days following myeloablative allogeneic HSCT. We compared three treatment strategies: empiric voriconazole, preemptive voriconazole (200 mg), or prophylactic posaconazole (300 mg) for the management of IFIs. Preemptive treatment was guided by scheduled laboratory surveillance with galactomannan (GM) testing. Endpoints were cost and survival at 100 days post-HSCT.

RESULTS

Empiric treatment was the least costly ($147 482) and was equally effective (85.2% survival at 100 days) as the preemptive treatment strategies. Preemptive treatments were slightly more costly than empiric treatment (GM cutoff ≥ 1.0 $147 910 and GM cutoff ≥ 0.5 $148 108). Preemptive therapy with GM cutoff ≥ 1.0 reduced anti-mold therapy by 5% when compared to empiric therapy. Posaconazole prophylaxis was the most effective (86.6% survival at 100 days) and costly ($152 240) treatment strategy with a cost of $352 415 per life saved when compared to empiric therapy.

CONCLUSIONS

One preemptive treatment strategy reduced overall anti-mold drug exposure but did not reduce overall costs. Prevention of IFI using posaconazole prophylaxis was the most effective treatment strategy and may be cost-effective, depending upon the willingness to pay per life saved.

Clinical diagnostic value of spiral CT in invasive pulmonary fungal infection

This study explored the diagnostic value of computed tomography (CT) in pulmonary fungal infection to provide a theoretical basis for the clinical diagnosis of pulmonary fungal infections. The clinical data of 82 suspected invasive fungal infection (IFI) patients admitted to the Department of Critical Care Medicine of The Affiliated Hospital of Qingdao University from January 2016 to May 2018 were retrospectively analyzed, and 64 of them were diagnosed with IFI by pathology and sputum culture. The CT results of the 82 patients were compared with the X-ray results in order to analyze the diagnostic value of CT imaging. Taking pathological diagnosis as the gold standard, the number of true-negative, true-positive, false-negative and false-positive results in X-ray diagnosis were 13, 43, 21 and 5, respectively, while those in CT diagnosis were 11, 59, 5 and 7, respectively. The sensitivity, specificity, accuracy, positive coincidence rate, negative coincidence rate, misdiagnosis rate and missed diagnosis rate of CT in IFI were 92.18, 61.11, 85.37, 89.39, 68.75, 38.89 and 7.81%, respectively, while those of X-ray in IFI were 67.19, 72.22, 68.29, 89.58, 38.24, 27.78 and 32.81%, respectively. The sensitivity, accuracy and negative coincidence rate of CT in the diagnosis of IFI were significantly higher than those of X-ray (P<0.05), with a sensitivity of 92.18%, which indicates that CT has a higher diagnostic value in IFI. The results of CT combined with the basic condition of the patients can be used to initially diagnose pulmonary fungal infections, which is of high diagnostic value and can improve clinical treatment.

Infection in Immunocompromised Hosts: Imaging

Immunocompromised patients are encountered with increasing frequency in clinical practice. In addition to the acquired immunodeficiency syndrome (AIDS), therapy for malignant disease, and immune suppression for solid organ transplants, patients are now rendered immunosuppressed by advances in treatment for a wide variety of autoimmune diseases. The number of possible infecting organisms can be bewildering. Recognition of the type of immune defect and the duration and depth of immunosuppression (particularly in hematopoietic and solid organ transplants) can help generate a differential diagnosis. Radiologic imaging plays an important role in the detection and diagnosis of chest complications occurring in immunocompromised patients; however, chest radiography alone seldom provides adequate sensitivity and specificity. High-resolution computed tomography (CT) can provide better sensitivity and specificity, but even CT findings may be nonspecific findings unless considered in conjunction with the clinical context. Combination of CT pattern, clinical setting, and immunologic status provides the best chance for an accurate diagnosis. In this article, CT findings have been divided into 4 patterns: focal consolidation, nodules/masses, small/micronodules, and diffuse ground-glass attenuation/consolidation. Differential diagnoses are suggested for each pattern, adjusted for both AIDS and non-AIDS immunosuppressed patients.

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Diagnostics and susceptibility testing in Aspergillus

Invasive aspergillosis is a major cause of morbidity and mortality in immunosuppressed patients. Early diagnosis and correct antifungal treatment have a direct impact on patient survival. A number of newer diagnostic procedures have been developed as alternatives to conventional microbiological methods. The detection of fungal components, largely antigens and DNA, are used in clinical laboratories to diagnose invasive aspergillosis. Other rapid diagnostic tests have been recently developed with promising results. However, antifungal resistance is becoming an emerging problem. The detection of this resistance is important to administer the proper antifungal agent. This text reviews the novelties on new diagnostics Aspergillus spp.

PROCEDURES

Intrinsic antifungal resistance and mechanisms of secondary resistance to triazoles in A. fumigatus are also reviewed.

How to manage lung infiltrates in adults suffering from haematological malignancies outside allogeneic haematopoietic stem cell transplantation

Pulmonary complications affect up to 40% of patients with severe neutropenia lasting for more than 10 d. As they are frequently associated with fever and elevation of C‐reactive protein or other signs of inflammation, they are mostly handled as pneumonia. However, the differential diagnosis is broad, and a causative microbial agent remains undetected in the majority of cases. Pulmonary side effects from cytotoxic treatment or pulmonary involvement by the underlying malignancy must always be taken into account and may provide grounds for invasive diagnostic procedures in selected patients. Pneumocystis jirovecii (in patients not receiving co‐trimoxazole as prophylaxis), multi‐resistant gram‐negative bacilli, mycobacteria or respiratory viruses may be involved. High‐risk patients may be infected by filamentous fungi, such as Aspergillus spp., but these infections are seldom proven when treatment is initiated. Microorganisms isolated from cultures of blood, bronchoalveolar lavage or respiratory secretions need careful interpretation as they may be irrelevant for determining the aetiology of pulmonary infiltrates, particularly when cultures yield coagulase‐negative staphylococci, enterococci or Candida species. Non‐culture based diagnostics for detecting Aspergillus galactomannan, beta‐D‐glucan or DNA from blood, bronchoalveolar lavage or tissue samples can facilitate the diagnosis, but must always be interpreted in the context of clinical and imaging findings. Systemic antifungal treatment with mould‐active agents, given in combination with broad‐spectrum antibiotics, improves clinical outcome when given pre‐emptively. Co‐trimoxazole remains the first‐line treatment for Pneumocystis pneumonia, while cytomegalovirus pneumonia will respond to ganciclovir or foscarnet in most cases. The clinical outcome of acute respiratory failure can also be successful with proper intensive care, when indicated.

Hematologic neoplasms: Interpreting lung findings in chest computed tomography

Lung disease is very common in patients with hematologic neoplasms and varies in function of the underlying disease and its treatment. Lung involvement is associated with high morbidity and mortality, so it requires early appropriate treatment. Chest computed tomography (CT) and the analysis of biologic specimens are the first line diagnostic tools in these patients, and sometimes invasive methods are necessary. Interpreting the images requires an analysis of the clinical context, which is often complex. Starting from the knowledge about the differential diagnosis of lung findings that radiologists acquire during training, this article aims to explain the key clinical and radiological aspects that make it possible to orient the diagnosis correctly and to understand the current role of CT in the treatment strategy for this group of patients.

Hematologic neoplasms: interpreting lung findings in chest computed tomography

La patología pulmonar en la historia de un paciente con neoplasia hematológica es muy frecuente y variable en función de la enfermedad de base y la terapia recibida. La morbimortalidad asociada es alta, por lo que requiere un tratamiento correcto y precoz. La tomografía computarizada (TC) torácica, junto con el análisis de muestras biológicas, son las herramientas de diagnóstico de primera línea empleadas en estos pacientes, y en determinados casos se requieren métodos invasivos. La interpretación de las imágenes exige el análisis de un contexto clínico en muchas ocasiones complejo. Partiendo del conocimiento que adquiere el radiólogo en su formación sobre el diagnóstico diferencial de los hallazgos pulmonares, el objetivo de este trabajo es explicar los aspectos clínicos y radiológicos claves que permiten orientar correctamente el diagnóstico y asimilar el papel actual de la TC en la estrategia terapéutica de este grupo de enfermos.

British Society for Medical Mycology best practice recommendations for the diagnosis of serious fungal diseases

Invasive fungal diseases are an important cause of morbidity and mortality in a wide range of patients, and early diagnosis and management are a challenge. We therefore did a review of the scientific literature to generate a series of key recommendations for the appropriate use of microbiological, histological, and radiological diagnostic methods for diagnosis of invasive fungal diseases. The recommendations emphasise the role of microscopy in rapid diagnosis and identification of clinically significant isolates to species level, and the need for susceptibility testing of all Aspergillus spp, if treatment is to be given. In this Review, we provide information to improve understanding of the importance of antigen detection for cryptococcal disease and invasive aspergillosis, the use of molecular (PCR) diagnostics for aspergillosis, and the crucial role of antibody detection for chronic and allergic aspergillosis. Furthermore, we consider the importance of histopathology reporting with a panel of special stains, and emphasise the need for urgent (<48 hours) and optimised imaging for patients with suspected invasive fungal infection. All 43 recommendations are auditable and should be used to ensure best diagnostic practice and improved outcomes for patients.

Computed tomography features of pulmonary nocardiosis in immunocompromised and immunocompetent patients

BACKGROUND

Nocardiosis primarily occurs in the setting of immunocompromising conditions. However, it may also occur in immunocompetent patients. We described computed tomography features of pulmonary nocardiosis and compared immunocompetent and immunocompromised patients.

MATERIAL/METHODS

CT images of 25 patients (Mean age of 39.5 years; 76% male) with pulmonary nocardiosis proved by bronchoalveolar lavage or biopsy were reviewed by two experienced pulmonary radiologists and detailed findings were reported on. Fourteen patients (56%) were immunocompetent, while 44% had an underlying immunocompromising condition, including chronic granulomatous disease (CGD) (n=4), diabetes mellitus (DM) (n=2), malignancy (n=2), HIV (n=1), concomitant CGD and DM (n=1), and steroid therapy for nephrotic syndrome (n=1).

RESULTS

Most patients had bilateral involvement with no zonal predominance. Multiple pulmonary nodules (96%) were the most common CT findings, followed by consolidation (76%) and cavity (52%). Other findings included bronchiectasis (48%), pleural thickening (40%), ground glass opacity (32%), mass-like consolidation (20%), intrathoracic lymphadenopathy (16%), pleural effusion (12%), reticular infiltration (4%), and pericardial effusion (4%). There was no statistically significant difference in the CT findings of immunocompromised and immunocompetent groups.

CONCLUSIONS

Pulmonary nocardiosis presents mainly as multiple pulmonary nodules, consolidations, and cavity in both immunocompromised and immunocompetent patients. However, these features are more suggestive of nocardiosis in the setting of an underling immunocompromised condition.

Biomarkers for invasive aspergillosis: the challenges continue

The incidence of invasive aspergillosis (IA), an opportunistic infection in immunocompromised individuals, is rising, but its early diagnosis remains challenging and treatment options are limited. Hence there is an urgent need to improve existing diagnostic procedures as well as develop novel approaches. The clinical usefulness of galactomannan and β-d-glucan, widely used assays detecting cell-wall antigens of Aspergillus, is unclear and depends on clinicians' awareness of their practical limitations. This leaves room for new methods that utilise genomic, proteomic and metabolomics approaches as well as novel detection procedures, for example point-of-care lateral-flow devices. Each of these strategies has its own limitations and it is likely that a combination of methods will be required to achieve optimal performance for the diagnosis of IA and subsequent appropriate patient management.

An update on pulmonary complications of hematopoietic stem cell transplantation

The indications for hematopoietic stem cell transplantation (HSCT) continue to expand. However, the risk for pulmonary complications post-HSCT continues to be high. Early recognition and treatment of pulmonary complications may improve outcomes. This is an overview of diagnosis, manifestations, and treatment of the most common infectious and noninfectious pulmonary complications post-HSCT. Knowing the patient's timeframe post-HSCT (preengraftment, postengraftment, late), type of HSCT (allogeneic vs autologous), radiographic findings, and clinical presentation can help to differentiate between the many pulmonary complications. This article will also address pretransplantation evaluation and infectious and noninfectious complications in the patient post-HSCT. While mortality post-HSCT continues to improve, respiratory failure continues to be the leading cause of ICU admissions for patients who have undergone HSCT. Mechanical ventilation is a predictor of poor outcomes in these patients, and further research is needed regarding their critical care management, treatment options for noninfectious pulmonary complications, and mortality prediction models posttransplantation.

Pulmonary radiological findings in patients with acute myeloid leukemia and their relationship to chemotherapy and prognosis: a single-center retrospective study

OBJECTIVE

Acute myeloid leukemia (AML) is the most common acute leukemia in adults. Pulmonary are among the most common causes of mortality in AML. This single-center retrospective study aimed to evaluate the relationship between radiological findings of pulmonary at presentation and post chemotherapy on prognosis and clinical outcome in a group of AML patients.

MATERIAL AND METHODS

The study included 278 AML patients. Clinical and radiological findings, laboratory findings, and microbiological culture results were evaluated. Pulmonary complications at presentation and post chemotherapy were compared.

RESULTS

Pulmonary complications were observed in 53 of the patients (19%). Mean age of the patients with and without pulmonary complications was 43.1 ± 15.2 years and 38.8 ± 16.3 years, respectively (P < 0.001). Pulmonary complications were not correlated with gender, AML subtype, or the serum lactate dehydrogenase (LDH) level. The most common cause of pulmonary complications was infection. Pulmonary complications were observed in 29% and 71% of the patients at presentation and post chemotherapy, respectively.

CONCLUSION

Pulmonary complications were observed more frequently at presentation in neutropenic AML patients of advanced age. The mortality rate was higher among the AML patients that had pulmonary complications at presentation.

How I manage pulmonary nodular lesions and nodular infiltrates in patients with hematologic malignancies or undergoing hematopoietic cell transplantation

Pulmonary nodules and nodular infiltrates occur frequently during treatment of hematologic malignancies and after hematopoietic cell transplantation. In patients not receiving active immunosuppressive therapy, the most likely culprits are primary lung cancer, chronic infectious or inactive granulomata, or even the underlying hematologic disease itself (especially in patients with lymphoma). In patients receiving active therapy or who are otherwise highly immunosuppressed, there is a wider spectrum of etiologies with infection being most likely, especially by bacteria and fungi. Characterization of the pulmonary lesion by high-resolution CT imaging is a crucial first diagnostic step. Other noninvasive tests can often be useful, but invasive testing by bronchoscopic evaluation or acquisition of tissue by one of several biopsy techniques should be performed for those at risk for malignancy or invasive infection unless contraindicated. The choice of the optimal biopsy technique should be individualized, guided by location of the lesion, suspected etiology, skill and experience of the diagnostic team, procedural risk of complications, and patient status. Although presumptive therapy targeting the most likely etiology is justified in patients suspected of serious infection while evaluation proceeds, a structured evaluation to determine the specific etiology is recommended. Interdisciplinary teamwork is highly desirable to optimize diagnosis and therapy.

Radiological and clinical findings of 25 patients with invasive pulmonary aspergillosis: retrospective analysis of 2150 liver transplantation cases

OBJECTIVE

The purpose of this study was to evaluate the radiological and clinical findings of invasive pulmonary aspergillosis (IPA) after liver transplantation.

METHODS

This study included 25 consecutive liver transplant recipients with histologically confirmed IPA after liver transplantation. Radiological examinations performed for diagnosis were available in all patients. Clinical findings and changes in clinical response and radiological findings after treatment were also evaluated.

RESULTS

3 main radiological findings were identified: nodules, 64% (16/25); masses, 36% (9/25); and consolidations in a patchy pattern, 20% (5/25). A tree-in-bud pattern was found in 12% (3/25) of patients. In 8 (32%) of 25 patients, we found a combination of 2 or more of these signs: 5 (20%) patients presented with concurrent nodules accompanied by patchy consolidations and/or tree-in-bud, and 3 (12%) patients showed masses accompanied by large consolidations. A halo sign was observed in 20 (80%) of 25 patients. Hypodense sign and cavitary lesions were encountered in 17 (68%) of 25 patients. Follow-up radiological findings after treatment showed improvement in 18 patients, no change in 4 patients and progression in 3 patients. There were three aspergillosis-associated deaths during the follow-up period. The onset time of IPA was a median of 31 days after transplantation. The most common symptom at diagnosis was fever (n=15). None of the 25 patients had leukopaenia at the time of the diagnosis of IPA.

CONCLUSIONS

The most common radiological findings of IPA after liver transplantation are multiple nodules with or without halo sign, masses and consolidations, which usually appear about 1 month after transplantation.

The diagnostic value of halo and reversed halo signs for invasive mold infections in compromised hosts

The halo sign is a CT finding of ground-glass opacity surrounding a pulmonary nodule or mass. The reversed halo sign is a focal rounded area of ground-glass opacity surrounded by a crescent or complete ring of consolidation. In severely immunocompromised patients, these signs are highly suggestive of early infection by an angioinvasive fungus. The halo sign and reversed halo sign are most commonly associated with invasive pulmonary aspergillosis and pulmonary mucormycosis, respectively. Many other infections and noninfectious conditions, such as neoplastic and inflammatory processes, may also manifest with pulmonary nodules associated with either sign. Although nonspecific, both signs can be useful for preemptive initiation of antifungal therapy in the appropriate clinical setting. This review aims to evaluate the diagnostic value of the halo sign and reversed halo sign in immunocompromised hosts and describes the wide spectrum of diseases associated with them.

Outbreak of invasive pulmonary aspergillosis among patients hospitalized in a bone marrow transplant ward: tomographic findings

OBJECTIVE

To evaluate the main aspects on CT scans of six patients hospitalized in a bone marrow transplant ward, diagnosed with invasive pulmonary aspergillosis (IPA), during an in-hospital outbreak of the disease.

METHODS

We reviewed 10 chest CT scans of six neutropenic or immunocompromised patients hospitalized in the hematology and bone marrow transplant ward of the Hospital São Paulo, in the city of São Paulo, Brazil, who were diagnosed with IPA between April of 2007 and October of 2007. The diagnosis of IPA was confirmed by anatomopathological findings (in 2 cases), culture (in 3 cases) or appropriate treatment response (in 1 case).

RESULTS

We evaluated the CT scans of three male and three female patients, ranging from 22 to 58 years of age. The most common tomographic findings were nodules (5/6 cases) and areas of consolidation (2/6 cases). The nodules were more often multiple (3/5 cases), with irregular contours (4/5 cases) and accompanied by the halo sign (3/5 cases). One case presented multiple, centrally distributed areas of consolidation, and another presented an isolated, peripheral area of consolidation. Areas of ground-glass attenuation and septal thickening were found in three and two patients, respectively. Bilateral pleural effusion occurred in three cases.

CONCLUSIONS

Consolidation, nodules, septal thickening, pleural effusion and ground-glass opacities were the principal tomographic findings in the six patients hospitalized in the above mentioned ward during the IPA outbreak. The nodules were often (in 67% of the cases) accompanied by the halo sign, a classically described finding in patients with IPA.

Discrimination between invasive pulmonary aspergillosis and pulmonary lymphoma using CT

OBJECTIVE

The purpose was to assess the characteristic CT features of invasive pulmonary aspergillosis (IPA) and pulmonary lymphoma (PL) and to analyze the potential to distinguish the two entities using CT.

METHODS

The CT images of 70 patients with either proven IPA (n = 35) or PL (n = 35) were evaluated retrospectively and independently by two radiologists (reader 1 [R1] and reader 2 [R2]), analyzing images for presence, number and characteristics of pulmonary nodules and masses, ground-glass opacities, consolidations and other interstitial changes.

RESULTS

Interreader agreement was moderate (4/33 CT features), good (9/33) or excellent (20/33). Pulmonary nodules (P = 0.045 [R1], P = 0.001 [R2]), nodules with spiculated outer contours (P < 0.001 [R1], P = 0.001 [R2]), nodules with a halo sign (P < 0.001 [R1 + R2]), nodules with homogeneous (P = 0.030 [R1], P = 0.006 [R2]) and inhomogeneous (P = 0.001 [R1], P < 0.001 [R2]) attenuation patterns, nodules with cavitation (P = 0.006 [R1], P = 0.003 [R2]) and wedge-shaped, pleural-based consolidations (P < 0.001 [R1 + R2]) occurred significantly more often in patients with IPA, while masses without a halo sign (P = 0.03 [R1], P = 0.01 [R2]), lobar consolidations with bronchogram (P = 0.02 [R1 + R2]) and consolidations with homogeneous attenuation patterns (P < 0.001 [R1 + R2]) were found significantly more frequent in PL-patients.

CONCLUSIONS

Those CT features can therefore be considered suggestive for either IPA or PL. However, in most cases the diagnosis cannot be made based on CT findings solely because no single feature gained a high sensitivity and specificity concomitantly. Furthermore, the logistic regression did not show a combination that was significantly better than the best univariate predictor.

Surgical management of invasive pulmonary fungal infection in hematology patients

BACKGROUND

The purpose of this study was to analyze our institutional results with pulmonary resection in neutropenic patients with hematologic malignancies and suspected invasive pulmonary fungal infections.

METHODS

We performed a retrospective medical record review of 25 immunocompromised patients with hematologic malignancies who underwent pulmonary resection between 2000 and 2007. We analyzed preoperative diagnostic technique, degree of pulmonary resection, and postoperative morbidity and mortality to determine whether surgery is a viable treatment option in this subset of patients.

RESULTS

Twenty-three of 25 patients had a minithoracotomy compared with 2 who had video-assisted thorascopic surgery resection only. Thirteen had wedge resections, 9 had lobectomies, and 3 had segmentectomies. Early surgical morbidity was 2 of 25, involving 1 pneumothorax and 1 empyema. In-hospital mortality was 2, with 1 death primarily related to surgery. Median survival was 342 days, and survival was significantly better in patients with only one lesion. No patient experienced late recurrence of invasive pulmonary fungal infection. Resected pulmonary tissue also provided the best chance for a proven diagnosis in 19 of 25 (76%).

CONCLUSIONS

This study confirms that pulmonary resection in high-risk immunocompromised patients with suspected invasive fungal infection can be carried out with excellent operative morbidity and mortality.

Diagnosis of invasive aspergillosis by galactomannan antigenemia detection using an enzyme immunoassay

Invasive aspergillosis is a serious and often fatal infection in patients who are neutropenic or have undergone solid organ or stem cell transplantation. Delayed diagnosis and therapy may lead to poor outcomes. Diagnosis may be facilitated by a test for galactomannan antigen detection using an enzyme immunoassay. Other rapid methods for diagnosis include (1-->3)-beta-D: -glucan determination and polymerase chain reaction. The sensitivity and specificity of galactomannan antigenemia testing in serum and bronchoalveolar lavage specimens are high in patients with hematological malignancy, neutropenia, and receipt of stem-cell transplants. False positivity can be seen with concomitant administration of some antibiotics and infection by fungi other than Aspergillus.