Hypersensitivity pneumonitis versus invasive pulmonary aspergillosis: two cases with unusual pathologic findings and review of the literature

Aspergillus and the Lung

The filamentous fungus Aspergillus causes a wide spectrum of diseases in the human lung, with Aspergillus fumigatus being the most pathogenic and allergenic subspecies. The broad range of clinical syndromes that can develop from the presence of Aspergillus in the respiratory tract is determined by the interaction between host and pathogen. In this review, an oversight of the different clinical entities of pulmonary aspergillosis is given, categorized by their main pathophysiological mechanisms. The underlying immune processes are discussed, and the main clinical, radiological, biochemical, microbiological, and histopathological findings are summarized.

The clinical spectrum of aspergillosis in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. In this review, we present the clinical spectrum and pathogenesis of syndromes caused by Aspergillus in COPD namely invasive aspergillosis (IA), community-acquired Aspergillus pneumonia, chronic pulmonary Aspergillosis and Aspergillus sensitisation. Some of these entities are clearly linked to COPD, while others may coexist, but are less clearly liked directly to COPD. We discuss current uncertainties as these pertain to IA in COPD cohorts and explore areas for future research in this field.

Pulmonary Aspergillosis: Spectrum of Disease

Aspergillus species are ubiquitous in the environment. Aspergillosis is acquired by inhalation of Aspergillus spores. In normal hosts, spore inhalation rarely causes lung disease. Pulmonary Aspergillosis covers a wide spectrum of clinical syndromes depending on the interaction between Aspergillus and the host (immune-status, prior bronchopulmonary disease). It runs the gamut from invasive Aspergillosis to Aspergillus bronchitis. Invasive Aspergillosis usually occurs in severely immunocompromised patients, typically in neutropenic but also in non-neutropenic patients. Chronic pulmonary Aspergillosis affects patients with chronic structural lung disease such as COPD or previous mycobacterial lung disease, but without other significant immunocompromise. Aspergillus bronchitis affects patients with bronchial disease such as bronchiectasis. Allergic bronchopulmonary Aspergillosis affects patients with bronchial asthma or cystic fibrosis, and is due to an allergic response to Aspergillus.

Aspergillus-related lung mass masquerading as a lung tumour

Aspergillus is a common environmental pathogen. However, clinically significant disease only occurs in a small proportion of patients. Although rare in its occurrence, it remains a considerable cause of morbidity and mortality in certain cohorts of patients. We describe a rare case of Aspergillus disease masquerading as a primary lung malignancy. Computer tomography pulmonary angiogram scan demonstrated a right upper lobe 8 x 6.5 cm soft-tissue lesion. Positron emission tomography CT demonstrated this lesion to be intensely fluorodeoxyglucose avid. Initial bronchoscopy demonstrated occluded subsegmental right upper lobe bronchus with white friable material. Follow-up bronchoscopy demonstrated evidence of a previous inflammatory process with cavitation and destruction of sub-lobar bronchial tree. Serial chest radiographs demonstrated almost complete resolution of the right upper lobe mass. Thus, this presentation of an Aspergillus-related lung mass masquerading as a primary lung malignancy provided several important learning points pertaining to diagnosis and ensuing management.

Eosinophilie bei pulmonalen Infektionen

Neben Allergien, Autoimmunerkrankungen, Vaskulitiden, Dermatosen, Malignomen und Medikamentennebenwirkungen können sowohl parasitäre als auch nichtparasitäre Infektionen Ursachen für eine Eosinophilie sein. Bei Tropenrückkehrern stellen parasitäre Infektionen die häufigste Ursache für eine Eosinophilie dar. Dabei kann das jeweilige Ausmaß der Eosinophilie Rückschlüsse auf die Art des Erregers liefern. Zur Abklärung der Eosinophilie nach Tropenaufenthalt sollten primär dreimalige Stuhluntersuchungen auf Wurmeier und zusätzlich ggf. Serologien bezüglich Helminthen veranlasst werden. Komplettiert wird die Diagnostik durch eine Thorax-Röntgenaufnahme, eine Sonographie des Oberbauchs und ein Elektrokardiogramm (EKG). In den letzten Jahren werden in spezialisierten Laboren molekulare Techniken (Multiplex-Polymerasekettenreaktion, PCR) für die Diagnostik von Wurmeiern und intestinalen Parasiten im Stuhl eingesetzt, die eine deutlich höhere Sensitivität als die klassischen Stuhlnachweismethoden haben. Nichtparasitäre Infektionen, die zu einer relevanten Blut- oder lediglich pulmonalen Eosinophilie (bronchoalveoläre Lavage, BAL) führen, umfassen die Kryptokokkose sowie endemische Systemmykosen (Kokzidioidomykose, sehr selten bei Histoplasmose) und Schimmelpilzinfektionen (Aspergillus fumigatus, Mucor spp.).

Invasive pulmonary mucormycosis: rare presentation with pulmonary eosinophilia

BACKGROUND

Fungi can cause a variety of infectious diseases, including invasive mycosis and non-invasive mycosis, as well as allergic diseases. The different forms of mycosis usually have been described as mutually exclusive, independent entities, with few descriptions of overlapping cases. Here, we describe the first reported case of a patient with the complication of pulmonary eosinophilia in the course of invasive mucormycosis.

CASE PRESENTATION

A 74-year-old Japanese man with asthma-COPD overlap underwent emergency surgery for a ruptured abdominal aortic aneurysm. The surgery was successful, but fever and worsening dyspnea appeared and continued from postoperative day (POD) 10. A complete blood count showed leukocytosis with neutrophilia and eosinophilia, and the chest X-ray showed consolidation of the left upper lung at POD 15. We suspected nosocomial pneumonia together with an exacerbation of the asthma-COPD overlap, and both antibiotics and bronchodilator therapy were initiated. However, the symptoms, eosinophilia and imaging findings deteriorated. We then performed a bronchoscopy, and bronchoalveolar lavage (BAL) fluid analysis revealed an increased percentage of eosinophils (82% of whole cells) as well as filamentous fungi. We first suspected that this was a case of allergic bronchopulmonary mycosis (ABPM) caused by Aspergillus infection and began corticosteroid therapy with an intravenous administration of voriconazole at POD 27. However, the fungal culture examination of the BAL fluid revealed mucormycetes, which were later identified as Cunninghamella bertholletiae by PCR and DNA sequencing. We then switched the antifungal agent to liposomal amphotericin B for the treatment of the pulmonary mucormycosis at POD 29. Despite replacing voriconazole with liposomal amphotericin B, the patient developed septic shock and died at POD 39. The autopsy revealed that filamentous fungi had invaded the lung, heart, thyroid glands, kidneys, and spleen, suggesting that disseminated mucormycosis had occurred.

CONCLUSIONS

We describe the first reported case of pulmonary mucormycosis with pulmonary eosinophilia caused by Cunninghamella bertholletiae, which resulted in disseminated mucormycosis. Although it is a rather rare case, two important conclusions can be drawn: i) mycosis can simultaneously cause both invasive infection and a host allergic reaction, and ii) Cunninghamella bertholletiae rarely infects immunocompetent patients.

Diagnosis, classification, and therapeutic interventions for sinopulmonary Aspergillosis

INTRODUCTION

Sinopulmonary aspergillosis represents a diverse collection of allergic, invasive, and chronic sinus and respiratory conditions. These diseases can affect patients with and without immune impairment and in some cases may be life-threatening. Areas covered: We review the diagnosis, classification, and therapeutic options available to treat sinopulmonary aspergillosis and look ahead to emerging diagnostic and therapeutic options that may soon play an important role in clinical practice. Expert commentary: Histopathology and tissue culture remain the gold standard for the diagnosis of invasive sinopulmonary aspergillosis, but several new molecular detection methods have recently emerged, including various PCR-based platforms, MALDI-TOF, and lateral flow assays. We examine these methodologies as well as the barriers associated with the standardization, validation, and implementation. We also explore the pipeline of antifungal agents in development to treat sinopulmonary aspergillosis.

Acute invasive pulmonary aspergillosis, shortly after occupational exposure to polluted muddy water, in a previously healthy subject

Invasive pulmonary aspergillosis (IPA) predominantly occurs in severely neutropenic immunocompromised subjects. The occurrence of acute IPA after brief but massive exposure to Aspergillus conidia in previously healthy subjects has been documented, although only six such cases have been reported. The diagnosis was delayed in all six of the affected patients, five of whom died. We report the case of a 50-year-old HIV-negative male, a water pipeline maintenance worker, who presented with acute-onset dyspnea and fever one day after working for 2 h in a deep pit containing polluted, muddy water. Over a one-month period, his general condition deteriorated markedly, despite antibiotic therapy. Imaging showed bilateral diffuse nodules with cavitation, some of which were surrounded by ground-glass opacity suggestive of a halo sign (a hallmark of IPA). Cultures (of sputum/bronchial aspirate samples) and serology were positive for Aspergillus fumigatus. After being started on itraconazole, the patient improved. We conclude that massive exposure to Aspergillus conidia can lead to acute IPA in immunocompetent subjects.

Lesson of the month 1: A cough that doesn't fit the mould

Aspergillus disease has a wide spectrum of manifestations within the lungs; however invasive Aspergillus is most commonly associated with immunocompromise or pre-existing respiratory disease. Here we present a case of Aspergillus tracheobronchitis causing right middle lobe collapse, masquerading as late-onset asthma in a patient with no pre-existing risk factors following massive inhalation of Aspergillus spores from working with compost. This case highlights the importance of having a high index of suspicion for Aspergillus-related disease even in those with no traditional risk factors.

Republished: The clinical spectrum of pulmonary aspergillosis

The clinical presentation of Aspergillus lung disease is determined by the interaction between fungus and host. Invasive aspergillosis develops in severely immunocompromised patients, including those with neutropenia, and increasingly in the non-neutropenic host, including lung transplant recipients, the critically ill patients and patients on steroids. A high index of suspicion is required in patients without the classical risk factors as early presentation is usually silent and non-specific, pyrexia uncommon and timely treatment is crucial for survival. Invasive aspergillosis has also been diagnosed in normal hosts after massive exposure to fungal spores. Chronic pulmonary aspergillosis affects patients without obvious immune compromise, but with an underlying lung condition such as COPD or sarcoidosis, prior or concurrent TB or non-tuberculous mycobacterial disease. Aspergillus bronchitis may be responsible for persistent respiratory symptoms in patients with Aspergillus detected repeatedly in sputum without evidence of parenchymal Aspergillus disease, especially in patients with bronchiectasis and cystic fibrosis. Allergic bronchopulmonary aspergillosis affects patients with asthma and cystic fibrosis, and is important to recognise as permanent lung or airways damage may accrue if untreated. Changes in the classification of Aspergillus allergic lung disease have been proposed recently. Cases of extrinsic allergic alveolitis and chronic pulmonary aspergillosis have been observed after Aspergillus exposure. Asymptomatic colonisation of the respiratory tract needs close monitoring as it can lead to clinical disease especially with ongoing immunosuppression. The various syndromes should be viewed as a semicontinuous spectrum of disease and one form may evolve into another depending on the degree of ongoing immunosuppression.

Acute eosinophilic pneumonia caused by Candida albicans

A 36-year-old man was transferred to the hospital for further evaluation of pulmonary infiltration. A diagnosis of acute eosinophilic pneumonia (AEP) was confirmed by clinical symptoms, bronchoalveolar lavage, and computed tomography findings. Skin tests with fungal antigens were performed by intradermal injection. Both the Arthus (8 h) and delay (24 h)-type skin tests were positive for only Candida albicans. A lymphocyte-stimulating test was also positive for C. albicans. The etiology of the AEP was confirmed by a C. albicans inhalation provocation test. In addition, peripheral blood mononuclear cells obtained from the patient produced Interleukin-5 following C. albicans stimulation. This is the first report of C. albicans as a probable cause of AEP. Evaluation of allergy to C. albicans should be performed in AEP before diagnosing the cause as idiopathic.

Pathological diagnosis of granulomatous lung disease: a review

Granulomas in the lung are common diagnostic problems encountered by pathologists. They occur in a wide range of pulmonary conditions, ranging from common entities to uncommon ones and including both infections and non-infectious diseases. This review summarizes the main histological features that help distinguish various granulomatous lung diseases. It concentrates on the most important and common entities that may be encountered and emphasizes helpful features in the differential diagnosis.

Acute pulmonary aspergillosis in immunocompetent subjects after exposure to bark chippings

We describe 2 cases of immunocompetent males with acute community-acquired invasive pulmonary aspergillosis developing shortly after spreading bark chippings. One patient with a fatal outcome was initially diagnosed as allergic alveolitis rather than infection and received steroid treatment illustrating the obvious challenges in the differential diagnosis between these disease entities.

Nonresolving or slowly resolving pneumonia

Given the variability in rate of radiographic resolution, it remains controversial to decide when to initiate an invasive diagnostic work-up for nonresolving or slowly resolving pulmonary infiltrates. In immunocompetent patients who present with classical features of CAP (i.e., fever, chills, productive cough, new pulmonary infiltrate), clinical response to therapy is the most important determinant for further diagnostic studies. Within the first few days, persistence or even progression of infiltrates on chest radiographs is not unusual. Defervescence, diminished symptoms, and resolution of leukocytosis strongly support a response to antibiotic therapy, even when chest radiographic abnormalities persist. In this context, observation alone is reasonable, and invasive procedures can be deferred. Serial radiographs and clinical examinations dictate subsequent evaluation. In contrast, when clinical improvement has not occurred and chest radiographs are unchanged or worse, a more aggressive approach is warranted. In this setting, we advise fiberoptic bronchoscopy with BAL and appropriate cultures for bacteria, legionella, fungi, and mycobacteria. When endobronchial anatomy is normal and there is no purulence to suggest infection, TBBs should be done to exclude noninfectious causes (discussed earlier) or infections attributable to mycobacteria or fungi. An aggressive approach is also warranted in patients who are clinically stable or improving when the rate of radiographic resolution is delayed. As discussed earlier, what constitutes excessive delay is controversial, and depends upon the acuity of illness, specific pathogen, extent of involvement (i.e., lobar versus multilobar), comorbidities, and diverse host factors. Stable infiltrates even 2 to 4 weeks after institution of antibiotic therapy does not mandate intervention provided patients are improving clinically. Invasive techniques can also be deferred when unequivocal, albeit incomplete, radiographic resolution can be demonstrated. Lack of at least partial radiographic resolution by 6 weeks, even in asymptomatic patients, however, deserves consideration of alternative causes (e.g., endobronchial obstructing lesions, or noninfectious causes). Fiberoptic bronchoscopy with BAL and TBBs has minimal morbidity and is the preferred initial invasive procedure for detecting endobronchial lesions or substantiating noninfectious causes. The yield of bronchoscopy depends on demographics, radiographic features, and pre-test likelihood. In the absence of specific risk factors, the incidence of obstructing lesions (e.g., bronchogenic carcinomas, bronchial adenomas, obstructive foreign body) is low. Bronchogenic carcinoma is rare in nonsmoking, young (< 50 years) patients but is a legitimate consideration in older patients with a history of tobacco abuse. Non-neoplastic causes (e.g., pulmonary vasculitis, hypersensitivity pneumonia, etc.) should be considered when specific features are present (e.g., hematuria, appropriate epidemiologic exposures). Ancillary serologic tests or biopsies of extrapulmonary sites are invaluable in some cases. In rare instances, surgical (open or VATS) biopsy is necessary to diagnose refractory or non-resolving "pneumonias."

Acute community-acquired pneumonia due to Aspergillus in presumably immunocompetent hosts: clues for recognition of a rare but fatal disease

This article reports a case of acute community-acquired pneumonia due to Aspergillus fumigatus in a healthy patient and reviews 11 previously reported cases occurring in presumably immunocompetent hosts. The diagnosis was delayed for all patients; mortality was 100%. Clues that might suggest Aspergillus as a pathogen in community-acquired pneumonia include a chest radiograph revealing diffuse infiltrates or new cavitation; lack of bacterial or viral cause; a preceding influenza A infection; and respiratory secretion cultures positive for Aspergillus. When these clues are present, the physician should consider an early biopsy of lung tissue. Increased recognition and more timely diagnosis in future cases will improve the outcome of this rare but fatal infection.

Acute eosinophilic pneumonia. A summary of 15 cases and review of the literature

Idiopathic acute eosinophilic pneumonia (AEP) is an acute febrile illness that may be mistaken for an infectious pneumonia. Patients are often young and otherwise healthy. Clues to considering this disorder in a differential diagnosis include the acuity and severity of the clinical presentation and an initial chest X-ray with diffuse infiltrates, often interstitial, and the presence of Kerley B lines and/or evidence of pleural fluid. The diagnosis can be made through examination of bronchoalveolar lavage fluid in most cases, with careful exclusion of other similar eosinophilic lung disease. Although it can lead to life-threatening respiratory failure, AEP is easily treatable with corticosteroids. This disease has not been reported to recur in any patients to this point.

Massive fungal contamination in animal care facilities traced to bedding supply

During the course of immunologic studies involving the gastrointestinal colonization of mice with Candida albicans, it became apparent that the animals were being exposed to large numbers of Aspergillus fumigatus spores which interfered with the C. albicans colonization. To determine the source of the A. fumigatus exposure and the extent of fungal contamination of the medical school vivarium and four satellite facilities, fungal analyses of feed, bedding, and air were undertaken. Initial samples from the air were collected with 3-h settle plates; air sampling following cleanup was done with an Anderson air sampler. The source of contamination in the mouse rooms was determined to be Beta Chip bedding, which came from the manufacturer highly contaminated. Beta Chip bedding (1 g) obtained from the manufacturer just prior to testing contained 10(4) CFU of A. fumigatus, 20 CFU of a zygomycete, and 10 CFU of a Penicillium sp. Coarse-grade Beta Chip had approximately one-half those levels of contamination. Pure Cob bedding was highly contaminated also, but with a Fusarium sp. and a Cladosporium sp. Untreated and heat-treated Sani-Chip as well as all other heat-treated preparations obtained from the manufacturer contained no detectable spores. Rodent chow direct from the manufacturer had no A. fumigatus, although it did contain 150 CFU of fungus per g, including 80 CFU of a Rhodotorula sp., 60 CFU of Cryptococcus uniguttulatus, and 1 CFU of a Penicillium sp.(ABSTRACT TRUNCATED AT 250 WORDS)

Invasive pulmonary aspergillosis complicating allergic bronchopulmonary aspergillosis

Invasive pulmonary aspergillosis is a frequent complication in immunocompromised patients. The role of the prolonged use of steroids in predisposing to invasive aspergillosis has been recognized, but exceptionally described in asthmatic patients. We report the case of a 59-year-old woman with bronchial asthma treated with steroid therapy for a long time, who developed an invasive pulmonary aspergillosis with an unusual combination of invasive and allergic disease. It seems reasonable to think that allergic disease due to allergic bronchopulmonary aspergillosis (ABPA) preceded the terminal invasive process. Adjunctive therapy with antifungal agents in patients with ABPA is considered, since there is the risk of an invasive pulmonary aspergillosis.

Differential diagnostic value of plasma cells in bronchoalveolar lavage fluid

The aim of this study was to investigate whether the demonstration of plasma cells (PC), which are normally absent in bronchoalveolar lavage (BAL) fluid, facilitates differentiation among pulmonary disorders. Initial BAL fluid samples of 1,260 patients were analyzed. In 83 of these, PC were found. Of these 83, 47 were obtained from individuals suffering from extrinsic allergic alveolitis (EAA). The number of PC in BAL fluid from EAA patients was found related to the time between antigen exposure and BAL. Drug-induced pneumonitis appeared to be another disorder with a high percentage of cases with PC in the BAL fluid (35.7 percent). Therefore, we conclude that determination of PC in BAL fluid has differential diagnostic value in discriminating among interstitial lung diseases of various origins. However, the exact role of BAL fluid and PC and the link to clinical manifestations of these diseases needs further investigation.