Chronic eosinophilic pneumonia progressing to lung fibrosis

Idiopathic Chronic Eosinophilic Pneumonia Evolving to Pulmonary Fibrosis: A Retrospective Analysis

BACKGROUND

Patients with idiopathic chronic eosinophilic pneumonia (ICEP) may have pulmonary fibrosis.

OBJECTIVES

To investigate the predictors of pulmonary fibrosis in ICEP, to describe the timeline of pulmonary fibrosis after ICEP diagnosis, and to detail the radiologic pattern of fibrosis.

METHODS

A retrospective computer-assisted search was performed to identify patients with ICEP seen at Mayo Clinic in Rochester, Minnesota, from January 1, 1997, through September 1, 2019. Patients with follow-up chest computed tomography (CT) beyond 12 months after the ICEP diagnosis were included in the study. Demographic, clinical, radiologic, and histopathologic characteristics were analyzed. Proportional hazards regression was used to assess the predictors of pulmonary fibrosis.

RESULTS

We identified 62 patients (mean [SD] age at ICEP diagnosis, 60 [13] years; female sex, 37 [60%]). Cough (87%) and shortness of breath (85%) were the most common presenting symptoms. Of patients, 27 (44%) had a history of smoking and 27 (44%) had a history of asthma. During follow-up, 23 patients (37%) had CT evidence of pulmonary fibrosis, of whom 16 patients (70%) had a CT pattern inconsistent with usual interstitial pneumonia. In 29% of the patients, the CT evidence of pulmonary fibrosis developed within 2 years after ICEP. Age and male sex were predictors of pulmonary fibrosis. Of note, a history of asthma decreased the likelihood of pulmonary fibrosis.

CONCLUSIONS

Development of pulmonary fibro-sis is not uncommon in patients with ICEP, especially older men, and is associated with increased risk of death.

Idiopathic Chronic Eosinophilic Pneumonia

Idiopathic chronic eosinophilic pneumonia (CEP) is a rare disease of unknown cause characterized by eosinophilic alveolar and interstitial infiltration. The authors describe the case of a 46-year-old black man, presenting with insidious onset and progressive course of dyspnea on minimum exertion, cough, fever, night sweats, and weight loss for one year and worsening in the last three months. The main findings were serum eosinophilia. Chest radiographs showed multifocal infiltrations of irregular distribution in both lungs and a restrictive functional impairment. The patient underwent open lung biopsy, and the anatomopathological examination revealed consolidation by exudate constituted predominantly by macrophages (25%) and eosinophils (51%), which filled small air spaces, including respiratory and membranous bronchioles. The anatomopathological diagnosis was eosinophilic pneumonia (eosinophils > 25% is widely accepted for diagnosing eosinophilic pneumonia). The patient had a good clinical response after starting corticosteroid therapy.

Long-term management and persistent impairment of pulmonary function in chronic eosinophilic pneumonia: A review of the previous literature

Chronic eosinophilic pneumonia (CEP) is an inflammatory disease characterized by accumulations of eosinophils in the lung with unknown etiology. Although corticosteroid treatment dramatically resolves these inflammations, relapse is common during the course of the disease. Approximately 50% of patients with CEP experience relapse. Subsequent to persistent disease and repeated relapse, and in cases of combined severe asthma, some CEP patients are administered corticosteroids indefinitely. Similar to patients with severe asthma who are often steroid dependent, a number of CEP patients exhibit prolonged persistent impairment of pulmonary function. Thus, CEP should be considered a potentially chronic disease requiring long-term management, rather than an acute or sub-acute disease requiring short-time therapy only. This review summarizes previous CEP studies, as well as our own cohort data, and discusses the long-term management of CEP with a particular focus on relapse, the prevalence of maintenance therapy, and persistent impairment of pulmonary function.

Persistent impairment on spirometry in chronic eosinophilic pneumonia: A longitudinal observation study (Shizuoka-CEP study)

BACKGROUND

Chronic eosinophilic pneumonia (CEP) is characterized by the accumulation of eosinophils in the lung with unknown etiology. Although systemic corticosteroid administration leads to dramatic improvement, nearly half the patients with CEP experience relapse and some develop persistent impairment of pulmonary function. However, predictive factors for this persistent impairment have not been determined.

OBJECTIVE

To investigate the occurrence of persistent impairment of pulmonary function in CEP and determine its predictive factors.

METHODS

This observational study consisted of 133 consecutive patients with CEP who were followed for longer than 1 year. Spirometry was performed at the time of diagnosis and at follow-up.

RESULTS

During the observational period (6.1 ± 4.1 years), relapse occurred in 75 patients (56.4%). Remarkably, 42 patients (31.6%) had a persistent pulmonary function defect (27 obstructive, 10 restrictive, and 4 obstructive and restrictive cases) at the last evaluation. Logistic analyses showed that the relapse was associated with neither persistent obstructive nor restrictive defects. Persistent obstructive defect was significantly associated with the comorbidity of asthma and obstructive defect at the initial CEP diagnosis, whereas persistent restrictive defect was significantly related to reticulation at high-resolution computer tomography and restrictive defect at diagnosis.

CONCLUSION

Persistent impairment of pulmonary function is common in CEP. Concurrent asthma and obstructive defects at diagnosis were predictors for persistent obstructive impairments, whereas reticulation at high-resolution computer tomography and restrictive defect at diagnosis predicted persistent restrictive impairment. Attention should be paid to these persistent impairments in the management of CEP.

TRIAL REGISTRATION

http://www.umin.ac.jp/ctr/index-j.htm Identifier: UMIN000019092 (principal investigator, Takafumi Suda, MD, PhD).

Chronic eosinophilic pneumonia: Adjunctive therapy with inhaled steroids

Idiopathic chronic eosinophilic pneumonia (ICEP) is a rare form of diffuse parenchymal lung disease first identified by Carrington et al. in 1969. It is characterized by the presence of constitutional and respiratory symptoms with associated peripheral opacities on imaging and elevated serum and/or bronchoalveolar eosinophilia. Although data is limited regarding etiology or prevalence, it is known that ICEP has a 2:1 female: male predominance and typically affects non-smokers. Diagnosis rests on the clinical constellation of respiratory symptoms of at least 2–4 weeks duration, the presence of diffuse pulmonary alveolar consolidation, classically described as the “photographic negative of pulmonary edema”, the presence of eosinophils ≥40% on bronchoalveolar lavage or ≥1000/mm³ eosinophils on peripheral blood and the exclusion of other known causes of eosinophilic lung diseases such as drugs, toxins, fungi, parasites, and collagen-vascular disorders. A dramatic response is achieved with systemic corticosteroids, which is typically dosed over 6 months to 1 year. Despite this response, approximately 30–50% of patients will relapse upon cessation of steroids or during the taper. Although these patients respond well to another trial of steroids, the side effects of long term steroids are well known, including osteoporosis, diabetes, hypertension and cataracts. Inhaled corticosteroids as monotherapy has been trialed in the past without success. However, we report a case of a patient who underwent treatment with systemic corticosteroids followed by inhaled steroids who has remained in remission for 2 years.

A Review of Clinical and Imaging Findings in Eosinophilic Lung Diseases

OBJECTIVE

The purpose of this article is to review the clinical and imaging findings associated with eosinophilic lung diseases.

CONCLUSION

The spectrum of eosinophilic lung diseases comprises a diverse group of pulmonary disorders that have an association with tissue or peripheral eosinophilia. These diseases have varied clinical presentations and may be associated with several other abnormalities. Characteristic imaging findings are often detected with chest radiography, and CT best shows parenchymal abnormalities. The integration of clinical, radiologic, and pathologic findings facilitates diagnosis and directs appropriate treatment.

Eosinophilic pneumonias in children: A review of the epidemiology, diagnosis, and treatment

Pediatric eosinophilic pneumonias (EPs) are characterized by a significant infiltration of the alveolar spaces and lung interstitium by eosinophils, with conservation of the lung structure. In developed countries, EPs constitute exceptional entities in pediatric care. Clinical symptoms may be transient (Löffler syndrome), acute (<1 month and mostly <7 days), or chronic (>1 month). Diagnosis relies on demonstration of alveolar eosinophilia on bronchoalveolar lavage, whether or not associated with blood eosinophilia. EPs are a heterogeneous group of disorders divided into: (i) secondary forms (seen mainly in parasitic infections, allergic bronchopulmonary aspergillosis, and drug reactions); and (ii) primary forms (eosinophilic granulomatosis with polyangiitis, hypereosinophilic syndrome, idiopathic chronic eosinophilic pneumonia, and idiopathic acute eosinophilic pneumonia). Despite their rarity, the etiological approach to EP must be well-defined as some causes can be rapidly life-threatening without initiation of the proper treatment. This approach (i) eliminates secondary forms, with comprehensive history taking and minimal biological assessment, (ii) is oriented in primary forms by the acute or chronic setting, and the existence of extrapulmonary symptoms. Treatment of primary forms has traditionally relied on corticosteroids, usually with a dramatic response. Specific treatments or the adjunction of corticosteroid-sparing treatment or immunosuppressors are currently being evaluated in order to improve the prognosis and the side effects associated with corticosteroid treatment in a pediatric setting.

Mast cells' integrated actions with eosinophils and fibroblasts in allergic inflammation: implications for therapy

Mast cells (MCs) and eosinophils (Eos) are the key players in the development of allergic inflammation (AI). Their cross-talk, named the Allergic Effector Unit (AEU), takes place through an array of soluble mediators and ligands/receptors interactions that enhance the functions of both the cells. One of the salient features of the AEU is the CD48/2B4 receptor/ligand binding complex. Furthermore, MCs and Eos have been demonstrated to play a role not only in AI but also in the modulation of its consequence, i.e., fibrosis/tissue remodeling, by directly influencing fibroblasts (FBs), the main target cells of these processes. In turn, FBs can regulate the survival, activity, and phenotype of both MCs and Eos. Therefore, a complex three players, MCs/Eos/FBs interaction, can take place in various stages of AI. The characterization of the soluble and physical mediated cross talk among these three cells might lead to the identification of both better and novel targets for the treatment of allergy and its tissue remodeling consequences.

Idiopathic eosinophilic pneumonia in children: the French experience

Background

Idiopathic eosinophilic pneumonia is extremely rare in children and adults. We present herein the first series describing the specificities of idiopathic chronic (ICEP) and acute (IAEP) eosinophilic pneumonia in children.

Methods

We retrospectively analyzed all cases of ICEP and IAEP in children that were retrieved from French Reference Centers for rare pediatric lung diseases.

Results

Five cases of pediatric ICEP were identified. Corticosteroid or immunosuppressive therapy dramatically improved the outcome in three cases. The remaining two cases had a persistent interstitial pattern with progressive development of cystic airspace lesions. Three cases of IAEP in adolescents were reported, with one requiring four days of extracorporeal membrane oxygenation.

Conclusion

ICEP is a rare disease with a polymorphic clinical presentation in children. We identified patients with persistent interstitial patterns progressing to cystic airspace regions, for which the boundaries with idiopathic interstitial pneumonias are difficult to establish. We therefore propose a specific pediatric definition and classification algorithm. IAEP in children remains an inflammatory reaction of the lung to an acute toxic exposure, mainly tobacco, as in adults. International studies are required to comprehensively assess the various clinical forms of the disease as well as the appropriate therapeutic regimens.

Diagnosis in just over a minute: a case of chronic eosinophilic pneumonia

Chronic eosinophilic pneumonia (CEP) is a rare interstitial lung disease characterized by subacute dyspnea, peripheral infiltrates on imaging, and pulmonary eosinophilia. We report a case of a 48-year-old man who presented to a "minute clinic" with cough and dyspnea. After improvement on a short course of steroids for a presumptive diagnosis of bronchospasm, he presented to our hospital with symptom recurrence. Computed tomography (CT) imaging revealed peripheral infiltrates and bronchoscopy confirmed pulmonary eosinophilia. In this clinical vignette, we review the typical presentation of chronic eosinophilic pneumonia, the differential diagnosis of pulmonary infiltrates with eosinophilia, and the challenges of diagnosing a rare condition that may mimic more common causes of dyspnea, especially in a "minute clinic" setting.

Eosinophilic pneumonias

This review starts with discussions of several infectious causes of eosinophilic pneumonia, which are almost exclusively parasitic in nature. Pulmonary infections due specifically to Ascaris, hookworms, Strongyloides, Paragonimus, filariasis, and Toxocara are considered in detail. The discussion then moves to noninfectious causes of eosinophilic pulmonary infiltration, including allergic sensitization to Aspergillus, acute and chronic eosinophilic pneumonias, Churg-Strauss syndrome, hypereosinophilic syndromes, and pulmonary eosinophilia due to exposure to specific medications or toxins.

Chronic eosinophilic pneumonia due to radiographic contrast administration: an orphan disease?

Pulmonary eosinophilia comprises a heterogeneous group of diseases that are defined by eosinophilia in pulmonary infiltrates or in tissue. Drugs can cause almost all histopathologic patterns of interstitial pneumonias, such as cellular and fibrotic nonspecific interstitial pneumonia, pulmonary infiltrates and eosinophilia, organizing pneumonia, lymphocytic interstitial pneumonia, desquamative interstitial pneumonia, a pulmonary granulomatosis-like reaction, and a usual interstitial pneumonia-like pattern. We present a very rare case of chronic eosinophilic pneumonia due to radiographic contrast infusion diagnosed with video-assisted thoracoscopy. The patient after 1 year is still under corticosteroid treatment with the disease stabilized.

Eosinophilic lung diseases

Accurate diagnosis of eosinophilic lung diseases is essential to optimizing patient outcomes, but remains challenging. Signs and symptoms frequently overlap among the disorders, and because these disorders are infrequent, expertise is difficult to acquire. Still, these disorders are not rare, and most clinicians periodically encounter patients with one or more of the eosinophilic lung diseases and need to understand how to recognize, diagnose, and manage these diseases. This review focuses on the clinical features, general diagnostic workup, and management of the eosinophilic lung diseases.

Pulmonary eosinophilia

Pulmonary eosinophilia comprises a heterogeneous group of diseases defined by eosinophilia in pulmonary infiltrates (bronchoalveolar lavage fluid) or in tissue (lung biopsy specimens). Although the inflammatory infiltrate is composed of macrophages, lymphocytes, neutrophils and eosinophils, eosinophilia is an important marker for the diagnosis and treatment. Clinical and radiological presentations can include simple pulmonary eosinophilia, chronic eosinophilic pneumonia, acute eosinophilic pneumonia, allergic bronchopulmonary aspergillosis and pulmonary eosinophilia associated with a systemic disease, such as in Churg-Strauss syndrome and hypereosinophilic syndrome. Asthma is frequently concomitant and can be a prerequisite, as in allergic bronchopulmonary aspergillosis and Churg-Strauss syndrome. In diseases with systemic involvement, the skin, the heart and the nervous system are the most affected organs. The radiological presentation can be typical, or at least suggestive, of one of three types of pulmonary eosinophilia: chronic eosinophilic pneumonia, acute eosinophilic pneumonia and allergic bronchopulmonary aspergillosis. The etiology of pulmonary eosinophilia can be either primary (idiopathic) or secondary, due to known causes, such as drugs, parasites, fungal infection, mycobacterial infection, irradiation and toxins. Pulmonary eosinophilia can be also associated with diffuse lung diseases, connective tissue diseases and neoplasia.

Pulmonary fibrosis associated with psychotropic drug therapy: a case report

Introduction

Sertraline and Risperidone are commonly used psychotropic drugs. Sertraline has previously been associated with eosinopilic pneumonia. Neither drug is recognised as a cause of diffuse fibrotic lung disease. Our report represents the first such case.

Case Presentation

We describe the case of a 33 year old Asian male with chronic schizophrenia who had been treated for three years with sertraline and risperidone. He presented to hospital in respiratory failure following a six month history of progressive breathlessness. High resolution CT scan demonstrated diffuse pulmonary fibrosis admixed with patchy areas of consolidation. Because the aetiology of this man's diffuse parenchymal lung disease remained unclear a surgical lung biopsy was undertaken. Histological assessment disclosed widespread fibrosis with marked eosinophillic infiltration and associated organising pneumonia - features all highly suggestive of drug induced lung disease. Following withdrawal of both sertraline and risperidone and initiation of corticosteroid therapy the patient's respiratory failure resolved and three years later he remains well albeit limited by breathlessness on heavy exertion.

Conclusion

Drug induced lung disease can be rapidly progressive and if drug exposure continues may result in respiratory failure and death. Prompt recognition is critical as drug withdrawal may result in marked resolution of disease. This case highlights sertraline and risperidone as drugs that may, in susceptible individuals, cause diffuse pulmonary fibrosis.

[Idiopathic chronic eosinophilic pneumonia - a diagnostic challenge]

CASE REPORT

A 43-year-old woman with clinical signs of a febrile respiratory infection with cough and dyspnea despite several antecedent antibiotic treatments was admitted to hospital because of persistent bilateral pulmonary infiltrates.

DIAGNOSIS, THERAPY, AND COURSE

In the diagnostic work-up, the most striking laboratory abnormality was an eosinophilia of 31% within the differential blood count. Specimen obtained from bronchoalveolar lavage showed an abnormally high level of eosinophils as well. In the absence of other known causes of an eosinophilic pulmonary disease the diagnosis of idiopathic chronic eosinophilic pneumonia was made. After initiation of corticosteroid medication the abnormal laboratory results, the clinical signs, and the radiologic findings almost completely normalized within 1 week.

CONCLUSION

If an apparent pneumonia fails to respond to conventional antibiotic treatment, a blood eosinophil count should be obtained. If blood eosinophils are abnormally high, diagnosis of idiopathic acute or chronic eosinophilic pneumonia should be considered and confirmed by demonstrating an excess of eosinophils in bronchoalveolar lavage fluid. Due to prognostic and therapeutic consequences idiopathic acute and chronic eosinophilic pneumonia should be distinguished from one another. A rapid response to glucocorticoid therapy supports the diagnosis. In order to avoid relapses, patients with chronic eosinophilic pneumonia have to complete a 6-month treatment.

Eosinophilia in bronchoalveolar lavage fluid and architectural destruction are features of desquamative interstitial pneumonia

AIMS

Desquamative interstitial pneumonia (DIP) is a rare pattern of diffuse parenchymal lung disease known to overlap with respiratory bronchiolitis-interstitial lung disease (RB-ILD). The aim was to review biopsy-proven cases of DIP to investigate further the clinical, imaging and histological features of this disease.

METHODS AND RESULTS

Twenty patients fulfilled the pathological criteria: 19 men and one woman with a mean age of 54 years. Clinical features, bronchoalveolar lavage (BAL) data, radiological findings, pathological findings other than criteria, effect of therapy and outcome were examined. The BAL data for 17 cases revealed marked eosinophilia (mean 18%) and moderate neutrophilia (mean 11%). Computed tomography in 17 patients showed peripheral involvement in all cases with a clear margin in 64% and thin-walled cysts in 35% of cases. Additional pathological features were a distinct lobular distribution (70%) and architectural destruction (70%) with cyst formation (55%). Eighteen of the 19 patients (95%) improved under steroid pulse and/or oral therapy. Sixteen subjects (80%) are alive, three died of other diseases and one died of DIP 74 months after the diagnosis. Percent vital capacity increased significantly and new thin-walled cysts appeared in one case.

CONCLUSIONS

BAL eosinophilia, lobular distribution and architectural destruction with cyst formation are characteristic features of DIP.

Desquamative interstitial pneumonia with a remarkable increase in the number of BAL eosinophils

A 57-year old man with desquamative interstitial pneumonia (DIP) showed a marked increase in eosinophils in the bronchoalveolar lavage (BAL) fluid. The patient was referred to our hospital for abnormal shadows on his chest X-ray with no symptoms in May 2007. Computed tomography (CT) showed patchy, peripheral predominate ground-glass opacity. The BAL fluid revealed an increase of the total number of cells, including markedly elevated levels of eosinophils (62.1%), in contrast with only a slight increase of peripheral blood eosinophils, or minimal eosinophils in the alveolar spaces and interstitium of the thoracoscopic lung biopsy specimen. Since the specimens showed findings compatible with a DIP pattern, we diagnosed the patient with DIP. Although it is a rare entity, we should therefore consider DIP in the differential diagnosis when we encounter patients with a marked increase in the number of BAL eosinophils.

Chronic eosinophilic pneumonia: a review

Chronic eosinophilic pneumonia (CEP) is a disease of unknown cause. The hallmark of CEP is eosinophil accumulation in the lungs. While the triggering factor is unknown, eosinophil accumulation in the lungs is now believed to be secondary to the actions of eosinophil-specific chemoattractants, including eotaxin and regulated upon activation, normal T-cell expressed and secreted (RANTES), and IL-5 released from Th2 lymphocytes in the lungs. There is a female preponderance in CEP, with a peak incidence in the 5th decade; the onset is insidious with weight loss, cough, and dyspnea. An atopic history is common, but asthma is not a prerequisite for the development of CEP. Airways obstruction may develop during the course of CEP, but may also result from CEP. The chest x-ray usually shows bilateral peripheral shadows, which may be migratory. Peripheral eosinophilia is usual. Standard treatment of CEP is with oral steroids, usually with dramatic resolution of symptoms and radiographic changes; however, relapses are common when the daily steroid dose is reduced below 15 mg. Current data suggest that when treatment is stopped, relapse is common in the majority of patients (>80%) followed for a sufficiently long period of time. Some recent reports suggest that treatment with inhaled steroids may be of some value in this condition.

[Churg-Strauss syndrome and pulmonary fibrosis: an unusual association]

INTRODUCTION

Churg-Strauss syndrome (CSS) is characterized by asthma, hypereosinophilia, and vasculitis involving at least two extrapulmonary organs.

CASE

We report a case of a patient with antineutrophilic cytoplasmic antibody-negative CSS who developed pulmonary interstitial fibrosis (PIF).

DISCUSSION

The possible relations between CSS and PIF are discussed. Because this case report is the first to describe features of pulmonary fibrosis in a patient with CSS, we cannot know whether this association is causal or fortuitous.

Pneumonia eosinofílica crônica

Pneumonia eosinofílica crônica é uma entidade clínica rara que se caracteriza por infiltração alveolar e intersticial eosinofílica, de causa desconhecida. Os autores descrevem o caso de uma mulher branca de 49 anos, admitida por dispnéia aos mínimos esforços, de início insidioso e progressivo havia seis meses. Apresentava eosinofilia sérica e no escarro, radiografias de tórax com áreas de infiltração multifocais de distribuição irregular em ambos os pulmões e, na avaliação funcional pulmonar, distúrbio restritivo. O exame histopatológico de tecido pulmonar obtido por biópsia a céu aberto evidenciou pneumonia eosinofílica crônica. Houve marcada melhora clínica, radiológica e funcional após corticoterapia.

Utility of a lung biopsy for the diagnosis of idiopathic pulmonary fibrosis

It is not known if a surgical lung biopsy is necessary in all patients for the diagnosis of idiopathic pulmonary fibrosis (IPF). We conducted a blinded, prospective study at eight referring centers. Initially, cases were evaluated by clinical history and examination, transbronchial biopsy, and high-resolution lung computed tomography scans. Pulmonologists at the referring centers then assessed their certainty of the diagnosis of IPF and provided an overall diagnosis, before surgical lung biopsy. The lung biopsies were reviewed by a pathology core and 54 of 91 patients received a pathologic diagnosis of IPF. The positive predictive value of a confident (certain) clinical diagnosis of IPF by the referring centers was 80%. The positive predictive value of a confident clinical diagnosis was higher, when the cases were reviewed by a core of pulmonologists (87%) or radiologists (96%). Lung biopsy was most important for diagnosis in those patients with an uncertain diagnosis and those thought unlikely to have IPF. These studies suggest that clinical and radiologic data that result in a confident diagnosis of IPF by an experienced pulmonologist or radiologist are sufficient to obviate the need for a lung biopsy. Lung biopsy is most helpful when clinical and radiologic data result in an uncertain diagnosis or when patients are thought not to have IPF.

Eosinophilic pneumonia-like areas in idiopathic usual interstitial pneumonia

Usual interstitial pneumonia is the most common idiopathic chronic interstitial pneumonia, characterized by a temporally heterogenous pattern of interstitial injury with interstitial mononuclear infiltrates, septal fibromyxoid nodules, and parenchymal scarring. This report details the presence of focal eosinophilic pneumonia in six cases of usual interstitial pneumonia in the absence of known causes of this reaction. The relationship of eosinophilic infiltrates in usual interstitial pneumonia with regard to pathogenesis, differential diagnosis, and prognosis is discussed.

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."

Idiopathic chronic eosinophilic pneumonia. A clinical and follow-up study of 62 cases. The Groupe d'Etudes et de Recherche sur les Maladies "Orphelines" Pulmonaires (GERM"O"P)

Idiopathic chronic eosinophilic pneumonia (CEP) is a rare disorder of unknown cause with nonspecific respiratory and systemic symptoms but rather characteristic peripheral alveolar infiltrates on imaging, developing mainly in women and in atopic subjects. The disorder is highly responsive to oral corticosteroid therapy, but relapses are frequent on reducing or stopping treatment. The long-term course of the disease and data regarding outcome, particularly the need for prolonged oral corticosteroid therapy and the development of severe asthma, are somewhat contradictory. A multicentric retrospective study was conducted in an attempt to describe better the initial features and, above all, the later course of CEP in a large homogeneous series of 62 stringently selected patients of whom 46 were followed for more than 1 year. The prevalence of smokers was low (6.5%) and about half of our patients (51.6%) had a previous, and often prolonged, history of asthma. The clinical and roentgenographic features were in keeping with previous studies, but we found that computed tomography could disclose ground glass opacities not detected by X-ray, and that migratory infiltrates before treatment were more frequent (25.5%) than reported previously. The bronchoalveolar lavage cellular count always showed a striking eosinophilic pattern, thus allowing distinction between CEP and cryptogenic organizing pneumonia, both syndromes sharing many common clinical and imaging features. About two-thirds of the patients (68%) showed a ventilatory defect in pulmonary function tests, with about one-half of these presenting with an obstructive pattern, sometimes without previous asthma. Along with the submucosal eosinophilic infiltration noted in 2 patients without ventilatory defect, this is strong evidence to confirm that CEP is not only an alveolointerstitial but also an airway disease. The dramatic response to oral corticosteroid therapy was observed in all treated patients. Although only 1 patient initially treated for less than 6 months did not relapse, longer oral corticosteroid therapy in no way provided protection from further relapses. We thus propose to try to wean oral corticosteroid therapy after 6 months in patients without severe asthma, because recurrences remain responsive to oral steroids. However, prolonged oral corticosteroid therapy was necessary in the majority of patients, with 68.9% of those followed for more than 1 year still on oral corticosteroid therapy at the last follow-up, either because of relapse or because of severe asthma.