[Interstitial lung diseases : Classification, differential diagnosis and treatment approaches in a heterogeneous group of chronic lung disorders]. / Interstitielle Lungenerkrankungen : Klassifikation, Differenzialdiagnostik und therapeutische Ansätze bei einer heterogenen Gruppe chronischer Lungenerkrankungen.

Interstitial lung diseases (ILD) comprise a heterogeneous group of chronic lung disorders of different etiologies that can not only affect the interstitium but also the alveolar space and the bronchial system. According to the "Global Burden of Disease Study" there has been an increase in incidence over the last decades and it is expected that the number of ILD-associated deaths will double over the next 20 years. ILD are grouped into those of unknown cause, e.g. idiopathic pulmonary fibrosis (IPF), and ILD of known cause, which include drug-induced and connective tissue disease-associated ILD as well as granulomatous ILD such as sarcoidosis and hypersensitivity pneumonitis. In addition, some ILD present a progressive fibrosing phenotype, which influences therapeutic decisions. Predominantly inflammatory entities are treated with immunosuppressives, whereas predominantly fibrosing ILD are treated with antifibrotic drugs; in some cases, a combination of both is necessary. The spectrum of differential diagnoses in ILD is broad, but definite diagnosis is essential for treatment selection; therefore, the multidisciplinary ILD board plays a pivotal role.

[Hypersensitivity Pneumonitis - an important differential diagnosis of infiltrative lung diseases]. / Exogen allergische Alveolitis ­ Eine wichtige Differenzialdiagnose der infiltrativen Lungenerkrankungen.

Hypersensitivity pneumonitis (HP) is an inflammatory and/or fibrotic disease of the lung parenchyma and terminal bronchioles caused by an allergic reaction to inhaled antigens. The immune response following antigen exposure results in lymphocytic inflammation as well as granuloma formation.The typical histologic pattern of HP consists of cellular interstitial pneumonia, cellular bronchiolitis, and epithelioid cell granulomas. The additional presence of fibrosis has a significant impact on the course as well as the prognosis of the disease and represents a therapeutic approach. Therefore, a classification into a non-fibrotic and a fibrotic phenotype is proposed.The diagnosis of HP is made by high-resolution computed tomography (HRCT) of the lung, evaluation of possible antigen exposure, and bronchoscopy with bronchoalveolar lavage and, if necessary, forceps biopsy. If the diagnosis is inconclusive, transbronchial cryobiopsy or surgical lung biopsy may need to follow. A multidisciplinary board is critical in making the diagnosis.

[Idiopathic interstitial pneumonias in 2016]. / Actualités dans les pneumopathies interstitielles idiopathiques en 2016.

Idiopathic interstitial pneumonias comprise 8 clinicopathological entities, most of them with a chronic course and various prognosis. Idiopathic pulmonary fibrosis is the most frequent and most severe of these. Computed tomography has an important role for its diagnosis. It can identify the corresponding pathological pattern of usual interstitial pneumonia in about 50 percent of cases. It can suggest differential diagnosis in other cases, most frequently fibrosing nonspecific interstitial pneumonia and chronic hypersensitivity pneumonitis. Imaging features should be integrated to clinical and available pathologic data during multidisciplinary team meetings involving physicians with a good knowledge of interstitial diseases. Some cases may be unclassifiable, but these could later be reclassified as new data may occur or imaging features may change. Surgical lung biopsy is being less frequently performed and an emerging less invasive technique, lung cryobiopsy, is under evaluation. Pleuroparenchymal fibroelastosis is a distinct entity only recently described, with uncertain prevalence and prognosis that seems being quite often associated to another pattern of interstitial pneumonia.

[The problems of classification of the occupational interstitial lung diseases, approaches to solving].

The analysis of the applied in Russia classifications of pneumoconiosis and occupational hypersensitivity pneumonitis in relation to the international classifications of occupational lung diseases and the classification of interstitial lung diseases (ILD) was performed. The necessity of a new approach to the classification of occupational ILD was proved and solutions of the problem were offered.

[Environmental causes of the distal airways disease. Hypersensitivity pneumonitis and rare causes]. / L'atteinte des voies aériennes distales d'origine environnementale. Pneumopathie d'hypersensibilité et étiologies rares.

Hypersensitivity pneumonitis is one of the most frequent causes of distal airways disease. It is associated with inflammation of the bronchioles, predominantly by lymphocytic infiltrates, and with granuloma formation causing bronchial obstruction. This inflammation explains the clinical manifestations and the airways obstruction seen on pulmonary function tests, most often in the distal airways but proximal in almost 20%. CT scan abnormalities reflect the lymphocytic infiltrates and air trapping and, in some cases, the presence of emphysema. Bronchiolitis induced by chronic inhalation of mineral particles or acute inhalation of toxic gases (such as NO2) are other examples of small airways damage due to environmental exposure. The pathophysiological mechanisms are different and bronchiolar damage is either exclusive or predominant. Bronchiolitis induced by tobacco smoke exposure, usually classified as interstitial pneumonitis, is easily diagnosed thanks to broncho-alveolar lavage. Its prognosis is linked to the other consequences of tobacco smoke exposure including respiratory insufficiency. Finally, the complex lung exposure observed in some rare cases (such as the World Trade Center fire or during wars) may lead to a less characteristic pattern of small airways disease.

Hypersensitivity pneumonitis and related conditions in the work environment.

Hypersensitivity pneumonitis can occur from a wide variety of occupational exposures. Although uncommon and difficult to recognize, through a detailed work exposure history, physical examination, radiography, pulmonary function studies, and selected laboratory studies using sera and bronchoalveolar lavage fluid, workers can be identified early to effect avoidance of the antigen and institute pharmacologic therapy, if necessary. A lung biopsy may be necessary to rule out other interstitial lung diseases. Despite the varied organic antigen triggers, the presentation is similar with acute, subacute, or chronic forms. Systemic corticosteroids are the only reliable pharmacologic treatment but do not alter the long-term outcome.

Neumonitis por hipersensibilidad / Pneumonitis related to hypersensitivity

Se presentó una paciente con antecedentes patológicos personales de asma bronquial leve persistente y de dermatitis atópica. Acudió por tener fiebre de 60 d de evolución, tos, disnea, anorexia y pérdida de peso, con empeoramiento progresivo. Se diagnosticó neumonitis por hipersensibilidad después de realizar estudios de imágenes e histológicos. Se describió la evolución clínica y radiológica.

Authors present the case of a woman with personal pathologic backgrounds of persistent light bronchial asthma and of an atopic dermatitis. She came to our service by fever of 60 days of evolution, cough, dyspnea, anorexia, and weight loss with a progressive worsening. A hypersensitivity pneumonitis was diagnosed after imaging and histological studies. Clinical and radiological course was described.

Causes and presenting features in 85 consecutive patients with hypersensitivity pneumonitis.

OBJECTIVE: To assess the current spectrum of causes and clinical features associated with hypersensitivity pneumonitis (HP). PATIENTS AND METHODS: We studied consecutive patients with HP diagnosed at the Mayo Clinic in Rochester, Minn, from January 1, 1997, through December 31, 2002. Diagnostic criteria for HP included the following: (1) presence of respiratory symptoms, (2) radiologic evidence of diffuse lung disease, (3) known exposure or a positive serologic test result to an inciting antigen, and (4) no other identifiable cause for the lung disease. If there was no identifiable inciting antigen, 1 of the following 2 criteria was required: (1) lung biopsy specimen that demonstrated features of HP or (2) bronchoalveolar lavage lymphocytosis and high-resolution computed tomographic evidence of ground-glass opacities or centrilobular nodules bilaterally. RESULTS: The mean +/- SD age of the 85 study patients was 53 +/- 14 years; 53 patients (62%) were women. Only 2 patients (2%) were current smokers. Chronic (> or = 4 months) respiratory symptoms were present in 66 patients (78%). Histopathologic confirmation was obtained in 64 patients (75%). The cause was identified in 64 patients (75%), and the most common causes were avian antigens (34%) and Mycobacterium avium complex in hot tub water (21%). Farmer's lung disease accounted for 11% of cases, and an additional 9% were related to household mold exposure. The inciting antigen was not identifiable in 25% of patients. CONCLUSION: Most patients with HP seen at this tertiary care referral center in the Midwest region of the United States had chronic HP, and the most common causes were exposure to birds and exposure to hot tubs.

Hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP) is a pulmonary disease with symptoms of dyspnea and cough resulting from the inhalation of an antigen to which the subject has been previously sensitized. The incidence of HP is unknown. A population-based study estimated the annual incidence of interstitial lung diseases as 30:100,000 and HP accounted for less than 2% of these cases. The diagnosis of HP can often be made or rejected with confidence, especially in areas of high or low prevalence respectively, using simple diagnostic criteria. Chest X-rays may be normal in active HP; High Resolution Computed Tomography is sensitive but not specific for the diagnosis of HP. The primary use of pulmonary function tests is to determine the physiologic abnormalities and the associated impairment. Despite the pitfalls of false positive and false negatives, antigen-specific IgG antibodies analysis can be useful as supportive evidence for HP. Bronchoalveolar lavage plays an important role in the investigation of patients suspected of having HP. A normal number of lymphocytes rules out all but residual disease. Surgical lung biopsy should be reserved for rare cases with puzzling clinical presentation or for verification the clinical diagnosis when the clinical course or response to therapy is unusual. Being an immune reaction in the lung, the most obvious treatment of HP is avoidance of contact with the offending antigen. Systemic corticosteroids represent the only reliable pharmacologic treatment of HP but do not alter the long-term outcome. The use of inhaled steroids is anecdotal. Treatment of chronic or residual disease is supportive.

Clinical diagnosis of hypersensitivity pneumonitis.

The diagnosis of hypersensitivity pneumonitis (HP) is difficult and often relies on histopathology. Our objective was to identify diagnostic criteria and to develop a clinical prediction rule for this disease. Consecutive patients presenting a condition for which HP was considered in the differential diagnosis underwent a program of simple standardized diagnostic procedures. High-resolution computed tomography scan and bronchoalveolar lavage (BAL) defined the presence or absence of HP. Patients underwent surgical lung biopsy when the computed tomography scan, BAL, and other diagnostic procedures failed to yield a diagnosis. A cohort of 400 patients (116 with HP, 284 control subjects) provided data for the rule derivation. Six significant predictors of HP were identified: (1) exposure to a known offending antigen, (2) positive precipitating antibodies to the offending antigen, (3) recurrent episodes of symptoms, (4) inspiratory crackles on physical examination, (5) symptoms occurring 4 to 8 hours after exposure, (6) and weight loss. The area under the receiver operating characteristic curve was 0.93 (95% confidence interval: 0.90-0.95). The rule retained its accuracy when validated in a separate cohort of 261 patients. The diagnosis of HP can often be made or rejected with confidence, especially in areas of high or low prevalence, respectively, without BAL or biopsy.