Idiopathic pulmonary fibrosis is a severe and progressive chronic fibrosing interstitial lung disease, a definitive diagnosis being established by specific combinations of clinical, radiological, and pathological findings. According to current international guidelines, HRCT plays a key role in establishing a diagnosis of usual interstitial pneumonia (UIP). Current guidelines describe three UIP patterns based on HRCT findings: a typical UIP pattern; a pattern designated "possible UIP"; and a pattern designated "inconsistent with UIP", each pattern having important diagnostic implications. A typical UIP pattern on HRCT is highly accurate for the presence of histopathological UIP, being currently considered to be diagnostic of UIP. The remaining patterns require further diagnostic investigation. Other known causes of a UIP pattern include drug-induced interstitial lung disease, chronic hypersensitivity pneumonitis, occupational diseases (e.g., asbestosis), and connective tissue diseases, all of which should be included in the clinical differential diagnosis. Given the importance of CT studies in establishing a diagnosis and the possibility of interobserver variability, the objective of this pictorial essay was to illustrate all three UIP patterns on HRCT.

Keywords: Tomography, X-ray computed; Lung diseases, interstitial; Pulmonary fibrosis.

Idiopathic pulmonary fibrosis (cryptogenic fibrosing alveolitis) is a progressive interstitia pulmonary disease of unknown etiology. Since Hamman's and Rich's (1944) reports, many studies have tried to find a histological marker for the correlation between prognosis and response to therapy. However, there are many doubts regarding pathogenesis. In addition, it is generally accepted that response to therapy is related to the relative degree of cellularity and fibrosis. The purpose of this study is to describe the results of inflammatory/exudative changes, fibrotic/reparative changes, and airway alterations, using a semi-quantitative method by independent evaluation of two pathologists, in 24 open lung biopsies with the diagnosis of idiopathic pulmonary fibrosis. Fourteen histological features were analyzed using the 0 to 5 scale for interstitial alterations and the 0 to 2 scale for the airway changes. There was significant interobserver agreement for all histological features with Kw (Kappa) variations between 0.47 and 0.92. There was significant disagreement only for septal inflammatory intensity analysis, suggesting that these features must be discussed by the pathologists. The semi-quantitative method assessment was effective.

Keywords: Idiopathic pulmonary fibrosis (IPF). Usual interstitial pneumonia (UIP). Semi-quantitative method assessment.

Objective: To evaluate the differences between surgical biopsies of distinct lung lobes in terms of the histopathological features of usual interstitial pneumonia, using a semiquantitative score. Methods: We selected all of the patients diagnosed with idiopathic pulmonary fibrosis and submitted to surgical biopsy in two distinct lobes between 1995 and 2005 at the Hospital São Paulo and other hospitals operated by the Federal University of São Paulo. In the histological evaluation of the specimens, we used a semiquantitative method based on previous studies, assigning a score to each of the biopsied sites. Results: In this sample of patients, we found no statistically significant differences that would alter the stage of the disease, based on the score used. This finding was independent of the biopsy site (middle lobe or lingular segment). Conclusions: No significant histological differences were found between the lung lobes studied. The definitive histological diagnosis of usual interstitial pneumonia did not alter the stage of the disease.

Keywords: Lung diseases, interstitial; Pulmonary fibrosis; Thoracic surgery; Pathology; Thoracic surgery, ­video-assisted.

Objective: To make a retrospective analysis of lung biopsy samples obtained from patients diagnosed with chronic idiopathic interstitial pneumonia, as defined in the American Thoracic Society/European Respiratory Society classification system made public in 2000. Methods: Samples from 252 open-lung biopsies of patients with interstitial lung disease, all performed between 1977 and 1999, were reviewed, and 39 cases of idiopathic interstitial lung disease were selected and re-evaluated by two pathologists in accordance with the American Thoracic Society/European Respiratory Society classification system. Results: Among those 39 cases, the diagnoses were maintained in 28 (71.8%). A new pathologic entity, nonspecific interstitial pneumonia, was included in the reclassification, and overlapping patterns were observed in 6 cases. Of the 28 cases in which the diagnosis of chronic idiopathic interstitial pneumonia remained unchanged, idiopathic pulmonary fibrosis was accompanied by cryptogenic organizing pneumonia in 4, cryptogenic organizing pneumonia was accompanied by nonspecific interstitial pneumonia in 1, and desquamative interstitial pneumonia was accompanied by nonspecific interstitial pneumonia in 1. All cases of idiopathic pulmonary fibrosis were confirmed, although 3 of those were found to be accompanied by cryptogenic organizing pneumonia. Virtually all prior diagnoses were maintained in the review of the biopsy samples (p > 0,05). Conclusion: The American Thoracic Society/European Respiratory Society system of classifying interstitial lung disease is a useful tool for pathologists who deal with lung biopsies.

Keywords: Pulmonary fibrosis; Lung diseases, interstitial

Objective: To assess proteinuria in patients with cystic fibrosis (CF), and to correlate proteinuria with genotype, CF-related diabetes and disease severity. Methods: A prospective study was carried out over a six-month period and involving 22 CF patients. After the collection and analysis of 24-h urine samples, the patients were divided into two subgroups: protein excretion < 150 mg/day (low-proteinuria); and protein excretion ≥ 150 mg/day (high-proteinuria). Patient charts were reviewed to obtain data on genotype and CF-related diabetes. Disease severity was assessed based on acute exacerbations in the last six months and FEV1 measured during the study period. To assess the correlation between genotype and proteinuria, the two main mutations (ΔF508 and R334W) were evaluated. Due to the existence of genotype ΔF508/R334W, two categories were created to enable statistical analysis, ΔF508 being evaluated in category 1 and R334W being evaluated in category 2. Results: The ΔF508 mutation tended to be associated with normal protein excretion: 100% of the low-proteinuria subgroup patients were considered ΔF508 in category 1, compared with 86.7% in category 2. Protein excretion tended to be higher in patients with the R334W mutation: 60.0% of the high-proteinuria subgroup patients were considered R334W in category 1, compared with 80.0% in category 2 (p = 0.009 and p = 0.014, respectively). No significant association was found for any of the other variables. Conclusions: The results suggest that genotype is associated with renal phenotype, depending on the mechanism by which the genotype alters the function of the cystic fibrosis transmembrane conductance regulator gene.

Keywords: Proteinuria; Cystic fibrosis; Genotype.

Objective: Many patients with proportional reductions in FVC and FEV1 on spirometry show no reduction in TLC. The aim of this study was to evaluate the role that measuring lung volumes and airway resistance plays in the correct classification of patients with a possible restrictive pattern on spirometry. Methods: This was a prospective study involving adults with reduced FVC and FEV1, as well as an FEV1/FV(C) ratio within the predicted range. Restrictive lung disease (RLD) was characterized by TLC below the 5th percentile, as determined by plethysmography. Obstructive lung disease (OLD) was characterized by high specific airway resistance, significant changes in post-bronchodilator FEV1, or an FEF25-75% < 50% of predicted, together with a high RV/TLC ratio. Nonspecific lung disease (NLD) was characterized by TLC within the predicted range and no obstruction. Combined lung disease (CLD) was characterized by reduced TLC and findings indicative of airflow obstruction. Clinical diagnoses were based on clinical suspicion, a respiratory questionnaire, and the review of tests of interest. Results: We included 300 patients in the study, of whom 108 (36%) were diagnosed with RLD. In addition, 120 (40%) and 72 (24%) were diagnosed with OLD/CLD and NLD, respectively. Among the latter, 24 (33%) were clinically diagnosed with OLD. In this sample, 151 patients (50.3%) were obese, and obesity was associated with all patterns of lung disease. Conclusions: Measuring lung volumes and airway resistance is often necessary in order to provide an appropriate characterization of the pattern of lung disease in patients presenting with a spirometry pattern suggestive of restriction. Airflow obstruction is common in such cases.

Keywords: Spirometry; Airway resistance; Lung volume measurements.

Objective: To describe clinical and laboratory characteristics in patients with tuberculosis-related or lymphoma-related lymphocytic pleural effusions, in order to identify the variables that might contribute to differentiating between these diseases. Methods: This was a retrospective study involving 159 adult HIV-negative patients with tuberculosis-related or lymphoma-related lymphocytic effusions (130 and 29 patients, respectively), treated between October of 2008 and March of 2010 at the Pleural Diseases Outpatient Clinic of the University of São Paulo School of Medicine Hospital das Clínicas Heart Institute, in the city of São Paulo, Brazil. Results: Mean age and the mean duration of symptoms were lower in the tuberculosis group than in the lymphoma group. The levels of proteins, albumin, cholesterol, amylase, and adenosine deaminase (ADA) in pleural fluid, as well as the serum levels of proteins, albumin, and amylase, were higher in the tuberculosis group, whereas serum cholesterol and triglycerides were higher in the lymphoma group. Pleural fluid leukocyte and lymphocyte counts were higher in the tuberculosis group. Of the tuberculosis group patients, none showed malignant cells; however, 4 showed atypical lymphocytes. Among the lymphoma group patients, cytology for neoplastic cells was positive, suspicious, and negative in 51.8%, 24.1%, and 24.1%, respectively. Immunophenotyping of pleural fluid was conclusive in most of the lymphoma patients. Conclusions: Our results demonstrate clinical and laboratory similarities among the patients with tuberculosis or lymphoma. Although protein and ADA levels in pleural fluid tended to be higher in the tuberculosis group than in the lymphoma group, even these variables showed an overlap. However, none of the tuberculosis group patients had pleural fluid ADA levels below the 40-U/L cut-off point.

Keywords: Pleural effusion; Tuberculosis; Lymphoma; Adenosine deaminase; Diagnosis, differential.

Objective: To evaluate alterations in pulmonary function in patients with systemic sclerosis-associated interstitial pneumonia over a five-year period. Methods: This was a longitudinal study involving 35 nonsmoking patients with systemic sclerosis and without a history of lung disease. At the first evaluation, performed at the time of the diagnosis of interstitial pneumonia, the patients were submitted to HRCT, spirometry, and measurement of DLCO. The patients were subdivided into two groups by the presence or absence of honeycombing on the HRCT scans. Approximately five years after the first evaluation, the patients were submitted to spirometry and measurement of DLCO only. Results: Of the 35 patients, 34 were women. The mean age was 47.6 years. The mean time between the two evaluations was 60.9 months. Honeycombing was detected on the HRCT scans in 17 patients. In the sample as a whole, five years after the diagnosis, FVC, FEV1 and DLCO significantly decreased (81.3 ± 18.2% vs. 72.1 ± 22.2%; 79.9 ± 17.8% vs. 72.5 ± 20.6%; and 74.0 ± 20.5% vs. 60.7 ± 26.8%, respectively; p = 0.0001 for all), and the FEV1/FVC ratio significantly increased (98.5 ± 7.2% vs. 101.9 ± 7.8%; p = 0.008). In the same period, FVC, FEV1, and DLCO values were significantly lower in the patients with honeycombing on the HRCT scans than in those without (p = 0.0001). Conclusions: In systemic sclerosis-associated interstitial lung disease, the detection of honeycombing on HRCT is crucial to predicting accelerated worsening of pulmonary function.

Keywords: Scleroderma, systemic; Respiratory function tests; Tomography, X-ray computed.

Leflunomide is an anti-rheumatic drug with immunomodulating effects. Granulomatous interstitial pneumonia has never been described in association with the use of this drug. We report the case of a 33-year-old female patient who presented with chest pain, weight loss and pulmonary infectious syndrome during the fifth month of monotherapy with leflunomide for rheumatoid arthritis, which advanced to respiratory insufficiency in the sixth month. Radiologic findings revealed pulmonary intersticial infiltrates, as well as bilateral alveolar infiltrates (mainly in the upper and medium lobes) and scattered micronodules. However, no mediastinal abnormalities were detected. Leflunomide was suspended. After resolution of the infection, interstitial reticulonodular lesions persisted, predominantly in the upper 2/3 of the right lung and in the center of the left lung, interspersed with a ground-glass pattern in the superior lobes. Surprisingly, pulmonary biopsy revealed tuberculoid granulomas without caseous necrosis. A thorough etiological investigation was carried out, but no etiologic agent was identified. After four months, the condition spontaneously and completely disappeared. This profile suggests that the pulmonary complications seen in this case were the result of leflunomide use.

Keywords: Lung diseases, interstitial/chemically induced. Lung/drugs effects.

Venlafaxine is a serotonin-norepinephrine reuptake inhibitor used as an antidepressant. Interindividual variability and herb-drug interactions can lead to drug-induced toxicity. We report the case of a 35-year-old female patient diagnosed with synchronous pneumonitis and acute cardiomyopathy attributed to venlafaxine. The patient sought medical attention due to dyspnea and dry cough that started three months after initiating treatment with venlafaxine for depression. The patient was concomitantly taking Centella asiatica and Fucus vesiculosus as phytotherapeutic agents. Chest CT angiography and chest X-ray revealed parenchymal lung disease (diffuse micronodules and focal ground-glass opacities) and simultaneous dilated cardiomyopathy. Ecocardiography revealed a left ventricular ejection fraction (LVEF) of 21%. A thorough investigation was carried out, including BAL, imaging studies, autoimmune testing, right heart catheterization, and myocardial biopsy. After excluding other etiologies and applying the Naranjo Adverse Drug Reaction Probability Scale, a diagnosis of synchronous pneumonitis/cardiomyopathy associated with venlafaxine was assumed. The herbal supplements taken by the patient have a known potential to inhibit cytochrome P450 enzyme complex, which is responsible for the metabolization of venlafaxine. After venlafaxine discontinuation, there was rapid improvement, with regression of the radiological abnormalities and normalization of the LVEF. This was an important case of drug-induced cardiopulmonary toxicity. The circumstantial intake of inhibitors of the CYP2D6 isoenzyme and the presence of a CYP2D6 slow metabolism phenotype might have resulted in the toxic accumulation of venlafaxine and the subsequent clinical manifestations. Here, we also discuss why macrophage-dominant phospholipidosis was the most likely mechanism of toxicity in this case.

Keywords: Cardiomyopathy, dilated; Lung diseases, interstitial; Antidepressive agents, second-generation/toxicity; Herb-drug interactions.

In patients with myositis, the lung is commonly involved, and the presence of anti-aminoacyl-tRNA synthetase (anti-ARS) antibodies marks the presence or predicts the development of interstitial lung disease (ILD). A distinct clinical entity-antisynthetase syndrome-is characterized by the presence of anti-ARS antibodies, myositis, ILD, fever, arthritis, Raynaud's phenomenon, and mechanic's hands. The most common anti-ARS antibody is anti-Jo-1. More recently described anti-ARS antibodies might confer a phenotype that is distinct from that of anti-Jo-1-positive patients and is characterized by a lower incidence of myositis and a higher incidence of ILD. Among patients with antisynthetase syndrome-related ILD, the response to immunosuppressive medications is generally, but not universally, favorable.

Keywords: Lung diseases, interstitial; Pneumonia; Infection.

Objective: To investigate the diagnostic accuracy of a chest X-ray (CXR) score and of clinical and laboratory data in predicting the clinical course of patients with SARS coronavirus 2 (SARS-CoV-2) infection. Methods: This is a pilot multicenter retrospective study including patients with SARS-CoV-2 infection admitted to the ERs in three hospitals in Italy between February and March of 2020. Two radiologists independently evaluated the baseline CXR of the patients using a semi-quantitative score to determine the severity of lung involvement: a score of 0 represented no lung involvement, whereas scores of 1 to 4 represented the first (less severe) to the fourth (more severe) quartiles regarding the severity of lung involvement. Relevant clinical and laboratory data were collected. The outcome of patients was defined as severe if noninvasive ventilation (NIV) or intubation was necessary, or if the patient died. Results: Our sample comprised 140 patients. Most of the patients were symptomatic (132/138; 95.7%), and 133/140 patients (95.0%) presented with opacities on CXR at admission. Of the 140 patients, 7 (5.0%) showed no lung involvement, whereas 58 (41.4%), 31 (22.1%), 26 (18.6%), and 18 (12.9%), respectively, scored 1, 2, 3, and 4. In our sample, 66 patients underwent NIV or intubation, 37 of whom scored 1 or 2 on baseline CXR, and 28 patients died. Conclusions: The severity score based on CXR seems to be able to predict the clinical progression in cases that scored 0, 3, or 4. However, the score alone cannot predict the clinical progression in patients with mild-to-moderate parenchymal involvement (scores 1 and 2).

Keywords: Coronavirus infections; Radiography, thoracic; Pneumonia; Respiratory insufficiency; Severe acute respiratory syndrome.

Aim: To evaluated the etiologic percentage of the atypical pneumoniae in outpatients and to identify the epidemiologic, clinical and radiographic features that permit to distinguish between atypical and non-atypical pneumonia. Methods: All patients underwent clinical and radiographic evaluation. Serum and sputum samples were obtained to serological tests including Legionella sp, Chlamydia sp, M. pneumoniae, Influenza A and Influenza B virus, and Gram stain, respectively. These procedures were performed on the first and 21 days after inclusion. Three independent observers reviewed chest X-rays. Results: During 22 months, 129 patients were evaluated. The final population under study comprised 69 patients (46 men - 23 women) with a mean age of 37 years. The etiologic diagnosis was defined in 34 (50%) of the patients. Etiologic agents included Chlamydia sp, 11 (16%) isolated cases; M. pneumoniae 7 (10%) cases. Influenza A was the third more frequent agent in 4 (6%) patients, and Legionella sp in 4 (6%). Mixed infections were observed with association of Chlamydia sp and M. pneumoniae in 5 (7.3%) cases, Chlamydia sp and Influenza B one (1.5%) case, and another of M. pneumoniae and Influenza A. The atypical pneumonia and non-atypical pneumonia groups were compared to respiratory symptoms and signs. There were no differences between them. The three independent observers' radiographic evaluation showed disagreement among them as to the type of pneumonia. Radiographic diagnoses of individual observers were compared to the clinical diagnoses, and no significant association was obtained for any observer. Conclusion: Pneumonia caused by "atypical" agents occurs in 50% of the outpatients with community acquired pneumonia. It is not possible to distinguish atypical pneumonia from non-atypical pneumonia. The clinical and radiographic presentations are similar in both groups.

Keywords: pneumonia; etiology; diagnosis; epidemiology

In humans, the most common types of infection are respiratory tract infections, among which viral infections predominate. Viruses can also infect the low respiratory tract, causing bronchiolitis, bronchitis and pneumonia. The objective of this review article was to show epidemiological, pathophysiological, clinical and therapeutic aspects of viral community-acquired pneumonia. These types of pneumonia are commonly caused by influenza A and B; parainfluenza 1, 2 and 3; respiratory syncytial virus; or adenovirus. We also address the types of pneumonia caused by hantaviruses, metapneumoviruses and rhinoviruses.

Keywords: Pneumonia, viral; Influenza, human; Respiratory syncytial virus infections; Hantavirus.