Francesco Bonella

Significance of Bronchoalveolar Lavage for the Diagnosis of Idiopathic Pulmonary Fibrosis

RATIONALE According to the 2002 ATS/ERS Consensus Classification, a confident diagnosis of idiopathic pulmonary fibrosis (IPF) without surgical lung biopsy is made with consistent clinical/physiological findings and the typical features on high-resolution computed tomography (HRCT). Bronchoalveolar lavage (BAL) and/or transbronchial biopsy, one of four major criteria in the 2000 ATS/ERS IPF Statement, was no more essential in the diagnostic algorithm of 2002 ATS/ERS Consensus Classification. OBJECTIVES To evaluate the additional utility of BAL for the diagnosis of IPF. METHODS A total of 101 patients with suspected IPF on HRCT were studied. Twenty-seven patients were excluded because of lack of functional impairment (n = 20), an underlying condition causing fibrosis (n = 5), or a clinical history inconsistent with IPF (n = 2). The remaining 74 patients met all the criteria recommended in the 2002 ATS/ERS Consensus Classification for making a diagnosis in the absence of surgical biopsy. The final diagnosis was made with further examinations, including pathological analysis, in patients who showed inconsistent findings for IPF on BAL. MEASUREMENTS AND MAIN RESULTS A cut-off level of 30% for lymphocytes in BAL demonstrated a favorable discriminative power for the diagnosis of IPF. Six of the 74 patients (8%) showed a lymphocytosis of 30% or greater in BAL. Their final diagnoses were idiopathic nonspecific interstitial pneumonia (n = 3) and extrinsic allergic alveolitis (n = 3). The change in perception of the diagnosis was validated by a surgical biopsy in two cases and by subsequent outcome in four cases. CONCLUSIONS BAL lymphocytosis changed the diagnostic perception in six of 74 patients who would have been misdiagnosed as having IPF without BAL.

Chronic Hypersensitivity Pneumonitis

Hypersensitivity pneumonitis (HP) is a complex syndrome caused by the inhalation of environmental antigens. Chronic HP may mimic other fibrotic lung diseases, such as idiopathic pulmonary fibrosis. Recognition of the antigen is important for diagnosis; avoidance of further exposure is critical for treatment. Fibrosis on biopsy or high-resolution computed tomography is a predictor of increased mortality. Additional research is needed to understand why the disease develops only in a minority of exposed individuals and why cases of chronic HP may progress without further antigen exposure.

Pulmonary alveolar proteinosis: new insights from a single-center cohort of 70 patients.

BACKGROUND Pulmonary alveolar proteinosis (PAP) is a rare syndrome characterized by the intra-alveolar accumulation of surfactant lipids and proteins. The aim of the study is to describe the epidemiologic, clinical, physiologic, and laboratory features of PAP in a large single-center cohort of patients with PAP. STUDY POPULATION Over 30 years, 70 patients with PAP were managed at our institution, 64 with primary and 6 with secondary PAP. RESULTS The mean age at diagnosis was 43 years with a male to female ratio of 1.3. BAL was the most commonly applied diagnostic method, performed in 83% of cases. A history of smoking was seen in 79%, and of dust exposure in 54%, most commonly to aluminum, silica and sawdust. GM-CSF autoantibody correlated with clinical outcome and KL-6 with diffusing capacity. The number of whole lung lavages (WLL) necessary to reach remission was higher in current smokers. CONCLUSIONS This study shows that the use of BAL for the diagnosis of PAP can reduce the need of histological confirmation. A history of dust or fume inhalation is strongly associated with PAP, also with the autoimmune form. Smoking seems to influence the response to treatment, increasing the number of WLL necessary to reach remission.

Update on therapeutic management of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive diffuse parenchymal lung disease of unknown origin, with a mortality rate exceeding that of many cancers. The diagnostic process is complex and relies on the clinician integrating clinical, laboratory, radiological, and histological data. In the last decade, major advances in our understanding of the pathogenesis of IPF have shifted the paradigm from a primarily inflammatory process evolving to fibrosis to a condition driven by aberrant wound healing following alveolar epithelial cell injury that results in scarring of the lung, architectural distortion, and irreversible loss of function. Improved understanding of disease pathogenesis has led to the identification of several therapeutic targets and the design of high-quality clinical trials evaluating novel compounds. However, the results of these studies have been mostly disappointing, probably due to the plethora of mediators, growth factors, and signaling pathways involved in the fibrotic process. Most recently, pirfenidone and nintedanib, two compounds with pleiotropic anti-fibrotic properties, have been proven effective in reducing functional decline and disease progression in IPF. This is a major breakthrough. Nevertheless, we still have a long way to go. In fact, neither pirfenidone nor nintedanib is a cure for IPF, and most patients continue to progress despite treatment. As such, comprehensive care of patients with IPF, including management of concomitant conditions and physical debility, as well as timely referral for lung transplantation, remains essential. Several agents with a high potential are currently being tested, and many more are ready for clinical trials. Their completion is critical for achieving the ultimate goal of curing patients with IPF.

Diagnostic Modalities in Sarcoidosis: BAL, EBUS, and PET

Advances have been made in minimally invasive diagnostic procedures in sarcoidosis, including bronchoalveolar lavage (BAL), endobronchial ultrasonography-guided transbronchial needle aspiration (EBUS-TBNA), and positron emission tomography (PET). Several independent groups found almost identical predictive values of the CD4:CD8 ratio in BAL for the diagnosis of sarcoidosis. A CD4:CD8 ratio greater than 3.5 shows a high specificity of 93 to 96% for sarcoidosis, but the sensitivity is low (53 to 59%). EBUS-TBNA is a safe and useful tool for diagnosing sarcoidosis stage I and II with a sensitivity of 83 to 93% and a specificity of 100%. Novel imaging techniques have been explored, such as PET using L-[3- (18)F] fluoro-alpha-methyltyrosine ( (18)F-F MT), which is more specific for malignancy than (18)F-fluorodeoxyglucose ( (18)F-FDG)-PET. The combined modality of FMT-PET with FDG-PET could successfully discriminate sarcoidosis from malignancy. These recent developments including novel biopsy procedures and novel imaging techniques could be of value to diagnosing sarcoidosis.

MUC5B promoter polymorphism in Japanese patients with idiopathic pulmonary fibrosis

A single nucleotide polymorphism (SNP) rs35705950 in the promoter of Mucin 5B (MUC5B) has been reported to be associated with idiopathic pulmonary fibrosis (IPF) mainly in Caucasian populations. This study was conducted to confirm the association between rs35705950 and IPF in a Japanese population.

Differential diagnosis of usual interstitial pneumonia: when is it truly idiopathic?

Idiopathic pulmonary fibrosis (IPF), the most common and lethal of the idiopathic interstitial pneumonias, is defined by a radiological and/or pathological pattern of usual interstitial pneumonia (UIP). However, UIP is not synonymous with IPF as other clinical conditions may be associated with UIP, including chronic hypersensitivity pneumonitis, collagen vascular disease, drug toxicity, asbestosis, familial IPF and Hermansky–Pudlak syndrome. Differentiating IPF (“idiopathic UIP”) from conditions that mimic IPF (“secondary UIP”) has substantial therapeutic and prognostic implications. A number of radiological and histological clues may help distinguish IPF from other conditions with a UIP pattern of fibrosis, but their appreciation requires extensive expertise in interstitial lung disease as well as an integrated multidisciplinary approach involving pulmonologists, radiologists and pathologists. In addition, multidisciplinary discussions may decrease the time to initial IPF diagnosis and, thus, enable more timely management. This concept was strongly emphasised by the 2011 ATS/ERS/JRS/ALAT guidelines. This article highlights, with the aid of a clinical case, the difficulties in making a diagnosis of IPF in clinical practice. Yet, an accurate diagnosis is critical, particularly given the availability of drugs that may reduce the pace of functional decline and disease progression in IPF.

Diagnosis of Sarcoidosis.

The diagnosis of sarcoidosis, a systemic granulomatous disease, is based on a compatible clinical–radiological picture and the histological evidence of noncaseating granulomas. Other diseases mimicking sarcoidosis, mostly infections and other granulomatoses, have to be excluded. There is no single test for sarcoidosis, and the presence of granulomas alone does not establish the diagnosis. Symptoms of sarcoidosis are not specific and can be markedly different according to organ involvement and disease course. Respiratory symptoms and fatigue are the most common symptoms at any stage of disease. Histological confirmation is not needed for Löfgren’s or Heerfordt’s syndrome and asymptomatic bihilar lymphadenopathy. The radiological staging system is still based on chest radiography, and computed tomography is not mandatory for routine follow-up. 18F-fluorodeoxyglucose positron emission tomography may be of value in special cases. For assessment of lung involvement and follow-up, pulmonary function tests are necessary with vital capacity being the most important single parameter and diffusion capacity the most sensitive. Bronchoscopy with biopsy is the most common procedure for detection of granulomas, when there is no easier biopsy site like skin or peripheral lymph nodes. Endobronchial ultrasonography-guided transbronchial needle aspiration has replaced mediastinoscopy for evaluation of mediastinal and hilar lymph nodes with a high diagnostic yield. Despite numerous studies, no single biomarker can be reliably used for correct diagnosis or exclusion of sarcoidosis. Genetic testing, despite promising advances, has still not been included in routine care for sarcoidosis patients. The long-term prognosis of sarcoidosis depends on the different organ manifestations: Cardiac or central nervous involvement, together with respiratory complications, is critical. A multidisciplinary approach is necessary for comprehensive care of the sarcoidosis patient.

Different MUC1 gene polymorphisms in German and Japanese ethnicities affect serum KL-6 levels

BACKGROUND KL-6 is a high-molecular-weight glycoprotein classified as human Mucin-1 (MUC1). KL-6 has been reported to be a sensitive biomarker for interstitial lung diseases (ILDs) in the Japanese population. It is also known that polymorphisms in the MUC1 gene affect serum levels of KL-6. This study was conducted to evaluate serum levels of KL-6 and MUC1 polymorphisms in both German and Japanese populations. METHODS Serum levels of KL-6 were measured in 267 patients with ILDs (152 German and 115 Japanese) and 186 healthy subjects (HS) (76 German and 110 Japanese). In addition, rs4072037 single nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction. The optimal cutoff values for discriminating patients with ILDs from HS was determined by receiver operating characteristic analysis based on ethnicity and rs4072037 genotypes. RESULTS The serum KL-6 levels in patients with ILDs were significantly higher compared with HS in both the German and the Japanese cohorts (both p<0.001). The discriminating cutoff value of serum KL-6 in the German cohort was significantly higher than the value in the Japanese cohort. The difference in the serum levels of KL-6 was significantly associated with the rs4072037 genotype distribution. CONCLUSIONS Even in the German cohort, the serum KL6 levels were significantly higher in patients with ILDs than HS. Because of differences in the genotype distribution of rs4072037, the KL-6 cutoff value for the German cohort that discriminated patients with ILDs from HS was significantly higher than the value in the Japanese cohort.

Pharmacological Treatment of Idiopathic Pulmonary Fibrosis: Current Approaches, Unsolved Issues, and Future Perspectives

Idiopathic pulmonary fibrosis (IPF) is a devastating condition with a 5-year survival of approximately 20%. The disease primarily occurs in elderly patients. IPF is a highly heterogeneous disorder with a clinical course that varies from prolonged periods of stability to episodes of rapid deterioration. In the last decade, improved understanding of disease mechanisms along with a more precise disease definition has allowed the design and completion of a number of high-quality clinical trials. Yet, until recently, IPF was essentially an untreatable disease. Finally, pirfenidone and nintedanib, two compounds with antifibrotic properties, have consistently proven effective in reducing functional decline and disease progression in IPF. This is a major breakthrough for patients and physicians alike, but there is still a long way to go. In fact, neither pirfenidone nor nintedanib is a cure for IPF, and most patients continue to progress despite treatment. As such, comprehensive care of patients with IPF, including management of comorbidities/complications and physical debility and timely referral for palliative care or, in a small number of highly selected patients, lung transplantation, remains essential. Several agents with high potential are currently being tested and many more are ready to be evaluated in clinical trials.