The Clinical Clues of Pulmonary Alveolar Proteinosis: A Report of 11 Cases and Literature Review

A Comprehensive Outlook on Pulmonary Alveolar Proteinosis-A Review

Pulmonary alveolar proteinosis (PAP) is an ultra-rare disease caused by impaired pulmonary surfactant clearance due to the dysfunction of alveolar macrophages or their signaling pathways. PAP is categorized into autoimmune, congenital, and secondary PAP, with autoimmune PAP being the most prevalent. This article aims to present a comprehensive review of PAP classification, pathogenesis, clinical presentation, diagnostics, and treatment. The literature search was conducted using the PubMed database and a total of 67 articles were selected. The PAP diagnosis is usually based on clinical symptoms, radiological imaging, and bronchoalveolar lavage, with additional GM-CSF antibody tests. The gold standard for PAP treatment is whole-lung lavage. This review presents a summary of the most recent findings concerning pulmonary alveolar proteinosis, pointing out specific features that require further investigation.

An exploratory study investigating biomarkers associated with autoimmune pulmonary alveolar proteinosis (aPAP)

Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare lung disorder involving production of autoantibodies against endogenous granulocyte–macrophage colony-stimulating factor (GM-CSF). This study aimed to identify biomarkers that could be used to monitor for aPAP, particularly in patients treated with anti-GM-CSF antibodies. This was an exploratory, prospective, observational, single-center study. Pre-specified biomarkers were evaluated between baseline and Day 120 in serum/plasma, whole blood, sputum and exhaled breath condensate from patients with aPAP, healthy volunteers, and patients with chronic obstructive pulmonary disease (COPD) and asthma (not treated with anti-GM-CSF and with no evidence of aPAP). Pulmonary function tests were also performed. Overall, 144 individuals were enrolled (aPAP: n = 34, healthy volunteers: n = 24, COPD: n = 40 and asthma: n = 46). Plasma GM-CSF levels were lower, and Krebs von den Lungen 6 and GM-CSF autoantibody ranges were higher, in patients with aPAP compared with other populations. Surfactant proteins-A and -D, lactate dehydrogenase and carcinoembryonic antigen ranges partially or completely overlapped across populations. Most plasma biomarkers showed high sensitivity and specificity for detection of aPAP; GM-CSF and GM-CSF autoantibody concentrations demonstrated equivalent sensitivity for differentiating aPAP. In addition to characteristic GM-CSF autoantibodies, assessment of plasma GM-CSF may identify individuals at risk of developing aPAP.

Trial registration: EudraCT, 2012-003475-19. Registered 23 July 2012—https://eudract.ema.europa.eu/.

Challenges and countermeasures of thoracic oncology in the epidemic of COVID-19

Since December, 2019, a 2019 novel coronavirus disease (COVID-19) infected by the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) emerged in Wuhan, Hubei province, and the epidemic situation has continued to spread globally. The epidemic spread of COVID-19 has brought great challenges to the clinical practice of thoracic oncology. Outpatient clinics need to strengthen the differential diagnosis of initial symptoms, pulmonary ground-glass opacity (GGO), consolidation, interstitial and/or interlobular septal thickening, and crazy paving appearance. In the routine of oncology, the differential diagnosis of adverse events from COVID-19 is also significant, including radiation pneumonitis, checkpoint inhibitor pneumonitis (CIP), neutropenic fever, and so on. During the epidemic, indications of transbronchial biopsy (TBB) and CT-guided percutaneous thoracic biopsy are strictly controlled. For patients who are planning to undergo biopsy operation, screening to exclude the possibility of COVID-19 should be carried out. For confirmed or suspected patients, three-level protection should be performed during the operation. Disinfection and isolation measures should be strictly carried out during the operation. At last, more attention to the protection of cancer patients and give priority to the treatment of infected cancer patients.

The Occupational Burden of Nonmalignant Respiratory Diseases. An Official American Thoracic Society and European Respiratory Society Statement

Rationale: Workplace inhalational hazards remain common worldwide, even though they are ameliorable. Previous American Thoracic Society documents have assessed the contribution of workplace exposures to asthma and chronic obstructive pulmonary disease on a population level, but not to other chronic respiratory diseases. The goal of this document is to report an in-depth literature review and data synthesis of the occupational contribution to the burden of the major nonmalignant respiratory diseases, including airway diseases; interstitial fibrosis; hypersensitivity pneumonitis; other noninfectious granulomatous lung diseases, including sarcoidosis; and selected respiratory infections. Methods: Relevant literature was identified for each respiratory condition. The occupational population attributable fraction (PAF) was estimated for those conditions for which there were sufficient population-based studies to allow pooled estimates. For the other conditions, the occupational burden of disease was estimated on the basis of attribution in case series, incidence rate ratios, or attributable fraction within an exposed group. Results: Workplace exposures contribute substantially to the burden of multiple chronic respiratory diseases, including asthma (PAF, 16%); chronic obstructive pulmonary disease (PAF, 14%); chronic bronchitis (PAF, 13%); idiopathic pulmonary fibrosis (PAF, 26%); hypersensitivity pneumonitis (occupational burden, 19%); other granulomatous diseases, including sarcoidosis (occupational burden, 30%); pulmonary alveolar proteinosis (occupational burden, 29%); tuberculosis (occupational burden, 2.3% in silica-exposed workers and 1% in healthcare workers); and community-acquired pneumonia in working-age adults (PAF, 10%). Conclusions: Workplace exposures contribute to the burden of disease across a range of nonmalignant lung conditions in adults (in addition to the 100% burden for the classic occupational pneumoconioses). This burden has important clinical, research, and policy implications. There is a pressing need to improve clinical recognition and public health awareness of the contribution of occupational factors across a range of nonmalignant respiratory diseases.

Pulmonary alveolar proteinosis with upper-lobe predominance in a non-smoking female

In this report, we describe an unusual manifestation of pulmonary alveolar proteinosis (PAP). The patient is a 43-year-old non-smoking female without underlying hematologic or auto-immune disorder. Her initial presentation included non-specific respiratory symptoms (exertional dyspnoea and cough), an unremarkable physical examination, a mild elevation in her serum level of lactate dehydrogenase, a mild impairment in the diffusion capacity for carbon monoxide but a normal spirometry, and multiple ground-glass opacities with a "crazy-paving" pattern predominantly in upper lung zones on her chest radiographic images. PAP was diagnosed histologically. PAP commonly occurs in males with smoking history, and tends to affect the lung parenchyma diffusely or, as in auto-immune PAP, lower lobes predominantly. Upper-lobe predominant PAP, particularly in a non-smoking female, is rare. This report would add PAP to the list of differential diagnosis for upper-lung ground-glass opacities. A review on the relevant literature is also included in the discussion.

Pulmonary alveolar proteinosis with peripheral adenocarcinom

Background: Pulmonary alveolar proteinosis (PAP) is a rare interstitial lung disease classified into congenital form, autoimmune form and secondary form. Secondary PAP is caused by underlying conditions including solid malignancies. Few cases reported PAP associated with lung cancers. Objective: To show the clinical features of PAP with adenocarcinom, tried to seek for possible mechanism to explain whole clinical course. Methods: Reported a case of PAP associated with lung adenocarcinom, and also reviewed the relevant literature on PAP. Results: The patient suffered from intermittent cough, fever, shortness of breath, thoracalgia or hemoptysis. Blood gas analysis showed hyoxemia. Spirometric abnormality is mildly restrictive defect. High-resolution computed tomography (HRCT) showed patchy, ground-glass opacities with interlobular septal thickening called as “crazy-paving” pattern. Positron emission tomography/computed tomography (PET/CT) revealed a nodule with characteristics of lobulation and spiculation in the right lung apex section and diffuse consolidation shadow spreading over rest of lung field. Bronchoalveolar lavage fluid (BALF) showed a large amount of amorphous red-dyed materials and a few alveolar macrophages scattered in endoalveolar space with PAS positive. Transbronchial lung biopsy found adenocarcinoma. Wedge resection with mediastinal lymphnode and then 2 cycles of postoperative chemotherapy was carried out. No ground-glass opacities were found in his chest CT pictures in the next nine months. This result may support the theory that lung cancer cells cause quantitative or functional damage to alveolar macrophages, which trend to secondary PAP. Conclusions: The patient had typical clinical features of PAP. PAP may be secondary to lung cancer. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 390-394)