Pulmonary alveolar proteinosis. Diagnostic technics and observations

Autoimmune Pulmonary Alveolar Proteinosis

Autoimmune pulmonary alveolar proteinosis (PAP) is a rare disease characterized by myeloid cell dysfunction, abnormal pulmonary surfactant accumulation, and innate immune deficiency. It has a prevalence of 7-10 per million; occurs in individuals of all races, geographic regions, sex, and socioeconomic status; and accounts for 90% of all patients with PAP syndrome. The most common presentation is dyspnea of insidious onset with or without cough, production of scant white and frothy sputum, and diffuse radiographic infiltrates in a previously healthy adult, but it can also occur in children as young as 3 years. Digital clubbing, fever, and hemoptysis are not typical, and the latter two indicate that intercurrent infection may be present. Low prevalence and nonspecific clinical, radiological, and laboratory findings commonly lead to misdiagnosis as pneumonia and substantially delay an accurate diagnosis. The clinical course, although variable, usually includes progressive hypoxemic respiratory insufficiency and, in some patients, secondary infections, pulmonary fibrosis, respiratory failure, and death. Two decades of research have raised autoimmune PAP from obscurity to a paradigm of molecular pathogenesis-based diagnostic and therapeutic development. Pathogenesis is driven by GM-CSF (granulocyte/macrophage colony-stimulating factor) autoantibodies, which are present at high concentrations in blood and tissues and form the basis of an accurate, commercially available diagnostic blood test with sensitivity and specificity of 100%. Although whole-lung lavage remains the first-line therapy, inhaled GM-CSF is a promising pharmacotherapeutic approach demonstrated in well-controlled trials to be safe, well tolerated, and efficacious. Research has established GM-CSF as a pulmonary regulatory molecule critical to surfactant homeostasis, alveolar stability, lung function, and host defense.

Artificial stone-associated silicosis with concurrent Cryptococcus infection

Acute silicoproteinosis is a disease that develops in weeks, and lasting for years, after massive exposure to silica dust in relatively closed spaces. It was rare, but the cases have recently increased worldwide due to the development of artificial stone industry. Compared with traditional silicosis, artificial stone-associated silicosis is more rapidly progressive and lethal. Hence, a correct diagnosis and optimal treatment are crucial. Here, we present the clinical course of a 33-year-old artificial stonemason who suffered from acute silicoproteinosis with concurrent Cryptococcus infection resulting in profound respiratory failure. This patient was treated by bronchoscope-assisted therapeutic segmental lung lavage and antifungal agent, under mechanical ventilator and ECMO support and recovered well. A brief review of acute silicoproteinosis and artificial stone-associated silicosis is also presented and highlights the new form of industry exposure to silica.

Pulmonary alveolar proteinosis

PAP is an ultra-rare disease in which surfactant components, that impair gas exchange, accumulate in the alveolae. There are three types of PAP. The most frequent form, primary PAP, includes autoimmune PAP which accounts for over 90% of all PAP, defined by the presence of circulating anti-GM-CSF antibodies. Secondary PAP is mainly due to haematological disease, infections or inhaling toxic substances, while genetic PAP affects almost exclusively children. PAP is suspected if investigation for ILD reveals a crazy-paving pattern on chest CT scan, and is confirmed by a milky looking BAL that gives a positive PAS reaction indicating extracellular proteinaceous material. PAP is now rarely confirmed by surgical lung biopsy. WLL is still the first-line treatment, with an inhaled GM-CSF as second-line treatment. Inhalation has been found to be better than subcutaneous injections. Other treatments, such as rituximab or plasmapheresis, seem to be less efficient or ineffective. The main complications of PAP are due to infections by standard pathogens (Streptococcus, Haemophilus and Enterobacteria) or opportunistic pathogens such as mycobacteria, Nocardia, Actinomyces, Aspergillus or Cryptococcus. The clinical course of PAP is unpredictable and spontaneous improvement can occur. The 5-year actuarial survival rate is 95%.

Noninvasive Ventilation-Facilitated Bronchofiberoscopy in Patients with Respiratory Failure

Respiratory failure is one of the most important risk factors for diagnostic bronchofiberoscopy (BF), whereas therapeutic bronchoscopies are typically performed in intubated patients. Only a few published studies analyzed the outcomes of noninvasive mechanical ventilation (NIV)-facilitated BF. In this case series, we present our experiences with NIV-facilitated diagnostic and therapeutic BF performed in patients with respiratory failure that was associated with acute interstitial pulmonary disease, chronic obstructive pulmonary disease, cystic fibrosis exacerbation, foreign body aspiration, tracheal stenosis, pneumonia, and in a patient with a neuromuscular disease. All of the patients were initially hypoxic and some had PaO₂/FiO₂ < 200, which corresponded to moderate-to-acute respiratory distress syndrome (ARDS). NIV-facilitated BF were performed for the diagnostic or therapeutic purposes. The former consisted of bronchoalveolar lavage and bacterial sampling in a patient with impaired cough reflex, airway assessment in otherwise unexplained respiratory failure and hemoptysis, and the latter of mucous plugs resolution, foreign body removal, and assistance in weaning from mechanical ventilation. All procedures were carried out using NIV in the spontaneous timed (ST) or average volume assured pressure support (AVAPS) mode with oxygen supplementation. There were no procedure-related complications noticed during NIV-facilitated BF. We conclude that NIV is a useful and safe tool that facilitates the performance of BF in severe pulmonary diseases. Prospective studies are required to set the recommendations for the procedure and to define the optimum ventilatory modes to be used.

Novel method of noninvasive ventilation supported therapeutic lavage in pulmonary alveolar proteinosis proves to relieve dyspnea, normalize pulmonary function test results and recover exercise capacity: a short communication

Whole lung lavage (WLL) under general anesthesia with a double-lumen endobronchial intubation has remained standard treatment option for pulmonary alveolar proteinosis (PAP) for over fifty years now. To the best of our knowledge, this is the first description of noninvasive ventilation (NIV) as an innovative alternative, which enables safe and effective treatment. NIV support enabled cost-effective lavage of the most affected segments and resulted in restoration and long-term maintenance of exercise capacity and diffusion, without WLL related hypoxaemia, volume overload, intubation, or mechanical ventilation related complications. The study presents all details of performed procedure, including anesthesia, NIV technique and bronchoscopy, therefore this may be easily implemented into clinical practice at other centers conducting PAP treatment. We assume that presented technique of therapeutic lung lavage (TLL) with NIV support may be considered a novel PAP treatment method, however, target population who will benefit the most from such therapy modification must be assessed in large scale prospective trials.

Pulmonary alveolar proteinosis: a case report and world literature review

Pulmonary alveolar proteinosis (PAP) is a lung disorder which was first described in 1958 by Rosen et al. and is indeed rare disease with a prevalence of 0.1 per 100,000 individuals. PAP is characterized by abnormal accumulation of pulmonary surfactant in the alveolar space, which impairs gas exchange leading to a severe hypoxemia. Pulmonary surfactant is an insoluble proteinaceous material that is rich in lipids and stains positive with periodic acid-Schiff (PAS). The most common type of PAP is the so-called autoimmune or idiopathic type. It has been hypothesized that deficiency in granulocyte macrophage-colony stimulating factor (GM-CSF), as a result of the anti-GM-CSF antibody production, is strongly related to impaired surfactant recycling that leads to the accumulation of surfactant in the alveolar space. Its clinical course is variable from spontaneous remission in the best case scenario, going through the entire spectrum of disease severity, towards fatal respiratory failure. Whole lung lavage has been the gold standard therapy in PAP until the advent of GM-CSF. Although the first case was reported to be idiopathic, subsequent analysis revealed that Pneumocystis jirovecii, silica, and other inhalational toxins were able to trigger this reaction. In this study, we report the case of a 52-year-old man who developed PAP syndrome after a 2-year exposure to silica dust. Our review of the world literature that includes 363 cases reported until now, reflects the evolution of science and technology in determining different aetiologies and diagnostic tests that lead to an improved perspective in the life of these patients.

Therapeutic limited bronchoalveolar lavage with fiberoptic bronchoscopy as a bridging procedure prior to total lung lavage in a patient with pulmonary alveolar proteinosis: a case report

INTRODUCTION

Therapeutic total lung lavage under general anesthesia is the current mainstay of treatment for pulmonary alveolar proteinosis, which is a rare lung disease characterized by alveolar accumulation of surfactant. Therapeutic limited bronchoalveolar lavage is considered an alternative treatment to conventional total lung lavage.

CASE PRESENTATION

A 61-year-old, previously healthy, Sri Lankan Moor woman presented to our facility with progressively worsening difficulty in breathing and persistent dry cough for one year. Her respiratory examination revealed bibasal fine end-inspiratory crepitations. A chest radiograph showed bilateral mid and lower zone alveolar interstitial shadows and a high-resolution computed tomography scan of her chest revealed septal thickening with ground-glass shadows more on mid and lower zones bilaterally. A diagnostic bronchoalveolar lavage fluid analysis revealed diastase-resistant protein clumps in periodic acid Schiff stain. The diagnosis was made as pulmonary alveolar proteinosis. An arterial blood gas analysis performed prior to intervention revealed a significant hypoxia (partial pressure of oxygen - 64 mmHg) with alveolar-arterial gradient was 35.4 mmHg. Therapeutic limited bronchoalveolar lavage was arranged and her right and her left lung were lavaged separately in two sessions done two weeks apart under local anesthesia. Our patient had significant clinical improvement and resolution of the bilateral septal thickening with minimal resolution of the ground-glass opacities in a repeat high-resolution computed tomography scan done two weeks later. Subsequently, a total lung lavage under general anesthesia was also done, which improved her dyspnea and arterial hypoxemia.

CONCLUSIONS

Therapeutic limited bronchoalveolar lavage can be successfully performed as an interval bridging procedure, as a 'prewash', prior to conventional total lung lavage for pulmonary alveolar proteinosis.

[Unusual alveolar proteinosis]

Pulmonary alveolar proteinosis (PAP), a rare infiltrative disease of unknown aetiology, is characterized by an accumulation of abnormal lung surfactant in the alveoli. The diagnosis is based on the results of the bronchoalveolar lavage (BAL) and sometimes on the lung biopsy. The authors report the case of a 49-year-old woman who was hospitalized for chronic expectoration of the membranes. The chest X-ray revealed alveolar opacities in the lowest part of the right lung. The chest CT scan detected alveolar ground glass opacities with interlobular thickening involving the middle lobe. The BAL was opaque with periodic acid-Schiff stain-positive acellular material. The anatomopathology analysis of the membranes concludes as to the presence of granular eosinophilic material and the absence of neoplasic cells or hydatidous membranes. The diagnosis of PAP was established. Since functional deterioration was not detected, therapy was based on physiotherapy alone. The evolution was favourable, with the disappearance of the symptomatology and the normalisation of the chest X-ray. This observation shows an unusual presentation of PAP based on membrane expectoration and unusual localized lesions.

Pulmonary alveolar proteinosis and successful therapy with combined lavage procedures: Case reports

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the accumulation of lipoproteinaceous material within alveolar spaces. Whole-lung lavage (WLL) has been the most common therapeutic intervention for this disorder. However, patients presenting with PAP are usually hypoxemic or in poor clinical condition, and WLL may be impossible to perform. In such cases, multiple segmental lavage (MSL) may be advocated as a first-choice therapy prior to WLL. Herein, we present two cases with idiopathic PAP treated successfully with both lavage techniques consecutively. After the MSL procedure, WLL was performed, and both patients showed a marked clinical and physiologic improvement. Therefore, for patients who are not good candidates for general anesthesia, we recommend MSL (or 'prewash') before WLL to produce an increase in the blood oxygen level for long-duration general anesthesia. In the surgical room, close monitoring and repositioning of the patient as well as maintenance and inspection of the correct tube position, and manual chest wall percussion are extremely important for the safety and success of the procedure.

Therapeutic bilateral lung lavage in a child with pulmonary alveolar proteinosis

OBJECTIVE

Pulmonary alveolar proteinosis is a rare condition that can cause life-threatening respiratory failure attributable to excessive alveolar accumulation of surfactant proteins. The standard treatment for removing these secretions is through therapeutic bilateral lung lavage. Descriptions of procedures for performing therapeutic bilateral lung lavage and methods used to evaluate the overall effectiveness of this invasive procedure in children with pulmonary alveolar proteinosis have not been adequately described in the medical literature. We successfully and safely performed therapeutic bilateral lung lavage and obtained lung mechanics measurements in a child with pulmonary alveolar proteinosis.

DESIGN

Case report.

SETTING

Operating room within a pediatric hospital.

PATIENTS/SUBJECTS

A 13-yr-old boy with pulmonary alveolar proteinosis requiring serial therapeutic bilateral lung lavage for recurrent respiratory distress.

INTERVENTIONS

The patient presented to the hospital operating room for therapeutic lung lavage after a recent history of progressive dyspnea, respiratory distress, declining lung function measurements, and worsening radiographic abnormalities. We obtained baseline spirometric and respiratory system compliance measurements before and after therapeutic bilateral lung lavage. The left lung was lavaged on the first day and the right lung was lavaged on the third day using selective endobronchial intubation and selective lung ventilation.

RESULTS

The procedure was well-tolerated and resulted in the removal of a significant volume of accumulated secretions. After the lavage, the patient demonstrated improvement in respiratory distress, chest radiograph appearance, lung compliance, and spirometric measurements.

CONCLUSIONS

This case report demonstrates that therapeutic bilateral lung lavage can be performed safely and effectively in a pediatric patient with pulmonary alveolar proteinosis by isolating individual lungs using a dual-lumen endotracheal tube. In this patient, therapeutic bilateral lung lavage was found to have a significant impact on lung function and mechanics after this procedure.

Whole lung lavage in alveolar proteinosis: manual clapping versus mechanical chest percussion

Alveolar proteinosis is an uncommon lung disease presenting in primary or secondary forms, characterised by surfactant derived proteinous material accumulation within the lungs. The most effective treatment remains whole lung lavage under general anaesthesia. We have recently performed whole lung lavage in a 46-year-old patient with alveolar proteinosis who presented with severe dyspnoea and hypoxia. During the left lung lavage, outwards flow was enhanced at random either by manual clapping or by mechanical chest percussion with a vest airway clearance system. The protein and surfactant protein A concentrations in the 13 successive samples of the left lavage solution showed an exponential decline, not different between manual clapping and chest mechanical percussion. The average concentration of surfactant protein was not different between manual clapping and chest percussion. We conclude that in alveolar proteinosis, manual clapping replacement by mechanical chest percussion during whole lung lavage merits further evaluation.

Pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis is a rare syndrome characterized by intra-alveolar accumulation of surfactant components and cellular debris, with minimal interstitial inflammation or fibrosis. The condition has a variable clinical course, from spontaneous resolution to respiratory failure and death due to disease progression or superimposed infections. The standard of care for alveolor proteinosis therapy is represented by whole lung lavage. Important discoveries have been made in the last decade with respect to disease pathogenesis and therapy of both congenital and acquired forms of the disease. Granulocyte-macrophage colony-stimulating factor (GM-CSF) pathway has been shown to be involved in the disease pathogenesis of both acquired and congenital disease. Furthermore, anti-GM-CSF blocking autoantibodies have been found in the serum and bronchoalveolar lavage fluid and seem to interfere with the surfactant clearance by alveolar macrophages in many acquired cases. In the congenital form, the most common defects identified to date are several mutations of the genes encoding GM-CSF receptor subunits or surfactant proteins. Using GM-CSF as a therapeutic tool has also been shown to be effective in at least half of the acquired cases treated, while the importance of quantitative determination of anti-GM-CSF antibodies before and during the course of the therapy, as well as the autoantibody titer-GM-CSF dose relationship are to be elucidated. The congenital form of the disease does not respond to therapy with GM-CSF, consistent with the known primary defects and differences in disease pathogenesis.

[Pulmonary alveolar phospholipoproteinosis]

Pulmonary alveolar phospholipoproteinosis is a rare lung disease of unknown cause characterized by surfactant plugging of the alveoli. At the present time, surgical lung biopsy, long considered as the gold standard, is not necessary for positive diagnosis of pulmonary alveolar phospholipoproteinosis when computed tomography anomalies and analysis of bronchial lavage fluids present a typical pattern. Treatment requires abundant lavage, but the demonstration of anti-GM-CSF antibodies in primary forms opens new therapeutic perspectives.

Pulmonary alveolar proteinosis: progress in the first 44 years

Pulmonary alveolar proteinosis is a rare clinical syndrome that was first described in 1958. Subsequently, over 240 case reports and small series have described at least 410 cases in the literature. Characterized by the alveolar accumulation of surfactant components with minimal interstitial inflammation or fibrosis, pulmonary alveolar proteinosis has a variable clinical course ranging from spontaneous resolution to death with pneumonia or respiratory failure. The most effective proven treatment--whole lung lavage--was described soon after the first recognition of this disease. In the last 8 years, there has been rapid progress toward elucidation of the molecular mechanisms underlying both the congenital and acquired forms of pulmonary alveolar proteinosis, following serendipitous discoveries in gene-targeted mice lacking granulocyte-macrophage colony-stimulating factor (GM-CSF). Impairment of surfactant clearance by alveolar macrophages as a result of inhibition of the action of GM-CSF by blocking autoantibodies may underlie many acquired cases, whereas congenital disease is most commonly attributable to mutations in surfactant protein genes but may also be caused by GM-CSF receptor defects. Therapy with GM-CSF has shown promise in approximately half of those acquired cases treated, but it is unsuccessful in congenital forms of the disease, consistent with the known differences in disease pathogenesis.

Serum and lavage lactate dehydrogenase isoenzymes in pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the accumulation of lipoproteinaceous material in the alveolar space. Serum lactate dehydrogenase (LDH) has been noted to be elevated in patients with PAP in previous studies. We sought to extend this observation in a series of patients with PAP by looking at total serum LDH concentrations and LDH isoenzyme fractions measured before and after whole lung lavage. Total LDH and LDH isoenzymes were also determined in the lavage effluent. Total serum LDH was elevated before lavage in 10 of 16 patients. Prelavage serum LDH and prelavage alveolar-arterial O2 gradient showed a significant correlation (r = 0.62, p less than 0.05). A decrease in serum LDH was found after lavage in all patients in whom postlavage data was available (paired t test, p less than 0.01, n = 11), although the magnitude of this decrease varied considerably. The isoenzyme pattern before lavage was isomorphic, and this pattern was unchanged after whole lung lavage. This was in marked contrast to the LDH isoenzyme pattern observed in the lavage effluent, which showed a lower percent LDH1 and LDH2 and a higher percent LDH3, LDH4, and LDH5 when compared with the corresponding prelavage isoenzyme percentages for serum (unpaired t test, p less than 0.001). There was no correlation between the total serum LDH concentration and the total lavage LDH concentration. These data confirm that elevated serum LDH is a common finding in PAP. Furthermore, the LDH elevation found consistently in the alveolar fluid points to this as the source of the serum LDH.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary alveolar phospholipoproteinosis: experience with 34 cases and a review

A retrospective review of Mayo Clinic records through 1983 revealed 84 patients (24 male and 10 female; mean age, 41 years) with the diagnosis of pulmonary alveolar phospholipoproteinosis. The major clinical features were dyspnea, cough, fever, and chest pain. Chest roentgenograms usually showed bilateral symmetric alveolar infiltrates, but asymmetric, unilateral, and chronic patchy patterns were also noted. Diagnosis was established by thoracotomy-lung biopsy in 26 patients. Histologic analysis revealed uniform filling of the alveoli by periodic acid-Schiff-positive material and maintenance of normal alveolar architecture. Electron microscopy showed enlarged alveolar macrophages with lamellar osmiophilic inclusions, dense granules, and myeloid bodies. Of the 21 patients who underwent therapeutic bronchoalveolar lavage, 13 had no recurrence of the disease during a mean follow-up of 8.8 years. In patients who underwent pulmonary function testing both before and after lavage, significant restrictive dysfunctions present before the procedure were alleviated afterward. Three deaths occurred among the 34 patients. Pulmonary alveolar phospholipoproteinosis may result from defective clearance of phospholipids by the alveolar macrophages, excessive production of phospholipids by type II pneumocytes, or both. It is likely a nonspecific response to a variety of injuries to the alveolar macrophage or type II pneumocyte or both, including exposure to certain dusts and chemicals and occurrence of hematologic diseases or infections. The uncommon occurrence of this disorder suggests individual susceptibility.

Lung response to particulates with emphasis on asbestos and other fibrous dusts

Many theories have been proposed to explain asbestosis and asbestos-related pulmonary disease. However, none of the theories give a completely plausible explanation for the pathogenesis. Recently, attention has been drawn to a theory that the fibrogenicity or carcinogenicity of fibrous dust particles is related to fiber diameter and length rather than to chemical properties. This theory may help partially elucidate the disease process but is still far from solving the enigma of pulmonary fibrosis or carcinogenesis. The theory cannot explain the absence of these pathological effects among fiberglass workers or experimental animals exposed by inhalation (even though mesotheliomas are induced by intrapleural implantation and fiber dimension-related fibrogenicity is demonstrated by intratracheal injection). Little information regarding the pulmonary response to manmade fibrous particles is available in animals following inhalation exposure. Attempts should be made to confirm the absence of adverse effects using animal inhalation experiments even though to this point there is no conclusive evidence that either lung cancer or pulmonary diseases can be produced among employees in manmade fiber industries. A new research trend seems concentrated on testing the durability of asbestos or manmade fibers. This is based on the concept that biological effects of fibrous particles are the result of relative durability and that particles which can be fragmented or shortened may be less pathogenic. In the last two decades, considerable understanding about pulmonary fibrosis and carcinogenesis of asbestos has been achieved by clinical and animal experiments. In vitro tests including cytotoxicity, hemolysis, immunology, and enzyme biochemistry have provided important information on the interrelationships among these various biological effects of asbestos.

Pulmonary alveolar proteinosis: successful treatment with aerosolized trypsin

A 37 year old man with pulmonary alveolar proteinosis and severe pulmonary physiologic impairment was treated empirically for 12 months with continuous oxygen, intermittent positive pressure breathing and aerosolized saline solution, heparin and acetylcysteine. Because of progression of disease, he was treated with aerosolized trypsin in a dose of 100,000 U twice daily for six months. This treatment was associated with dramatic symptomatic, chest roentgenographic and pulmonary physiologic improvement that has lasted for two and a half years without remission. The absence of adverse effects of trypsin aerosol allowed its administration in the patient's home. It is suggested that the preferred initial therapy for symptomatic alveolar proteinosis is aerosolized trypsin.

Changes in ventilation and perfusion in anesthetized dogs following lobar lavage with saline solution

The therapeutic application of endobronchial lavage has been inhibited by concern regarding alterations in the exchange of gases, particularly hypoxemia, and by the technical complexity of the procedure. Using a cuffed fiberoptic bronchoscope with which lavage could be restricted to one lobe, we studied the sequence of alterations in the exchange of gases after lavage and the attendant disturbances in ventilation and perfusion in ten mongrel dogs following lobar lavage with 1,850 ml of physiologic saline solution. Sequential scintiphotographs of ventilation and perfusion and sequential measurements of arterial blood gas levels were obtained. Linkage of the computer to the scintillation camera allowed quantification of data on ventilation and perfusion from the lobar area of interest. Lavage induced a reduction in regional ventilation and perfusion in all dogs. The decline in ventilation preceded that in perfusion, and the computed ratio of ventilation over perfusion reached its lowest point during the first 30 minutes after lavage. The arterial oxygen pressure (PaO2) declined in all dogs from a mean baseline value of 87 mm Hg to a mean value of 76 mm Hg at 30 minutes after lavage and gradually returned to a mean of 85 mm Hg by six hours after lavage. The lowest value for PaO2 occurred after balloon occlusion prior to lavage. Calculations of shunt showed a minimal increment in the intrapulmonary shunt (Qs/Qt). In the normal dog, lobar lavage induces mild hypoxemia due to an imbalance of ventilation and perfusion that resolves within six hours.