Pulmonary alveolar proteinosis: clinical aspects and current concepts on pathogenesis

Whole lung lavage and GM-CSF use for pulmonary alveolar proteinosis in an infant with lysinuric protein intolerance: a case report

BACKGROUND

Lysinuric protein intolerance (LPI) is a multi-organ metabolic disorder characterized by the imbalance in absorption and excretion of cationic amino acids like lysine, ornithine and arginine. Infants with LPI typically present with recurrent vomiting, poor growth, interstitial lung disease or renal impairment. The early onset of pulmonary alveolar proteinosis (PAP) has been reported to be associated with a severe form of LPI. Treatment of PAP most commonly consists of whole-lung lavage (WLL) and in autoimmune PAP, granulocyte-macrophage colony stimulating factor (GM-CSF) administration. Nevertheless, GM-CSF therapy in LPI-associated PAP has not been scientifically justified.

CASE PRESENTATION

We describe the case of an 8-month-old infant presenting with respiratory failure due to LPI associated with PAP, who was twice treated with WLL; firstly, while on veno-venous ECMO assistance and then by the use of a selective bronchial blocker. After the two treatments with WLL, she was weaned from daytime respiratory support while on initially subcutaneous, then on inhaled GM-CSF therapy.

CONCLUSIONS

This case supports the notion that GM-CSF therapy might be of benefit in patients with LPI-associated PAP. Further studies are needed to clarify the exact mechanism of GM-CSF in patients with LPI-associated PAP.

Alveolar macrophage metabolic programming via a C-type lectin receptor protects against lipo-toxicity and cell death

Alveolar macrophages (AM) hold lung homeostasis intact. In addition to the defense against inhaled pathogens and deleterious inflammation, AM also maintain pulmonary surfactant homeostasis, a vital lung function that prevents pulmonary alveolar proteinosis. Signals transmitted between AM and pneumocytes of the pulmonary niche coordinate these specialized functions. However, the mechanisms that guide the metabolic homeostasis of AM remain largely elusive. We show that the NK cell-associated receptor, NKR-P1B, is expressed by AM and is essential for metabolic programming. Nkrp1b^-/- mice are vulnerable to pneumococcal infection due to an age-dependent collapse in the number of AM and the formation of lipid-laden AM. The AM of Nkrp1b^-/- mice show increased uptake but defective metabolism of surfactant lipids. We identify a physical relay between AM and alveolar type-II pneumocytes that is dependent on pneumocyte Clr-g expression. These findings implicate the NKR-P1B:Clr-g signaling axis in AM-pneumocyte communication as being important for maintaining metabolism in AM.

Characteristics of hospital admissions for pulmonary alveolar proteinosis: analysis of the nationwide inpatient sample (2012-2014)

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare clinical syndrome involving the accumulation of lipid-rich proteinaceous material in the alveoli. There is a paucity of published studies on this condition. To better characterize the demographics, complication rates, mortality, and healthcare costs of patients hospitalized for PAP in the United States, a secondary analysis on the Hospital Cost and Utilization Project's Nationwide Inpatient Sample (NIS) was performed on patients admitted from 2012 to 2014 with a diagnosis of pulmonary alveolar proteinosis.

METHODS

Using the NIS database, a secondary analysis was performed on 500 admissions with the diagnosis "pulmonary alveolar proteinosis." The clinical variables and outcome measures extracted were: patient demographics, hospital costs, length of stay, frequency of admissions, and inpatient mortality rate.

RESULTS

Among a weighted estimate of 500 hospital admissions from 2012 to 2014, the number of PAP admissions averaged 4.7 per million. The population was predominantly male (55%) with a mean age of 41.45 (CI 38.3-44.5) from all socioeconomic levels. Inpatient mortality was calculated to be 5%, which may result from the fact that the majority of admitted patients had few or no comorbid conditions (CCI 0.72). The most common procedure performed during admission was a bronchoalveolar lavage. Mean length of stay was 6.2 days (CI 3.9-8.5) and average cost of admission was $29,932.20 (CI 13,739-46,124). Of note, 50% of these admissions were considered "elective."

CONCLUSIONS

Demographics of patients with PAP who have been hospitalized in the United States are similar to previously reported demographics from prior patient cohorts, specifically a male predominance and a mean age in the 40 s. The inpatient mortality rate of 5% we found is consistent with prior studies demonstrating good disease-specific survival rates. Notably, the cost per admission and overall annual cost associated with PAP hospitalization was calculated to be $29932.20 and $5 million respectively. This reflects the high economic cost associated with hospitalization of PAP patients, and provokes thought about ways to make treatment more cost-effective.

How We Do It: Whole Lung Lavage

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disorder characterized by the accumulation of surfactant in the alveolar spaces resulting in hypoxemic respiratory failure. Whole lung lavage (WLL), the preferred treatment for PAP, physically removes the lipoproteinaceous material from the alveolar spaces. Since its initial description in 1963, the WLL procedure has undergone various modifications. However, the procedure has not been standardized yet. After securing a double lumen endotracheal tube, we perform WLL under general anesthesia. One lung is ventilated, while the other is lavaged using one-liter aliquots of pre-warmed saline. We use gravity-assisted drainage of the lavaged lung after each cycle till the milky white and opaque fluid becomes clear (usually 15-20 cycles). Herein, we describe the step-by-step procedure, precautions, and monitoring of WLL. We also provide videos demonstrating one-lung ventilation and bronchoscopic confirmation of lung isolation.

Update on Diagnosis and Treatment of Adult Pulmonary Alveolar Proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary surfactant homeostasis disorder resulting in buildup of lipo-proteinaceous material within the alveoli. PAP is classified as primary (autoimmune and hereditary), secondary, congenital and unclassifiable type based on the underlying pathogenesis. PAP has an insidious onset and can, in some cases, progress to severe respiratory failure. Diagnosis is often secured with bronchoalveolar lavage in the setting of classic imaging findings. Recent insights into genetic alterations and autoimmune mechanisms have provided newer diagnostics and treatment options. In this review, we discuss the etiopathogenesis, diagnosis and treatment options available and emerging for PAP.

Bilateral whole lung lavage by lung isolation in a child with pulmonary alveolar proteinosis: A new technique

We present two rare cases of children who presented with progressive exertional breathlessness and dry cough. They also had history of bluish discoloration of mucous membranes, hands and feet on exertion. Both were diagnosed to have pulmonary alveolar proteinosis after a high-resolution computed tomography and bronchoalveolar lavage. They were subjected to bilateral whole lung lavage (WLL) as a salvage therapy. Bilateral WLL was performed in a single sitting with the help of a modified endotracheal tube. The anesthetic technique included a modified cuffed endotracheal tube for accomplishing WLL. After the procedure, both children improved clinically and functionally.

Mild dyspnea presenting as 'crazy-paving' on chest computed tomography

Pulmonary alveolar proteinoisis (PAP) is a rare disease characterized by accumulation of proteinaceous material in the alveolar spaces. Here, we report a case of mild dyspnea with incidental ‘crazy-paving’ pattern on chest computed tomography (CT). Further evaluation and bronchoscopy found to have PAP.

Chronic myelomonocytic leukemia-associated pulmonary alveolar proteinosis: A case report and review of literature

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare condition that can cause progressive symptoms including dyspnea, cough and respiratory insufficiency. Secondary PAP is generally associated with hematological malignancies including chronic myelomonocytic leukemia (CMML). To the best of our knowledge, this is the first reported case of PAP occurring secondary to CMML.

CASE SUMMARY

We report the case of a 63-year-old male who presented with a recurrent cough and gradually progressive dyspnea in the absence of fever. Based upon clinical symptoms, computed tomography findings, bone marrow aspiration, flow cytometry studies and cytogenetic analyses, the patient was diagnosed with PAP secondary to CMML. He underwent whole lung lavage in March 2016 to alleviate his dyspnea, after which he began combined chemotherapeutic treatment with decitabine and cytarabine. The patient died in January 2020 as a consequence of severe pulmonary infection.

CONCLUSION

This case offers insight regarding the mechanistic basis for PAP secondary to CMML and highlights potential risk factors.

Alveolar proteinosis due to toxic inhalation at workplace

We report a clinical case of a 39-year old male, without any known previous medical condition but with occupational exposure to paints and dust cement, who presented an autoimmune pulmonary alveolar proteinosis (PAP) triggered by exposure to toxic inhalation at his workplace. PAP is a rare lung disease characterized by intra-alveolar abnormal accumulation of surfactant. The presence of a crazy-paving pattern in high-resolution computed tomography scan brings the suspicion of PAP although histopathology results of bronchoalveolar lavage are always required for its final diagnosis. The autoimmune form of PAP due to toxic inhalation, such as the one here described, is rare and it is usually difficult to establish a causal relationship.

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%.

Granulocyte-Macrophage Colony-Stimulating Factor Inhalation Therapy for Severe Pulmonary Alveolar Proteinosis

BACKGROUND

Some patients with pulmonary alveolar proteinosis (PAP) still present with high recurrence rate after large-volume whole lung lavage (WLL). Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been proved to be effective for PAP, but clinical research on GM-CSF inhalation therapy combined with WLL for severe PAP is rare in Asia.

STUDY QUESTION

This study aimed to investigate the clinical efficacy of GM-CSF inhalation combined with WLL in Chinese patients with PAP.

STUDY DESIGN

We performed regression analysis on 33 patients with severe PAP who underwent WLL alone or WLL combined with GM-CSF inhalation. The patients were put into 2 groups, WLL group and GM-CSF/WLL group.

MEASURES AND OUTCOMES

Physiologic, serologic, and radiologic features of the 2 groups at different time points after treatment and the recurrence rates at 1-year follow-up were compared.

RESULTS

There were no significant differences in lung function, blood gas analysis indices, and lung CT between the 2 groups after 1-week treatment (P > 0.05). After 3-month treatment, the GM-CSF/WLL group showed significantly faster improvement in FEV1%Pred (P = 0.028), FVC%Pred (P = 0.014), PaO2 (P = 0.022), PA-aO2 (P = 0.009), PaO2/FiO2 (P = 0.025), 6-minute walking test (P = 0.002), and lung CT parameters (P < 0.05) compared with the WLL group. The recurrence rate at the 1-year follow-up in the GM-CSF/WLL group (5.5%) was significantly higher than that in the WLL group (46.67%; P < 0.05).

CONCLUSIONS

GM-CSF inhalation therapy combined with WLL is an effective treatment for patients with severe PAP, with further improvement in lung function at the base of WILL as well as reduction on re-WLL incidence.

Effects of one-lung flooding on porcine haemodynamics and gas exchange

Background and aim: We established a porcine model of one-lung flooding (OLF) that can be used for research on the use of ultrasound for lung tumour detection, ultrasound-guided transthoracic needle biopsy, and tumour ablation. However, OLF requires one-lung ventilation (OLV) and eliminates the recruitment strategies of the nonventilated lung. During thoracic surgery, OLV alone can be associated with hypoxia, hypercapnia, and right ventricular overload. Here, we examined whether OLF influences haemodynamics and gas exchange indices during and after OLV/OLF compared with OLV/apnoea and two-lung ventilation (TLV) following deflooding. Methods: Fourteen pigs were included in this study: five were allocated to the control group (CO) and nine were assigned to the OLF group (OLF). Assessments of haemodynamics, gas exchange, and lung sonography were performed after baseline measurements, during OLV/apnoea, OLV/OLF, and after deflooding and TLV. The volume of extravascular lung water was also measured. Results: OLF induced no significant deterioration of oxygenation or ventilation during OLF or after deflooding and TLV. Color-coded duplex sonography of the pulmonary artery in the flooded lung demonstrated an oscillating flow that corresponded to intrapulmonary circulatory arrest. After flooding of the nonventilated lung, the partial pressure of O₂ in the arterial blood increased and the shunt fraction decreased significantly compared to OLV/apnoea conditions. After deflooding and TLV, haemodynamics and gas exchange indices showed no differences compared to the CO group and baseline values, respectively. Conclusions: OLF is safe to use during acute animal experimentation. No clinically relevant deterioration of haemodynamics or gas exchange occurred during or after OLF. Due to the circulatory arrest in the flooded lung, the right-to-left shunt volume in the nonventilated lung was minimized. Survival experiments are necessary to further assess the utility of this method.

Isolated cerebral aspergillus abscess as a complication of pulmonary alveolar proteinosis in a child

Abstract

Background

Pulmonary alveolar proteinosis (PAP) poses a risk of opportunistic infections with a variety of organisms with Nocardia being the most common pathogen followed by mycobacteria and fungi.

Case presentation

A 7-year-old female child, presented with headache and multiple episodes of vomiting. There was no fever or altered sensorium. On examination, there were no focal deficits or cranial nerve palsies. An MRI brain showed a small T2 hyperintense lesion in the left superior parietal lobe suggestive of an abscess. She was diagnosed as PAP based on CT chest and bronchioloalveolar lavage 7 months earlier and treated with corticosteroids. A left parieto-occipital craniotomy was done with drainage of abscess and abscess wall excision. Histopathology revealed a suppurative lesion with slender septate acute angle branching hyphae which were positive on fungal stains. Culture done on the pus was positive for Aspergillus fumigatus. The patient was treated with voriconazole and stable at 1 year follow-up.

Conclusion

Opportunistic infections are common in patients diagnosed with PAP. High index of clinical suspicion and early diagnosis are important for favorable outcome.

Characterization and outcomes of pulmonary alveolar proteinosis in Brazil: a case series

OBJECTIVE

Pulmonary alveolar proteinosis (PAP) is a rare disease, characterized by the alveolar accumulation of surfactant, which is composed of proteins and lipids. PAP is caused by a deficit of macrophage activity, for which the main treatment is whole-lung lavage (WLL). We report the experience at a referral center for PAP in Brazil.

METHODS

This was a retrospective study involving patients with PAP followed between 2002 and 2016. We analyzed information regarding clinical history, diagnostic methods, treatments, and outcomes, as well as data on lung function, survival, and complications.

RESULTS

We evaluated 12 patients (8 of whom were women). The mean age was 41 ± 15 years. Most of the patients were diagnosed by means of BAL and transbronchial biopsy. The mean number of WLLs performed per patient was 2.8 ± 2.5. One third of the patients never underwent WLL. Four patients (33.3%) had associated infections (cryptococcosis, in 2; nocardiosis, in 1; and tuberculosis, in 1), and 2 (16.6%) died: 1 due to lepidic adenocarcinoma and 1 due to complications during anesthesia prior to WLL. When we compared baseline data with those obtained at the end of the follow-up period, there were no significant differences in the functional data, although there was a trend toward an increase in SpO2. The median follow-up period was 45 months (range, 1-184 months). The 5-year survival rate was 82%.

CONCLUSIONS

To our knowledge, this is the largest case series of patients with PAP ever conducted in Brazil. The survival rate was similar to that found at other centers. For symptomatic, hypoxemic patients, the treatment of choice is still WLL. Precautions should be taken in order to avoid complications, especially opportunistic infections.

Removal of lung lavage fluid during whole-lung lavage using biphasic cuirass ventilation chest percussion in a patient with autoimmune pulmonary alveolar proteinosis

Autoimmune pulmonary alveolar proteinosis (PAP) is a rare lung disease. Although recombinant human granulocyte macrophage colony-stimulating factor (GM-CSF) therapy has emerged as a new therapeutic modality, whole-lung lavage (WLL) with manual chest percussion has been a standard therapy in advanced cases. The application of biphasic cuirass ventilation (BCV) instead of chest percussion has rarely been reported. We describe the case of a patient with advanced PAP who recovered well in both lungs, without complication, after we performed WLL with BCV under anesthetic mechanical ventilation. Both radiographical chest findings and clinical symptoms were improved, and oxygen therapy was finally withdrawn. This case illustrates that BCV can enhance the effective removal of lavage fluid and is an alternative to manual percussion.

The effectiveness of N-acetylcysteine for an adult case of pulmonary alveolar proteinosis: A case report

Introduction

Pulmonary alveolar proteinosis is a rare disease that is characterized by accumulation of surfactant and phospholipids in the pulmonary alveoli. The current mainstay of treatment is whole lung lavage. There have been rare reports that have revealed the effectiveness of N-acetylcysteine on a secondary PAP.

Case presentation

A 45-year old man complained of shortness of breath and a productive cough with white sputum. He inhaled stone powder as an occupational hazard. CT scan of his chest radiograph showed ground glass changes superimposed on a reticular pattern as the so-called ‘crazy paving’ pattern. Lung biopsy revealed alveolar proteinaceous material with positive PAS stain. He eventually was diagnosed as PAP. He refused a whole lung lavage therapy, so the patient was rendered N-acetylcysteine as an antioxidant, enhanced immunotherapy and anti-infective treatment. His clinical symptoms and radiological manifestation improved gradually. No substantial adverse reactions were reported.

Conclusions

Persistent oral N-acetylcysteine may be an alternative treatment option for secondary PAP.

CT findings in pulmonary alveolar proteinosis: serial changes and prognostic implications

Background

Pulmonary alveolar proteinosis (PAP) is a rare disease of unknown origin, characterized by impaired surfactant metabolism. In some patients, residual disease is observed after treatment; notably, this may progress to end-stage pulmonary fibrosis. This study was performed to evaluate changes in lung abnormalities on serial CT scans performed on the lungs of patients diagnosed with PAP, as well as to identify factors that can be used to predict clinical improvement in PAP.

Methods

Twenty-five patients (16 men, nine women) were diagnosed with PAP at a single tertiary hospital. The extent and distribution of PAP were assessed on baseline and follow-up CT scans (median, 38 months; range, 2-96 months). Serial CT scans and clinical findings were analyzed to identify the predictive factors for clinical improvement in PAP.

Results

Baseline CT scans of patients diagnosed with PAP revealed that ground-glass opacity was the most common abnormality (100%); the second most common abnormality was interlobular/intralobular septal thickening (88%). Importantly, the final follow-up CT scans showed that the extent of lung abnormalities had decreased (n=13), including complete resolution (n=5), unchanged (n=9), and increased (n=3). Traction bronchiectasis and architectural distortion were detected in two patients (8%). On univariate and multivariate analyses, the change in the overall extent of lung abnormalities was a predictive factor for clinical improvement in PAP (odds ratio: 55.780; P=0.038).

Conclusions

Most patients with PAP exhibited residual disease; however, progression to pulmonary fibrosis was rare. Analyses of overall changes, with respect to lung abnormalities on serial CT scans, may be predictive of the extent of clinical improvement in given patient.

Whole-lung lavage in a patient with pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a rare syndrome in which phospholipoproteinaceous matter accumulates in the alveoli leading to compromised gas exchange. Whole-lung lavage is considered the gold standard for severe autoimmune PAP and offers favorable long-term outcomes. In this case report, we describe the perioperative management and procedural specifics of a patient undergoing WLL for PAP in which an anesthesiologist serves as the proceduralist and a separate anesthesiologist provides anesthesia care for the patient.

Pulmonary alveolar proteinosis in children: An unusual presentation with significant clinical impact

Pulmonary alveolar proteinosis (PAP) - an unusual diffuse lung disease characterized by alveolar accumulation of phospholipoprotein material, with a peak incidence in third to fourth decade and male predominance is also described in children. Recorded prevalence is 0.1/100,000 individuals. Major clinicopathogenetic subtypes include autoimmune (idiopathic) associated with granulocyte-macrophage colony-stimulating factor autoantibodies, secondary form, and the congenital form (associated with surfactant gene mutations). Common presenting features include dyspnea, cough, low-grade fever, inspiratory crackles, and digital clubbing. Pulmonary function shows a restrictive ventilatory defect. X-rays show bilateral patchy to extensive consolidations, and bronchial lavage yields a milky fluid. Characteristic microscopic findings on lung biopsy include filling of terminal bronchioles and alveolar spaces by deep pink granular PAS-positive material. Whole lung lavage is the safest and most effective form of treatment. We present brief profiles of two young children identified as having PAP, along with follow-up data on one of them.

Rituximab for auto-immune alveolar proteinosis, a real life cohort study

Background

Whole lung lavage is the current standard therapy for pulmonary alveolar proteinosis (PAP) that is characterized by the alveolar accumulation of surfactant. Rituximab showed promising results in auto-immune PAP (aPAP) related to anti-GM-CSF antibody.

Methods

We aimed to assess efficacy of rituximab in aPAP in real life and all patients with aPAP in France that received rituximab were retrospectively analyzed.

Results

Thirteen patients were included. No patients showed improvement 6 months after treatment, but, 4 patients (30%) presented a significant decrease of alveolar-arterial difference in oxygen after 1 year. One patient received lung transplantation and one patient was lost of follow-up within one year. Although a spontaneous improvement cannot be excluded in these 4 patients, improvement was more frequent in patients naïve to prior specific therapy and with higher level of anti-GM-CSF antibodies evaluated by ELISA. No serious adverse event was evidenced.

Conclusions

These data do not support rituximab as a second line therapy for patients with refractory aPAP.

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 in adults: pathophysiology and clinical approach

Pulmonary alveolar proteinosis (PAP) is a diffuse lung disease that results from the accumulation of lipoproteinaceous material in the alveoli and alveolar macrophages due to abnormal surfactant homoeostasis. Identification of the granulocyte-macrophage colony-stimulating factor (GM-CSF) as an indispensable mediator of macrophage maturation and surfactant catabolism was the key discovery leading to the current understanding of the pathogenesis of most forms of PAP. Impaired GM-CSF bioavailability due to anti-GM-CSF autoimmunity is the cause of approximately 90% of adult PAP cases. Abnormal macrophage function due to endogenous or exogenous triggers, GM-CSF receptor defects, and other genetic abnormalities of surfactant production account for the remainder of causes. The usual physiological consequence of PAP is impairment of gas exchange, which can lead to dyspnoea, hypoxaemia, or even respiratory failure and death. Pulmonary fibrosis occurs occasionally in patients with PAP. For patients with moderate to severe disease, whole lung lavage is still the first-line treatment of choice. Supplemental GM-CSF is also useful, but details about indications, choice of agent, and dosing remain unclear. Other therapies, including rituximab, plasmapheresis, and lung transplantation have been described but should be reserved for refractory cases.

Clinical significance of cigarette smoking and dust exposure in pulmonary alveolar proteinosis: a Korean national survey

BACKGROUND

This study aimed to investigate clinical characteristics of Korean PAP patients and to examine the potential risk factors of PAP.

METHODS

We retrospectively reviewed medical records of 78 Korean PAP patients diagnosed between 1993 and 2014. Patients were classified into two groups according to the presence/absence of treatment (lavage). Clinical and laboratory features were compared between the two groups.

RESULTS

Of the total 78 PAP patients, 60% were male and median age at diagnosis was 47.5 years. Fifty three percent were ever smokers (median 22 pack-years) and 48% had a history of dust exposure (metal 26.5%, stone or sand 20.6%, chemical or paint 17.7%, farming dust 14.7%, diesel 14.7%, textile 2.9%, and wood 2.9%). A history of cigarette smoking or dust exposure was present in 70.5% of the total PAP patients, with 23% having both of them. Patients who underwent lavage (n = 38) presented symptoms more frequently (38/38 [100%] vs. 24/40 [60%], P < 0.001) and had significantly lower PaO₂ and DL_CO with higher D(A-a)O₂ at the onset of disease than those without lavage (n = 40) (P = 0.006, P < 0.001, and P = 0.036, respectively). Correspondingly, the distribution of disease severity score (DSS) differed significantly between the two groups (P = 0.001). Based on these, when the total patients were categorized according to DSS (low DSS [DSS 1-2] vs. high DSS [DSS 3-5]), smoking status differed significantly between the two groups with the proportion of current smokers significantly higher in the high DSS group (11/22 [50%] vs. 7/39 [17.9%], P = 0.008). Furthermore, current smokers had meaningfully higher DSS and serum CEA levels than non-current smokers (P = 0.011 and P = 0.031), whereas no difference was found between smokers and non-smokers. Regarding type of exposed dust, farming dust was significantly associated with more severe form of PAP (P = 0.004).

CONCLUSION

A considerable proportion of PAP patients had a history of cigarette smoking and/or dust exposure, suggestive of their possible roles in the development of PAP. Active cigarette smoking at the onset of PAP is associated with the severity of PAP.

mTOR regulates metabolic adaptation of APCs in the lung and controls the outcome of allergic inflammation

Antigen-presenting cells (APCs) occupy diverse anatomical tissues, but their tissue-restricted homeostasis remains poorly understood. Here, working with mouse models of inflammation, we found that mechanistic target of rapamycin (mTOR)-dependent metabolic adaptation was required at discrete locations. mTOR was dispensable for dendritic cell (DC) homeostasis in secondary lymphoid tissues but necessary to regulate cellular metabolism and accumulation of CD103⁺ DCs and alveolar macrophages in lung. Moreover, while numbers of mTOR-deficient lung CD11b⁺ DCs were not changed, they were metabolically reprogrammed to skew allergic inflammation from eosinophilic T helper cell 2 (T_H2) to neutrophilic T_H17 polarity. The mechanism for this change was independent of translational control but dependent on inflammatory DCs, which produced interleukin-23 and increased fatty acid oxidation. mTOR therefore mediates metabolic adaptation of APCs in distinct tissues, influencing the immunological character of allergic inflammation.

Twenty-Eight-Day Repeated Inhalation Toxicity Study of Nano-Sized Neodymium Oxide in Male Sprague-Dawley Rats

Neodymium is a future-oriented material due to its unique properties, and its use is increasing in various industrial fields worldwide. However, the toxicity caused by repeated exposure to this metal has not been studied in detail thus far. The present study was carried out to investigate the potential inhalation toxicity of nano-sized neodymium oxide (Nd₂O₃) following a 28-day repeated inhalation exposure in male Sprague-Dawley rats. Male rats were exposed to nano-sized Nd₂O₃-containing aerosols via a nose-only inhalation system at doses of 0 mg/m³, 0.5 mg/m³, 2.5 mg/m³, and 10 mg/m³ for 6 hr/day, 5 days/week over a 28-day period, followed by a 28-day recovery period. During the experimental period, clinical signs, body weight, hematologic parameters, serum biochemical parameters, necropsy findings, organ weight, and histopathological findings were examined; neodymium distribution in the major organs and blood, bronchoalveolar lavage fluid (BALF), and oxidative stress in lung tissues were analyzed. Most of the neodymium was found to be deposited in lung tissues, showing a dose-dependent relationship. Infiltration of inflammatory cells and pulmonary alveolar proteinosis (PAP) were the main observations of lung histopathology. Infiltration of inflammatory cells was observed in the 2.5 mg/m³ and higher dose treatment groups. PAP was observed in all treatment groups accompanied by an increase in lung weight, but was observed to a lesser extent in the 0.5 mg/m³ treatment group. In BALF analysis, total cell counts, including macrophages and neutrophils, lactate dehydrogenase, albumin, interleukin-6, and tumor necrosis factor-alpha, increased significantly in all treatment groups. After a 4-week recovery period, these changes were generally reversed in the 0.5 mg/m³ group, but were exacerbated in the 10 mg/m³ group. The lowest-observed-adverse-effect concentration of nano-sized Nd₂O₃ was determined to be 0.5 mg/m³, and the target organ was determined to be the lung, under the present experimental conditions in male rats.

Whole lung lavage-technical details, challenges and management of complications

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by alveolar accumulation of surfactant material with resulting hypoxemia and reduced lung function. Whole lung lavage (WLL) to physically remove the proteinaceous material from the affected lung is the standard treatment. Since its original description in 1964, there have been increasing numbers of WLL procedures done worldwide and the technique has been variously refined and modified. When done in experienced centers, WLL provides long lasting benefit in the majority of patients. It is considered safe and effective. There are no guidelines standardizing the procedure. Our preferred method is to lavage one lung at a time, with the patient supine, filling to functional residual capacity (FRC) and repeating cycles of drainage and instillation with chest percussion until the effluent is clear. The aim of this article is to provide a detailed description of the technique, equipment needed and logistic considerations as well as providing a physiologic rationale for each step of WLL. We will also review the available data concerning variations of the technique described in the literature.

Herpes Simplex Virus, Cytomegalovirus, and Pneumocystis jiroveci Pneumonia in a Treatment-Naive HIV-Positive Patient with Pulmonary Alveolar Proteinosis: Case Report

Infection with multiple pathogens concurrently has become less common since the introduction of potent antiretroviral agent and effective prophylactic agents. We describe a patient with pulmonary alveolar proteinosis (PAP) admitted with pneumonia who was found to have AIDS and diagnosed with Pneumocystis jiroveci pneumonia, human herpesvirus type 1 (HHV-1), and a concomitant cytomegalovirus viremia. Polymerase chain reaction viral load was used for diagnosis of HHV-1 and follow-up. The patient was treated with trimethoprim-sulfamethoxazole and ganciclovir and had a resolution of pneumonia. Since patients with PAP who are diagnosed as having AIDS could be concomitantly infected with multiple pathogens, rapid accurate diagnosis and treatment may have a positive effect on outcome.

Rare case of ocular tuberculosis in a diabetic patient: diagnostic and therapeutic dilemmas

We present the case of a patient who was diagnosed by chance with macular hypopyon during a conventional interdisciplinary examination. The clinical context and the association of a systemic disease, such as uncontrolled type 1 diabetes, rendered further investigations in this patient. Due to his immunocompromised status, etiology such as ocular fungi, lymphomas, tuberculosis was taken into account. Thorough complex investigations oriented the diagnosis towards ocular tuberculosis involvement.

Pulmonary alveolar proteinosis and first successful whole lung lavage in Sri Lanka: a case report

BACKGROUND

Pulmonary alveolar proteinosis is a rare disease characterized by accumulation of lipoproteinaceous material within alveoli. There are three clinically distinct forms: congenital, acquired and secondary. Whole lung lavage is currently the gold standard therapy for severe cases of pulmonary alveolar proteinosis. In Sri Lanka this is the first reported successful whole lung lavage for a patient with pulmonary alveolar proteinosis.

CASE PRESENTATION

We describe the case of a 15-year-old Sri Lankan girl who presented with symptoms of progressive shortness of breath and dry cough for 6 months' duration. She had a history of exposure to silica in her household environment. High-resolution computed tomography revealed crazy paving appearance in both lungs suggestive of pulmonary alveolar proteinosis. An open lung biopsy revealed intra-alveolar granular amphophilic material which was strongly periodic acid-Schiff positive and diastase resistant, which is consistent with pulmonary alveolar proteinosis. She was followed up for 2 years with periodical segmental bronchoalveolar lavages which showed minimal improvement in her symptoms as well as in exercise desaturation. Due to severe dyspnea and hypoxemia on exertion, she underwent whole lung lavage. It resulted in a marked improvement in her symptoms, exercise desaturation, and chest X-ray results.

CONCLUSION

Whole lung lavage was successfully performed for the first time in Sri Lanka for a patient with pulmonary alveolar proteinosis.

Whole-Genome Sequencing of a Family with Hereditary Pulmonary Alveolar Proteinosis Identifies a Rare Structural Variant Involving CSF2RA/CRLF2/IL3RA Gene Disruption

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease in which the abnormalities in alveolar surfactant accumulation are caused by impairments of GM-CSF pathway attributing to defects in a variety of genes. However, hereditary PAP is extremely uncommon and a detailed understanding in the genetic inheritance of PAP in a family may provide timely diagnosis, treatment and proper intervention including genetic consultation. Here, we described a comprehensive analysis of genome and gene expression for a family containing one affected child with a diagnosis of PAP and two other healthy siblings. Family-based whole-genome analysis revealed a homozygous deletion that disrupts CSF2RA, CRLF2, and IL3RA gene in the pseudoautosomal region of the X chromosome in the affected child and one of asymptomatic siblings. Further functional pathway analysis of differentially expressed genes in IL-1β-treated peripheral blood mononuclear cells highlighted the insufficiency of immune response in the child with PAP, especially the protection against bacterial infection. Collectively, our results reveal a novel allele as the genetic determinant of a family with PAP and provide insights into variable expressivity and incomplete penetrance of this rare disease, which will be helpful for proper genetic consultation and prompt treatment to avoid mortality and morbidity.

Pulmonary alveolar proteinosis: Experience from a tertiary care center and systematic review of Indian literature

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare disorder characterized by deposition of lipoproteinaceous material within alveoli, with a variable clinical course. Here, we report an experience of management of PAP at our center. A systematic review of previously reported cases from India is also included in the article.

MATERIALS AND METHODS

This study included patients with primary PAP managed at our center from 2009 to 2015. Diagnosis of primary PAP was based on histopathologic diagnosis on bronchoalveolar lavage or transbronchial lung biopsy and absence of causes of secondary PAP. For systematic review of Indian publications, the literature search was performed using PubMed and EMBASE databases using the terms "pulmonary alveolar proteinosis'" or "alveolar proteinosis" and "India" or "Indian."

RESULTS

During the above-specified period, five patients with diagnosis of PAP were admitted at our center. Median age of patients was 32 years (interquartile range [IQR] 30.5-59); 80% were female. Mean duration (± standard deviation) of symptoms was 6.2 (±1.79) months. Anti-granulocyte-macrophage colony stimulating factor (GM-CSF) antibodies were elevated in 4 out of 5 patients (80%). For management, whole lung lavage (WLL) was done for four patients with median volume of 32.5 (IQR 18-74) L per patient. All the patients showed significant symptomatic as well as improvement in physiological parameters. Subcutaneous GM-CSF and ambroxol were given to 3 patients and 1 patient, respectively. The median follow-up of all patients was 18 (IQR 5-44) months. A systematic review of all Indian studies of PAP revealed thirty publications.

CONCLUSIONS

WLL is the most common, effective, and safe therapy in patients with PAP. GM-CSF administration is an efficacious treatment for patients with incomplete response after WLL.

Metabolic Functions of the Lung, Disorders and Associated Pathologies

The primary function of the lungs is gas exchange. Approximately 400 million years ago, the Earth's atmosphere gained enough oxygen in the gas phase for the animals that emerged from the sea to breathe air. The first lungs were merely primitive air sacs with a few vessels in the walls that served as accessory organs of gas exchange to supplement the gills. Eons later, as animals grew accustomed to a solely terrestrial life, the lungs became highly compartmentalized to provide the vast air-blood surface necessary for O2 uptake and CO2 elimination, and a respiratory control system was developed to regulate breathing in accordance with metabolic demands and other needs. With the evolution and phylogenetic development, lungs were taking a variety of other specialized functions to maintain homeostasis, which we will call the non-respiratory functions of the lung and that often, and by mistake, are believed to have little or no connection with the replacement gas. In this review, we focus on the metabolic functions of the lung, perhaps the least known, and mainly, in the lipid metabolism and blood-adult lung vascular endothelium interaction. When these functions are altered, respiratory disorders or diseases appear, which are discussed concisely, emphasizing how they impact the most important function of the lungs: external respiration.

Successful Treatment of Autoimmune Pulmonary Alveolar Proteinosis in a Pediatric Patient

Patient: Male, 13

Final Diagnosis: Pulmonary alveolar protinosis (autoimmune subtype)

Symptoms: Dyspnea • general weakness • subfebrile episodes

Medication: Vincristine

Clinical Procedure: Bronchoscopy • bronchoalveolar lavage • CT scan • lung biopsy • GM CSF antibody testing • diagnosis confirmation • therapy with inhaled GM-CSF • bilateral lung transplantation • chemotherapy due to PTLD

Specialty: Pediatrics and Neonatology

Nanoparticles in the lung and their protein corona: the few proteins that count

The formation of protein coronae on nanoparticles (NPs) has been investigated almost exclusively in serum, despite the prevailing route of exposure being inhalation of airborne particles. In addition, an increasing number of nanomedicines, that exploit the airways as the site of delivery, are undergoing medical trials. An understanding of the effects of NPs on the airways is therefore required. To further this field, we have described the corona formed on polystyrene (PS) particles with different surface modifications and on titanium dioxide particles when incubated in human bronchoalveolar lavage fluid (BALF) from patients with pulmonary alveolar proteinosis (PAP). We show, using high-resolution quantitative mass spectrometry (MS(E)), that a large number of proteins bind with low copy numbers but that a few "core" proteins bind to all particles tested with high fidelity, averaging the surface properties of the different particles independent of the surface properties of the specific particle. The averaging effect at the particle surface means that differing cellular effects may not be due to the protein corona but due to the surface properties of the nanoparticle once inside the cell. Finally, the adherence of surfactant associated proteins (SP-A, B and D) suggests that there may be interactions with lipids and pulmonary surfactant (PSf), which could have potential in vivo health effects for people with chronic airway diseases such as asthma and chronic obstructive pulmonary disease (COPD), or those who have increased susceptibility toward other respiratory diseases.

Pulmonary alveolar proteinosis-like change: A fairly common reaction associated with the severity of idiopathic pulmonary fibrosis

BACKGROUND

We have seen cases of chronic interstitial pneumonia (IP) with pulmonary alveolar proteinosis (PAP)-like changes that are focal histological features similar to PAP. To our knowledge, the association between PAP-like changes and chronic IP has not been investigated. We aimed to evaluate the incidence of PAP-like changes in chronic IP cases, and the association between the existence of PAP-like changes and the clinical features seen in patients with idiopathic pulmonary fibrosis (IPF).

METHODS

We selected 144 cases of chronic IP that had a video-assisted thoracoscopic surgery biopsy between 2008 and 2011. Clinical records and hematoxylin and eosin-stained slides were reviewed, and clinicopathological findings, including the cumulative survival probability, were compared between IPF cases with and without a PAP-like change.

RESULTS

A PAP-like change was identified in 20 of 144 cases (13.9%) of chronic IP and 14 of 61 IPF cases (23.0%). When comparing IPF cases with and without a PAP-like change, histological findings of honeycomb cysts and fibroblastic foci were associated with PAP-like changes (p=0.022 and 0.036, respectively). The percent-predicted values for forced vital capacity and diffusion capacity of carbon monoxide were lower (p=0.006 and 0.015, respectively), and concentrations of serum Krebs von den Lungen-6 and lactate dehydrogenase were higher (p=0.007 and 0.037, respectively) in cases of IPF with a PAP-like change than in those without one.

CONCLUSIONS

The presence of a PAP-like change in IPF cases was fairly common in our study, and may be a secondary reaction associated with IPF severity.

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

Pulmonary alveolar proteinosis (PAP) is a rare interstitial lung disease characterized by the abnormal alveolar accumulation of surfactant components. The diagnosis of PAP can be easily missed since it is rare and lacks specific clinical symptoms. It is of great importance to have a better understanding of the crucial clue to clinically diagnose PAP and take PAP into consideration in the differential diagnosis of interstitial pulmonary diseases or other diseases with similar manifestations. Here, we analyze the clinical characteristics of 11 cases of PAP patients in local hospital and review the relevant literature in order to provide more information in diagnosis and management of PAP. In our observation, cyfra21-1 and neuron-specific enolase (NSE) known as tumor markers probably can be useful serum markers for diagnosis of PAP. As for the method of pathologic diagnosis, open-lung biopsy was the gold standard but now it is less required because findings on examination of bronchoalveolar lavage fluid (BALF) can help to make the diagnosis. We also have deep experience about when and how to carry out lung lavage.

Induced sputum deposition improves diagnostic yields of pulmonary alveolar proteinosis: A clinicopathological and methodological study of 17 cases

Pulmonary alveolar proteinosis (PAP) is a rare diffuse lung disease characterized by the accumulation of intra-alveolar lipoprotein-like surfactants. Lung core biopsy and bronchoalveolar lavage (BAL) fluid are currently the two major sources of sampling for diagnosis. In the present study, we assessed the value of induced sputum in diagnosing PAP by transmission electron microscopy and examined the PAP 2-year death rate in Asians. Transmission electron microscopy was performed on the samples from 17 patients with PAP, 13 patients with inflammatory lung diseases, and 13 healthy adults. The PAP patients were followed up for 3-156 months, and inflammatory lung diseases patients or healthy adults for 12-36 months. The ultrastructural features including diagnostic lamellar bodies of induced sputum deposition (ISD) samples were similar to that of the BAL fluid sediment. However, the rates of lamellar bodies were 73.7% in the ISD group, significantly higher than the spontaneous sputum deposition (SSD) group (42.1%, P < .0487) and similar to the BAL sediment (76.2%) and the lung biopsy (54.5%) groups. The overall 2-year death rate of our PAP patients was 17.6% (3/17), not statistically different from the healthy adults and patients with inflammatory diseases (0/13, P = .237 for both). ISD may be the preferred non-invasive sampling method for diagnosing PAP by electronic microscopy because of the higher diagnostic yield than SSD. The diagnostic yields of this noninvasive method were similar to that of lung core biopsy and BAL.

Respiratory strategies and airway management in patients with pulmonary alveolar proteinosis: a review

BACKGROUND

Pulmonary alveolar proteinosis is a rare disorder characterized by a large accumulation of lipoproteinaceous material within the alveoli. This causes respiratory failure due to a restriction of gas exchange and changes in the ventilation/perfusion ratio. Treatment methods include noninvasive pharmacological approaches and invasive procedures, such as whole-lung lavage under general anesthesia.

METHODS

Based on the literature search using free-term key words, we have analyzed published articles concerning the perioperative management of adult and pediatric patients with pulmonary alveolar proteinosis.

RESULTS AND DISCUSSION

In total, 184 publications were analyzed. Only a few manuscripts were related to anesthetic, respiratory, and airway management in patients suffering from pulmonary alveolar proteinosis. Airway should be strictly separated using a double-lumen tube. Respiratory strategies involve the use of manual clapping, continuous positive airway pressure, high-frequency jet ventilation of the affected lung, and employment of venovenous extracorporeal membrane oxygenation in the most serious of cases.

CONCLUSION

The goal of this review is to summarize the current published information about an anesthetic management strategy with a focus on airway management, ventilation, and oxygenation techniques in PAP patients.

An unusual cause of respiratory failure in a 25-year-old heart and lung transplant recipient

A 25-year-old woman, a never smoker with a history of heart-lung transplantation for World Health Organization group 1 pulmonary arterial hypertension performed 20 months prior to presentation, was evaluated for shortness of breath. Following transplantation, she was initiated on standard therapy of prednisone, tacrolimus, and azathioprine, along with routine antimicrobial prophylaxis. Her posttransplant course was complicated by persistent acute cellular rejection, as determined from a transbronchial biopsy specimen, without evidence of rejection in an endomyocardial biopsy specimen. The immunosuppressive medications were supplemented with pulse-dosed steroids, and the patient was transitioned from azathioprine to mycophenolate mofetil. Sirolimus was added 9 months prior to presentation. Three months prior to presentation, she was admitted for increasing oxygen requirements, shortness of breath, and bilateral infiltrates on the CT scans of the chest.

Is Cryptococcus gattii a Primary Pathogen?

The two etiologic agents of cryptococcal meningoencephalitis, Cryptococcus neoformans and C. gattii, have been commonly designated as either an opportunistic pathogen for the first species or as a primary pathogen for the second species. Such a distinction has been based on epidemiological findings that the majority of patients presenting meningoencephalitis caused by C. neoformans are immunocompromised while C. gattii infection has been reported more often in immunocompetent patients. A recent report, however, showed that GM-CSF (granulocyte-macrophage colony-stimulating factor) neutralizing antibodies were prevalent in the plasma of "apparently immunocompetent" C. gattii patients with meningoencephalitis. Because GM-CSF is essential for differentiation of monocytes to macrophages and modulating the immune response, it is not surprising that the lack of GM-CSF function predisposes otherwise healthy individuals to infection via inhalation of environmental pathogens such as C. gattii. Since the test for anti-GM-CSF autoantibodies is not included in routine immunological profiling at most hospitals, healthy patients with GM-CSF neutralizing antibodies are usually categorized as immunocompetent. It is likely that a comprehensive immunological evaluation of patients with C. gattii meningoencephalitis, who had been diagnosed as immunocompetent, would reveal a majority of them had hidden immune dysfunction. This paper reviews the relationship between GM-CSF neutralizing antibodies and the risk for C. gattii infection with CNS involvement.

Pulmonary alveolar proteinosis in a 10-year-old girl masquerading as tuberculosis

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease. Diagnosis is established by bronchoalveolar lavage (BAL), which has macroscopic ‘milky appearance’, and in the presence of typical computed tomography, findings are diagnostic of PAP but, however, the feature of periodic acid–Schiff-positive eosinophilic proteinaceous fluid raises the confidence of the diagnosis. We report late-onset PAP in a 10-year-old girl who had acid fast bacilli on an initial BAL examination, but was subsequently diagnosed as PAP.