Pulmonary alveolar proteinosis in Taiwan.

BACKGROUND/PURPOSE: Pulmonary alveolar proteinosis (PAP) is rare disease manifested as alveolar macrophage dysfunction and abnormal accumulation of surfactant protein in the alveoli. In this nationwide, population-based study, we investigated the epidemiology of PAP in Taiwan, and discovered the comorbidities and prognostic factors of PAP. METHODS: From the National Health Insurance Research Database (NHIRD), we obtained comprehensive information about all patients of PAP in Taiwan between 1995 and 2013. The incidence, baseline characteristics comorbidities, and prognostic factors of PAP were investigated. RESULTS: The annual incidence rate of PAP was around 0.79 (range: 0.49-1.17) patients per million people after 2000, and the prevalence rate was 7.96 patients per million people by the end of 2013. In total, 276 patients of PAP were identified, including 177 (64%) and 99 (36%) patients with primary and secondary PAP, respectively. The median age of diagnosis was 53.8 years. The median survival was 9.6 years after the initial PAP diagnosis, and the 5-year survival rate was 65.96%. Twenty (7%) patients received whole lung lavage (WLL) within three months after the diagnosis had significantly better survival compared to the others. Multivariable Cox regression analyses showed that elder age, secondary PAP, and malignancy were associated with poorer survival, while WLL within 3 months of diagnosis might greatly improve the survival. CONCLUSION: We demonstrated the epidemiology of PAP in Taiwan, showing several poor prognostic factors and the potential effectiveness of WLL. Further prospective studies based on registry are warranted to improve the diagnosis and treatment of PAP.

Nationwide survey of adult patients with pulmonary alveolar proteinosis using the National Database of designated intractable diseases of Japan.

BACKGROUND: Autoimmune pulmonary alveolar proteinosis (APAP) and congenital/hereditary PAP were labeled intractable diseases in Japan in 2015. Since then, patients registered in the National Database of Designated Incurable Diseases (NDDID) who met certain requirements became eligible for medical subsidies. Epidemiological studies using recent data are needed for the development of management protocols for patients with PAP. METHODS: We conducted the first nationwide study describing the epidemiology and characteristics of PAP using data for patients registered in the Japanese NDDID between 2015 and 2020. We focused on patient demographics, diagnosis, disease severity score (DSS), symptoms, test results, and treatment. RESULTS: We identified 110 patients with PAP, among whom 96.4% had APAP/idiopathic PAP (IPAP). The median age was 58 years, with a slight male predominance. Most patients had a DSS ≥3 (64.5%) and reported symptoms (e.g., dyspnea on exertion). High-resolution computed tomography typically revealed ground glass opacity and crazy paving appearances. Pulmonary function was relatively preserved, except for carbon monoxide diffusing capacity. Only 27.4% of patients underwent therapeutic whole-lung lavage and/or bronchoalveolar lavage, while 25% required long-term oxygen therapy. Serum Krebs von den Lungen-6, surfactant protein D, and lactate dehydrogenase levels significantly and positively correlated with the DSS. CONCLUSIONS: Most patients registered in the NDDID have APAP/IPAP with a DSS ≥3, and about one-quarter require long-term oxygen therapy and infrequent lavages. Our results provide important details of the current prevalence and clinical practice related to APAP/IPAP with a DSS ≥3 in Japan.

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%.

Pulmonary Alveolar Proteinosis Syndrome.

Pulmonary alveolar proteinosis (PAP) is a syndrome characterized by progressive accumulation of pulmonary surfactant. This results in dyspnea, secondary pulmonary and systemic infection, and in some cases respiratory failure. PAP syndrome occurs in distinct diseases, classified according to pathogenetic mechanism; these include primary PAP (due to disruption of granulocyte-macrophage colony-stimulating factor [GM-CSF] signaling), secondary PAP (due to reduction in alveolar macrophage numbers/functions), and congenital PAP (due to disruption of surfactant production). In primary PAP, the most common cause is autoimmune PAP, which accounts for over 90% of all PAP syndrome. The pathogenesis is driven by reduced GM-CSF-signaling causing abnormal alveolar macrophage function which subsequently results in impaired alveolar surfactant clearance. Autoimmune PAP can be accurately diagnosed by serum GM-CSF autoantibody levels and there now exist other diagnostic tests for rare causes of PAP syndrome. The current standard treatment is whole lung lavage; however, there is emerging evidence to support the use of novel therapeutic approaches, including inhaled GM-CSF, immune modulation, gene and cell therapy, and targeting macrophage cholesterol homeostasis. Furthermore, several innovative approaches to monitor disease severity and response to therapy have recently been developed.

Pulmonary alveolar proteinosis in Korea: analysis of prevalence and incidence via a nationwide population-based study.

BACKGROUND: Pulmonary alveolar proteinosis (PAP) is a very rare lung disease and its prevalence and incidence remain unclear. The prevalence and incidence of PAP were investigated by using nationwide claims data from the Korean Health Insurance Review and Assessment service. METHODS: Data were extracted for adults who visited any secondary or tertiary medical institute between 2010 and 2016 with the PAP-related Korean Classification of Disease, 7th edition code J84.0 and the Rare Intractable Disease exempted calculation code V222. To robust case definition, a narrow case definition was made when all following factors were met: 1) more than two PAP-coded visits within 1 year of the first claim, and 2) more than one claim for both chest computed tomography and diagnostic procedures (bronchoscopy or surgical lung biopsy) within 90 days before or after the first claim. RESULTS: A total of 182 patients (narrow, n = 82) with PAP-related codes were identified from 2010 to 2016 and 89 new patients (narrow, n = 66) visited medical institutes between 2012 and 2015. The prevalence of PAP was 4.44 (narrow: 2.27) per 106 population, with a peak age of 60-69 years. The incidence of PAP was 0.56 (narrow: 0.41) per 106 population at risk, with a peak age of 50-59 years. Among incident cases, the male-to-female ratio was 1.52 and about two-thirds had comorbidities, dyslipidaemia being the most common. CONCLUSIONS: The prevalence and incidence of PAP in Korea are low, similar to those in other countries; however, Korean patients with PAP are characterized by older diagnostic age and a lower male-to-female ratio.

Systemic Juvenile Idiopathic Arthritis-Associated Lung Disease: Characterization and Risk Factors.

OBJECTIVE: Systemic juvenile idiopathic arthritis (JIA) is associated with a recently recognized, albeit poorly defined and characterized, lung disease (LD). The objective of this study was to describe the clinical characteristics, risk factors, and histopathologic and immunologic features of this novel inflammatory LD associated with systemic JIA (designated SJIA-LD). METHODS: Clinical data collected since 2010 were abstracted from the medical records of patients with systemic JIA from the Cincinnati Children's Hospital Medical Center. Epidemiologic, cellular, biochemical, genomic, and transcriptional profiling analyses were performed. RESULTS: Eighteen patients with SJIA-LD were identified. Radiographic findings included diffuse ground-glass opacities, subpleural reticulation, interlobular septal thickening, and lymphadenopathy. Pathologic findings included patchy, but extensive, lymphoplasmacytic infiltrates and mixed features of pulmonary alveolar proteinosis (PAP) and endogenous lipoid pneumonia. Compared to systemic JIA patients without LD, those with SJIA-LD were younger at the diagnosis of systemic JIA (odds ratio [OR] 6.5, P = 0.007), more often had prior episodes of macrophage activation syndrome (MAS) (OR 14.5, P < 0.001), had a greater frequency of adverse reactions to biologic therapy (OR 13.6, P < 0.001), and had higher serum levels of interleukin-18 (IL-18) (median 27,612 pg/ml versus 5,413 pg/ml; P = 0.047). Patients with SJIA-LD lacked genetic, serologic, or functional evidence of granulocyte-macrophage colony-stimulating factor pathway dysfunction, a feature that is typical of familial or autoimmune PAP. Moreover, bronchoalveolar lavage (BAL) fluid from patients with SJIA-LD rarely demonstrated proteinaceous material and had less lipid-laden macrophages than that seen in patients with primary PAP (mean 10.5% in patients with SJIA-LD versus 66.1% in patients with primary PAP; P < 0.001). BAL fluid from patients with SJIA-LD contained elevated levels of IL-18 and the interferon-γ-induced chemokines CXCL9 and CXCL10. Transcriptional profiling of the lung tissue from patients with SJIA-LD identified up-regulated type II interferon and T cell activation networks. This signature was also present in SJIA-LD human lung tissue sections that lacked substantial histopathologic findings, suggesting that this activation signature may precede and drive the lung pathology in SJIA-LD. CONCLUSION: Pulmonary disease is increasingly detected in children with systemic JIA, particularly in association with MAS. This entity has distinct clinical and immunologic features and represents an uncharacterized inflammatory LD.

Shaping the future of an ultra-rare disease: unmet needs in the diagnosis and treatment of pulmonary alveolar proteinosis.

PURPOSE OF REVIEW: Pulmonary alveolar proteinosis (PAP) can be considered the archetype of ultra-rare diseases with a prevalence of under 10 cases per million. We discuss the classification of PAP, the current diagnostic practice and the supplementary role of genetic testing and granulocyte-macrophage colony-stimulating factor (GM-CSF) signalling in the diagnosis of congenital and hereditary PAP. We report on novel therapeutic approaches such as GM-CSF substitution, stem cell transplantation, pioglitazone, statins and immunomodulation. RECENT FINDINGS: The discovery of new genetic mutations underlying this syndrome raises the question whether the classification should be radically revised in the future. Serum GM-CSF autoantibody is the best diagnostic marker for autoimmune PAP, the most common form, but does not correlate with disease severity. Several circulating biomarkers have been investigated to assess disease activity and predict outcome. Imaging techniques have also enormously evolved and offer new tools to quantify disease burden and possibly drive therapeutic decisions. Promising clinical trials are ongoing and will generate new treatment strategies besides or in addition to whole lung lavage in the next future. SUMMARY: Despite impressive advances in understanding pathogenesis, PAP remains a rare syndrome with several unanswered questions impacting diagnosis, management and treatment, and, as a result, patients' quality of life.

Pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a syndrome characterized by the accumulation of alveolar surfactant and dysfunction of alveolar macrophages. PAP results in progressive dyspnoea of insidious onset, hypoxaemic respiratory failure, secondary infections and pulmonary fibrosis. PAP can be classified into different types on the basis of the pathogenetic mechanism: primary PAP is characterized by the disruption of granulocyte-macrophage colony-stimulating factor (GM-CSF) signalling and can be autoimmune (caused by elevated levels of GM-CSF autoantibodies) or hereditary (due to mutations in CSF2RA or CSF2RB, encoding GM-CSF receptor subunits); secondary PAP results from various underlying conditions; and congenital PAP is caused by mutations in genes involved in surfactant production. In most patients, pathogenesis is driven by reduced GM-CSF-dependent cholesterol clearance in alveolar macrophages, which impairs alveolar surfactant clearance. PAP has a prevalence of at least 7 cases per million individuals in large population studies and affects men, women and children of all ages, ethnicities and geographical locations irrespective of socioeconomic status, although it is more-prevalent in smokers. Autoimmune PAP accounts for >90% of all cases. Management aims at improving symptoms and quality of life; whole-lung lavage effectively removes excessive surfactant. Novel pathogenesis-based therapies are in development, targeting GM-CSF signalling, immune modulation and cholesterol homeostasis.

Prevalence and healthcare burden of pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare syndrome of alveolar surfactant accumulation, resulting hypoxemic respiratory failure, and increased infection risk. Despite advances in our understanding of disease pathogenesis and the availability of improved diagnostics, the epidemiology and healthcare burden of PAP remain poorly defined. To determine the prevalence, and healthcare utilization and costs associated with PAP, we interrogated a large health insurance claims database containing comprehensive data for approximately 15 million patients in the United States. We also evaluated data from a referral-based diagnostic testing program collected over a 15-year period. The prevalence of PAP was determined to be 6.87 ± 0.33 per million in the general population, similar in males and females, and increased with age, however considering difficulties and delays in diagnosing this is likely a minimum estimate of true prevalence. PAP patients had significantly more comorbidities, health care utilization and associated costs compared to control patients precisely matched for age and gender. Between 2004 and 2018, 249 patients confirmed to have PAP were evaluated to identify the PAP-causing disease; 91.5% had autoimmune PAP, 3% had hereditary PAP caused by GM-CSF receptor mutations, 4% had secondary PAP, and 1.5% had congenital PAP. Considering the high diagnostic accuracy of serum GM-CSF autoantibody testing and predominance of autoimmune PAP, these results emphasize the importance of utilizing blood-based testing in PAP syndrome to identify the PAP-causing disease rather than invasive lung biopsies, resulting in earlier diagnosis, reduced morbidity and lower healthcare costs.

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.

An eleven-year retrospective cross-sectional study on pulmonary alveolar proteinosis.

INTRODUCTION: Pulmonary alveolar proteinosis (PAP) is a rare disease in the field of pulmonary medicine. The efficacy of whole-lung lavage (WLL) as the treatment of PAP had never been evaluated in the Iranian population. Therefore, there is a real need to investigate the characteristics of PAP and also to evaluate the efficacy of WLL in this rare disease. The study aimed to investigate demographic features, clinical presentation and treatment outcomes of the disease in Iranian PAP patients. MATERIAL AND METHODS: Data of 45 patients with definite diagnosis of PAP, who had regular follow-ups from March 2004 to March 2015 at an Iranian referral respiratory hospital, were collected. Whole-lung lavages (WLL) efficacy was assessed by comparing spirometric, arterial blood gas parameters and six-minute walk test (6MWT) results before and after all lavages. RESULTS: Mean age at diagnosis of disease was 30.33 ± 14.56 years. Four patients (8.8%) reported non-massive hemoptysis and three subjects (6.6%) had concomitant pulmonary tuberculosis. In 71.1% of cases, transbronchial lung biopsy and bronchoalveolar lavage were sufficient for diagnosis. Spirometric results and arterial blood gas parameters and 6MWD improved significantly after all the lavages. Four patients (8.8%) died because of respiratory failure. The only variable capable of predicting treatment failure was the history of hemoptysis. CONCLUSION: The study revealed sufficiency of WLL as the PAP patients' treatment. Also hemoptysis was found to be the independent factor that can predict treatment failure.

[A retrospective study of the perioperative complications following whole lung lavage in the treatment of pulmonary alveolar proteinosis].

Objective: To evaluate the safety of the procedures of whole lung lavage(WLL) for pulmonary alveolar proteinosis(PAP) in perioperative period. Methods: In this retrospective study, we collected clinical data from 78 WLL procedures of PAP patients from January 2006 to June 2016 in Guangzhou Institute of Respiratory Disease. The causes of perioperative complications were analyzed. Results: Eighteen (23.07%) of the 78 procedures developed complications, including pleural effusion(n=4), pneumonia(n=4), cardiac failure(n=2), cardiac arrhythmia (n=2), pneumothorax(n=2), atelectasis(n=1), lung edema(n=1), laryngeal edema(n=1), pleural effusion and pneumonia(n=1). All complications were mild and easy to treat. Seventy-four procedures had successful extubation, but 4 procedures developed a prolonged time of extubation. Age, DSS, PaCO(2,)FEV(1,)lavage volume, lavage times and underlying diseases were not predictors for any complications(each P>0.05). High fluid recovering rate had a protective effect against the occurring of complications (Wald=7.672, OR<0.01, P<0.05). Conclusions: Whole lung lavage was a safe procedure in the treatment of PAP. Complications could recovery after proper therapy. The perioperative complications showed a correlation with low fluid recover rate. Operation under guideline was the key to avoid complications.

GATA2 deficiency in children and adults with severe pulmonary alveolar proteinosis and hematologic disorders.

BACKGROUND: The majority of cases with severe pulmonary alveolar proteinosis (PAP) are caused by auto-antibodies against GM-CSF. A multitude of genetic and exogenous causes are responsible for few other cases. Goal of this study was to determine the prevalence of GATA2 deficiency in children and adults with PAP and hematologic disorders. METHODS: Of 21 patients with GM-CSF-autoantibody negative PAP, 13 had no other organ involvement and 8 had some form of hematologic disorder. The latter were sequenced for GATA2. RESULTS: Age at start of PAP ranged from 0.3 to 64 years, 4 patients were children. In half of the subjects GATA2-sequence variations were found, two of which were considered disease causing. Those two patients had the typical phenotype of GATA2 deficiency, one of whom additionally showed a previously undescribed feature - a cholesterol pneumonia. Hematologic disorders included chronic myeloic leukemia, juvenile myelo-monocytic leukemia, lymphoblastic leukemia, sideroblastic anemia and two cases of myelodysplastic syndrome (MDS). A 4 year old child with MDS and DiGeorge Syndrome Type 2 was rescued with repetitive whole lung lavages and her PAP was cured with heterologous stem cell transplant. CONCLUSIONS: In children and adults with severe GM-CSF negative PAP a close cooperation between pneumologists and hemato-oncologists is needed to diagnose the underlying diseases, some of which are caused by mutations of transcription factor GATA2. Treatment with whole lung lavages as well as stem cell transplant may be successful.

Treatment of Adult Primary Alveolar Proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by the accumulation of surfactant-like lipoproteinaceous material in the distal air spaces and terminal bronchi, which may lead to impaired gas exchange. This accumulation of surfactant is due to decreased clearance by the alveolar macrophages. Its primary, most common form, is currently considered an autoimmune disease. Better knowledge of the causes of PAP have led to the emergence of alternatives to whole lung lavage, although this is still considered the treatment of choice. Most studies are case series, often with limited patient numbers, so the level of evidence is low. Since the severity of presentation and clinical course are variable, not all patients will require treatment. Due to the low level of evidence, some objective criteria based on expert opinion have been arbitrarily proposed in an attempt to define in which patients it is best to initiate treatment.

Characteristics of serum lipid metabolism in patients with autoimmune pulmonary alveolar proteinosis.

OBJECTIVE: To study the serum lipid panels in consecutive autoimmune pulmonary alveolar proteinosis(APAP)patients and analyze their relationship with anti-granulocyte macrophage-colony stimulating factor(GM-CSF)antibody and other markers. METHODS: Thirty-two non-diabetic APAP patients were enrolled in the study. Serum lipids of these patients and 100 healthy volunteers were tested after an overnight fasting. Anti-GM-CSF antibody levels were measured with enzyme-linked immunosorbent assay. The correlation of serum lipids with lactate dehydrogenase,carcinoembryonic antigen,pulmonary function,and artery blood gas parameters were analyzed. RESULTS: Total cholesterol and low-density lipoprotein cholesterol levels [(5.54±0.99)and(3.73±0.83)mmol/L respectively] were significantly higher in APAP patients than in healthy volunteers [(5.05±0.97)and(3.17±0.89)mmol/L respectively](all P<0.05). High-density lipoprotein cholesterol(HDL-C)level of the APAP group [(1.10±0.18)mmol/L ]was significantly lower than that of the healthy group(P<0.05). Low-density lipoprotein/HDL and total cholesterol/HDL ratios in the APAP group(3.47±0.90 and 5.14±1.12 respectively)were significantly higher than those in the healthy group[(2.63±0.87)and(4.18±1.12)](all P<0.05). There was no significant difference in triglyceride level between the two groups(P>0.05). HDL-C level was negatively correlated with alveolar-arterial oxygen pressure difference(r=-0.436,P<0.05)and positively correlated with arterial oxygen saturation(r=0.459,P<0.05). None of the lipid markers correlated with serum anti-GM-CSF antibody levels(all P>0.05). CONCLUSIONS: APAP patients were likely to suffer from disturbed lipid metabolism,which was correlated with disease severity to some degree. Lipid markers deserved more attention in the management of APAP patients.

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

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

Pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease characterised by alveolar accumulation of surfactant. It may result from mutations in surfactant proteins or granulocyte macrophage-colony stimulating factor (GM-CSF) receptor genes, it may be secondary to toxic inhalation or haematological disorders, or it may be auto-immune, with anti-GM-CSF antibodies blocking activation of alveolar macrophages. Auto-immune alveolar proteinosis is the most frequent form of PAP, representing 90% of cases. Although not specific, high-resolution computed tomography shows a characteristic "crazy paving" pattern. In most cases, bronchoalveolar lavage findings establish the diagnosis. Whole lung lavage is the most effective therapy, especially for auto-immune disease. Novel therapies targeting alveolar macrophages (recombinant GM-CSF therapy) or anti-GM-CSF antibodies (rituximab and plasmapheresis) are being investigated. Our knowledge of the pathophysiology of PAP has improved in the past 20 yrs, but therapy for PAP still needs improvement.

Pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis is a rare but potentially treatable disease, characterized by impaired surfactant metabolism that leads to accumulation in the alveoli of proteinaceous material rich in surfactant protein and its component. Novel insights from an animal model aided the discovery of granulocyte macrophage colony stimulating factor (GM-CSF) antibodies as a pathogenetic mechanism in human pulmonary alveolar proteinosis. The vast majority of pulmonary alveolar proteinosis occurs as an autoimmune disease; less commonly, it is congenital or secondary to an underlying disorder such as infection, hematological malignancy, or immunodeficiency. The subacute indolent course of this disease often delays the diagnosis by months to years. Crazy-paving appearance in a geographic distribution is a characteristic feature of this disease visible on high-resolution computed tomography (CT). A definitive diagnosis, however, requires lung biopsy, which typically shows partial or complete filling of alveoli with periodic-acid-Schiff-positive granular and eosinophilic material in preserved alveolar architecture. Patients with minimal symptoms are managed conservatively, whereas patients with hypoxemia require a more aggressive approach. Whole-lung lavage is the most widely accepted therapy for symptomatic pulmonary alveolar proteinosis. Correction of GM-CSF deficiency with exogenous GM-CSF is an alternative therapy. The combination of a systemic treatment (GM-CSF) and a local treatment (whole-lung lavage) augmenting the action of one another is a promising new approach. As the knowledge about this rare disease increases, the role of novel therapies is likely to be better defined and optimized.

Indium lung--case reports and epidemiology.

PURPOSE: The present review is aimed to introduce an new occupational lung disease, Indium Lung. METHODS: We searched case reports and epidemiological studies concerning indium-related lung diseases and reviewed. RESULTS: Up to March, 2010, 7 cases of interstitial pneumonia in Japanese indium-exposed workers, two cases of pulmonary alveolar proteinosis (PAP) in US indium-exposed workers, one case of PAP in a Chinese indium-exposed worker, and 4 cross-sectional surveys in Japan had been published. All cases and epidemiological studies in Japan indicate that exposure to hardly soluble indium compounds causes interstitial as well as emphysematous lung damages, which we call "Indium Lung". Based on the epidemiological studies, the Japan Society for Occupational Health proposed 3 µg/l of indium in serum as an occupational exposure limit based on biological monitoring to prevent significant increase of KL-6. COMMENTS: Long-term follow-up of currently and formerly indium-exposed workers is essential not only to clarify the natural history of indium lung but also to trace the incidence of lung cancer. It is also necessary to elucidate the mechanism of indium lung and difference in clinical manifestations between Japanese and US cases.