Alveolar macrophage lipid burden correlates with clinical improvement in patients with pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a life-threatening, rare lung syndrome for which there is no cure and no approved therapies. PAP is a disease of lipid accumulation characterized by alveolar macrophage foam cell formation. While much is known about the clinical presentation, there is a paucity of information regarding temporal changes in lipids throughout the course of disease. Our objectives were to define the detailed lipid composition of alveolar macrophages in PAP patients at the time of diagnosis and during treatment. We performed comprehensive mass spectrometry to profile the lipid signature of alveolar macrophages obtained from three independent mouse models of PAP and from PAP and non-PAP patients. Additionally, we quantified changes in macrophage-associated lipids during clinical treatment of PAP patients. We found remarkable variations in lipid composition in PAP patients, which were consistent with data from three independent mouse models. Detailed lipidomic analysis revealed that the overall alveolar macrophage lipid burden inversely correlated with clinical improvement and response to therapy in PAP patients. Specifically, as PAP patients experienced clinical improvement, there was a notable decrease in the total lipid content of alveolar macrophages. This crucial observation suggests that the levels of these macrophage-associated lipids can be utilized to assess the efficacy of treatment. These findings provide valuable insights into the dysregulated lipid metabolism associated with PAP, offering the potential for lipid profiling to serve as a means of monitoring therapeutic interventions in PAP patients.

Murine Ex Vivo Cultured Alveolar Macrophages Provide a Novel Tool to Study Tissue-Resident Macrophage Behavior and Function.

Tissue-resident macrophages are of vital importance as they preserve tissue homeostasis in all mammalian organs. Nevertheless, appropriate cell culture models are still limited. Here, we propose a novel culture model to study and expand murine primary alveolar macrophages (AMs), the tissue-resident macrophages of the lung, in vitro over several months. By providing a combination of granulocyte-macrophage colony-stimulating factor, TGFß, and the PPARγ activator rosiglitazone, we maintain and expand mouse ex vivo cultured AMs (mexAMs) over several months. MexAMs maintain typical morphologic features and stably express primary AM surface markers throughout in vitro culture. They respond to microbial ligands and exhibit an AM-like transcriptional profile, including the expression of AM-specific transcription factors. Furthermore, when transferred into AM-deficient mice, mexAMs efficiently engraft in the lung and fulfill key macrophage functions, leading to a significantly reduced surfactant load in those mice. Altogether, mexAMs provide a novel, simple, and versatile tool to study AM behavior in homeostasis and disease settings.

A murine model of hereditary pulmonary alveolar proteinosis caused by homozygous Csf2ra gene disruption.

Hereditary pulmonary alveolar proteinosis (hPAP) is a rare disorder caused by recessive mutations in GM-CSF receptor subunit α/ß genes (CSF2RA/CSF2RB, respectively) characterized by impaired GM-CSF-dependent surfactant clearance by alveolar macrophages (AMs) resulting in alveolar surfactant accumulation and hypoxemic respiratory failure. Because hPAP is caused by CSF2RA mutations in most patients, we created an animal model of hPAP caused by Csf2ra gene disruption (Csf2ra-/- mice) and evaluated the effects on AMs and lungs. Macrophages from Csf2ra-/- mice were unable to bind and clear GM-CSF, did not exhibit GM-CSF signaling, and had functional defects in phagocytosis, cholesterol clearance, and surfactant clearance. Csf2ra-/- mice developed a time-dependent, progressive lung disease similar to hPAP in children caused by CSF2RA mutations with respect to the clinical, physiological, histopathological, biochemical abnormalities, biomarkers of PAP lung disease, and clinical course. In contrast, Csf2ra+/- mice had functionally normal AMs and no lung disease. Pulmonary macrophage transplantation (PMT) without myeloablation resulted in long-term engraftment, restoration of GM-CSF responsiveness to AMs, and a safe and durable treatment effect that lasted for the duration of the experiment (6 mo). Results demonstrate that homozygous (but not heterozygous) Csf2ra gene ablation caused hPAP identical to hPAP in children with CSF2RA mutations, identified AMs as the cellular site of hPAP pathogenesis in Csf2ra-/- mice, and have implications for preclinical studies supporting the translation of PMT as therapy of hPAP in humans.

A mini-whole lung lavage to treat autoimmune pulmonary alveolar proteinosis (PAP).

BACKGROUND: PAP is an ultra-rare respiratory syndrome characterized by the accumulation of surfactant within the alveoli. Whole lung lavage (WLL) is the current standard of care of PAP, however it is not a standardized procedure and the total amount of fluid used to wash each lung is still debated. Considering ICU hospitalization associated risks, a "mini-WLL" with anticipated manual clapping and reduced total infusion volume and has been proposed in our center. The aim of the study is to retrospectively analyze the efficacy of mini-WLL compared to standard WLL at the Pavia center. METHODS: 13 autoimmune PAP patients eligible for WLL were included: 7 patients were admitted to mini-WLL (9 L total infusion volume for each lung) and 6 patients underwent standard WLL (14 L of infusion volume). Functional data (VC%, FVC%, TLC%, DLCO%) and alveolar-arterial gradient values (A-aO2) were collected at the baseline and 1, 3, 6, 12, 18 months after the procedure. RESULTS: A statistically significant improvement of VC% (p = 0.013, 95%CI 3.49-30.19), FVC% (p = 0.016, 95%CI 3.37-32.09), TLC% (p = 0.001, 95%CI 7.38-30.34) was observed in the mini-WLL group in comparison with the standard WLL group, while no significant difference in DLCO% and A-aO2 mean values were reported. CONCLUSION: Mini-WLL has demonstrated higher efficacy in ameliorating lung volumes, suggesting that a lower infusion volume is sufficient to remove the surfactant accumulation and possibly allows a reduced mechanical insult of the bronchi walls and the alveoli. However, no statistically significant differences were found in terms of DLCO% and Aa-O2.

N-acetylcysteine alleviates pulmonary alveolar proteinosis induced by indium-tin oxide nanoparticles in male rats: involvement of the NF-κB signaling pathway.

Indium-tin oxide (ITO) was previously found to have a toxic effect on lung tissues, and oxidative stress and the inflammatory response are two important mechanisms of ITO­induced lung injury. N-acetylcysteine (NAC) has been found to exhibit antioxidant and anti­inflammatory properties. The current study aimed to evaluate the possible protective effects of NAC against ITO nanoparticle (Nano-ITO)-induced pulmonary alveolar proteinosis (PAP) in adult male Sprague-Dawley rats, especially via modulation of nuclear factor-kappa B (NF-κB) signaling. For this purpose, 50 rats were randomly allocated into five groups (10 rats each) as follows: (1) control group; (2) saline group; (3) NAC (200 mg/kg) group; (4) PAP model group receiving a repeated intratracheal dose of Nano-ITO (6 mg/kg); and (5) PAP model+NF-κB inhibitor (NAC) group pre-treated intraperitoneally with NAC (200 mg/kg) twice per week before the administration of an intratracheal dose of Nano-ITO (6 mg/kg). Rats were then euthanized under anesthesia, and their lungs were removed for histopathological and biochemical investigations. A 6 mg/kg dose of Nano-ITO markedly altered the levels of some oxidative stress biomarkers. The histological examination of Nano-ITO-exposed rats demonstrated diffused alveolar damage that involved PAP, cholesterol crystals, alveolar fibrosis, pulmonary fibrosis, and alveolar emphysema. The immunohistochemical results of Nano-ITO-exposed rats revealed strongly positive NF-κB p65 and inhibitory kappa B kinase (IKK)-ß and weakly positive inhibitor of kappa-B subunit alpha (IκB-α) staining reactivity in the nuclei of cells lining the epithelium of the bronchioles and alveoli. Moreover, Nano-ITO activated the NF-κB pathway. However, pre-treatment with NAC significantly attenuated Nano-ITO-evoked alterations in the previously mentioned parameters, highlighting their antioxidant, anti-inflammatory, and anti-apoptotic potential. The results indicated that the degree of pulmonary fibrosis and proteinosis in the NAC­treated group was improved compared with that in the Nano-ITO-induced PAP model group. The level of malondialdehyde was also decreased overall in the NAC-treated group compared with that in the Nano-ITO-induced model group, indicating that the pulmonary fibrosis degree and oxidation levels were decreased. The present study also demonstrated that NAC increased the activity of antioxidant enzyme superoxide dismutase and total antioxidant capacity, indicating that it could alleviate oxidative stress in the lung tissue of Nano-ITO­exposed rats. In addition, NAC reduced the production of pro­inflammatory cytokines interleukin (IL)­1ß, IL­6, and tumor necrosis factor (TNF)­α, and increased the levels of anti­inflammatory factor IL­10. The current study demonstrated that NAC can effectively attenuate Nano-ITO­induced lung injury by reducing oxidative damage and the inflammatory response.

Pulmonary storage.

Interstitial lung diseases (ILDs) are not just a matter of scarring or inflammation in the lung tissue. The lungs can also serve as a repository for products that can be produced in excessive amounts in the human body as a result of disease. Geneticaly based dysfunctions of lysosomal enzymes, which leads to an unefficient degradation and transport of various macromolecules from lysosomes, are considered to be storage diseases sensu stricto. ILDs were described in patients with Gaucher disease, Niemann-Pick disease and Fabry disease. In a broader context, however, the accumulation of various substances in the lung tissue is also encountered in cases of pediatric pulmonary interstitial glycogenosis (PIG), alveolar lipoproteinosis or pulmonary amyloidosis. The cause of PIG is not clear. The disease was first described in 2002 and a lung tissue sample is required to establish this diagnosis. Even though PIG usually goes well in childhood and the patients difficulties spontaneously subside over time, the long-term prognosis of the patients is unknown. Alveolar lipoproteinoses can be acquired (e.g. after massive exposure to silica dust), autoimmune, but also genetically determined. Unlike lysosomal storage diseases, in the case of pulmonary alveolar lipoproteinosis, accumulation of abnormal macromolecules occurs only in the lungs of affected individuals. Similarly, amyloidosis is not a single disease, but a group of diseases with different etiopathogenesis, as a result of which amyloid - a group of different proteins with a distinctvive conformation, which can be deposited in various organs, including the lungs - is formed. The diagnosis of pulmonary alveolar lipoproteinosis is based on the typical appearance and biochemical composition of the fluid obtained by bronchoalveolar lavage, the diagnosis of amyloidosis is histological.

Beyond "Big Eaters": The Versatile Role of Alveolar Macrophages in Health and Disease.

Macrophages act as immune scavengers and are important cell types in the homeostasis of various tissues. Given the multiple roles of macrophages, these cells can also be found as tissue resident macrophages tightly integrated into a variety of tissues in which they fulfill crucial and organ-specific functions. The lung harbors at least two macrophage populations: interstitial and alveolar macrophages, which occupy different niches and functions. In this review, we provide the latest insights into the multiple roles of alveolar macrophages while unraveling the distinct factors which can influence the ontogeny and function of these cells. Furthermore, we will highlight pulmonary diseases, which are associated with dysfunctional macrophages, concentrating on congenital diseases as well as pulmonary infections and impairment of immunological pathways. Moreover, we will provide an overview about different treatment approaches targeting macrophage dysfunction. Improved knowledge of the role of macrophages in the onset of pulmonary diseases may provide the basis for new pharmacological and/or cell-based immunotherapies and will extend our understanding to other macrophage-related disorders.

Structure and activity of human surfactant protein D from different natural sources.

Surfactant protein D (SP-D) is a C-type lectin that participates in the innate immune defense of lungs. It binds pathogens through its carbohydrate recognition domain in a calcium-dependent manner. Human surfactant protein D (hSP-D) has been routinely obtained from bronchoalveolar lavage of patients suffering from pulmonary alveolar proteinosis (PAP) and from amniotic fluid (AF). As a consequence of the disease, hSP-D obtained from PAP is found in higher amounts and is mainly composed of higher order oligomeric forms. However, PAP-hSP-D has never been directly compared with nonpathological human protein in terms of structure and biological activity. Moreover, the quantitative distribution of the different hSP-D oligomeric forms in human protein obtained from a natural source has never been evaluated. In this work, we have determined the quantitative distribution of AF-hSP-D oligomers, characterized the sugars attached through the N-glycosylation site of the protein, and compared the activity of hSP-D from AF and PAP with respect to their ability to bind and agglutinate bacteria. We have found that fuzzy balls (40%) are the most abundant oligomeric form in AF-hSP-D, very closely followed by dodecamers (33%), with both together constituting 73% of the protein mass. The glycan attached to the N-glycosylation site was found to be composed of fucose, galactose, sialic acid, and N-acetylglucosamine. Finally, in the functional assays performed, hSP-D obtained from PAP showed higher potency, probably as a consequence of its higher proportion of large oligomers compared with hSP-D from AF.

Quantitative Lipidomics in Pulmonary Alveolar Proteinosis.

Rationale: Pulmonary alveolar proteinosis (PAP) is characterized by filling of the alveolar spaces by lipoprotein-rich material of ill-defined composition, and is caused by molecularly different and often rare diseases that occur from birth to old age.Objectives: To perform a quantitative lipidomic analysis of lipids and the surfactant proteins A, B, and C in lavage fluids from patients with proteinosis of different causes in comparison with healthy control subjects.Methods: During the last two decades, we have collected BAL samples from patients with PAP due to autoantibodies against granulocyte-macrophage colony-stimulating factor; genetic mutations in CSF2RA (colony-stimulating factor 2 receptor α-subunit), MARS (methionyl aminoacyl-tRNA synthetase), FARSB (phenylalanine-tRNA synthetase, ß-subunit), and NPC2 (Niemann-Pick disease type C2); and secondary to myeloid leukemia. Their lipid composition was quantified.Measurements and Main Results: Free cholesterol was largely increased by 60-fold and cholesteryl esters were increased by 24-fold. There was an excessive, more than 130-fold increase in ceramide and other sphingolipids. In particular, the long-chain ceramides d18:1/20:0 and d18:1/24:0 were elevated and likely contributed to the proapoptotic environment observed in PAP. Cellular debris lipids such as phosphatidylethanolamine and phosphatidylserine were only moderately increased, by four- to sevenfold. The surfactant lipid class phosphatidylcholine expanded 17-fold, lysophosphatidylcholine expanded 54-fold, and the surfactant proteins A, B, and C expanded 144-, 4-, and 17-fold, respectively. These changes did not differ among the various diseases that cause PAP.Conclusions: This insight into the alveolar lipidome may provide monitoring tools and lead to new therapeutic strategies for PAP.

Indium oxide nanoparticles induce lung intercellular toxicity between bronchial epithelial cells and macrophages.

Concerns have been raised over the safety and health of industrial workers exposed to indium oxide nanoparticles (IO-NPs) when working. IO-NPs were previously shown in vitro and in vivo to be cytotoxic, but the mechanism of pathogenesis was unclear. In this study, the effects of IO-NPs on lung cells associated with respiratory and immune barriers and the toxic effects of intercellular cascades were studied. Here IO-NPs had acute toxicity to Wistar rats over a time course (5 days post-intratracheal instillation). Following treatment epithelial cells (16HBE) or macrophages (RAW264.7) with IO-NPs or IO fine particles (IO-FPs), the damage of 16HBE cells caused by IO-NPs was serious, mainly in the mitochondrial and rough endoplasmic reticulum. The lactate dehydrogenase level also showed that cytotoxicity in vitro was more serious for IO-NPs compared with IO-FPs. The level of In3+ (examined by inductively coupled plasma mass spectrometry) in 16HBE cells was 10 times higher than that in RAW cells. In3+ , releasing from IO-NPs absorbed by 16HBE cells, could not only significantly inhibit the phagocytosis and migration of macrophages (P < .0001), but also stimulate RAW cells to secrete high levels of inflammatory cytokines. IO-NPs can directly damage pulmonary epithelial cells. The In3+ released by epithelial cells affect the phagocytosis and migration of macrophages, which may be a new point for the decrease in the clearance of alveolar surfactants and the development of IO-related pulmonary alveolar proteinosis.

Respiratory complications of metabolic disease in the paediatric population: A review of presentation, diagnosis and therapeutic options.

Inborn errors of metabolism (IEMs) whilst individually rare, as a group constitute a field which is increasingly demands on pulmonologists. With the advent of new therapies such as enzyme replacement and gene therapy, early diagnosis and treatment of these conditions can impact on long term outcome, making their timely recognition and appropriate investigation increasingly important. Conversely, with improved treatment, survival of these patients is increasing, with the emergence of previously unknown respiratory phenotypes. It is thus important that pulmonologists are aware of and appropriately monitor and manage these complications. This review aims to highlight the respiratory manifestations which can occur. It isdivided into conditions resulting primarily in obstructive airway and lung disease, restrictive lung disease such as interstitial lung disease or pulmonary alveolar proteinosis and pulmonary hypertension, whilst acknowledging that some diseases have the potential to cause all three. The review focuses on general phenotypes of IEMs, their known respiratory complications and the basic metabolic investigations which should be performed where an IEM is suspected.

Pulmonary Transplantation of Human Induced Pluripotent Stem Cell-derived Macrophages Ameliorates Pulmonary Alveolar Proteinosis.

RATIONALE: Although the transplantation of induced pluripotent stem cell (iPSC)-derived cells harbors enormous potential for the treatment of pulmonary diseases, in vivo data demonstrating clear therapeutic benefits of human iPSC-derived cells in lung disease models are missing. OBJECTIVES: We have tested the therapeutic potential of iPSC-derived macrophages in a humanized disease model of hereditary pulmonary alveolar proteinosis (PAP). Hereditary PAP is caused by a genetic defect of the GM-CSF (granulocyte-macrophage colony-stimulating factor) receptor, which leads to disturbed macrophage differentiation and protein/surfactant degradation in the lungs, subsequently resulting in severe respiratory insufficiency. METHODS: Macrophages derived from human iPSCs underwent intrapulmonary transplantation into humanized PAP mice, and engraftment, in vivo differentiation, and therapeutic efficacy of the transplanted cells were analyzed. MEASUREMENTS AND MAIN RESULTS: On intratracheal application, iPSC-derived macrophages engrafted in the lungs of humanized PAP mice. After 2 months, transplanted cells displayed the typical morphology, surface markers, functionality, and transcription profile of primary human alveolar macrophages. Alveolar proteinosis was significantly reduced as demonstrated by diminished protein content and surfactant protein D levels, decreased turbidity of the BAL fluid, and reduced surfactant deposition in the lungs of transplanted mice. CONCLUSIONS: We here demonstrate for the first time that pulmonary transplantation of human iPSC-derived macrophages leads to pulmonary engraftment, their in situ differentiation to an alveolar macrophage phenotype, and a reduction of alveolar proteinosis in a humanized PAP model. To our knowledge, this finding presents the first proof-of-concept for the therapeutic potential of human iPSC-derived cells in a pulmonary disease and may have profound implications beyond the rare disease of PAP.

Inducible Slc7a7 Knockout Mouse Model Recapitulates Lysinuric Protein Intolerance Disease.

Lysinuric protein intolerance (LPI) is a rare autosomal disease caused by defective cationic amino acid (CAA) transport due to mutations in SLC7A7, which encodes for the y+LAT1 transporter. LPI patients suffer from a wide variety of symptoms, which range from failure to thrive, hyperammonemia, and nephropathy to pulmonar alveolar proteinosis (PAP), a potentially life-threatening complication. Hyperammonemia is currently prevented by citrulline supplementation. However, the full impact of this treatment is not completely understood. In contrast, there is no defined therapy for the multiple reported complications of LPI, including PAP, for which bronchoalveolar lavages do not prevent progression of the disease. The lack of a viable LPI model prompted us to generate a tamoxifen-inducible Slc7a7 knockout mouse (Slc7a7-/-). The Slc7a7-/- model resembles the human LPI phenotype, including malabsorption and impaired reabsorption of CAA, hypoargininemia and hyperammonemia. Interestingly, the Slc7a7-/- mice also develops PAP and neurological impairment. We observed that citrulline treatment improves the metabolic derangement and survival. On the basis of our findings, the Slc7a7-/- model emerges as a promising tool to further study the complexity of LPI, including its immune-like complications, and to design evidence-based therapies to halt its progression.

Inflammatory responses induce an identity crisis of alveolar macrophages, leading to pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a severe respiratory disease characterized by dyspnea caused by accumulation of surfactant protein. Dysfunction of alveolar macrophages (AMs), which regulate the homeostasis of surfactant protein, leads to the development of PAP; for example, in mice lacking BTB and CNC homology 2 (Bach2). However, how Bach2 helps prevent PAP is unknown, and the cell-specific effects of Bach2 are undefined. Using mice lacking Bach2 in specific cell types, we found that the PAP phenotype of Bach2-deficient mice is due to Bach2 deficiency in more than two types of immune cells. Depletion of hyperactivated T cells in Bach2-deficient mice restored normal function of AMs and ameliorated PAP. We also found that, in Bach2-deficient mice, hyperactivated T cells induced gene expression patterns that are specific to other tissue-resident macrophages and dendritic cells. Moreover, Bach2-deficient AMs exhibited a reduction in cell cycle progression. IFN-γ released from T cells induced Bach2 expression in AMs, in which Bach2 then bound to regulatory regions of inflammation-associated genes in myeloid cells. Of note, in AMs, Bach2 restricted aberrant responses to excessive T cell-induced inflammation, whereas, in T cells, Bach2 puts a brake on T cell activation. Moreover, Bach2 stimulated the expression of multiple histone genes in AMs, suggesting a role of Bach2 in proper histone expression. We conclude that Bach2 is critical for the maintenance of AM identity and self-renewal in inflammatory environments. Treatments targeting T cells may offer new therapeutic strategies for managing secondary PAP.

Hepatic Steatosis Accompanies Pulmonary Alveolar Proteinosis.

Maintenance of tissue-specific organ lipid compositions characterizes mammalian lipid homeostasis. The lungs and liver synthesize mixed phosphatidylcholine (PC) molecular species that are subsequently tailored for function. The lungs progressively enrich disaturated PC directed to lamellar body surfactant stores before secretion. The liver accumulates polyunsaturated PC directed to very-low-density lipoprotein assembly and secretion, or to triglyceride stores. In each tissue, selective PC species enrichment mechanisms lie at the heart of effective homeostasis. We tested for potential coordination between these spatially separated but possibly complementary phenomena under a major derangement of lung PC metabolism, pulmonary alveolar proteinosis (PAP), which overwhelms homeostasis and leads to excessive surfactant accumulation. Using static and dynamic lipidomics techniques, we compared (1) tissue PC compositions and contents, and (2) in lungs, the absolute rates of synthesis in both control mice and the granulocyte-macrophage colony-stimulating factor knockout model of PAP. Significant disaturated PC accumulation in bronchoalveolar lavage fluid, alveolar macrophage, and lavaged lung tissue occurred alongside increased PC synthesis, consistent with reported defects in alveolar macrophage surfactant turnover. However, microscopy using oil red O staining, coherent anti-Stokes Raman scattering, second harmonic generation, and transmission electron microscopy also revealed neutral-lipid droplet accumulations in alveolar lipofibroblasts of granular macrophage colony-stimulating factor knockout animals, suggesting that lipid homeostasis deficits extend beyond alveolar macrophages. PAP plasma PC composition was significantly polyunsaturated fatty acid enriched, but the content was unchanged and hepatic polyunsaturated fatty acid-enriched PC content increased by 50% with an accompanying micro/macrovesicular steatosis and a fibrotic damage pattern consistent with nonalcoholic fatty liver disease. These data suggest a hepatopulmonary axis of PC metabolism coordination, with wider implications for understanding and managing lipid pathologies in which compromise of one organ has unexpected consequences for another.

ABCG1 regulates pulmonary surfactant metabolism in mice and men.

Idiopathic pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by accumulation of surfactant. Surfactant synthesis and secretion are restricted to epithelial type 2 (T2) pneumocytes (also called T2 cells). Clearance of surfactant is dependent upon T2 cells and macrophages. ABCG1 is highly expressed in both T2 cells and macrophages. ABCG1-deficient mice accumulate surfactant, lamellar body-loaded T2 cells, lipid-loaded macrophages, B-1 lymphocytes, and immunoglobulins, clearly demonstrating that ABCG1 has a critical role in pulmonary homeostasis. We identify a variant in the ABCG1 promoter in patients with PAP that results in impaired activation of ABCG1 by the liver X receptor α, suggesting that ABCG1 basal expression and/or induction in response to sterol/lipid loading is essential for normal lung function. We generated mice lacking ABCG1 specifically in either T2 cells or macrophages to determine the relative contribution of these cell types on surfactant lipid homeostasis. These results establish a critical role for T2 cell ABCG1 in controlling surfactant and overall lipid homeostasis in the lung and in the pathogenesis of human lung disease.

[Bilateral total lung lavage in a patient with pulmonary alveolar proteinosis]. / Pulmoner alveoler proteinozisli hastada iki tarafli total akciger lavaji.

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease characterised by alveolar accumulation of surfactant composed of proteins and lipids. Three main categories of PAP have been defined depending on the aetiology: primer/idiopathic, neonatal/congenital, secondary and exogenous/environmental exposure. Radiologically diffuse ground glass opacities, interlobular and intralobular septal thickening is seen. Although open lung biopsy is accepted as the gold standard in diagnosis, it can be diagnosed by showing bronchoalveolar lavage (BAL) fluid with a milky appearance and periodic acid-schiff (PAS) positive globules in biopsy with clinical and radiological findings. Theraphy for PAP are supportive care (oxygen), total lung lavage, inhale/subcutaneous granulocyte macrophage colony stimulating factor (GM-CSF), rituximab, plasmapheresis, lung transplantation. We report a case of PAP presented with cough and shortness of breath, diagnosed with BAL and transbronchial lung biopsy, treated by total lung lavage by reviewing literature.

[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.

IL-1α induces CD11b(low) alveolar macrophage proliferation and maturation during granuloma formation.

Macrophages play a central role in immune and tissue responses of granulomatous lung diseases induced by pathogens and foreign bodies. Circulating monocytes are generally viewed as central precursors of these tissue effector macrophages. Here, we provide evidence that granulomas derive from alveolar macrophages serving as a local reservoir for the expansion of activated phagocytic macrophages. By exploring lung granulomatous responses to silica particles in IL-1-deficient mice, we found that the absence of IL-1α, but not IL-1ß, was associated with reduced CD11b(high) phagocytic macrophage accumulation and fewer granulomas. This defect was associated with impaired alveolar clearance and resulted in the development of pulmonary alveolar proteinosis (PAP). Reconstitution of IL-1α(-/-) mice with recombinant IL-1α restored lung clearance functions and the pulmonary accumulation of CD11b(high) phagocytic macrophages. Mechanistically, IL-1α induced the proliferation of CD11b(low) alveolar macrophages and differentiated these cells into CD11b(high) macrophages which perform critical phagocytic functions and organize granuloma. We newly discovered here that IL-1α triggers lung responses requiring macrophage proliferation and maturation from tissue-resident macrophages.

Characterization of pathogenic human monoclonal autoantibodies against GM-CSF.

The origin of pathogenic autoantibodies remains unknown. Idiopathic pulmonary alveolar proteinosis is caused by autoantibodies against granulocyte-macrophage colony-stimulating factor (GM-CSF). We generated 19 monoclonal autoantibodies against GM-CSF from six patients with idiopathic pulmonary alveolar proteinosis. The autoantibodies used multiple V genes, excluding preferred V-gene use as an etiology, and targeted at least four nonoverlapping epitopes on GM-CSF, suggesting that GM-CSF is driving the autoantibodies and not a B-cell epitope on a pathogen cross-reacting with GM-CSF. The number of somatic mutations in the autoantibodies suggests that the memory B cells have been helped by T cells and re-entered germinal centers. All autoantibodies neutralized GM-CSF bioactivity, with general correlations to affinity and off-rate. The binding of certain autoantibodies was changed by point mutations in GM-CSF that reduced binding to the GM-CSF receptor. Those monoclonal autoantibodies that potently neutralize GM-CSF may be useful in treating inflammatory disease, such as rheumatoid arthritis and multiple sclerosis, cancer, and pain.