[Show abstract][Hide abstract] ABSTRACT: Histidine-rich glycoprotein (HRG) is an enigmatic glycoprotein able to interact with a variety of ligands such as IgG, complement components, heparan sulfate, thrombospondin, fibrinogen and plasminogen. HRG is present at high concentrations in plasma and there is evidence indicating that it is able to modulate the course of biological processes such as angiogenesis, fibroblast proliferation, complement activation, coagulation and fibrinolysis. Because these processes are involved in the pathogeneses of lung fibrosis we here analyzed a possible link between HRG and idiopathic pulmonary fibrosis (IPF). We found that plasma concentrations of HRG are significantly diminished in IPF patients compared to healthy subjects. Moreover, we found a positive correlation between HRG plasma levels and forced vital capacity (FVC) values, suggesting that plasma concentration of HRG would be a useful indicator of disease activity in IPF. HRG has been described as a negative acute phase reactant able to accumulate at sites of tissue injury. Hence, we also measured the concentrations of HRG in BAL samples from IPF patients. We found that the concentrations of HRG in samples from IPF patients were significantly higher compared to controls, suggesting that the reduced concentration of HRG in plasma from IPF patients could be due, at least in part, to an enhanced uptake of this protein in the lung.
Full-text · Article · Oct 2015 · Respiratory medicine
[Show abstract][Hide abstract] ABSTRACT: During the late stages of the HIV-1 replication cycle, the viral polyprotein Pr55Gag is recruited to the plasma membrane (PM), where it binds phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and directs HIV-1 assembly. We show that Rab27a controls the trafficking of late endosomes carrying phosphatidylinositol 4-kinase type 2 α (PI4KIIα) toward the PM of CD4+ T cells. Hence, Rab27a promotes high levels of PM phosphatidylinositol 4-phosphate and the localized production of PI(4,5)P2, therefore controlling Pr55Gag membrane association. Rab27a also controls PI(4,5)P2 levels at the virus-containing compartments of macrophages. By screening Rab27a effectors, we identified that Slp2a, Slp3, and Slac2b are required for the association of Pr55Gag with the PM and that Slp2a cooperates with Rab27a in the recruitment of PI4KIIα to the PM. We conclude that by directing the trafficking of PI4KIIα-positive endosomes toward the PM, Rab27a controls PI(4,5)P2 production and, consequently, HIV-1 replication.
Full-text · Article · May 2015 · The Journal of Cell Biology
[Show abstract][Hide abstract] ABSTRACT: Respiratory syncytial virus (RSV) infection is the leading cause of bronchiolitis and hospitalization in young infants and causes 100 000-200 000 deaths annually. There is still no licensed vaccine against RSV infection and the therapeutic options are mainly supportive. Despite almost six decades of research, important knowledge gaps remain with respect to the characterization of immune mechanisms responsible for protection and pathogenesis, as well as to the identification of risk factors that predict the severity of infection.
Observations made in mouse models and young children suggest that the early innate immune response plays a major role in the pathogenesis of bronchiolitis due to RSV infection. Recent studies have improved our understanding of the role of the adaptive immune response mediated by TH1, TH2, TH17, regulatory T cells, and CD8 T cells in the pathogenesis and resolution of RSV infection. Moreover, investigations performed in the last years have made important contributions to our knowledge of the immune response in young children, the principal risk group for severe disease.
A comprehensive understanding of how the protective and deleterious immune response during the course of RSV infection is induced in young children remains a challenge over the coming years.
No preview · Article · Apr 2015 · Current Opinion in Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: Idiopathic pulmonary fibrosis (IPF) is a chronic and fibrosing disease characterized by a progressive loss of lung function and poor prognosis. The pathogenesis of the IPF is complex and the mechanisms involved are still unknown. Histidine-rich glicoprotein (HRG) is a plasma protein that interacts with many ligands and regulates a number of important biological processes. HRG is constitutively present at high concentrations in plasma. Previous studies have shown that HRG is able to modulate the activation of the fibroblast growth factor receptor. The aim of this study was to determine whether the levels of HRG in plasma of IPF patients were predictive of lung function.
METHODS: We collected plasma samples from 14 IPF patients (12/2: males/female); with an average age of 62.5 ± 2.0 years; 9 ex-smokers, 1 current-smoker and 4 non-smokers. Eleven of them showed typical topographic images (HRTC) of IPF, and the others presented a suggestive pattern. We confirmed diagnosis by lung biopsy in 3 patients. As the control group we used plasma from 10 healthy non-smoking subjects. Plasma levels of HRG were measured by ELISA. Data were analyzed with Mann-Whitney test and linear regression analyses.
RESULTS: We observed a significant decrease of HRG plasma levels in IPF patients compared with the control group (81.9 ± 5.3 μg/ml vs 103.8 ± 4.1 μg/ml; p<0.001). We found a positive and significant relationship between HRG plasma levels and both DLCO (percentage of predicted value) and 6 minutes walking test (meters walked) (Spearman r = 0.39; p<0.05, and r = 0.61; p<0.001, respectively). We also found a positive relationship between the decreased levels of HRG in plasma and pack/years smoked (r = 0.66; p<0.001).
CONCLUSIONS: Our results illustrate that a decreased plasmatic levels of HRG is associated to the progression of illness in IPF patients.
CLINICAL IMPLICATIONS: Our data suggest that HRG could be used as a biomarker to evaluate the evolution and prognosis of IPF patients, supporting the need for a larger study.
[Show abstract][Hide abstract] ABSTRACT: Seminal plasma is not just a spermatozoa carrier. It induces the expression of inflammatory cytokines and chemokines and a massive infiltration of neutrophils, monocytes and dendritic cells in the female genital mucosa after coitus, enabling the innate immune system to fight against sexually transmitted pathogens. However, exposure to seminal plasma not only turns on an inflammatory response but also induces regulatory mechanisms that allow the fetus (a semiallograft) to grow and develop in the uterus. In mouse models it has been shown that seminal plasma induces the expansion of regulatory T cells specific to seminal Ags in the receptive partner, thus promoting tolerance to paternal alloantigens and avoiding allogeneic fetal rejection. These mechanisms appear to be mainly induced by prostaglandins of the E series (PGE) and TGF-β, which are present at huge concentrations in the seminal plasma. Moreover, we have recently shown that exposure to seminal plasma induces the differentiation of dendritic cells into a tolerogenic profile through a mechanism dependent on the activation of the prostanoid receptors EP2 and EP4 by seminal PGE.
Our hypothesis proposes that this tolerogenic response induced by seminal PGE, while promoting fertility by inducing tolerance toward paternal alloantigens, might also compromise the development of the adaptive immune response against sexually transmitted pathogens in the receptive partner.
No preview · Article · Aug 2014 · Medical Hypotheses
[Show abstract][Hide abstract] ABSTRACT: γδ T cells have been shown to stimulate the recruitment and activation of neutrophils through the release of a range of cytokines and chemokines. Here, we investigated the reverse relationship, showing that human neutrophils suppress the function of human blood γδ T cells. We show that the upregulation of CD25 and CD69 expression, the production of IFN-γ, and the proliferation of γδ T cells induced by HMBPP are inhibited by neutrophils. Spontaneous activation of γδ T cells in culture is also suppressed by neutrophils. We show that inhibitors of prostaglandin E2 and arginase I do not exert any effect, although in contrast, catalase prevents the suppression of γδ T cells induced by neutrophils, suggesting the participation of neutrophil-derived ROS. We also show that the ROS-generating system xanthine/xanthine oxidase suppresses γδ T cells in a similar fashion to neutrophils, while neutrophils from chronic granulomatous disease patients only weakly inhibit γδ T cells. Our results reveal a bidirectional cross-talk between γδ T cells and neutrophils: while γδ T cells promote the recruitment and the activation of neutrophils to fight invading pathogens, neutrophils in turn suppress the activation of γδ T cells to contribute to the resolution of inflammation. This article is protected by copyright. All rights reserved.
Full-text · Article · Mar 2014 · European Journal of Immunology
[Show abstract][Hide abstract] ABSTRACT: Neutrophils are essential players in acute inflammatory responses. Upon stimulation, neutrophils activate NADPH oxidase, generating an array of reactive oxygen species (ROS). Interleukin-1β (IL-1β) is a major pro-inflammatory cytokine synthesized as a precursor which has to be proteolytically processed to become biologically active. The role of ROS in IL-1β processing is still controversial and has not been previously studied in neutrophils. We report here that IL-1β processing in human neutrophils is dependent on caspase-1 and on the serine-proteases elastase and/or proteinase-3. NADPH oxidase-deficient neutrophils activated caspase-1 and did not exhibit differences in NALP3 expression, indicating that ROS are neither required for inflammasome activation nor for its priming, as has been reported for macrophages. Strikingly, ROS exerted opposite effects on the processing and secretion of IL-1β; whereas ROS negatively controlled caspase-1 activity, as reported in mononuclear phagocytes, ROS were found to be necessary for the exportation of mature IL-1β out of the cell, a role never previously described. The complex ROS-mediated regulation of neutrophil IL-1β secretion might constitute a physiological mechanism to control IL-1β-dependent inflammatory processes where neutrophils play a crucial role. This article is protected by copyright. All rights reserved.
Full-text · Article · Dec 2013 · European Journal of Immunology
[Show abstract][Hide abstract] ABSTRACT: Asthma PostersSESSION TYPE: Original Investigation PosterPRESENTED ON: Wednesday, October 30, 2013 at 01:30 PM - 02:30 PMPURPOSE: The aim of this study was to compare the levels of IL-8 and IL17-A in sputum samples from patients admitted for an asthma exacerbation classified in two different categories based on WHO criteria: a) Difficult to treat severe asthma (DTTSA) due to non-adherence or accessibility issues and b) Treatment resistant severe asthma (TRSA), in order to understand the role of these molecules in the pathogenesis of the diverse presentations of the disease. The third category, Untreated severe asthma was not found between our patients.METHODS: Cross sectional prospective observational study of admissions to a respiratory hospital. DTTSA and TRSA were diagnosed according to WHO criteria; FeNO and spirometry were first measured, followed by assisted sputum. Samples were processed with dithiotreitol, cytospined and stained. Supernatants were stored at -80°C. IL-8 and IL17-A were measured by ELISA. Data were expressed as the mean ± SEM and were analyzed using a non-parametric Mann Whitney test.RESULTS: We recruited 12 patients with TRSA (9 of them never smoked and 2 were past-smokers); and 38 with DTTSA (24 of them never smoked, 6 were past-smokers and 7 were active smokers). No significant differences were found between initial FEV1or FeNO between both groups: 775.5±86.L/S and 37.7±10.8 ppb in TRSA vs 911.4±60.4 L/S and 39.4±5.2 ppb in DTTSA patients. A significant increase of neutrophils in sputum samples from patients with TRSA vs DTTSA (32.5±7.5% vs 14.8±2.0%, p<0.05) was found. Moreover, 25% of TRSA but only 2.6% of DTTSA were neutrophilics. Sputum levels of IL-8 were higher in TRSA compared with DTTSA patients (724.8±47.1pg/ml vs 419.5±80.1pg/ml, p<0.05). No differences were found when the levels of IL17-A were analyzed (13.6±4.6pg/ml vs 14.1±3.3pg/ml respectively).CONCLUSIONS: Consistent with previous data, we did not find differences in FeNO and FEV-1 between TRSA and DTTSA patients. A significant increase of IL-8, but not IL-17A, was found in the sputum of TRSA vs DTTSA patients.CLINICAL IMPLICATIONS: This work contributes to understand the role of IL-8 in the pathogenesis of TRSA.DISCLOSURE: The following authors have nothing to disclose: Glenda Ernst, Auteri Santiago, Fabian Caro, Daniel Colodenco, Ricardo Del Olmo, Martin Fernandez, Jorge Geffner, Dora Lombardi, Guillermo Menga, Jose Luis Morero, Hugo Neffen, Santiago Rossi, Eduardo SchiaviNo Product/Research Disclosure Information.
[Show abstract][Hide abstract] ABSTRACT: Macrophages are one of the most important HIV-1 target cells. Unlike CD4(+) T cells, macrophages are resistant to the cytophatic effect of HIV-1. They are able to produce and harbor the virus for long periods acting as a viral reservoir. Candida albicans (CA) is a commensal fungus that colonizes the portals of HIV-1 entry, such as the vagina and the rectum, and becomes an aggressive pathogen in AIDS patients. In this study, we analyzed the ability of CA to modulate the course of HIV-1 infection in human monocyte-derived macrophages. We found that CA abrogated HIV-1 replication in macrophages when it was evaluated 7 days after virus inoculation. A similar inhibitory effect was observed in monocyte-derived dendritic cells. The analysis of the mechanisms responsible for the inhibition of HIV-1 production in macrophages revealed that CA efficiently sequesters HIV-1 particles avoiding its infectivity. Moreover, by acting on macrophages themselves, CA diminishes their permissibility to HIV-1 infection by reducing the expression of CD4, enhancing the production of the CCR5-interacting chemokines CCL3/MIP-1α, CCL4/MIP-1β, and CCL5/RANTES, and stimulating the production of interferon-α and the restriction factors APOBEC3G, APOBEC3F, and tetherin. Interestingly, abrogation of HIV-1 replication was overcome when the infection of macrophages was evaluated 2-3 weeks after virus inoculation. However, this reactivation of HIV-1 infection could be silenced by CA when added periodically to HIV-1-challenged macrophages. The induction of a silent HIV-1 infection in macrophages at the periphery, where cells are continuously confronted with CA, might help HIV-1 to evade the immune response and to promote resistance to antiretroviral therapy.
[Show abstract][Hide abstract] ABSTRACT: Bacterial superantigens (SAgs) are exotoxins produced mainly by Staphylococcus aureus and Streptococcus pyogenes that can cause toxic shock syndrome (TSS). According to current paradigm, SAgs interact directly and simultaneously with T cell receptor (TCR) on the T cell and MHC class II (MHC-II) on the antigen-presenting cell (APC), thereby circumventing intracellular processing to trigger T cell activation. Dendritic cells (DCs) are professional APCs that coat nearly all body surfaces and are the most probable candidate to interact with SAgs. We demonstrate that SAgs are taken up by mouse DCs without triggering DC maturation. SAgs were found in intracellular acidic compartment of DCs as biologically active molecules. Moreover, SAgs co-localized with EEA1, RAB-7 and LAMP-2, at different times, and were then recycled to the cell membrane. DCs loaded with SAgs are capable of triggering in vitro lymphocyte proliferation and, injected into mice, stimulate T cells bearing the proper TCR in draining lymph nodes. Transportation and trafficking of SAgs in DCs might increase the local concentration of these exotoxins where they will produce the highest effect by promoting their encounter with both MHC-II and TCR in lymph nodes, and may explain how just a few SAg molecules can induce the severe pathology associated with TSS.
[Show abstract][Hide abstract] ABSTRACT: Neutrophils not only play a critical role as a first line of defense against bacteria and fungi infections but also contribute to tissue injury associated with autoimmune and inflammatory diseases. Neutrophils are rapidly and massively recruited from the circulation into injured tissues displaying an impressive arsenal of toxic weapons. Although effective in their ability to kill pathogens, these weapons were equally effective to induce tissue damage. Therefore, the inflammatory activity of neutrophils must be regulated with exquisite precision and timing, a task mainly achieved through a complex network of mechanisms, which regulate neutrophil survival. Neutrophils have the shortest lifespan among leukocytes and usually die via apoptosis although new forms of cell death have been characterized over the last few years. The lifespan of neutrophils can be dramatically modulated by a large variety of agents such as cytokines, pathogens, danger-associated molecular patterns as well as by pharmacological manipulation. Recent findings shed light about the complex mechanisms responsible for the regulation of neutrophil survival in different physiological, pathological, and pharmacological scenarios. Here, we provide an updated review on the current knowledge and new findings in this field and discuss novel strategies that could be used to drive the resolution of neutrophil-mediated inflammatory diseases.
No preview · Article · Feb 2013 · Seminars in Immunopathology
[Show abstract][Hide abstract] ABSTRACT: Recently, it was shown that peripheral blood FOXP3+CD4+ T cells are composed of three phenotypic and functionally distinct subpopulations. Two of them having in vitro suppressive effects were characterized as resting Treg cells (rTregs) and activated Treg cells (aTregs). A third subset, identified as FOXP3+ non-Tregs, does not display any suppressor activity and produce high levels of Th1 and Th17 cytokines upon stimulation. In the present study we focus on the characteristics of these three subsets of FOXP3+CD4+ T cells in untreated HIV-1-infected patients. We found that the absolute counts of rTregs, aTregs and FOXP3+ non-Tregs were reduced in HIV-1 patients compared with healthy donors. The relative frequency of rTregs and aTregs was similar in HIV-1 patients and healthy donors, while the frequency of FOXP3+ non-Tregs was significantly higher in HIV-1 patients, reaching a maximum in those patients with the lower values of CD4 counts. Contrasting with the observations made in FOXP3- CD4+ T cells, we did not find a negative correlation between the number of rTregs, aTregs or FOXP3+ non-Tregs and virus load. Studies performed with either whole PBMCs or sorted aTregs and FOXP3+ non-Tregs cells showed that these two populations of FOXP3+ T cells were highly permissive to HIV-1 infection. Upon infection, FOXP3+ non-Tregs markedly down-regulates its capacity to produce Th1 and Th17 cytokines, however, they retain the ability to produce substantial amounts of Th2 cytokines. This suggests that FOXP3+ non-Tregs might contribute to the polarization of CD4+ T cells into a Th2 profile, predictive of a poor outcome of HIV-1-infected patients.
[Show abstract][Hide abstract] ABSTRACT: Seminal plasma is not just a carrier for spermatozoa. It contains high concentrations of cytokines, chemokines, and other biological compounds that are able to exert potent effects on the immune system of the receptive partner. Previous studies have shown that semen induces an acute inflammatory response at the female genital mucosa after coitus. Moreover, it induces regulatory mechanisms that allow the fetus (a semiallograft) to grow and develop in the uterus. The mechanisms underlying these regulatory mechanisms, however, are poorly understood. In this study, we show that seminal plasma redirects the differentiation of human dendritic cells (DCs) toward a regulatory profile. DCs differentiated from human monocytes in the presence of high dilutions of seminal plasma did not express CD1a but showed high levels of CD14. They were unable to develop a fully mature phenotype in response to LPS, TNF-α, CD40L, Pam2CSK4 (TLR2/6 agonist), or Pam3CSK4 (TLR1/2 agonist). Upon activation, they produced low amounts of the inflammatory cytokines IL-12p70, IL-1β, TNF-α, and IL-6, but expressed a high ability to produce IL-10 and TGF-β. Inhibition of the PG receptors E-prostanoid receptors 2 and 4 prevented the tolerogenic effect induced by seminal plasma on the phenotype and function of DCs, suggesting that E-series PGs play a major role. By promoting a tolerogenic profile in DCs, seminal plasma might favor fertility, but might also compromise the capacity of the receptive partner to mount an effective immune response against sexually transmitted pathogens.
No preview · Article · Oct 2012 · The Journal of Immunology
[Show abstract][Hide abstract] ABSTRACT: SESSION TYPE: ILD PostersPRESENTED ON: Wednesday, October 24, 2012 at 01:30 PM - 02:30 PMPURPOSE: Recruitment of macrophages in BAL is associated to the development of inflammatory processes during the course of Interstitial Lung Diseases (ILD). However, the mechanisms responsible for macrophage recruitment are poorly defined. Hyaluronan (HA) is a glycosaminoglycan found at high concentrations in BAL from ILD patients. Hyaluronan can regulate different cell functions by interacting with different receptors, among them, CD44 and RHAAM. In the present study we analyzed whether HA was able to induce the chemotaxis of BAL macrophages from ILD patients and the involvement of CD44 and RHAAM in this response.METHODS: Alveolar macrophages were purified from BAL recovered from ILD patients (n=31) by adherence on plastic tissue culture dishes. Migration was measured using a transwell system, in which macrophages were seeded on the upper compartment chamber, and RPMI (diluent), HA (2 μg/mL) or BAL from ILD patients were added into the lower compartment chamber, either in the presence or absence of hialuronidase (5U/mL). To evaluate the role of CD44 and RHAAM in cell migration, macrophages were preincubated with saturating concentrations of specific blocking monoclonal antibodies, before the onset of the migration assay. The results were expressed as a migration index: migration of macrophages in response to HA or BAL/migration of macrophages toward culture medium.RESULTS: We found that both HA and BAL from ILD patients induced the migration of macrophages: migration index = 2.39 ± 0.12 and 2.64 ± 0.43, respectively (p<0.05). Of note, the presence of hialuronidase abrogated the migration response induced by BAL from ILD patients: % inhibition >95, n=4. Treatment of macrophages with antibodies directed to CD44, markedly decreased the migratory response induced by HA: 1,24 ± 0.08 vs 2.40 ± 0.12 for anti-CD44-treated vs untreated macrophages, respectively, p<0.05). Anti-RHAAM antibodies did not mediate any effect.CONCLUSIONS: BAL from patients with ILD induces the migration of macrophages through a mechanism strongly dependent on the presence of HA.CLINICAL IMPLICATIONS: CD44 could be a novel therapeutic target involved in the recruitment of inflammatory cells in the lung of ILD patientsDISCLOSURE: The following authors have nothing to disclose: Glenda Ernst, Carolina Jancic, Auteri Santiago, Fabían Caro, Fernando Galíndez, Jorge Geffner, Silvia Hajos, Pedro GrynblatNo Product/Research Disclosure InformationMaría Ferrer Hospital, Buenos Aires, Argentina.
[Show abstract][Hide abstract] ABSTRACT: SESSION TYPE: ILD - Bench to BedsidePRESENTED ON: Wednesday, October 24, 2012 at 02:45 PM - 04:15 PMPURPOSE: Interstitial lung diseases (ILD) are a heterogeneous group of illnesses characterized by variable degrees of fibrosis and an imbalance of pro-inflammatory cytokines. Hyaluronan (HA) is a glycosaminoglycan which plays an important role in certain inflammatory diseases. We previously reported a significant increase in HA levels in bronchoalveolar lavage (BAL) from ILD patients compared with healthy subjects. In vitro studies have shown that HA induces the expression of pro-inflammatory genes in alveolar macrophages. In the present study we quantified HA and cytokine levels in BAL and evaluated lung function parameters in ILD patients and control subjects.METHODS: Patient population: idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP: n=6); non-specific interstitial pneumonia (NSIP: n=4); sarcoidosis (n= 6); hypersensitivity pneumonitis (HP: n=12) and pulmonary Langerhans cell histiocytosis (Hx: n=3). Controls were individuals with healthy lungs (n=13). Cytokine and HA levels in BAL samples were determined by enzyme immunoassay. Pulmonary function tests included lung diffusing capacity for carbon monoxide (DLCO) and alveolar volume (VA).RESULTS: We found a significant increase of HA levels in BAL from patients with NSIP (2.057,00 ± 419,90 ng/mL, p<0,01); HP (1.975,00 ± 199,30 ng/mL, p<0,001); Sarcoidosis (1.839,00 ± 47,90 ng/mL, p<0,01) and Hx (1.918,00 ± 404,20 ng/mL; p<0,05) compared with controls (623,50±48,10 ng/mL). However, there were not differences between IPF/UIP (961,90 ± 118,79 ng/mL) and the control group. When we analyzed the levels of proinflammatory cytokines (IL-1β, IL-6, TNF-α and IL-8) in BAL we observed no significant differences between ILD patients and control subjects. However, there was a correlation between IL-6 and HA levels in BAL (Spearman r = 0,57 and p<0,01). Moreover, we observed an inverse correlation between the concentrations of HA and lung functional parameters: patients with higher concentrations of HA had lower values of DLCO/VA (Spearman r = -0,28).CONCLUSIONS: Our results show a relationship between BAL HA levels and the severity of ILD.CLINICAL IMPLICATIONS: HA could be a marker of ILD progression.DISCLOSURE: The following authors have nothing to disclose: Glenda Ernst, Pedro Grynblat, Carolina Jancic, Auteri Santiago, Fernando Galíndez, Juan Carlos Moncalvo, Jorge Geffner, Silvia HajosNo Product/Research Disclosure InformationMaría Ferrer Hospital, Buenos Aires, Argentina.
[Show abstract][Hide abstract] ABSTRACT: SESSION TYPE: ILD PostersPRESENTED ON: Wednesday, October 24, 2012 at 01:30 PM - 02:30 PMPURPOSE: Idiopathic Pulmonary Alveolar Proteinosis (PAP) is a rare illness characterized by the accumulation of phospholipids, surfactants and a high cellularity in the alveolar space as well as by the presence of antibodies anti-GM-CSF in the patient serum. The aim of this study was to determine the levels of IL-8 in bronchoalveolar lavage fluid (BALF) from patients with PAP, patients with other Interstitial Lung Diseases (ILDs), and healthy subjects.METHODS: PAP was confirmed by lung biopsies. In 3 patients we detected by ELISA the presence of antibodies anti-GM-CSF working with serum samples diluted 1:750. IL-8 was determined by ELISA in BALF from 13 healthy subjects (to whom bronchoscopy was performed as follow up for post-intubation tracheal stenosis surgery), BALF from 31 patients with ILDs with histopathology confirmation (idiopathic pulmonary fibrosis/usual interstitial pneumonia (IPF/UIP: n=6); non-specific interstitial pneumonia (NSIP: n; =4); hypersensitivity pneumonitis (HP: n=12), sarcoidosis (n= 6); pulmonary Langerhans cell histiocytosis (Hx: n=3), and BALF from 4 patients with PAP.RESULTS: We found a significant increase in IL-8 levels in BALF from patients with PAP compared with either healthy subjects (769.9 ± 133.2 vs 64.9 ± 28.5 pg/mL; p<0.05), or ILD patients (UIP/FPI: 111.0 ± 33.0 pg/mL; NSIP: 68.6 ± 23.3 pg/mL; HP: 59.3 ± 20.8 pg/mL; sarcoidosis: 112.6 ± 77.65 pg/mL and Hx: 93.7 ± 48.3 pg/mL, p<0.05). By contrast, we found no differences among the different groups in the BALF levels of the proinflammatory cytokines IL-1β, IL-6 and TNF-α.CONCLUSIONS: We found that IL-8 levels in BALF from patients with PAP are significantly increased compared with healthy subjects and patients with others ILD.CLINICAL IMPLICATIONS: The presence of elevated levels of IL-8 may contribute to the recruitment of inflammatory cells observed in PAP.DISCLOSURE: The following authors have nothing to disclose: Glenda Ernst, Carolina Jancic, Fabían Caro, Patricia Vujacich, Gabriela Tabaj, Artemio Garcia, Silvia Hajos, Jorge Geffner, Pedro GrynblatNo Product/Research Disclosure InformationMaría Ferrer Hospital, Buenos Aires, Argentina.