The value of bronchoalveolar lavage for discrimination between healthy and diseased individuals.

BACKGROUND: Bronchoalveolar lavage (BAL) is standard diagnostic procedure. Procedural recommendations have been made by pneumological societies including normal values for interpretation of BAL cytology. These normal values derive from small studies in healthy volunteers and have never been analysed for their sensitivity and specificity. OBJECTIVES: This study aims to analyse sensitivity and specificity of these normal values by assessing lavage cell composition in healthy and diseased individuals. METHODS: More than 6000 BAL were retrospectively analysed for their cellular distribution including BALs of 250 healthy individuals. All BALs were obtained under similar conditions. RESULTS: Bronchoalveolar lavage cytology of healthy individuals mirrors data from previous studies with smoking being the most important manipulator of BAL cytology. Analyses of proposed normal values demonstrate specificity between 80% and 95%, whereas sensitivity ranges between 35% and 65%. Using different mathematical models, a value summing up the differences to ATS-proposed normal values of the cytological pattern was found to best discriminate between healthy and diseased individuals with a sensitivity of nearly 60% with a predefined specificity of 95%. CONCLUSION: In summary, our analysis confirmed prior results for healthy volunteers and enlarged these findings by analysing sensitivity and specificity of lavage results in an independent validation cohort of diseased individuals. Thereby, the study may influence the acceptance of BAL in the diagnostic workup of individuals with pulmonary diseases. Additionally, the study proposes a novel value that facilitates lavage interpretation and may therefore be useful in further studies.

[New Pathogenetic Concepts and Early Pharmacological Studies in Sarcoidosis]. / Neue pathogenetische Konzepte und frühe pharmakologische Studien bei der Sarkoidose.

The etiology of sarcoidosis is still elusive, yet there has been considerable progress in various areas of basic and clinical research. This review focuses on mechanisms of granuloma formation and on new findings in autoimmunity and genetics of sarcoidosis. A new promising concept arose, where serum amyloid A and/or mycobacterial antigens serve as nidus for granuloma formation. Furthermore, autoimmunity in sarcoidosis was neglected for a long time, yet new studies found autoantigens and abnormalities in antigen presentation in sarcoidosis. Last but not least, large genome-wide association studies discovered several new predisposing genes, leading to new hypotheses on pathomechanisms of sarcoidosis.In the second part, we focus on ongoing or recently completed clinical-pharmacological studies in patients with sarcoidosis: Positive studies were published in well characterized and homogenous subcohorts of sarcoid patients. Several drugs have shown a positive effect on sarcoidosis-associated fatigue, on sarcoidosis of the skin and on pulmonary hypertension in sarcoid patients. It seems that the generation of clinically closely defined subcohorts is necessary to achieve positive outcomes in studies on sarcoidosis.

[Genetic risk profile of sarcoidosis]. / Genetisches Risikoprofil der Sarkoidose.

Sarcoidosis is a multifactorial and polygenic disorder. The current knowledge of its genetic basis will be presented and functional consequences of the genetic variants that influence the immunopathogenesis of this disorder will be depicted. In the near future it is expected that this knowledge will yield clinically applicable genetic risk profiles.

Generation and evaluation of a monoclonal antibody, designated MAdL, as a new specific marker for adenocarcinomas of the lung.

BACKGROUND: Different therapy regimens in non-small-cell lung cancer (NSCLC) are of rising clinical importance, and therefore a clear-cut subdifferentiation is mandatory. The common immunohistochemical markers available today are well applicable for subdifferentiation, but a fraction of indistinct cases still remains, demanding upgrades of the panel by new markers. METHODS: We report here the generation and evaluation of a new monoclonal antibody carrying the MAdL designation, which was raised against primary isolated human alveolar epithelial cells type 2. RESULTS: Upon screening, one clone (MAdL) was identified as a marker for alveolar epithelial cell type II, alveolar macrophages and adenocarcinomas of the lung. In a large-scale study, this antibody, with an optimised staining procedure for formalin-fixed tissues, was then evaluated together with the established markers thyroid transcription factor-1, surfactant protein-A, pro-surfactant protein-B and napsin A in a series of 362 lung cancer specimens. The MAdL displays a high specificity (>99%) for adenocarcinomas of the lung, together with a sensitivity of 76.5%, and is capable of delivering independent additional diagnostic information to the established markers. CONCLUSION: We conclude that MAdL is a new specific marker for adenocarcinomas of the lung, which helps to clarify subdifferentiation in a considerable portion of NSCLCs.

Local administration of uridine suppresses the cardinal features of asthmatic airway inflammation.

BACKGROUND: The immuno-modulatory properties of nucleotides such as adenosine or inosine, have been described extensively. Recently, the nucleoside uridine and its analogue 4-thiouridine have gained attention for their protective role in acute lung inflammation. OBJECTIVE: In this study, we investigated the influence of uridine on asthmatic airway inflammation. METHODS: We used the classical ovalbumin (OVA)-alum model, as well as a model of house dust mite-(HDM)-induced airway inflammation. The degree of inflammation was determined by bronchoalveolar lavage (BAL), histology, and measurement of bronchial hyperresponsiveness. RESULTS: Intratracheal treatment of OVA-sensitized animals with uridine before allergen challenge resulted in a reduction in total BAL cells and BAL eosinophils. This was accompanied by reduced tissue infiltration and diminished production of T helper type 2-cytokines by mediastinal lymph node cells. Additionally, mice treated with uridine developed less bronchial hyperresponsiveness. Uridine was also effective in reducing airway inflammation in HDM-induced asthma. The protective effects of uridine were independent of myeloid dendritic cell (mDC) function, because in vitro pre-treatment of allergen-pulsed DCs with uridine did not alter the degree of inflammation. However, uridine inhibited the release of pro-inflammatory mediators in vivo and by cultured lung epithelial cells, suggesting an effect on lung structural cells. CONCLUSION: In summary, we were able to show that uridine inhibits the classical features of asthmatic airway inflammation. As uridine supplementation is well tolerated in humans, it might be a new therapeutic approach for the treatment of bronchial asthma.

[Genetics of sarcoidosis: a key to understanding its pathogenesis]. / Genetik der Sarkoidose: Ein Schlüssel zum Verständnis ihrer Pathogenese.

Sarcoidosis is a multifactorial and polygenic disorder. The current knowledge of its genetics will be presented and discussed in the context of other granulomatous disorders of known and unknown aetiology. The differing and common features of these disorders lead to the perspective that in near future it will be possible to establish genotype-phenotype correlations which will predict the course and therapy response in an individual case.

Gene polymorphisms of ACE and the angiotensin receptor AT2R1 influence serum ACE levels in sarcoidosis.

Angiotensin converting enzyme (ACE) is thought to influence susceptibility, disease progression, and/or outcome of sarcoidosis by functional mutations/polymorphisms of the ACE gene, such as the ACE gene deletion/insertion (D/I) polymorphism or the angiotensin receptors like the angiotensin II receptor type 1 (AT2R1) A1166 --> C polymorphism. The aim of our study was to examine the distribution of the ACE D/I genotypes and the AT2R1 A1166 --> C genotypes in sarcoidosis and healthy controls, and to test their influence on disease progression. In this study, we assessed ACE and AT2R1 genotypes by PCR in 264 healthy Caucasians and 95 sarcoidosis patients. Serum ACE levels were determined using a kinetic test. Genotyping sarcoidosis patients for the AT2R1 A166 --> C polymorphism revealed an increase in homozygous genotypes CC (sarcoidosis: 11.6%, controls: 9.2%) and AA (sarcoidosis: 61.1%, controls: 47.3%) but a lower frequency in heterozygous genotypes (sarcoidosis: 27,4%, controls: 43,5%; p = 0.024) which was more pronounced in male patients. The co-incidence of DI and AC was less frequent in patients with sarcoidosis, suggesting protection by the combination of DI and AC. The AT2R1 A1166 --> C gene polymorphism modulated the effect of the ACE D/I polymorphism on serum ACE levels with the A allele promoting its influence and the C allele reducing it. We conclude that neither the ACE D/I nor the AT2R1 A1166 --> C polymorphism has a role in sarcoidosis disease progression. In males, the homozygous AT2R1 genotypes CC and AA possibly increase the risk for sarcoidosis. Co-incidence of the heterozygous genotypes DI and AC might be protective against sarcoidosis.

Interleukin-13 acts as an apoptotic effector on lung epithelial cells and induces pro-fibrotic gene expression in lung fibroblasts.

BACKGROUND: IL-13 promotes acute allergic asthma and is discussed to play a role in late asthmatic features such as fibrotic processes and airway remodelling. The contributions of IL-13-mediated mechanisms to subepithelial events related to fibrosis are not yet settled. OBJECTIVE: We investigated the impact of IL-13 on lung epithelial cells as apoptotic effector and on lung fibroblasts as inducer of pro-fibrotic gene expression. METHODS: Using the two lung epithelial cell lines A549 and BEAS-2B as well as primary lung epithelial cells, we investigated the capability of IL-13 to induce apoptosis by both flow-cytometry and ELISA. The ability of IL-13 to increase the expression of pro-fibrotic genes and to exert influence on the expression of its own receptor was investigated by real-time quantitative PCR measurement of mRNAs encoding collagen I, collagen III, basic fibroblast growth factor (bFGF), alpha-smooth muscle actin (alpha-SMA) and the IL-13 receptor alpha1 (IL-13Ralpha1) chain in human primary lung fibroblasts. The specificity of IL-13-mediated cellular responses was confirmed by means of an inhibitory monoclonal antibody directed to the IL-13 receptor. RESULTS: IL-13 induces apoptosis in lung epithelial cell lines as well as in primary lung epithelial cells. Furthermore, IL-13 increases the expression of mRNA for alpha-SMA and collagen III, but not for bFGF in human primary lung fibroblasts. The susceptibility of lung fibroblasts to IL-13-induced up-regulation of pro-fibrotic genes is associated with the regulation of IL-13 receptor expression. IL-13-dependent fibrosis-associated effects could be inhibited by antibody-mediated blockade of the IL-13Ralpha1 subunit. CONCLUSION: Our findings indicate a function of IL-13 as a mediator in fibrotic processes leading to loss of functional airway tissue in asthma. They also highlight the therapeutic potential of specifically targeting the interaction between IL-13 and its receptor.

Inhibition of PDGF, VEGF and FGF signalling attenuates fibrosis.

BIBF 1000 is a small molecule inhibitor targeting the receptor kinases of platelet-derived growth factor (PDGF), basic fibroblast growth factor and vascular endothelial growth factor, which have known roles in the pathogenesis of pulmonary fibrosis. The anti-fibrotic potential of BIBF 1000 was determined in a rat model of bleomycin-induced lung fibrosis and in an ex vivo fibroblast differentiation assay. Rats exposed to a single intra-tracheal injection of bleomycin were treated with BIBF 1000 starting 10 days after bleomycin administration. To gauge for anti-fibrotic activity, collagen deposition and pro-fibrotic growth factor gene expression was analysed in isolated lungs. Furthermore, the activity of BIBF 1000 was compared with imatinib mesylate (combined PDGF receptor, c-kit and c-abl kinase inhibitor) and SB-431542 (transforming growth factor (TGF)-beta receptor I kinase inhibitor) in an ex vivo TGF-beta-driven fibroblast to myofibroblast differentiation assay, performed in primary human bronchial fibroblasts. Treatment of rats with BIBF 1000 resulted in the attenuation of fibrosis as assessed by the reduction of collagen deposition and the inhibition of pro-fibrotic gene expression. In the cellular assay both SB-431542 and BIBF 1000 showed dose-dependent inhibition of TGF-beta-induced differentiation, whereas imatinib mesylate was inactive. BIBF 1000, or related small molecules with a similar kinase inhibition profile, may represent a novel therapeutic approach for the treatment of idiopathic pulmonary fibrosis.

[Chronic berylliosis]. / Chronische Berylliose.

Chronic Berylliosis (CB) is an occupational disorder which needs to be considered in the diagnostic work-up of granulomatous pulmonary diseases. Germany imports increasing amounts of beryllium which causes increased occupational exposure and this fact suggests that CB is underdiagnosed. Since CB is a perfect phenocopy of sarcoidosis, it is assumed that many cases are hidden in the cohort of sarcoidosis patients. This review presents the epidemiology, pathogenesis, diagnostics, and therapy of CB.

Genotype-corrected reference values for serum angiotensin-converting enzyme.

The deletion (D)/insertion (I) polymorphism in intron 16 of the angiotensin-converting enzyme (ACE) gene has the greatest impact on serum ACE level in Caucasians of any factor yet discovered. The aim of the present study was to establish new ACE genotype-corrected normal ranges for serum ACE level in a population of central European origin. After a medical examination, 159 healthy Caucasians volunteered to donate blood for the study. ACE genotypes were assessed by PCR and serum ACE levels were determined using two different kinetic tests. The distribution of the D/I polymorphism of the ACE gene was in accordance with the Hardy-Weinberg equilibrium. Serum ACE levels and ACE genotypes correlated significantly, with the highest serum ACE levels in subjects with ACE genotype D/D, and the lowest serum ACE levels in subjects with genotype I/I (mean+/-sd, assay 1: D/D 59.3+/-15.1 U x L(-1), D/I 45.5+/-15.2 U x L(-1), I/I 34.8+/-13.7 U x L(-1); assay 2: D/D 43.7+/-14.1 U x L(-1), D/I 33.7+/-12.1 U x L(-1), I/I 25.4+/-9.5 U x L(-1)). Although they gave different absolute values of serum ACE levels, the results of the two test kits correlated significantly. In conclusion, the present authors recommend the use of new, genotype-specific reference values for serum angiotensin-converting enzyme levels, especially to improve the sensitivity and specificity of tests for angiotensin-converting enzyme in the follow-up of sarcoidosis.

Diagnoses of chronic beryllium disease within cohorts of sarcoidosis patients.

An increase in chronic beryllium disease (CBD) has been suggested due to higher industrial use of beryllium alloys. Since occupational CBD is a perfect phenocopy of sarcoidosis, it might be misdiagnosed as sarcoidosis. In the current it was hypothesised that CBD exists in cohorts of sarcoidosis patients. In a prospective case study, sarcoidosis patients were evaluated for potential beryllium exposure. In those patients in whom beryllium exposure was confirmed and beryllium hypersensitivity demonstrated, the diagnosis of sarcoidosis was rejected and corrected to CBD. In 84 patients seen for re-evaluation or making a diagnosis of sarcoidosis, beryllium exposure was recognised and a diagnosis of CBD was made in 34 out of 84 patients. The time lag between clinical diagnosis of sarcoidosis and the final diagnosis of CBD ranged 0-18 yrs (median 3 yrs) and the mean (range) age at time of diagnosis of CBD was 43.9(25-80) yrs. Beryllium-contaminated workplaces causing disease encompassed a wide spectrum of industries and technical trades in which beryllium-exposure is generally not perceived as a health hazard. In conclusion, chronic beryllium disease still belongs to the spectrum of differential diagnoses of granulomatous disorders.

HOPE-fixation enables improved PCR-based detection and differentiation of Mycobacterium tuberculosis complex in paraffin-embedded tissues.

Standard PCR-based detection of mycobacterial DNA in paraffin-embedded specimens may lack sufficient sensitivity because of the degradation of nucleic acids caused by routinely used formalin fixation. Therefore, we set up an approach that aimed at improving the results by applying the novel HOPE-fixative in PCR-detection of mycobacteria in paraffin-embedded tissues. Comparison of PCR-results using DNA extracted from either HOPE- or formalin-fixed specimens in BCG-infected SCID-mice revealed a more than 100fold enhanced sensitivity for the HOPE-fixed material. Owing to the preservation of DNA from degradation in HOPE-fixed tissues, even differentiation within the M. tuberculosis complex was possible by spoligotyping. We therefore conclude that the HOPE-fixative is a useful tool for molecular pathology that enhances the sensitivity of PCR-based methods for the detection of pathogens in paraffin-embedded tissues compared to formalin-fixation. Owing to the better preserved DNA, improved differentiation of mycobacteria from archived materials is possible. These results promise new and a substantially wider range of possibilities in the field of molecular pathology.

Alveolar macrophages are the main source for tumour necrosis factor-alpha in patients with sarcoidosis.

Tumour necrosis factor (TNF)-alpha is known to play a major role in the formation of noncaseating granuloma, a hallmark of sarcoidosis. The main cellular source in situ is still ambiguous. Serial sections of transbronchial biopsies from 14 patients with and 12 without sarcoidosis were studied, using immunohistochemistry (IHC), for TNF-alpha, T-cells (CD3), macrophages (CD68), and epithelial cells (MNF116). TNF-alpha spontaneously released (sr-TNF-alpha) by freshly isolated bronchoalveolar lavage cells, isolated from the same patients and cultured without any stimulus over a 24-h period was measured using an enzyme-linked immunosorbent assay. IHC revealed colocalisation of TNF-alpha with CD68 cells only. Cases with TNF-alpha tissue immunoreactivity exhibited higher sr-TNF-alpha (1,667 +/- 504 pg x mL(-1)) than cases without tissue immunoreactivity (211 +/- 60 pg x mL(-1)). In an explorative approach, a subgroup of patients could be identified and characterised by the presence of alveolar macrophage aggregates. It was found that sr-TNF-alpha was highest in this subgroup (2,700 +/- 769 pg x mL(-1)) compared with patients with normal histology (221 +/- 61 pg x mL(-1)) or with prominent granuloma (460 +/- 137 pg x mL(-1)), whereas in most clinical parameters this subgroup was intermediate. The findings from this study strongly corroborate the view that alveolar macrophages are the main cellular source for tumour necrosis factor-alpha in the initial phase of sarcoidosis. The authors suggest that in these patients, aggregates of alveolar macrophages may represent at least predecessors to granulomas if not granulomas in statu nascendi.

Human alveolar epithelial cells induce nitric oxide synthase-2 expression in alveolar macrophages.

It was hypothesized that cell-to-cell interaction between human alveolar macrophages (AM) and alveolar epithelium, might be an important factor leading to nitric oxide synthase-2 (NOS2) messenger ribonucleic acid (mRNA) and protein expression by constituent cells of the alveolar wall and/or AM. NOS2 mRNA and the protein expression patterns of human AM and alveolar epithelial cells type II (AEC-II) isolated from normal parts of lung resections of patients with pulmonary malignancies were determined. In addition, NOS2 mRNA expression in human AM co-cultured with autologous AEC-II in the presence of pro-inflammatory cytokines interleukin (IL)-1beta, tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma or lipopolysaccharide (LPS) was investigated. The effect of human surfactant protein-A (SP-A) on IFN-gamma-mediated NOS2 mRNA expression in human AM was also studied. Neither NOS2 mRNA nor protein could be detected in freshly isolated, unstimulated or cytokine-stimulated AEC-II. In contrast, freshly isolated AM from bronchoalveolar lavage or lung tissue samples expressed immunoreactivity for NOS2 protein, but no NOS2 mRNA could be detected by reverse transcriptase polymerase chain reaction. All stimuli tested failed to induce NOS2 mRNA expression in human AM in vitro. Only AM-AEC-II co-culture in the presence of IFN-gamma led to NOS2 mRNA and protein expression. In situ hybridization of NOS2 mRNA on lung tissue explants and immunohistochemical staining of cytospin preparations of AM-AEC-II co-cultures demonstrated that NOS2 is expressed in AM but not in AEC-II. This co-culture effect could not be reproduced by substitution of AEC-II with SP-A. These data give evidence of a regulatory network controlling human nitric oxide synthase-2 expression in the lower respiratory tract.

Assessment of transcriptional gene activity in situ by application of HOPE-fixed, paraffin-embedded tissues.

We report the use of HOPE-fixation (HOPE = Hepes-Glutamic acid buffer mediated Organic solvent Protection Effect) for specimens utilized for in situ hybridization targeting mRNA. For this purpose, an optimized protocol was developed and repeatedly tested on HOPE-fixed lung specimens. We observed that neither pretreatment, permeabilizing the cells, nor prehybridization is necessary to generate signals. After deparaffinizing, the random primed digoxigenin-labeled probes are directly hybridized together with yeast tRNA for blocking unspecific signals. Detection was performed using anti digoxigenin antibodies conjugated with alkaline phosphatase and new-fuchsine or NBT/BCIP as substrates. The results were verified by RT-PCR and adequate negative controls. Signals for human surfactant protein-A and interferon-gamma-inducible protein-10 developed rapidly within 10 min, accompanied by high signal intensities comparable to those observed in immunohistochemistry. Signal enhancement by biotinyl-tyramide, although giving suitable results as well, did not lead to higher signal intensities, and thus was not necessary in conjunction with the probes tested so far. These experiments were performed with material stored under appropriate conditions (at +4 degrees C) up to five years. To sum up, these initial results, obtained with the novel HOPE-fixative, are promising as regards the enhancement of the capabilities of in situ hybridization in the future.

Pattern of NOS2 and NOS3 mRNA expression in human A549 cells and primary cultured AEC II.

The human alveolar type II epithelium-like cell line A549 expresses nitric oxide synthase type 2 (NOS2), but not NOS3, and produces nitric oxide (NO) upon appropriate stimulation. However, relatively little is known regarding the NOS2 and NOS3 expression of type II human alveolar epithelial cells (AEC II) in primary culture. We detected NOS3 mRNA in freshly isolated AEC II and after 24 h of culture. NOS3 mRNA levels were much higher in AEC II cultured for 24 h with or without interferon-gamma, interleukin-1beta, and tumor necrosis factor-alpha, compared with freshly isolated cells. Cytokine stimulation did not change the NOS3 mRNA expression level in AEC II compared with unstimulated cells. NOS3 protein expression was verified by Western blot, and measuring nitrate/nitrite revealed that the protein is active. In contrast, neither NOS2 mRNA nor protein could be detected in freshly isolated, unstimulated or cytokine-stimulated human AEC II in 24- or 72-h primary cultures, whereas A549 cells expressed NOS2 message and protein upon stimulation with proinflammatory cytokines. In situ hybridization confirmed that AEC II express NOS3, but not NOS2 mRNA in vivo. These data demonstrate that there are significant differences between primary AEC II and A549 cells in NOS mRNA expression pattern.

Analysis of gene polymorphisms in interleukin-10 and transforming growth factor-beta 1 in sarcoidosis.

BACKGROUND AND AIM OF WORK: Interleukin-10 (IL-10) and transforming growth factor-beta 1 (TGF-beta 1) are anti-inflammatory cytokines that play important roles in the immunoregulatory processes of numerous granulomatous diseases. In sarcoidosis polymorphisms (PMs) within these cytokine genes are suspected of modifing the course of the disorder. Therefore, we were interested in whether the genotype frequencies for a PM at position -1082 of the IL-10 or in codon 25 of the TGF-beta 1 gene differ in sarcoidosis or its distinct phenotypes in comparison with healthy individuals. METHODS: In 51 sarcoidosis patients and 72 healthy blood donors, genotyping for the named PMs was performed by PCR methodology and restriction enzyme digestion. Patients were retrospectively classified according to their course of disease, namely spontaneous remission, regressive under therapy, or chronic-progressive. RESULTS: For TGF-beta 1 PM the genotype frequencies ranged between 81.8-90.5, 9.6-13.9 and 0-5.3 percent for genotype GG, CG and CC respectively. For IL-10 PM the values ranged between 17.7-23.2, 54.4-68.4 and 21.1-26.4 percent for AA, AG and GG. Statistical comparisons of the allele and genotype frequencies between the clinical defined sarcoidosis groups and the healthy blood donors revealed no significant differences.

Effect of proinflammatory cytokines on interleukin-8 mRNA expression and protein production by isolated human alveolar epithelial cells type II in primary culture.

Alveolar epithelial cells type II (AEC-II) are ideally situated to regulate the recruitment and activation of different types of cells through the production of chemokines in response to inflammatory stimulation from the alveolar space. We hypothesized that these cells are important producers of interleukin-8 (IL-8) in the lung. This lead us to investigate the capacity of isolated human AEC-II cells to release IL-8 and whether this IL-8 release is regulated by proinflammatory cytokines, i.e. IL-1 beta, TNF-alpha and IFN-gamma. We isolated AEC-II from tumor-free sections of human lungs obtained by pneumectomy and purified the cells by magnetic activated cell sorting. For control experiments the AEC-II-like cell line A549 was used. IL-8 concentration was measured by ELISA in supernatants of unstimulated and LPS-, IL-1 beta-, TNF-alpha- and IFN-gamma- stimulated cells. IL-8 mRNA expression was evaluated by RT-PCR. Spontaneous IL-8 mRNA expression and protein secretion by AEC-II were significantly higher in comparison with A549 cells. TNF-alpha increased both IL-8 mRNA expression and protein production, whereas IL-1 beta slightly increased IL-8 release but did not change mRNA expression in AEC-II. LPS and IFN-gamma did not influence IL-8 expression in AEC-II and A549 cells. These results show considerable differences between A549 cell and AEC-II. The latter are capable of producing IL-8 under the control of proinflammatory cytokines. Our findings demonstrate that the modulation of IL-8 release in AEC-II may have an important impact on the immunoreactivity of these cells during pulmonary inflammation in vivo.