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C oncern about the use of nanomaterials has increased signifi cantly in recent years due to potentially hazardous impacts on human health. Mast cells are critical for innate and adaptive immune responses, often modulating allergic and pathogenic conditions. Mast cells are well known to act in response to danger signals through a variety of receptors and pathways including IL-33 and the IL-1-like receptor ST2. Here, the involvement of mast cells and the IL-33/ST2 axis in pulmonary and cardiovascular responses to multi-walled carbon nanotube (MWCNT) exposure are examined. Toxicological effects of MWCNTs are observed only in mice with a suffi cient population of mast cells and are not observed when mast cells are absent or incapable of responding to IL-33. Our fi ndings establish for the fi rst time that mast cells and the IL-33/ST2 axis orchestrates adverse pulmonary and cardiovascular responses to an engineered nanomaterial, giving insight into a previously unknown mechanism of toxicity. This novel mechanism of toxicity could be used for assessing the safety of engineered nanomaterials and provides a realistic therapeutic target for potential nanoparticle induced toxicities.

Chronic obstructive pulmonary diseases (COPD) may increase air pollution-related mortality. The relationship of immune mechanisms to mortality caused by fine particulates in healthy and COPD populations is incompletely understood. The objective of this study was to determine whether fine particulates from a single biomass fuel alter stress and inflammation biomarkers in people with COPD. Healthy and COPD subjects were exposed to smoke in a controlled indoor setting. Immune responses were quantified by measuring cell surface marker expression with flow-cytometric analysis and mRNA levels with quantitative reverse transcriptase-polymerase chain reactions in whole blood before and after exposure. Preexposure COPD subjects had more leukocytes, mainly CD14(+) monocytes and neutrophils, but fewer CD3(+) T cells. Fifty-seven of 186 genes were differentially expressed between healthy and COPD subjects' peripheral blood mononuclear cells (PBMCs). Of these, only nuclear factor (NF)-kappa B1, TIMP-1, TIMP-2, and Duffy genes were up-regulated in COPD subjects. At 4 hours post smoke exposure, monocyte levels decreased only in healthy subjects. Fifteen genes, particular to inflammation, immune response, and cell-to-cell signaling, were differentially expressed in COPD subjects, versus 4 genes in healthy subjects. The authors observed significant differences in subjects' PBMCs, which may elucidate the adverse effects of air pollution particulates on people with COPD.

The clinical manifestations and pathophysiology of allergic airways diseases result from complex responses of the innate and acquired immune systems to environmental stimuli leading to structural and functional changes in the neural networks, smooth muscle, connective tissue, circulation, and epithelium in the airway wall. Allergic airways diseases are common, and the impacts on health range from minor discomfort to debilitating and life-threatening airway obstruction. Many of the cells, transmitters, cytokines, and receptors involved in the responses to inhaled allergens have been identified, but integration of these components is not fully understood, particularly outside of the laboratory and clinic where diverse intrinsic and extrinsic factors can affect the responses. The intent in this chapter is to review the information that has accrued up to this point in time and equip the reader to interpret future discoveries in the context of previous findings. The pathophysiology of allergic lung disease is described, complexities of the cellular and cytokine networks are explored, and intrinsic and extrinsic factors that impact these mechanisms are identified. Animal models, particularly murine models of asthma and genetically-modified mouse strains, have contributed significantly to understanding of allergic diseases and immune mechanisms, and strengths and weaknesses of these models that have contributed to knowledge in this area are discussed.

The causal role of immunoglobulin E (IgE) in triggering the cascade of biochemical events leading to allergic disease is well established. Treatments that selectively inhibit IgE activity are a logical approach in managing the allergic response. One such strategy utilizes rhuMAb-E25, a recombinant humanized IgG 1 monoclonal anti-IgE antibody, which binds to IgE. This anti-IgE antibody binds at the same epitope site of IgE that binds to FceRI and is thus non-anaphylactogenic. By binding to IgE and removing it via immune complex formation, the pool of IgE available to interact with mast cells and basophils is thereby reduced and the allergic response is attenuated. The clinical safety and efficacy of rhuMAb-E25 demonstrated in phase II studies of allergic asthma will be outlined.

Study objective To study the safety and efficacy of aerosolized recombinant human DNase I in the treatment of idiopathic bronchiectasis. Design Double-blind, randomized, placebo-controlled, multicenter study. Populations Three hundred forty-nine adult outpatients in stable condition with idiopathic bronchiectasis from 23 centers in North America, Great Britain, and Ireland. Interventions and measurements Study patients received aerosolized rhDNase or placebo twice daily for 24 weeks. Primary end points were incidence of pulmonary exacerbations and mean percent change in FEV1 from baseline over the treatment period. Results Pulmonary exacerbations were more frequent and FEV1 decline was greater in patients who received rhDNase compared with placebo during this 24-week trial. Conclusions rhDNase was ineffective and potentially harmful in this group of adult outpatients in stable condition with idiopathic bronchiectasis. This contrasts with previously published results that demonstrated efficacy of rhDNase in patients with cystic fibrosis bronchiectasis.

Inhaled allergens, acting through IgE-dependent mechanisms, are important triggers of asthma symptoms and inducers of airway hyperresponsiveness and airway inflammation. The effect of anti-IgE recombinant humanized monoclonal antibody-E25 (rhuMAb-E25) on the provocation concentration of allergen causing a 15% fall in FEV1 (allergen PC15) during the allergen-induced early asthmatic response (EAR) was assessed in a multicenter, randomized, double-blind, parallel group study. Ten of 11 allergic asthmatic subjects randomized to receive intravenous rhuMAb-E25, 2 mg/kg on study day 0 and 1 mg/kg on Days 7, 14, 28, 42, 56, and 70 completed the study; nine received intravenous placebo. The allergen PC15 was measured on Days -1, 27, 55, and 77 and methacholine PC20 on Days -2, 42, and 76. rhuMAb-25 was well tolerated and only one patient (active group) was withdrawn because of a generalized urticarial rash after the first dose. Compared with baseline values (Day -1), the median allergen PC15 on Days 27, 55, and 77...

Background Biomarkers facilitate early detection of disease and measurement of therapeutic efficacy, both at clinical and experimental levels. Recent advances in analytics and disease models allow comprehensive screening for biomarkers in complex diseases, such as asthma, that was previously not feasible. Objective Using murine and nonhuman primate (NHP) models of asthma, identify biomarkers associated with early and chronic stages of asthma and responses to steroid treatment. Methods The total protein content from thymic stromal lymphopoietin transgenic (TSLP Tg) mouse BAL fluid was ascertained by shotgun proteomics analysis. A subset of these potential markers was further analyzed in BAL fluid, BAL cell mRNA, and lung tissue mRNA during the stages of asthma and following corticosteroid treatment. Validation was conducted in murine and NHP models of allergic asthma. Results Over 40 proteins were increased in the BAL fluid of TSLP Tg mice that were also detected by qRT-PCR in lung tissue and BAL cells, as well as in OVA-sensitive mice and house dust mite-sensitive NHP. Previously undescribed as asthma biomarkers, KLK1, Reg3γ, ITLN2, and LTF were modulated in asthmatic mice, and Clca3, Chi3l4 (YM2), and Ear11 were the first lung biomarkers to increase during disease and the last biomarkers to decline in response to therapy. In contrast, GP-39, LCN2, sICAM-1, YM1, Epx, Mmp12, and Klk1 were good indicators of early therapeutic intervention. In NHP, AMCase, sICAM-1, CLCA1, and GP-39 were reduced upon treatment with corticosteroids. Conclusions and clinical relevance These results significantly advance our understanding of the biomarkers present in various tissue compartments in animal models of asthma, including those induced early during asthma and modulated with therapeutic intervention, and show that BAL cells (or their surrogate, induced sputum cells) are a viable choice for biomarker examination.

Idiopathic interstitial pneumonias are a group of idiopathic interstitial lung diseases of which idiopathic pulmonary fibrosis (IPF) is the lesion of usual interstitial pneumonia. Although the pathogenic mechanisms remain incompletely understood, disease-specific changes in blood, a readily accessible biospecimen, have not been fully characterized. To identify biomarkers from blood and sera, the immune status of IPF patients and control subjects without structural lung disease was quantified by measuring cell surface markers, mRNA levels, and serum proteins. Statistically significant differences in cellular and molecular markers were observed between the 2 groups. The cytokine receptor IL-17RB was significantly higher in CD14+ peripheral blood mononuclear cells (PBMCs) from IPF patients, whereas expression of the chemokine receptor CXCR4 was lower. Gene expression analyses identified 18 differentially expressed genes out of 195 selected. Of these, EMR1, CCR3, UPAR, FCGR2A, OPN, CEACAM3, CD16a, CD18, CD11b, LTF, and LCN2 were up-regulated, whereas IL-17RB, IL-10, PDGFA, CD301/Clec10a, CD25/IL-2RA, IL-23p19, and IL-15 were down-regulated in IPF. Differentially regulated genes were in the functional areas of inflammation and cell signaling. Serum levels of UPAR and OPN were higher in IPF. These observations reveal significant differences in cell and molecular markers involved in monocyte/macrophage activation and migration, and suggest a role for IL-17RB in IPF.

The aim of the present study was to determine whether systemic sensitisation and chronic aeroallergen challenge in macaques replicate the classical and emerging immunology and molecular pathology of human asthma. Macaques were immunised and periodically challenged over 2 yrs with house dust mite allergen. At key time-points, serum, bronchoalveolar lavage (BAL) and bronchial biopsies were assayed for genes, proteins and lymphocyte subpopulations relevant to clinical asthma. Immunisation and periodic airway challenge induced changes in immunoglobulin E, airway physiology and eosinophilia consistent with chronic, dual-phase asthma. Sensitisation increased interleukin (IL)-1β and -6 concentrations in serum, and IL-13 expression in BAL cells. Airway challenge increased: early expression of IL-5, -6, -13 and -19, and eotaxin; and variable late-phase expression of IL-4, -5 and -13, and thymus- and activation-regulated chemokine in BAL cells. CD4+ lymphocytes comprised 30% of the CD3+ cells in BAL, increasing to 50% in the late phase. Natural killer T-cells represented

Background: Efalizumab is a humanized IgG 1 mAb against the lymphocyte function antigen-1 (LFA-1) alpha chain, CD11a. Blocking of LFA-1/intercellular adhesion molecule interactions could inhibit asthmatic inflammation by blocking adhesion and activation of LFA-1-positive leukocytes. Objective: A randomized, double-blinded, placebo-controlled, parallel group, multicenter study investigated the effects of efalizumab on allergen-induced airway responsiveness and airway inflammation. Methods: Thirty-five nonsmoking subjects with mild allergic asthma were randomized to receive efalizumab (n = 24) or placebo (n = 11) in 8 weekly subcutaneous doses (0.7 mg/kg conditioning dose followed by 7 weekly doses of 2.0 mg/kg). Allergen challenges were performed at screening and after 4 and 8 weeks of treatment. Samples of sputum (n = 18 subjects) and blood (n = 35 subjects) were collected the day before challenges, and sputum was collected again at 7 and 24 hours after each challenge. Nonparametric tests were used to compare allergen-induced differences between efalizumab and placebo groups. Results: Subjects receiving efalizumab developed headache (48%) and flu syndrome (28%) compared to subjects receiving placebo (0%). After 8 weeks of efalizumab, the maximum late percent fall in FEV 1 (late asthmatic response) was inhibited by 50%, but neither the late response nor the late area under the curve was statistically different than placebo ( P = .098 and .062, respectively). Efalizumab had no effect on the maximum early percent fall in FEV 1 (early asthmatic response) or early area under the curve compared to placebo ( P > .59). Efalizu-mab significantly reduced the postallergen increase in sputum EG2-positive cells and metachromatic cells ( P Conclusions: Blocking of LFA-1/intercellular adhesion module interactions by efalizumab inhibits the development of allergen-induced cellular inflammatory responses measured in induced sputum and might attenuate the late asthmatic response. Larger studies are needed to confirm this. (J Allergy Clin Immunol 2003;112:331-8.)

Introduction James D. Reimann, Sharon Safrin, and Robert B. Fick, Jr. Understanding the Binding of IgE to Its High-Affinity Receptor and to an Anti-IgE Antibody Leonard G. Presta and Robert L. Shields Mediator Release from Basophils and Mast Cells and Its Relationship to FceRI Expression and IgE-Suppressing Therapies Donald W. MacGlashan, Jr., John T. Schroeder, Lawrence M. Lichtenstein, Sarbjit S. Saini, and Bruce S. Bochner Expression of IgE Receptors on Eosinophils David Dombrowicz, Andre Capron, and Monique Capron Eosinophil IgE Receptors: Controversy and Consensus Hirohito Kita and Cheryl R. Adolphson Murine Models of Asthma: Caveats and Conclusions on the Contribution of IgE and Mast Cells to Allergic Inflammation, Airway Hyperresponsiveness, and Airflow Obstruction Jeffrey S. Tepper and Daniel B. Tumas Role of IgE in Asthma: Pathogenesis and Novel Therapeutic Strategies James Laurence Lordan, Stephen T. Holgate, and Ian Sayers IgE-Mediated Response to Allergen in the Bronchoprovocation Laboratory Louis-Philippe Boulet and Donald W. Cockcroft Pathophysiology of the Airway Response to Inhaled Allergen in Asthmatic Subjects: Role of IgE John V. Fahy Efficacy and Safety of Xolair Anti-IgE Monoclonal Antibody in Adult Asthmatics Robert B. Fick, Jr., and W. James Metzger The Role of IgE in Pediatric Asthma Henry Milgrom and Charles Johnson Anti-inflammatory Activities of Omalizumab (Xolair), a Recombinant Humanized Monoclonal Antibody Binding IgE Robert B. Fick, Jr. Pulmonary Delivery of Anti-IgE: Rationale for Topical Delivery to the Airway Theresa D. Sweeney, Melinda Marian, Jane Ruppel, and Jeanine L. Bussiere Treatment of Seasonal Allergic Rhinitis Thomas B. Casale and Patricia W. Rohane Anti-IgE and Allergic Skin Diseases Michael F. Hofer and Donald Y. M. Leung Role of IgE and Food Allergens Ricki M. Helm and A. Wesley Burks Role of IgE in Allergic Bronchopulmonary Aspergillosis Priscilla S. A. Sarinas and Rajinder K. Chitkara IgE and Its Role in Parasitic Helminth Infection: Implications for Anti-IgE-Based Therapies Philip J. Cooper and Thomas B. Nutman The Rise of Antibodies as Therapeutics Maureen P. Quan and Paul Carter Author Index

The history of effective attempts to understand, treat, and manage asthma may be condensed into the past 40 years. By the mid-1960s asthma was recognized to have a significant allergic component even though the precise triggers of the disease were poorly characterized. IgE was described in 1967 reports by Ishizaka et al. (1) and Johansson and coworkers (2). Antecedent work had already demonstrated a role in the disease for basophil leukocytes (3). At the beginning of the 1980s short-term cell culture experiments incriminated specific mediators and the underlying involvement of the immune system. It was reasoned that when cell-bound IgE on basophils or tissue mast cells is crosslinked by an antigen, the cell degranulates, releasing preformed and newly synthesized mediators of immediate hypersensitivity such as histamine, leukotrienes, and platelet-activating factor. It was postulated that these pro-inflammatory chemicals identified in biological fluids might be responsible for the swelling, erythema and smooth muscle contraction characteristic of the asthmatic reaction.

Monoclonal antibodies are potentially useful therapeutic agents in a variety of immunologically mediated diseases, since they offer the theoretical advantage of selectively targeting the mediators of the immuno–pathogenesis. It has been well established that IgE antibody synthesized by the immune system plays a pivotal role in the cascade of biochemical events leading to the allergic reaction. The aim of these studies was to eliminate IgE with a monoclonal antibody as the approach for treatment of atopic disease. To this end, a murine monoclonal antibody (MAE11) directed against IgE was identified which had all of the properties necessary to interfere with IgE responses. To avoid the problems of antigenicity associated with chronic administration of murine antibodies MAE11 was humanized. The best of several humanized variants, version 25 (rhuMAb–E25), was selected for clinical trials in allergic asthma and seasonal allergic rhinitis. In a series of phase I safety studies, rhuMAb–E25, by single or multidose administrations, was shown to be very well tolerated. Phase II studies were then designed to determine whether elimination of serum IgE, as a result of rhuMAb–E25 administration, had a significant impact on allergic symptoms. Results of these clinical trials establish the involvement of IgE in the pathophysiology of rhinitis and asthma and suggest a novel treatment for allergic disease.

Study objectives The peak inspiratory flow rates (PIFRs) generated by cystic fibrosis (CF) and COPD patients through a range of clinically relevant resistances have not yet been reported (to our knowledge). The objectives of this study were to (1) explore a relevant range of resistive loads and address whether patients with stable CF and COPD can generate the PIFR sufficient to disperse dry-powder inhalants (DPI) and (2) determine whether the optimal inspiratory flow rate effective for delivery of aerosolized pharmacologic therapeutic agents can be attained with a comfort rating acceptable to subjects. Design Prospective, controlled, subject-blinded study. Setting Pulmonary function laboratory at the VA Palo Alto Health Care System. Patients or participants Thirty-six subjects, including 12 healthy volunteers, 12 subjects with CF, and 12 subjects with COPD were studied. Measurements Studies of dynamic lung function and PIFR without and with varying resistances were obtained at a single laboratory visit. Results Dynamic lung function and PIFR varied inversely with the resistive load for all patient groups and did not correlate with the disease severity, as indicated by FEV1 of percent predicted. The average subjective comfort rating for any given resistive load was similar for subjects with CF and COPD. Conclusions These results support the conclusion that subjects with stable CF and COPD of varying severity can comfortably generate the necessary flow rates to operate new and currently available DPIs over a wide range of inspiratory resistances.

It has been shown that pulmonary macrophage (PM) phagocytosis of Pseudomonas aeruginosa (PA) is inhibited in the presence of serum from cystic fibrosis (CF) patients colonized by Pseudomonas, and that these sera contain high concentrations of IgG2 antibodies. The goal of these studies was to investigate the role that IgG2-containing immune complexes (IC) play in this inhibition of both PM and neutrophil phagocytosis. We found that serum IgG2 concentrations were elevated significantly in CF patients with chronic PA colonization and that in selected sera from CF patients with chronic PA colonization (CF + IC, n = 10), the mean IC level was significantly elevated (2.90 +/- 0.22 mg/dl [SEM]). IgG2 comprised 74.5% of IgG precipitated in IC from CF + IC sera. An invitro phagocytic assay of [14C]PA uptake using CF + IC whole-sera opsonins confirmed that endocytosis by normal PM and neutrophils was significantly depressed. Removal of IC from CF + IC sera resulted in significantly decreased serum IgG2 concentrations without a significant change in the other subclass concentrations, and enhanced [14C]PA uptake by PM (26.6% uptake increased to 47.3%) and neutrophils (16.9% increased to 52.6%). Return of the soluble IgG2 IC to the original CF sera supernatants and the positive control sera resulted in return of the inhibitory capacity of the CF + IC sera. We conclude that immune sera from patients with chronic Pseudomonas infections characterized by elevated IgG2 subclass level functions poorly as an opsonin. In these individuals, IgG2 contributes significantly to circulating IC and removal of IC, matched by a simultaneous fall in IgG2, improves bacterial uptake by neutrophil and mononuclear phagocytes. IgG2 antibodies exert antiphagocytic effects by both direct inhibition and the formation of IC.

ContextSeasonal allergic rhinitis is a common IgE-mediated disorder that produces troublesome symptoms. A recombinant humanized monoclonal anti-IgE antibody (omalizumab) forms complexes with free IgE, blocking its interaction with mast cells and basophils and lowering free IgE levels in the circulation.ObjectiveTo assess the efficacy and safety of omalizumab for prophylaxis of symptoms in patients with seasonal allergic rhinitis.DesignRandomized, double-blind, dose-ranging, placebo-controlled trial conducted from July 25 through November 21, 1997.SettingTwenty-five outpatient centers throughout the United States.PatientsFive hundred thirty-six patients aged 12 to 75 years with at least a 2-year history of moderate to severe ragweed-induced seasonal allergic rhinitis and a baseline IgE level between 30 and 700 IU/mL.InterventionsPatients were randomly assigned to receive omalizumab, 50 mg (n = 137), 150 mg (n = 134), or 300 mg (n = 129), or placebo (n = 136) subcutaneously just prior to ragweed season and repeated during the pollen season every 3 weeks in patients with baseline IgE levels of 151 to 700 IU/mL (4 total treatments) and every 4 weeks in patients with baseline IgE levels of 30 to 150 IU/mL (3 total treatments).Main Outcome MeasuresSelf-assessed daily nasal symptom severity scores (range, 0-3), rescue antihistamine use, and rhinitis-specific quality of life during the 12 weeks from the start of treatment.ResultsNasal symptom severity scores were significantly lower in patients who received 300 mg of omalizumab than in those who received placebo (least squares means, 0.75 vs 0.98, respectively; P = .002). A significant association was observed between IgE reduction and nasal symptoms and rescue antihistamine use. Rhinitis-specific quality of life scores were consistently better in patients who received 300 mg of omalizumab than in those who received lower dosages or placebo and did not decline during peak season. The frequency of adverse events was not significantly different among the omalizumab and placebo groups.ConclusionOmalizumab decreased serum free IgE levels and provided clinical benefit in a dose-dependent fashion in patients with seasonal allergic rhinitis.

The sera from 32 patients with cystic fibrosis who were chronically colonized with mucoid strains of Pseudomonas aeruginosa (MPA) were tested for anti-MPA antibodies. Using an enzyme-linked immunosorbent assay we measured IgA, IgG, and IgM antibody titers to three MPA strains, extracts of those strains, and seaweed-derived sodium alginate, which is similar chemically to the exopolysaccharide of MPA. These titers were compared with identical tests performed on the sera of eight cystic fibrosis patients who never were colonized with MPA and 10 normal adults. The IgG titers were significantly higher in tests of sera from the colonized patients compared with the other two groups but the IgA and IgM titers were not significantly higher. In colonized patients antibody titers to the different antigens correlated with each other suggesting that the major antibody response was to common antigenic determinants. Using these titers as a data base, eight patients whose clinical status was unknown to the testers, had IgG-enzyme-linked immunosorbent assay tests of their sera and the four colonized patients with cystic fibrosis were correctly identified. Three of them had substantial titers of antibody in the bronchoalveolar lavage fluid.

In the disease cystic fibrosis (CF), pulmonary infection with Pseudomonas aeruginosa is a common clinical complication that determines most morbidity and almost all excess mortality. We postulated that in this disease a defect in Pseudomonas-reactive IgG antibodies may contribute to chronic Pseudomonas infections. Bronchoalveolar lavages were performed upon 13 patients with CF, 7 patients with chronic bronchitis characterized by recurrent Pseudomonas infections, and 4 normal volunteers. The levels of various proteins important to host defenses and proteases were determined; enzyme inhibition studies were performed. CF respiratory immunoglobulin levels were significantly elevated when compared with both normals and patients with chronic bronchitis (P less than 0.05). Albumin and transferrin levels were decreased in the CF lung fluids. CF elastolytic activity was strikingly elevated (means = 6.02 micrograms/mg total protein) and the inhibitory profile suggested such activity resembled a serine-proteinase. Alpha-1-antitrypsin antigenic levels were not altered in CF respiratory fluids. There was a tendency for the lavage IgG to fall as elastase levels rose (r = -0.29). IgG opsonins for two Pseudomonas immunotypes were isolated with affinity chromatography for functional and immunochemical studies. Bacterial phagocytic rates in the presence of these Pseudomonas-reactive IgG opsonins derived from CF lavage fluid were depressed (0.3% uptake/unit time) when compared with similarly titered positive controls (uptake = 1.3%/unit time, P less than 0.001). Additionally, normal pulmonary macrophage intracellular killing of Pseudomonas was severely altered in the presence of opsonins derived from CF respiratory fluids. At some time points, less than 30% of the bacteria were killed. CF IgG opsonins contain a cleavage fragment (100,000 D, 5S sedimentation coefficient) with antigenic determinants similar to the Fab portion of IgG. The presence of such a fragment was inversely correlated with phagocytic functional activity. Intact IgG comprised as little as 18% of the CF lavage fluid specimens. Aliquots of intact human IgG, when mixed with the CF opsonins, augmented Pseudomonas uptake and improved intracellular killing. Conversely, peptide fragments of IgG opsonins, which are proteolytically derived in vitro, duplicated in our system the defect observed with opsonins derived from CF lung fluids; bacterial uptake was inversely related to the concentration of F(ab')2 and to a greater degree, to Fc present in the opsonic mixture. We concluded that IgG respiratory opsonins are fragmented, inhibiting phagocytosis and serving a permissive role in the chronic Pseudomonas pulmonary infection in the disease CF.

The gram-negative organism Pseudomonas aeruginosa plays a major role in the morbidity and mortality of patients with cystic fibrosis (CF). Inherent properties of this organism, together with alterations in the CF airway, lead to colonization of the CF patient and, ultimately, contribute to the destructive lung lesion of CF. Innovative antibiotic therapies for the CF patient are discussed, including new potent oral and parenteral pseudomonicidal antibiotics, the re-emergence of nebulized delivery systems, and the validation of home intravenous therapy.

A nonsurgical, less aggressive, less toxic chemotherapeutic protocol for the management of nontuberculous mycobacterial (NTB) pulmonary infections has been uniformly applied to patients in our institution between 1972 and 1985. Forty-three nonimmunocompromised patients with active lung disease caused by Mycobacterium avium-intracellulare (MAI) (n = 26), M kansasii (n = 16), and M xenopi (n = 1) were identified retrospectively. Eighteen MAI patients were treated with three or four antituberculosis agents resulting in sputum conversion and clinical improvement in 12 (67 percent). Additionally, 11 out of 16 (69 percent) patients completing therapy or still undergoing therapy for persistent MAI disease, achieved sputum conversion and clinical improvement after prolonged therapy (3.6 ± 0.5 years [SEM]). When M kansasii was identified as the etiologic agent, all patients were treated with four or fewer antituberculosis agents and 14 out of 16 patients (88 percent) achieved sputum conversion and clinical improvement throughout the follow-up period. We conclude that the use of three or four chemotherapeutic agents in the treatment of NTM lung disease provides an excellent probability of successful outcome even in MAI infections.

The purpose of such a, necessarily, circumscribed review is to highlight therapeutic modalities of promise and to expose common treatments based on inadequate data, in an attempt to provide debate between colleagues, to stimulate clinical trials, and to suggest directions for future clinical investigation

1. β-Adrenergic responsiveness may be decreased in cystic fibrosis. In order to determine whether this reflects an alteration in the human lymphocyte β-receptor complex, we studied 12 subjects with cystic fibrosis (six were stable and ambulatory and six were decompensated, hospitalized) as compared with 12 normal controls. 2. Lymphocyte β-receptor mediated adenylate cyclase activity (EC 4.6.1.1) was not decreased in the ambulatory cystic fibrosis patients as compared with controls. In contrast, decompensated hospitalized cystic fibrosis patients demonstrated a significant reduction in β-receptor mediated lymphocyte adenylate cyclase activity expressed as the relative increase over basal levels stimulated by the β-agonist isoprenaline compared with both normal controls and stable ambulatory cystic fibrosis patients (control 58 ± 4%; ambulatory cystic fibrosis patients 51 ± 7%; decompensated hospitalized cystic fibrosis patients 28 ± 5%; P < 0.05). 3. Our data suggest that defects in lymphocyte β-receptor properties in cystic fibrosis patients may be better correlated with clinical status than with presence or absence of the disease state.

To study how fragmented IgG antibodies might arise within the respiratory secretions of individuals with cystic fibrosis (CF), we screened protease extracts from CF polymorphonuclear leukocytes and mucoid and nonmucoid transformants of Pseudomonas aeruginosa from patients with CF for IgG proteolytic activity. All strains of P. aeruginosa tested exhibited IgG proteolytic activity. Incubation for 7 hr at 37 C was required to demonstrate generation of free Fc gamma immunoreactivity. Further analysis of these cleavage products of CF IgG demonstrated generation of Fc gamma polypeptides with 4S sedimentation coefficients and F(ab')2 fragments with 5S coefficients. Bacterial IgG proteolytic activity was inhibited by EDTA and was associated with levels of bacterial elastase exceeding 5 micrograms/mg of total protein. Pseudomonas elastase was significantly more active on IgG1 and IgG3; IgG2 and IgG4 were more resistant. This bacterial exoproduct appears to digest IgG molecules into Fab gamma, F(ab')2 fragments, and a free Fc gamma piece with a molecular weight of 40,000.

Pseudomonas aeruginosa infection plays a primary pathogenetic role in the chronic respiratory tract disease of cystic fibrosis (CF) patients. Despite pronounced humoral immune responses, reflected by high levels of antibodies against Pseudomonas in serum and in sputum, the antibodies do not eliminate this bacterium. In the present study we have used affinity chromatography with a lipopolysaccharide substituted immunoadsorbent gel to isolate high titers (meanCF = 1:256) of immunotype specific Pseudomonas IgG antibodies from the sera of nine CF subjects, and have evaluated the functional ability of these antibodies to promote phagocytosis and intracellular killing of P. aeruginosa in an in vitro human alveolar macrophage culture system. The phagocytic and intracellular bactericidal kinetics revealed that CF IgG antibodies function in an inhibitory fashion. Both the rate of phagocytosis (rateCF = 204 cpm/unit time) and absolute bacterial uptakes maximal at 120 min (uptakeCF = 18 x 10(3) 14C cpm) were inhibited compared with appropriate positive controls (hyperimmune serum, HIS; [rateHIS = 399; uptakeHIS = 29 x 10(3), P less than 0.005]). The ability of such CF-derived opsonins to potentiate macrophage intracellular bactericidal processes was mildly impaired (bacterial survivalCF = 15 x 10(3) colony forming units (CFU)/min, survivalHIS = 9 x 10(3)). Further characterization of this defect, assessed with functional studies of the Fab and Fc portions of the immunoglobulin molecule, revealed an impairment in the attachment of these specific antibodies to the alveolar macrophage membrane Fc gamma receptors. Preliminary studies of the physical-chemical properties of these immunoglobulins were normal. The expression of this inhibitory activity in vivo may facilitate Pseudomonas colonization and the subsequent established infections in the respiratory tracts of CF subjects.

Peumonia, a microbial infection involving the terminal airways and alveoli of the lung, is an ancient respiratory affliction. It is a disease that, during the recent decades of spectacular progress in the control of infectious diseases, should have been greatly ameliorated or eradicated altogether. However, so many microbes can infect the lungs and they have proved to be so adaptable and hardy throughout years of antibiotic onslaught that pneumonia still exists and is quite prevalent. Pneumonia remains the most common cause of infectious disease death in the United States and the fifth leading cause of overall mortality [ 11. It should have been expected that some of the early optimism about the inevitable control of infection would fade despite strong reassurances to the contrary by Alexander

Experiments performed in vitro have demonstrated that leukocyte neutral proteases produce an important mediator of inflammation, C5a, by proteolysis of the C5 component of the complement system. Cystic fibrosis (CF) lung fluids were characterized by high levels of neutrophils (39% of total cells versus 2% in normals) and contained significantly elevated amounts of elastolytic activity (mean 17.7 ng/micrograms total protein) compared to the lung fluids obtained from normal volunteers (0.2 ng elastolytic activity/micrograms protein, p = 0.001). The objective of these studies was to determine if complement activation and complement-derived chemotactic activity are present in CF lung fluids. C3c peptide representing activation of C3 could not be identified in the bronchial-alveolar lung lavage fluids of normal subjects but was readily identified by means of crossed immunoelectrophoresis in CF lung fluids (n = 9, mean 49% of C3); the mean level of C3 was decreased in CF lung specimens. Chemotactic activity was significantly elevated in lung fluids of the CF patients when compared to normal lung fluids. Using gel-filtration chromatography and a sensitive radioimmunoassay the chemotaxin present in CF specimens was identified as the anaphylatoxin C5a. C5a levels in the bronchial-alveolar lavage fluids of CF patients was inversely related to volume in liters expired in 1 s of a forced expiratory maneuver expressed as a percent of vital capacity determined from a forced expiratory maneuver (r = -0.72). Because there was a direct relationship between the total elastolytic activity present in CF airways and the concentration of C5a (r = 0.97, p = 0.03), it was postulated that airway proteases with elastolytic activity also cleave C5, nonimmunologically producing C5a. Detailed inhibition assays revealed that much of the total elastolytic activity had the inhibition profile of a serine proteinase. The levels of the serine proteinases were closely correlated with the numbers of neutrophilic leukocytes present per ml of lavage fluid (r = 0.7, p = 0.05). However, inhibitors of leukocyte serine proteases did not prevent the generation of additional chemotactic activity and the proteolysis of radiolabeled C5 substrate was not prevented by inhibitors of neutrophil elastase. Although the purified metalloelastase of Pseudomonas aeruginosa was active on cell-bound and free C5 yielding C5a, inhibition of this bacterial protease in CF lung fluids only partially blocked cleavage of the alpha- and beta-chains of C5.(ABSTRACT TRUNCATED AT 400 WORDS)

Potent, mono-specific anti-Pseudomonas immunoglobulins were isolated from serum and lung lavage fluid from patients with cystic fibrosis using immunotype specific Pseudomonas aeruginosa lipopolysaccharide (LPS) substituted immunoadsorbent gel. Iodinated monovalent Pseudomonas LPS somatic antigens, Fisher immunotypes, were used as ligands for two different insoluble gel matrices. LPS iodination, using the water insoluble chloroglycoluril reagent, permitted quantitation of the percent LPS bound as a ligand. The coupling efficiencies of epoxy-activated and cyanogen bromide-activated Sepharose matrices for various Pseudomonas immunotype specific LPS preparations were compared. Although each of the 7 LPS somatic antigens produced an equivalent amount of coupling, higher percentages of coupling were found using the cyanogen bromide-activated gel when compared to the epoxy-activated gel. IgG fractions prepared from cystic fibrosis sera and lung lavage fluid were passed through the LPS affinity gels, and Pseudomonas LPS immunotype specific antibodies were eluted. The presence of specific antibody activity against individual Pseudomonas immunotypes was determined with a passive micro-hemagglutination assay. Bronchial lavage fluid seemed to be as effective as serum as a source of Pseudomonas specific antibody. Use of such a LPS substituted gel permits direct recovery of Pseudomonas monospecific antibodies suitable for physical-chemical analyses and for biologic functional assays.