Rationale: Among patients with nontuberculous mycobacterial lung disease is a subset of previously healthy women with a slender body morphotype, often with scoliosis and/or pectus excavatum. We hypothesize that unidentified factors predispose these individuals to pulmonary nontuberculous mycobacterial disease. Objectives: To compare body morphotype, serum adipokine levels, and whole-blood cytokine responses of patients with pulmonary nontuberculous mycobacteria (pNTM) with contemporary control subjects who are well matched demographically. Methods: We enrolled 103 patients with pNTM and 101 uninfected control subjects of similar demographics. Body mass index and body fat were quantified. All patients with pNTM and a subset of control subjects were evaluated for scoliosis and pectus excavatum. Serum leptin and adiponectin were measured. Specific cytokines important to host-defense against mycobacteria were measured in whole blood before and after stimulation. Measurements and Main Results: Patients with pNTM and control subjects were well matched for age, gender, and race. Patients with pNTM had significantly lower body mass index and body fat and were significantly taller than control subjects. Scoliosis and pectus excavatum were significantly more prevalent in patients with pNTM. The normal relationships between the adipokines and body fat were lost in the patients with pNTM, a novel finding. IFN-g and IL-10 levels were significantly suppressed in stimulated whole blood of patients with pNTM. Conclusions: This is the first study to comprehensively compare body morphotype, adipokines, and cytokine responses between patients with NTM lung disease and demographically matched controls. Our findings suggest a novel, predisposing immunophenotype that should be mechanistically defined.Keywords: leptin; adiponectin; pectus excavatum; scoliosis; Marfan syndrome Chronic lung disease due to nontuberculous mycobacteria (NTM) is a growing public health concern (1-3). Recent studies estimate the incidence in the United States to be five to six cases per 100,000 and as high as 15.5 cases per 100,000 in persons over 50 years of age (3-5). Because the duration of symptomatic NTM lung disease is often years, the prevalence of disease is estimated to be 10 to 40 cases per 100,000 (1).In the United States, the most common NTM species associated with lung disease are Mycobacterium avium complex (MAC), Mycobacterium kansasii, and Mycobacterium abscessus. Although NTM are widespread in water and soil (6, 7), relatively few persons develop disease. Thus, intact immunity is likely pivotal for protection against NTM.Chronic lung disease is the most common form of NTM infection, manifested by two main radiographic patterns: (i) an upper lobe fibrocavitary pattern that occurs mostly in men with underlying lung disease such as chronic obstructive pulmonary disease (COPD) and (ii) a nodular-bronchiectasis pattern that often involves the right middle lobe and lingula and which appears to be more common in women with no clear risk factors (8)...
Purpose: Several observations suggest the presence of HIV-suppressive factors in the fluid phase of blood. Alpha-1-antitrypsin (AAT), the most abundant serine protease inhibitor in the circulation, has potent anti-HIV activity in vitro, and may function as an endogenous HIV suppressor. Therefore, we assessed serum AAT concentrations for association with HIV infection. Methods: In this cross-sectional study, serum AAT concentrations were measured in 66 persons with HIV infection and in 45 healthy persons (Controls). In the HIV-infected group, antiretroviral therapy (ART) use was assessed and CD4+ T cell levels and plasma HIV RNA were quantified. Results: Median AAT concentration was significantly lower in the HIV-infected group (1.64 mg/mL) in comparison with Controls (1.94 mg/mL; p=0.001). AAT reduction was most pronounced in the HIV-infected subgroup with CD4+ T cell levels > 200 cells/µL in comparison with Controls (p < 0.01). Serum AAT concentrations < 1.0 mg/mL are clinically significant, and concentrations below this level were identified in 4.5% of the HIV-infected group and in no Control subjects. No association between AAT levels and viral load or use of ART was observed in HIV-infected subjects. Conclusion: The association between reduced serum AAT concentration and HIV infection is consistent with a role for AAT as an endogenous HIV suppressor.
Nosocomial pneumonia (NP) is the third most common hospital-acquired infection and the leading cause of death due to hospital-acquired infection in the US. During pneumonia and non-pneumonia severe illness, respiratory tract secretions become enriched with the serine protease neutrophil elastase (NE). Several NE activities promote onset and severity of NP. NE in the airways causes proteolytic tissue damage, augments inflammation, may promote invasion of respiratory epithelium by bacteria, and disrupts respiratory epithelial barrier function. These NE activities culminate in enhanced bacterial replication, impaired gas exchange, fluid intrusion into the airways, and loss of bacterial containment that can result in bacteremia. Therefore, neutralizing NE activity may reduce the frequency and severity of NP. We evaluated human alpha-1 antitrypsin (AAT), the prototype endogenous NE inhibitor, as a suppressor of bacterial pneumonia and pneumonia-related pathogenesis. In AAT+/+ transgenic mice that express human AAT in lungs, mortality due to Pseudomonas aeruginosa (P.aer) pneumonia was reduced 90% compared to non-transgenic control animals. Exogenous human AAT given to non-transgenic mice also significantly reduced P.aer pneumonia mortality. P.aer-infected AAT+/+ mice demonstrated reduced lung tissue damage, decreased bacterial concentrations in lungs and blood, and diminished circulating cytokine concentrations compared to infected non-transgenic mice. In vitro, AAT suppressed P.aer internalization into respiratory epithelial cells and inhibited NE or P.aer-induced disruption of epithelial cell barrier function. The beneficial effects of human AAT in murine P.aer pneumonia raise the possibility of AAT use as a prophylactic treatment for NP in humans, and suggest a role for AAT as an innate immune mediator.
NO is an endogenously produced gas that regulates inflammation, vascular tone, neurotransmission, and immunity. NO production can be increased by exposing cells to several endogenous and exogenous proinflammatory mediators, including IFN-γ, TNF-α, IL-1β, and LPS. As AAT has been shown to inhibit cell activation and suppress cytokine production associated with proinflammatory stimulation, we examined AAT for NO-suppressive function. In RAW 264.7 murine macrophagic cells, physiological AAT concentrations significantly inhibited combined LPS- and IFN-γ-induced NO synthesis, and NO synthesis inhibition was associated with decreased expression of iNOS, suppressed NF-κB activation, and reduced translocation of extracellular AAT into the interior of RAW 264.7 cells. CE-2072, a synthetic inhibitor of serine proteases, also suppressed NO production, iNOS expression, and NF-κB activation. However, AAT did not alter activation of intracellular MAPKs. In subjects with genetic AAT deficiency, exhaled NO was increased significantly compared with exhaled NO in healthy controls. These in vitro and in vivo studies suggest that AAT is an endogenous inhibitor of NO production. Administering AAT or AAT-like molecules may have use as a treatment for diseases associated with excessive NO production.
Exposure to cigarette smoke (CS) profoundly increases one's risk of developing primary and reactivation tuberculosis (TB) as : RATIONALE well as experiencing more severe disease and higher mortality following infection. The mechanisms by which CS predisposes to reactivation TB are widely unknown although CS, nicotine,a nd acrolein have been shown to suppress innate immune and T cell function. Since intact non-caseating granulomas are considered important in preventing reactivation of latent TB infection (LTBI) and preventing the spread of active disease, we determined the effects of CS on the formation and maintenance of granulomas using primary in vitro human monocytes and lymphocytes.Peripheral Blood Mononuclear Cells (PBMC) were isolated from the blood of a healthy : METHODS individual and separated into lymphocyte and monocyte subpopulations. Equal numbers (2 x 10 ) of each cell type were added to each 5 well of a 24-well ultra-low attachment tissue culture plate to allow for cell migration. Cells were infected with Mycobacterium tuberculosis ( ) W Beijing HN878 at a very low multiplicity-of-infection of one bacterium to 400 cells and incubated over a course of 9 days, with MTB control wells left uninfected. Cigarette smoke extract (CSE) was prepared by "smoking" a single unfiltered 3R4F research cigarette (University of Kentucky) into 10 mL of pre-warmed medium via a vacuum pump, with the flow adjusted at 3 L/min using an Accucal flowmeter (Gilmont Instruments). The extract was then filtered through a 0.22 µm syringe filter and adjusted to a pH of 7.4. This stock solution is arbitrarily designated as 100% CSE. CSE was added to cells at concentrations ranging from 1% to 5% on the same day of infection.After seven to nine days of incubation, no cellular aggregates formed in uninfected conditions. In contrast, : RESULTS well-formed cellular aggregates resembling non-caseating granulomas were apparent in cell conditions infected with . Low MTB concentrations of CSE (1 and 2.5%) added at the time of initial infection prevented the formation of -induced granulomas. MTB Additionally, treating infected cells with 1, 2.5 and 5% CSE granulomas had formed (Day 7 post-infection) disrupted intact after granulomas within 24 hours. CSE at relatively low concentrations prevents the establishment of TB-induced granulomas : CONCLUSIONS and disrupts intact cellular aggregates formed by human PBMC in repsonse to infection. These studies suggest that one potential in vitro mechanism by which CS exposure predisposes individuals to primary progressive TB and reactivation TB may be impaired formation and maintenance of host-protective -induced granulomas. MTB This abstract is funded by: None Am J Respir Crit Care Med 183;2011:A3337 Internet address: www.atsjournals.org Online Abstracts Issue
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