Environmental, occupational, and genetic risk factors for alpha-1 antitrypsin deficiency.
(65/411)
Alpha-1 antitrypsin (AAT) deficiency is an inherited genetic disorder currently diagnosed in approximately 5,000 people in the United States. Although some individuals with AAT deficiency are asymptomatic, the condition often leads to deterioration of lung function in adults and is associated with emphysema, asthma, chronic obstructive pulmonary disease, and other respiratory diseases. In children, AAT deficiency can result in severe liver disease, including fatal cirrhosis in newborn infants. Although much is known about the clinical pathology of AAT deficiency, researchers are just beginning to characterize environmental, occupational, and genetic modifiers affecting the onset and progression of diseases related to AAT deficiency. On 19 August 2002, a group of basic scientists, clinicians, environmental health researchers, and public interest groups gathered at the National Institute of Environmental Health Sciences in Research Triangle Park, North Carolina, to discuss ongoing research on these topics. The goals of this workshop were to a) assess the present state of knowledge regarding environmental and occupational risk factors contributing to AAT deficiency morbidity and mortality, b) define future research needs in this area, and c) explore collaborative opportunities to advance understanding of risk factors affecting the progression of AAT deficiency-related disease. Participants agreed that new research initiatives in these areas represent an opportunity to benefit both basic science, through enhanced understanding of gene-environment interaction, and the AAT deficiency patient community, through innovative new approaches to disease management and treatment. (+info)
Role of human neutrophil peptides in lung inflammation associated with alpha1-antitrypsin deficiency.
(66/411)
Individuals with alpha(1)-antitrypsin (alpha(1)-AT) deficiency are at risk for early-onset destructive lung disease as a result of insufficient lower respiratory tract alpha(1)-AT and an increased burden of neutrophil products such as elastase. Human neutrophil peptides (HNP), the most abundant protein component of neutrophil azurophilic granules, represent another potential inflammatory component in lung disease characterized by increased numbers of activated or deteriorating neutrophils. The purpose of this study was to determine the role of HNP in lower respiratory tract inflammation and destruction occuring in alpha(1)-AT deficiency. alpha(1)-AT-deficient individuals (n = 33) and healthy control subjects (n = 21) were evaluated by bronchoalveolar lavage. HNP concentrations were significantly higher in alpha(1)-AT-deficient individuals (1,976 +/- 692 vs. 29 +/- 12 nM, P < 0.0001), and levels correlated with markers of neutrophil-mediated lung inflammation. In vitro, HNP produced a dose-dependent cytotoxic effect on alveolar macrophages and stimulated production of the potent neutrophil chemoattractants leukotriene B(4) and interleukin-8 by alveolar macrophages, with a 6- to 10-fold increase in chemoattractant production over negative control cultures (P < 0.05). A synergistic effect was noted between HNP and neutrophil elastase with regard to leukotriene B(4) production. Importantly, the proinflammatory effects of HNP were blocked by alpha(1)-AT. HNP likely play an important role in amplifying and maintaining neutrophil-mediated inflammation in the lungs. (+info)
Circulating monocytes from healthy individuals and COPD patients.
(67/411)
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is characterized by incompletely reversible airflow obstruction associated with inflammation in which monocytes/macrophages are the predominant inflammatory cells. The only known genetic factor related to COPD is inherited PiZZ deficiency of alpha1-antitrypsin (AAT), an inhibitor of serine proteases. METHODS: We investigated the basal and LPS-stimulated release of pro-inflammatory molecules from blood monocytes isolated from age and gender matched healthy (n = 30) and COPD (n = 20) individuals with and without AAT deficiency. RESULTS: After 18 h of cell culture the basal release of MMP-9 was 2.5-fold, p < 0.02 greater, whereas IL-8 was 1.8-fold (p < 0.01) lower from COPD patient monocytes than from controls. LPS-stimulated release of IL-6 and MCP-1 was greater from COPD patient's monocytes relative to controls, while activation of control cells resulted in enhanced secretion of ICAM-1 and MMP-9 compared to COPD patients. Independent of disease status, monocytes from PiZZ AAT carriers released less TNFalpha (by 2.3-fold, p < 0.03). CONCLUSIONS: The basal and LPS-stimulated secretion of specific pro-inflammatory molecules from circulating monocytes differs between healthy and COPD subjects. These findings may be valuable for further studies on the mechanisms involved in recruitment and activation of inflammatory cells in COPD. (+info)
Predictors of mortality in alpha1-antitrypsin deficiency.
(68/411)
BACKGROUND: Lung density measurements by computed tomography have previously been found to be a more sensitive indicator of disease progression in emphysema of alpha(1)-antitrypsin deficiency than lung function measurements. The aim of this study was to investigate the predictive potential of several parameters, including CT scanning, for mortality in patients with severe alpha(1)-antitrypsin deficiency. METHODS: Over a 5 year period, 256 patients with alpha(1)-antitrypsin deficiency (PiZ phenotype) were assessed, of whom 254 underwent lung function testing and 197 had thoracic CT scans. Lung function, CT scans, health status (St George's Respiratory Questionnaire, SGRQ), and other clinical data of survivors and non-survivors were compared and these parameters were applied to survival analyses. RESULTS: There were 22 deaths in this patient cohort, 10 of which were classified as "respiratory" deaths. Baseline lung function parameters (forced expiratory volume in 1 second (FEV(1)), carbon monoxide transfer coefficient (KCO)), and CT scores were significantly lower in the non-survivors than in the survivors. 170 of the 256 patients had complete data for entry into multiple regression analyses (Cox proportional hazards model). In the univariate analysis, upper zone expiratory scan had the best association with all cause (p = 0.001) and respiratory mortality (p<0.001), whereas FEV(1) (p = 0.158 all cause, 0.015 respiratory) and KCO (p = 0.002 all cause, 0.012 respiratory) had poorer associations with mortality. Only age gave further independent predictive information regarding all cause or respiratory mortality when the CT scan was entered into the survival analyses. CONCLUSIONS: CT scanning predicts respiratory and all cause mortality in alpha(1)-antitrypsin deficiency and appears to be superior to lung function parameters, especially FEV(1). (+info)
Correlation between annual change in health status and computer tomography derived lung density in subjects with alpha1-antitrypsin deficiency.
(69/411)
BACKGROUND: There is increasing recognition that questionnaires of health status and lung density measurements are more sensitive tools for assessing progression of emphysema than forced expiratory volume in 1 second (FEV(1)) and transfer coefficient (KCO). A study was undertaken to investigate prospectively the correlation between annual change in health status and computer tomography (CT) derived lung density in subjects with alpha(1)-antitrypsin deficiency. METHODS: Twenty two patients of mean (SD) age 40.7 (9.2) years with ZZ type alpha(1)-antitrypsin deficiency were investigated at baseline and 30 months later by FEV(1) and KCO, St George Respiratory Questionnaire (SGRQ), and by a spiral CT scan of the chest. CT data of chest images were analysed using software designed for automated lung contour detection and lung density measurements. The density data were corrected for changes in inspiration levels. RESULTS: Changes in lung density, expressed as 15th percentile point or relative area below -950 HU, correlated well with changes in health status (SGRQ total score): R = -0.56, p = 0.007 or R = 0.6, p = 0.003. Neither changes in health status nor changes in lung density correlated significantly with changes in FEV(1) or changes in KCO. CONCLUSIONS: The SGRQ total score (which is a global measure in COPD) and lung density (a specific measure of emphysema) are sensitive to deterioration in patients with alpha(1)-antitrypsin deficiency. This finding may facilitate future studies with new drugs specific for emphysema, a frequently occurring component of COPD. (+info)
Key current clinical issues in alpha-1 antitrypsin deficiency.
(70/411)
Alpha-1 antitrypsin deficiency is a common but under-recognized condition on which respiratory therapists can have a large impact. A key recent development is the issuance of an international evidence-based standards document regarding diagnosis and management of individuals with alpha-1 antitrypsin deficiency. This report summarizes that standards document, which recommends more widespread testing for alpha-1 antitrypsin deficiency, in order to extend the benefits of diagnosis to individuals found to have alpha-1 antitrypsin deficiency. An important aspect of the standards document is that evidence regarding the clinical efficacy of intravenous alpha-1 antitrypsin augmentation therapy is reviewed. Though no definitive support from a randomized clinical trial is available, the weight of evidence favors the clinical efficacy of alpha-1 antitrypsin augmentation therapy, at least in individuals with moderate degrees of established airflow obstruction. On that basis the standards document recommends intravenous augmentation therapy in specified clinical circumstances. (+info)
Alpha-1 antitrypsin deficiency is not a rare disease but a disease that is rarely diagnosed.
(71/411)
Articles in the literature on alpha-1 antitrypsin (AAT) deficiency have been interpreted as indicating that AAT deficiency is a rare disease that affects mainly Caucasians (whites) from northern Europe. In a recent publication on the worldwide racial and ethnic distribution of AAT deficiency, new data were presented demonstrating that it is also found in various populations of African blacks; Arabs and Jews in the Middle East; and Central, Far East, and Southeast Asians, as well as whites in Australia, Europe, New Zealand, and North America. The new data on the prevalence of AAT deficiency in other major racial groups worldwide will affect the standards for the diagnosis of AAT deficiency by the medical community, with the realization that is not a rare disease of whites in northern Europe and immigrants from these countries in the New World. In a total population of 4.4 billion in the 58 countries surveyed, there are at least 116 million carriers (those with Pi phenotypes PiMS and PiMZ) and 3.4 million with deficiency allele combinations (phenotypes PiSS, PiSZ, and PiZZ) for the two most prevalent deficiency alleles PiS and PiZ; therefore, the new data suggest that AAT deficiency may be one of the most common serious single-locus genetic diseases in the world. Particularly important is the unique susceptibility of AAT-deficient individuals to exposure to chemical and particulate environmental agents. Such exposures are known to result in both lung and liver disease as well as other adverse health effects. (+info)
Brain haemorrhage in five infants with coagulopathy.
(72/411)
Most intracranial haemorrhages in infants after the neonatal period are secondary to non-accidental injury. Occasionally brain haemorrhages in non-mobile infants are due to an inherited coagulopathy. This may often be diagnosed with a coagulation screen on admission. Little is known about the neurological outcome of infants in the latter group. Five infants are described who presented with acute spontaneous brain haemorrhage secondary to an inherited coagulopathy (n = 3) and vitamin K deficiency in alpha(1) antitrypsin deficiency (n = 1) and Alagille's syndrome (n = 1). Despite the critical clinical presentation and the severe imaging findings, these five infants made a good neurological recovery. Infants presenting with spontaneous ICH due to a significant (inherited) coagulopathy are usually easy to differentiate from non-accidental shaking injury; their bleeding pattern within the brain seems different from non-accidental shaking injury and neurodevelopment outcome appears better. (+info)