European Respiratory Journal 2009; 34:346-353
The aim of this study was to determine whether long-term air pollution exposure is associated with clinical phenotype in alpha 1-antitrypsin deficiency.
In total, 304 PiZZ subjects underwent full lung function testing and quantitative high-resolution computed tomography to identify the presence and severity of the disease. Mean annual air pollutant data for 2006 was matched to the location of patients' houses and used in regression models to identify phenotypic associations with pollution, controlling for covariates. Relative trends in pollution levels were assessed to validate use of a single year's data to indicate long-term exposure.
Pollutant levels correlated significantly with one another, with higher levels of primary particles, SO2 and NO2 being associated with lower ozone levels. Regression models showed that estimated higher exposure to ozone was associated with worse gas transfer and more severe emphysema. Regression parameters suggested that significance from other pollutants was due to collinearity with ozone. The 2006 pollutant levels showed linear relationships with cumulative years, thus validating the model.
Higher exposures to ozone may be associated with worse respiratory status in 1-antitrypsin deficiency, identifying a group susceptible to ambient air pollution.
Division of Medical Sciences, School of Geography, Earth and Environmental Sciences, Dept of Occupational and Environmental Medicine, University of Birmingham, and 4Lung Investigation Unit, University Hospitals Birmingham, Birmingham, UK.
Tuesday
Thursday
Lung volume reduction surgery for patients with alpha-1 antitrypsin deficiency emphysema
Currently, A1AD is recognized in approximately 2% of patients who have emphysema, although this may be an underestimation of the prevalence of this disease. Given the relatively young age at which patients who have A1AD present with emphysema, therapies aimed at slowing the progression of this disease are imperative. In addition to abstaining from smoking, the use of augmentation therapy may benefit some patients who have moderate airflow obstruction. For patients who have severe airflow obstruction, the most effective therapy is surgical.
Despite a possible increased risk for infectious complications, transplantation remains a viable option for these patients who have long-term results mirroring those of patients transplanted for smoking-related COPD. Given limited donor availability, however, LVRS must be considered in these patients possibly as definitive therapy but more likely as a bridge to transplantation. LVRS for patients who have A1AD remains relatively uncommon despite a general perception that it remains a surgical option.
In a survey of European thoracic surgical centers, Hamacher and colleagues42 found that two thirds of respondents included A1AD in their list of indications for LVRS. Although the durability of the benefits derived from LVRS in patients who have A1AD seems inferior to that of patients who have COPD, the available data show improved 6-minute walk distances and decreased dyspnea persisting for 1 to 2 years after LVRS in patients who had A1AD. Further experience is necessary to determine whether or not subgroups of patients who have A1AD, such as those who have clear heterogeneous distribution, may derive more long-lasting improvement from LVRS.
Donahue JM, Cassivi SD.
Division of General Thoracic Surgery, University of Maryland, 22 South Greene Street, N4E35, Baltimore, MD 21201, USA
Despite a possible increased risk for infectious complications, transplantation remains a viable option for these patients who have long-term results mirroring those of patients transplanted for smoking-related COPD. Given limited donor availability, however, LVRS must be considered in these patients possibly as definitive therapy but more likely as a bridge to transplantation. LVRS for patients who have A1AD remains relatively uncommon despite a general perception that it remains a surgical option.
In a survey of European thoracic surgical centers, Hamacher and colleagues42 found that two thirds of respondents included A1AD in their list of indications for LVRS. Although the durability of the benefits derived from LVRS in patients who have A1AD seems inferior to that of patients who have COPD, the available data show improved 6-minute walk distances and decreased dyspnea persisting for 1 to 2 years after LVRS in patients who had A1AD. Further experience is necessary to determine whether or not subgroups of patients who have A1AD, such as those who have clear heterogeneous distribution, may derive more long-lasting improvement from LVRS.
Donahue JM, Cassivi SD.
Division of General Thoracic Surgery, University of Maryland, 22 South Greene Street, N4E35, Baltimore, MD 21201, USA
Wednesday
Mortality in alpha-1-antitrypsin deficiency in the United Kingdom.
University Hospital Birmingham/ University of Birmingham, UK.
BACKGROUND: Four hundred and eighty-eight PiZ alpha-1-antitrypsin deficient patients, who had joined the UK registry over a 9-year period, were followed in an observational study to determine mortality. None had received A1AT augmentation therapy.
METHODS: Cause of death was confirmed from death certification and medical records. Patients were censored according to length of time on the program or until they withdrew from the program. RESULTS: There were 56 deaths of which 30 were attributed to respiratory causes. Of the remaining 26 deaths, 4 were due to complications from lung transplant, 6 due to liver disease (including 2 post-liver transplant) and the other 16 due to a variety of causes. Kaplan-Meier plots indicated a cumulative hazard for mortality of 18.1% in 9 years, correcting for time of follow up. When categorised for FEV(1) percent-predicted, the group with severe impairment had increased mortality (p=<0.001) compared with the mild group and there was a direct relationship between severity and mortality. The severe group had increased mortality compared with the mild group when categorised for KCO percent-predicted (p<0.001), RV/TLC ratio (p<0.001) or emphysema score on CT scan (p<0.001 upper zone). Cox regression analyses indicated that these relationships remained when corrected for age. There were no differences in mortality after categorisation for educational level or occupational group.
CONCLUSION: Mortality in a cohort of A1AT deficient patients (PiZ phenotype) in the UK was 2% per year and was associated with lung function impairment and emphysema severity on CT scan, but not social status
BACKGROUND: Four hundred and eighty-eight PiZ alpha-1-antitrypsin deficient patients, who had joined the UK registry over a 9-year period, were followed in an observational study to determine mortality. None had received A1AT augmentation therapy.
METHODS: Cause of death was confirmed from death certification and medical records. Patients were censored according to length of time on the program or until they withdrew from the program. RESULTS: There were 56 deaths of which 30 were attributed to respiratory causes. Of the remaining 26 deaths, 4 were due to complications from lung transplant, 6 due to liver disease (including 2 post-liver transplant) and the other 16 due to a variety of causes. Kaplan-Meier plots indicated a cumulative hazard for mortality of 18.1% in 9 years, correcting for time of follow up. When categorised for FEV(1) percent-predicted, the group with severe impairment had increased mortality (p=<0.001) compared with the mild group and there was a direct relationship between severity and mortality. The severe group had increased mortality compared with the mild group when categorised for KCO percent-predicted (p<0.001), RV/TLC ratio (p<0.001) or emphysema score on CT scan (p<0.001 upper zone). Cox regression analyses indicated that these relationships remained when corrected for age. There were no differences in mortality after categorisation for educational level or occupational group.
CONCLUSION: Mortality in a cohort of A1AT deficient patients (PiZ phenotype) in the UK was 2% per year and was associated with lung function impairment and emphysema severity on CT scan, but not social status
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