Study objectives: To determine whether the adenine
(A)-guanine (G) substitution polymorphism at position - 308 on the
tumor necrosis factor-α gene confers susceptibility to COPD or to the
development of a more severe form of disease.
A cross-sectional study was undertaken to compare the frequency of the
A allele in a group of 106 patients with COPD with that in a control
population (n = 99). Patients were followed up prospectively for a
period of 2 years.
Participants and setting:
Participants included 106 COPD patients recruited from a respiratory
outpatient clinic and 99 control subjects recruited from patients
admitted for cardiac catheterization.
results: DNA was extracted from venous blood, and each subject
was genotyped for the polymorphism by polymerase chain reaction
amplification and restriction digestion using Nco1. There was no
increased frequency of the A allele in patients compared to control
subjects. AA homozygous patients had less reversible airflow
obstruction (p < 0.05) and a significantly greater mortality (both
all-cause and respiratory deaths) on follow-up (p < 0.001), despite
a shorter cigarette smoking history.
study suggests that homozygosity for this A allele predisposes to more
severe airflow obstruction and a worse prognosis in