Association of TNF-alpha -308 G/A and IL-4 -589 C/T gene promoter polymorphisms with asthma susceptibility in the south of Iran.
BACKGROUND
Both tumor necrosis factor alpha (TNF-alpha) and interleukin (IL) 4 have been implicated in the pathogenesis of asthma. Furthermore, a G/A substitution at position -308 of the TNF-alpha gene promoter and a C/T substitution at position -589 of the IL-4 gene promoter have been associated with increased production of TNF-alpha and IL-4, respectively.


OBJECTIVE
The aim of the present study was to analyze the association between TNF-alpha-308 G/A and IL-4-589 C/T polymorphisms and susceptibility to asthma in a group of patients from southern Iran.


METHODS
We analyzed the frequency of TNF-alpha -308 G/A and IL-4-589 C/T polymorphisms in a total of 203 asthmatic patients compared to 113 nonasthmatic control subjects.


RESULTS
An association was observed between the TNF-alpha -308 G/A polymorphism and susceptibility to asthma in patients with a ratio between forced expiratory volume in 1 second and forced vital capacity of less than 75% compared with normal subjects; however, the association did not achieve statistical significance (P = .054). The IL-4-589 C/T polymorphism was associated with asthma susceptibility (P = .02). In addition, the association between this polymorphism and asthma severity approached statistical significance (P = .07).


CONCLUSIONS
These results provide further evidence for a role of TNF-alpha-308 G/A and IL-4-589 C/T polymorphisms in susceptibility to and severity of asthma. Further studies involving a larger number of patients may help to confirm our observations.
Kamali-Sarvestani
E
E
Department of Immunology, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran. immunol2@sums.ac.ir
Ghayomi
M A
MA
Nekoee
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000235:genetics*; D005260:Female; D005541:Forced Expiratory Volume; D020022:Genetic Predisposition to Disease; D006801:Humans; D015847:Interleukin-4 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*; D014797:Vital Capacity
D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4