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Original Article
 

Association of TNF- α -308 G/A and IL-4 -589 C/T Gene Promoter Polymorphisms With Asthma Susceptibility in the South of Iran
 

E Kamali-Sarvestani,1,2 MA Ghayomi,3 A Nekoee1

1Department of Immunology, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
2Autoimmune Diseases Research Center, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
3Department of Internal Medicine, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran

J Investig Allergol Clin Immunol 2007; Vol. 17 (6): 361-366
 

 Abstract


Background: Both tumor necrosis factor α (TNF-α) and interleukin (IL) 4 have been implicated in the pathogenesis of asthma. Furthermore, a G/A substitution at position -308 of the TNF-α gene promoter and a C/T substitution at position –589 of the IL –4 gene promoter have been associated with increased production of TNF-α and IL-4, respectively.

Objective: The aim of the present study was to analyze the association between TNF-α -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- α -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-α –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).

Conclusion: These results provide further evidence for a role of TNF-α -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 confi rm our observations.

Key words: Asthma. Interleukin-4. Tumor necrosis factor-α. Polymorphism.