Polymorphism in the interleukin-1 receptor antagonist gene is associated with alcoholism in Spanish men

Background: A polymorphism located in intron 2 of the interleukin-1 recepto r antagonist (IL1RN) gene recently has been associated with the development of hepatic fibrosis in Japanese alcoholics. In the present study, we analy zed whether there is an association between this polymorphism, alcoholism, and alcoholic liver disease in a Spanish male population of alcoholics. Methods: The IL1RN genotype was assessed by polymerase chain reaction by us ing oligonucleotides that flank a variable nucleotide tandem repeat polymor phism located in intron 2 of this gene in 90 male alcoholic patients from S pain: 30 alcohol-dependent men, 30 alcohol abusers, and 30 alcoholics with liver cirrhosis. We also studied 40 healthy subjects. Results: The distribution of the IL1RN allelic frequencies in Spanish healt hy subjects is similar to that previously reported in White subjects. Howev er, the A1 allele is overrepresented in Spanish alcoholics when compared wi th healthy subjects. No significant differences in allelic frequencies were observed between alcoholics with liver cirrhosis and alcoholics without li ver disease or between alcohol-dependent subjects and alcohol abusers. Conclusion: The presence of the A1 allele of the IL1RN gene is associated w ith a higher risk of alcoholism in Spanish men.