The 3'UTR 1188 A/C polymorphism in the interleukin-12p40 gene (IL-12B) is associated with lepromatous leprosy in the west of Mexico

• Published in: Immunology letters Vol. 118; no. 2; pp. 148 - 151
• Main Authors: Alvarado-Navarro, Anabell, Montoya-Buelna, Margarita, Muñoz-Valle, José Francisco, López-Roa, Rocio Ivette, Guillén-Vargas, Cecilia, Fafutis-Morris, Mary
• Format: Journal Article
• Language: English
• Published: Netherlands 30-06-2008
• Subjects: 3' Untranslated Regions - genetics; Adult; Aged; Case-Control Studies; Female; Gene Expression Regulation; Gene Frequency; Genetic Predisposition to Disease; Genotype; Humans; Interleukin-12 - blood; Interleukin-12 Subunit p40 - blood; Interleukin-12 Subunit p40 - genetics; Leprosy, Lepromatous - genetics; Male; Mexico; Middle Aged; Mycobacterium leprae; Polymorphism, Genetic; RNA, Messenger - metabolism; Mexico
• ISSN: 0165-2478
• DOI: 10.1016/j.imlet.2008.03.015

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. IL-12 participates in the immune response against M. leprae by regulating T cell differentiation into the Th1-type response. Several single nucleotide polymorphisms have been identified in the IL-12 gene such as 3'UTR 1188 A/C polymorphism, which is associated with different diseases. However, the relationship of this polymorphism with the immune response in leprosy has not been explored. In this case-control study, we evaluated 44 patients with lepromatous leprosy (LL) and 51 healthy subjects (HS). We aimed to determine the relationship between 3'UTR 1188 A/C polymorphism of IL-12 p40, mRNA expression, and soluble IL-12 concentration in LL patients and HS. Genotype frequencies were 41% A/A, 36% A/C, and 23% C/C in LL patients, and 47% A/A, 49% A/C, and 4% C/C in HS (p<0.05). LL patients had a lower mRNA expression of IL-12 p40 gene, whereas HS had a higher expression level. Soluble IL-12 p40 concentration was higher in LL patients than in HS (p<0.05). IL-12 p70 concentration did not differ between groups, and IL-12 p40 concentration was not significantly correlated with mRNA expression in either group. These data suggest that IL-12 p40 3'UTR 1188 A/C polymorphism is associated with greater susceptibility to lepromatous leprosy in patients from western Mexico, independently of IL-12 p40 and p70 expression levels.