title: Human leukocyte antigen class I, class II, and tumor necrosis factor-alpha polymorphisms in a healthy elder Mexican Mestizo population.
abstract: BACKGROUND
  There is strong evidence that an individual's genetic background is an important predisposing factor to longevity. In the present study we analysed the frequency of HLA class I, class II, as well as the TNF-alpha -308 polymorphism that may be related to an increased life span in Mexican Mestizo healthy elders.
  
  
  RESULTS
  HLA typing was performed by polymerase chain reaction sequence specific oligonucleotide (PCR SSO) reverse dot blot. The TNF-alpha -308 polymorphism was assessed by PCR restriction fragment length polymorphism. A significant increased frequency of HLA-DRB1*11 was found in elderly women whereas this allele was not present in elderly males. The TNF2 allele was also increased in the elder group when compared to young controls. The frequencies of the remaining alleles tested were not statistically different among groups.
  
  
  CONCLUSIONS
  These data suggest an ethnicity independent tendency of HLA-DRB1*11 in elder females to increase life span and a possible role of the TNF2 allele with the successful remodelling of senescent immune system.
authors.affiliation: Department of Immunology and Rheumatology, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico. elenasoto_74@yahoo.com
authors.forename: Elena
authors.initials: E
authors.lastname: Soto-Vega
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Richaud-Patin
authors.forename: Luis
authors.initials: L
authors.lastname: Llorente