RESUMEN
The authors report the results of an investigation of witness cases realized in collaboration between occupational medecine service and immunology laboratory of hedi CHAKER university hospital SFAX during the year 2000. the purpose was to seartch the genetic control of the HLA class l system for the non response to hepatitis B vaccine and to evaluate the contribution of other favorite factors as tabac, sex age. Thus, in a population of 32 healthy agents found nonresponders to hepatitis B vaccine by the titers of anti HBs antibody, we have performed the HLA-A, -B phenotypes by the technique of complement dependent microcytotoxicity. The frequency of studied HLA class l antigens, was compared for the non responders group, to the frequency observed in witnesses group, done with 52 responders health agents. The rate of nonresponsiveness hepatitis B vaccine was evaluated up to 5%. Statistically significant difference was observed for HLA A1 and B44 markers showing frequencies which were considerably higher in the non responders than in witnesses