Significantly increased frequency of the apolipoprotein E epsilon 4 allele in elderly non-demented leprosy patients

Apolipoprotein E (apo E) genotypes in 350 leprosy patients were examined and compared with those of 870 age-matched controls. The allelic frequencies of the apo E gene did not differ between demented patients with leprosy and controls. However, the frequency of apo E epsilon 4 allele was significantly higher in non-demented leprosy patients than in controls (P < 0.001). Of special interest is that the prevalence of E3/4 genotype in non-demented leprosy patients increased significantly with age, being 14.1%, 24.4%, and 28.3% in the 60s, 70s, and 80s, respectively (P < 0.05). These data suggest that apo E epsilon 4 is not a risk factor for senile dementia in elderly leprosy patients, and there exist factors to overcome the risk of apo E4 in leprosy patients.