APOE genotype is associated with oral herpetic lesions but not genital or oral herpes simplex virus shedding

Abstract

Background: Apolipoprotein E is polymorphic in the human population. APOE4 has previously been reported to correlate with symptomatic oral and genital herpes disease.

Methods: APOE was genotyped in 182 subjects with herpes simplex virus (HSV) 2 and in 62 subjects with HSV-1, including 44 subjects with both viral types for a total of 200 adults. HSV shedding was measured by PCR from swab samples obtained daily from mucosa for at least 30 days. Participants also maintained a diary of oral or genital lesions.

Results: The APOE genotypes observed reflected the US white population and the Hardy-Weinberg equilibrium. Genital and oral HSV shedding was detected on 17.2% and 3.7% of overall days, respectively, whereas genital and oral lesion rates were 10.1% and 2.9%. Using Poisson regression and adjusting for known correlates of HSV shedding, a significant association was not observed between the APOE genotype and genital or oral HSV shedding, or genital HSV lesions. However, the presence of the APOE4 allele was associated with a higher rate of oral herpetic lesions, with a relative risk of 4.64 (95% CI 1.32 to 15.05, p=0.016).

Conclusions: Variation at the APOE locus may be associated with clinical manifestations of HSV-1 infection, but does not appear to correlate with herpes simplex viral reactivation in humans.

Fig. 1

Association of APOE genotypes and oral HSV shedding and oral lesions. The left bars refer to genital shedding rates (top) and lesion rates (bottom), while the right bars depict oral shedding (top) and lesions (bottom). The abscissa values differ between genital and oral sites. The numbers of days with data available are indicated over the bars for each genotype, anatomic site, and study endpoint. The number of persons with each genotype is listed below the APOE genotypes across the ordinates.