RESUMO
BACKGROUND: Focal epithelial hyperplasia is a benign proliferative condition that is more frequently found in children of certain ethnic groups. Human papillomavirus 13 and 32 DNA has been consistently detected in these lesions. OBJECTIVE: To demonstrate the epidemiological association of HPV 13 with FEH in the Emberá-Chamí community of Antioquia, Colombia. METHODS: A population-based, case-control study was conducted. One hundred and thirty-eight children were screened and 17 clinical and histologically-confirmed cases were sex and age-matched with 27 controls. Biopsies from FEH lesions and mouth washes from controls were obtained for DNA analysis. HPV 13 DNA was identified using a previously described type-specific PCR test. HPV 13 VLPs were produced by cloning of L1 from the HPV 13 cloned genome and seroreactivity against HPV 13 VLPs of sera from cases and controls were evaluated by ELISA. RESULTS: Among the whole population the prevalence of FEH was 13%. One-hundred-percent of the cases and 29.6% of the controls were HPV 13 positive. There was a significant difference in HPV DNA status between cases and controls (one-tailed Fisher exact test: P<0.0001). Antibodies against HPV 13 VLPs were found in 58.8% of cases and in 33.3% of controls, this difference was not statistically significant (P=0.089 Fisher exact test). However, the median of the ODs of the ELISA positive sera of the cases was 0.596 (interquartile range: 0.5075-0.8245) versus 0.452 (interquartile range: 0.337-0.479) in the controls and this was significantly different (P=0.0041 Man-Whitney test). CONCLUSIONS: We demonstrated a risk for association of FEH with infection with HPV 13. The higher level of antibodies against HPV 13 VLPs in cases may suggest the requirement of higher viral load or viral persistence for disease development.