Different rates of spontaneous clearance of HPV infections in anal and cervical lesions
Abstract number: O415
Ravanini P., Omodeo-Zorini E., Fila F., Costantino S., Godino A., Ilaria V., Krizmancic L., Servino L., Antonacci C.M., Pagano F., Beretta R., Orlando G., Bandi M., Nicosia A.M., Crobu M.G.
Objectives: HPV is a risk factor for the onset of both cervical and anal carcinoma. The aim of the study is the estimate of the persistence and clearance of the different genotypes of HPV in male anal and female cervical samples during a one-year follow-up period.
Methods: We analyzed 440 cervical samples from 220 female patients (CF group) and 46 anal samples from 23 male immunodeficient patients (AM group). For each patient, two samples were collected after an interval of one year. 52 female and 11 male patients underwent a biopsy within the follow-up period. The remaining 172 female and 12 male patients did not undergo a biopsy. The samples were tested for the presence of HPV-DNA and genotyped by a PCR-based molecular method.
Results: The genotype prevalence results considerably different between the two groups. In AM group, the most frequent genotypes are, in order of frequency, HPV 31, 11, 16, 6, 52, while in CF group the most frequent ones are HPV 53, 16, 31, 66, 58. The persistence rate results higher in AM group than in CF group (51.1% vs. 37.5%). The biopsy does not seem to play any role in regression or persistence (not significant differences between biopsy and non-biopsy groups). Interestingly, some genotypes show different rates of persistence compared to the others. While HPV 6, 11, 16, 33, 53 show a higher persistence rate in AM group, HPV-31 shows a higher rate of spontaneous clearance in AM group (80.0%) than in CF group (64.7%). In the AM group, the difference between the persistence rate of genotype 11 (88.9%) and 31 (20.0%) is statistically significant (p < 0.01).
Conclusion: Our data point a different rate of spontaneous clearance and persistence of HPV genotypes between two groups of patients that differ for the immunitary status (immunodeficient vs. immunocompetent) and for the site of infection (anal vs. cervical). The high rate of spontaneous clearance of HPV-31 in anal samples from immunodeficient patients in comparison with cervical samples is opposite of the low rate of clearance of the other genotypes. It can reflect a different mechanism of persistence or of response of the immune system or both. Interestingly, the genotype that seems to persist in a higher proportion of cases is HPV-11, a low-risk type, instead of HPV-31, a high-risk type. Further evaluations are needed to assess whether these differences are primarily due to the different type of mucosal tissue or to the different degree of immune response.
|Session name:||Abstracts of 21st ECCMID / 27th ICC|
|Location:||Milan, Italy, 7 - 10 May 2011|
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