Prevalence study of HPV mixed infections in Italian HIV positive women

Introduction: HIV positive women, show a higher frequency of multiple HPV infections than HIV negative.The immune response seems to be genotype-specific, but evidence on different genotypes distribution and involvement of coinfections in the development of invasive cervix cancer (ICC) remains limited. The aim of our study was to assess the prevalence of multiple infections in a group of Italian HIV positive women, the distribution of High risk (HR) strains and Low Risk (LR) strains in multiple and single infections, and their correlation with immune status and cervical lesions. Methods: 553 women were considered in the study. HPV search was performed with MY09-MY11 primers. HPV positive samples were typed with the Clinical Genomic array (HPV) test (Genomica, Spain). Results: 244 samples were HPV positive (44.1%).129/244 (52.9%) had a single infection and 103/244 (42.2%) multiple infections.Among the 412 performed typing, 223 (54.1%) were HR strains, while 189 (45.9%) were LR strains.The HPV61 (40 times) was more frequent among the LR strains.Among HR strains, the most frequently observed was the HPV16 (30 times). In 92% of multiple infections, at least one HR strain was found. 36% of LR strains was presented in single infections compared to 27% of HR strains (p = 0.06). The clades A3 (n = 124, 65.3% multiple infections) and A10 (n = 37, 56.8% multiple infections) were the most represented in LR;A9 (n = 95, 67.4% multiple infections) and A6 (n = 57, 70.2%) clades were the most representative among HR strains. Differences in age between women with single infection and those with multiple infection were not observed (p = 0.33) .Women with the best immune status (CD4 cell count of >500 cell/ mm3) showed a higher prevalence of single infection. HPV was positive in 75% of ASCUS/LSIL lesion and 77.3% of H-SIL. Conclusions: HPV-16 is the most frequent in both single and multiple infections as reported in a recent study about HIV negative women. Follow-up studies are necessary to assess the impact of multiple infections on the progression of different cervical lesion degrees