| Backgroud HPV (Human Papillomavirus) is an important infectious agent that is related to cervical precancerous lesion, cervical cancer and genital warts etiologically. Tha data from China CDC National Center for AIDS/STD showed 154,922 new CA patients in 2003 (12.02/100,000). The data published by IARC WHO in 2004 shows 45,689 new invasive cancers comes from China, accounting for one tenth in whole world. With the development of biomolecular technology, recombinant vaccines against HPV, which can prevent HPV infection effectively, are available in the market. There are no evidences from well-designed epidemiology study using standardized and sensitive technology for HPV detection, which can facilitates accurate evaluation on prophylactic vaccine's effects.Objectives Hospital-based epidemiology study across China are carried out to study HPV distribution in genital warts, invasive cervical cancer (ICC) and CIN2/3 samples.Material and Methods Stratified sampling method was applied to get representive samples of the cases from the hospitals in 7 geographic regions, including Northeast, North, Northwest, Central, Southwest, South and East. Genital warts from the cases were provide by 18 hopitals, and archived paraffin blocks for cervical lesions are provided by 19 hospitals.We employed standard phenol-chloroform extracting and ethanol precipitation procedures on genital wards to refine DNA. Consensus primers MY09/11, MY09/GP5+ and GP5+/GP6+and nested PCR are applied to amplify 140 bp target DNA segment. For single infection, the amplimor is separated by electrophoresis and sequenced. For multiple infections, the amplimor is inserted into T-vector for E. coli. transformation. Five single clones were randomly selected for sequencing separately. Sequence information was blasted with NCBI database to ascertain HPV types.A sandwich technique was used to cut paraffin sections for Haematoxylin and Eosin (H&E) staining and paraffin sections for HPV DNA analysis from each cervical specimen. After confirmation of histological diagnosis, qualified cervical specimens were digested in Proteinase K buffer at 70 centigrade. SPF10 PCR on the 1:10 diluted DNA was applied to amplify HPV DNA and then the generic amplification products were detected by DNA enzyme immunoassay (DEIA). HPV-positive specimens were typed by reverse hybridization line probe assay SPF10 LiPA25 (version 1). Results Among 1295 genital warts patients with genital tissues collected,290 subjects were excluded due to no beta-globin and cyt B amplification, or PCR inhibition, or insufficient DNA for further testing and 1005 subjects were qualified for this study. The mean age is 32 years, female GW patients (55.3%; 556/1005) are more than male (44.7%; 449/1005). HPV prevalence was 88.7%(N=1005); HPV6 (46.6%) and HPV11 (42.4%) were the most common HPV types, accounting for 87.3%, followed by HPV16 (11.8%). Other HPV types were less than 1.0%. Besides, single infection was 97.2% of the total HPV positive GW patients, comparing with 2.8% multiple infections composed of HPV6, HPV11 and/or HPV16. Cumulative prevalence of HPV 6,11, and 16 is 97.9%. Neither HPV6 nor HPV11 significantly differed by urban and rural, sex, age levels and geographical regions.Archived paraffin blocks for 664 ICC (630 squamous cell carcinoma [SCC]; 34 adenocarcinoma [ADC]),569 CIN 2/3 cases from 7 regions of China were collected. HPV prevalence was 97.6% in SCC,85.3% in adenocarcinoma,98.9% in CIN 2/3. HPV16 (76.7%) and HPV18 (7.8%) were the most common, together accounting for 84.0% of SCC, followed by HPV31 (3.2%), HPV52 (2.2%), and HPV58 (2.2%). HPV prevalence in SCC did not differ notably by region. However, SCC cases from women≤34 years and 35-49 years had significantely higher HPV 16 prevalence than women over 50 years(P=0.003), among whom HPV52,58, and 39 were more common. In contrast to SCC, HPV16 prevalence in women over 50 years is singnificantely more than women≤34 years and 35-49 years, among whom HPV52,58, and 39 were more common. HPV16 and 18 were under-represented, whereas HPV31,52 and 58 were over-represented in CIN2/3(P=0.01),.Conclusion HPV 16 and 18 are the most common types for cervcia cancer, and HPV 6, 11 and 18 are the most common types for genital warts. It was suggested that the potential impact of prophylactic HPV vaccines is estimated to be high. |
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