Lea Hošnjak (Slovenia)
University of Ljubljana, Faculty of Medicine INSTITUTE OF MICROBIOLOGY AND IMMUNOLOGYPresenter of 2 Presentations
ASSESSING GAMMAPAPILLOMAVIRUS INFECTIONS OF MUCOSAL EPITHELIA WITH TWO BROAD-SPECTRUM PCR PROTOCOLS (ID 147)
Abstract
Introduction
Human papillomaviruses (HPVs) have been divided into mucosal and cutaneous types according to their primary epithelial tissue tropism. However, recent studies have shown the presence of several cutaneous HPV types in mucosal lesions and healthy mucosa from different anatomical sites.
Methods
In the present study the HPV prevalence and type-specific distribution were assessed in a variety of mucosal samples obtained from 435 individuals, using a combination of two established broad-spectrum PCR primer systems: Gamma-PV PCR and CUT PCR, designed and developed by our research group.
Results
Overall HPV prevalence in anal canal swabs, genital warts, cervical cancer biopsies and oral swabs was 85%, 62%, 47% and 4%, respectively. In anal canal swab samples, Alpha-PVs were the most frequently detected (59%), followed by Gamma- (37%) and Beta-PVs (4%). The prevalence and persistence of HPV infection in the anal canal of 226 individuals were further explored. Overall HPV, Gamma-PVs and multiple HPV infections were significantly higher in men vs. women (p=0.034, p=0.027 and p=0.003, respectively), multiple HPV infections were more common in individuals ≤ 40 years of age (p=0.05), and significantly higher prevalence of Gamma-PVs and multiple HPV infections was observed in HIV-1-positive vs. HIV-1-negative individuals (p=0.003 and p=0.04, respectively). Out of 21 patients with follow-up anal canal swabs, only one persistent infection with the same HPV type (HPV58) was detected.
Conclusions
Our findings suggest that Gamma-PVs (except Gamma-6-PVs) are ubiquitous viruses with dual muco-cutaneous tissue tropism. Anal canal Gamma-PV infections may be associated with sexual behavior and the host immune status. This study expands the current knowledge on Gamma-PVs’ tissue tropism, providing valuable data on the characteristics of HPV infection in the anal canal and its transmission dynamics.
HUMAN PAPILLOMAVIRUS TYPING IN PAIRED FRESH-FROZEN AND FORMALIN-FIXED, PARAFFIN-EMBEDDED COMMON WART TISSUE SAMPLES (ID 932)
Abstract
Introduction
Formalin-fixed, paraffin-embedded (FFPE) tissue specimens are an invaluable source for research and diagnostic purposes when fresh clinical samples are unavailable and their prospective collection is not feasible. However, nucleic acids extracted from FFPE tissues are often degraded and chemically modified making the molecular studies challenging. In order to evaluate the use of FFPE specimens in etiological studies of common warts (CWs) a total of 128 paired fresh-frozen and FFPE tissue specimens of histologically confirmed CWs were analyzed.
Methods
Following DNA extraction from fresh and FFPE CWs, using a Qiagen DNA Mini Kit, all samples were tested using type-specific quantitative multiplex RT-PCR, allowing sensitive detection and differentiation of HPV2/27/57 infection in a single PCR reaction, and three different type-specific quantitative Mu-PV RT-PCRs.
Results
Single HPV infections were found in 72/128 (56.3%) fresh-tissue CWs, of which the concordant single HPVs (HPV1, 2, 27, 57 in 2, 8, 21 and 33 specimens, respectively) were also detected in 64/72 (88.9%) paired FFPE samples. HPV DNA was not detected in 8/72 (11.1%) FFPE samples, in which low concentrations of single HPV types (HPV1 or 63) were previously found in fresh CWs. Additionally, multiple HPV infections were detected in 51/128 (39.8%) fresh tissue samples, of which concordant results (double infections with HPV1, 27, and 57 in 11 cases and triple infection with HPV1, 27, and 57 in a single case) were found in 12/51 (23.5%) paired FFPE samples, most probably due to low viral loads in fresh tissues. In 5/128 (3.9%) CW samples HPV1/2/27/57/63/204 DNA was not detected, even though the DNA extraction was successful from all samples according to amplification of the housekeeping gene.
Conclusions
FFPE samples can be used for HPV detection in CWs in which high viral load is present, but may be less suitable for detecting multiple HPV infections.