Validation of Serological Antibody Profiles Against Human Papillomavirus Type 16 Antigens as Markers for Early Detection of Cervical Cancer

Abstract

Cervical cancer (CC) is the second most frequent neoplasia among women worldwide. Cancer prevention programs around the world have used the Papanicolaou (Pap) smear as the primary diagnostic test to reduce the burden of CC. Nevertheless, such programs have not been effective in developing countries, thus leading to research on alternative tests for CC screening. During the virus life cycle and in the process toward malignancy, different human papillomavirus (HPV) proteins are expressed, and they induce a host humoral immune response that can be used as a potential marker for different stages of the disease. We present a new Slot blot assay to detect serum antibodies against HPV16 E4, E7, and VLPs-L1 antigens. The system was validated with sera from a female population (n = 485) aged 18 to 64 years referred to the dysplasia clinic at the General Hospital in Cuautla, Morelos, Mexico. To evaluate the clinical performance of the serological markers, the sensitivity, specificity, positive, and negative predictive values and receiver-operating characteristic curves (for antibodies alone or in combination) were calculated in groups of lesions of increasing severity. The results showed high prevalence of anti-E4 (73%) and anti-E7 (80%) antibodies in the CC group. Seropositivity to 1, 2, or 3 antigens showed associations of increasing magnitude with CC (odds ratio [OR] = 12.6, 19.9, and 58.5, respectively). The highest association with CC was observed when the analysis was restricted to only anti-E4+E7 antibodies (OR = 187.7). The best clinical performance to discriminate CC from cervical intraepithelial neoplasia 2 to 3 was the one for the combination of anti-E4 and/or anti-E7 antibodies, which displayed high sensitivity (93.3%) and moderate specificity (64.1%), followed by anti-E4 and anti-E7 antibodies (73.3% and 80%; 89.6% and 66%, respectively). In addition, the sensitivity of anti-E4 and/or anti-E7 antibodies is high at any time of sexual activity (TSA), which suggests they can be biomarkers for the early detection of CC. The sensitivity of anti-E4 antibodies was low (<10%) when the TSA was <10 years, and it increased up to 100% in relation to the TSA, suggesting that anti-E4 antibodies can be useful as HPV exposure markers at early stages of the disease.

Profiling of serum antibodies against human papillomavirus antigens in Korean women with cervical intraepithelial neoplasia and cervical cancer

“…Meanwhile, we noted little difference in the frequencies of anti‐HPV16 or 18 L1 antibodies between CIN stages and cervical cancer proper (Table and Table ). In contrast, an increased prevalence of anti‐HPV16 L1 antibody in cervical cancer compared to CIN stages was found in Mexico …”

Serological Biomarkers for the Prediction and Detection of Human Papillomavirus Associated Cancers

“…To evaluate the serum antibodies against HPV antigens, generated during infection, precancerous lesions and cancer, several laboratory technics have been used, such as the ELISA (enzyme linked immunosorbent assay), western blot, radioimmunoassay (RIA) and more recently, Luminex multiplex. These methods use different antigens such as L1 virus like particles (VLPs) from different HPV types; synthetic peptides from L1, L2, E2, E4, and E7, bacterial recombinant proteins, or in vitro-translated viral antigens [7,69].…”

“…antibodies for OC [62,91]. In this way, several studies have been carried out and showed that antibodies against E7 have been commonly associated with AC and CC, with prevalence that goes from 45% in the anus [78] and up to 75% in the cervix [62,69], while in the penis, vulva, and vagina, the antibody prevalence was under 15% [79]. In contrast, although serological antibodies against E6 prevalence were high in CC patients by using different tests (from 37 to 44%) [70,86], the association of anti-E6 antibodies with this type of cancer has not been very well defined [70,74,75,88].…”

“…These studies suggest that the same serological markers are not present at the different anatomical site where the HPV-associated cancers appear. These results are very promising in the search for serological biomarkers, which in combination, they generate profiles that could differentiate the anatomical sites where the HPV-associated cancer is present, as it has been the case for the profile anti-E1/E2 + anti-E6 that has been associated to OPC [91], and for CC, the suggested antibody profile is anti-E4 + anti-E7 [69].…”

“…It would be of great interest to study early stages of the HPV-associated cancers as some of these anti-HPV antibodies seem to be important in early diagnostic and during follow-up as possible prognostic markers. In the case of CC, there are several studies of anti-HPV antibodies carried out with precancerous uterine cervical lesions, where it has been suggested that anti-E4 antibodies are important markers for CIN1-2 [61,62], while the profile anti-E4 + anti-E7 is a good marker for CC [69]. In the case of other HPV-associated cancers, there are only few studies that measured anti-HPV antibodies in early stages of the disease, as it is the case of anus and oral cavity lesions, where anti-VLPs antibodies presented the highest prevalence (43 and 30%, respectively) [111][112][113][114][115].…”