Presence of infection and analysis of HPV subtypes in girls younger than 9 years old attended at a referral service in Espírito Santo, Brazil

PCR-RFLP and FTIR-based detection of high-risk human papilloma virus for cervical cancer screening and prevention

Background

Approximately 70% of cervical carcinoma cases show the presence of high-risk Human Papilloma Virus (HPV), especially HPV-16 and HPV-18, and can be used to stratify high risk patients from low risk and healthy. Currently, molecular biology techniques such as polymerase chain reaction (PCR) are used to identify the presence of virus in patient samples. While the methodology is highly sensitive, it is labor intensive and time-consuming. Alternative techniques, such as vibrational spectroscopy, has been suggested as a possible rapid alternative. Therefore, in this study, we evaluate the efficiency of cervical fluid Fourier Transform Infrared spectroscopy (FTIR) in patient risk stratification informed by PCR.

Methods

Cervical fluid samples (n = 91) were obtained from patients who have undergone routine Papanicolaou (Pap) test. Viral genome was identified and classified as high/low-risk by PCR-Restriction Fragment Length Polymorphism (PCR-RFLP). FTIR spectra were acquired from samples identified by PCR-RFLP as No-HPV (n = 10), high-risk HPV (n = 7), and low-risk HPV (n = 7).

Results

Of the 91 samples, was detected the viral genome by PCR in 36 samples. Of these 36 samples, nine samples were identified to contain high-risk HPV (HR-HPV) and nine samples were found to have low-risk HPV (LR-HPV). The FTIR spectra acquired from No-HPV, LR-HPV, and HR-HPV showed differences in 1069, 1437, 1555, 1647, 2840, 2919, and 3287 cm^-1 bands. Principal Component Analysis (PCA) showed distinct clusters for No-HPV and HR-HPV and No-HPV and LR-HPV, but there was significant overlap in the clusters of HR-HPV and LR-HPV. PCA-Linear Discriminant Analysis (PC-LDA) after Leave One Out Cross Validation (LOOCV) classified No-HPV from HR-HPV and No-HPV from LR-HPV with 100% efficiency in the 1400-1800 cm^-1 spectral range. LOOCV classifications for LR-HPV and HR-HPV from each other were 71 and 75%, respectively, in the 2800-3400 cm^-1 spectral range.

Conclusions

The results highlight the high sensitivity of PCR-RFLP in HPV identification and show that FTIR can classify samples identified as healthy, low, and high-risk samples by PCR-RFLP.

General significance

We show the possibility of using FTIR for initial cervical cancer risk stratification followed by detailed PCR-RFLP investigations for suspect cases.

•

Molecular biology showed high sensitivity and specificity in HPV detection compared with cytological analysis.

•

PCR-RFLP technique identify high-risk variants of HPV can significantly assist in the prevention of cervical cancer.

•

PC-LDA and LOOCV classified normal from high-risk HPV and normal from low-risk HPV with 100% efficiency.

•

FTIR can be used for initial cervical cancer risk stratification followed by more detailed investigations by PCR-RFLP.

Molecular detection of HPV and FT-IR spectroscopy analysis in women with normal cervical cytology

BACKGROUND

The increase in the incidence of Cervical Cancer in the female population worldwide has been an issue that deserves further attention from the scientific community. Several studies have already proven the relationship of its development with the molecular mechanisms that Human Papillomavirus (HPV) induces in cervical cells. The gene amplification provided by molecular biology techniques has been used as the gold standard diagnostic method of this virus because of its high specificity and sensitivity.However, the high investments associated with the acquisition of reagents, equipment and labor demonstrate the need for the development of more accessible techniques that present the same accuracy. FT-IR spectroscopy has been studied as an inexpensive and easily accessible technology that can provide the differentiation of malignant and benign cells. This study aimed to demonstrate the effectiveness and sensitivity of molecular analysis by PCR in relation to cytological analysis and to evaluate the sensitivity of FT-IR spectroscopy in the diagnosis of HPV for cervical cancer prevention.

METHODS

Cervical fluid samples obtained from 50 patients with absence of cellular lesion by cytological analysis were analyzed by molecular and spectroscopic analyzes. Oncotic colpocitology analysis was performed by the Papanicolaou staining, amplification of the L1 viral gene by PCR was performed using primers MY09 and MY11 and biochemical analysis of the fluids by FT-IR was performed using the Spectrum 400 system equipped with a microscope.

RESULTS

Of the 50 patients without evident morphological alteration of the cells, seven were diagnosed by molecular analysis as positive for presence of HPV. Principal component analysis of spectroscopy was not able to separate the negative samples from the HPV positive samples and, therefore, did not present as an effective diagnostic technique.

CONCLUSIONS

We highlight the efficacy, sensitivity and specificity of molecular biology by PCR in the identification of the virus and we emphasize that more studies should be used for the application of FT-IR spectroscopy in the diagnosis of this infection and its application in the prevention of cervical cancer.

Seroprevalence of HPV serotypes 6, 11, 16 and 18 in unvaccinated children from Mexico City

Data regarding humoral immunity against HPV infection are scarce. Most analyses focus on the identification of viruses on mucous membranes and primarily refer to women of reproductive age. The aim of this work was to estimate the seroprevalence of antibodies against HPV serotypes 6, 11, 16 and 18 among unvaccinated boys living in Mexico City. A cross-sectional study of 257 male students from 48 public primary schools in Mexico City, whose ages fluctuated between 9 and 14 years, was carried out. Immunological status was assessed by applying the competitive Luminex Immunoassay of HPV (cLIA). Among the study population, we initially found that 38.52% (n = 99) of the children tested positive against one or more of the HPV 6, 11, 16 and/or 18 serotypes. The most commonly found serotype was isolated HPV 18 or in combination with other serotypes (22% and 31%, respectively), followed by HPV 6 with frequencies of 4.7% and 11%, respectively; however, lower frequencies were estimated for HPV 16 (2%; 6%) and isolated HPV 11, 4%. If a second set of cut-off points for seropositivity is applied, the overall prevalence for any serotype is reduced to 15.2%. As it appears that a significant sector of the study population has had basal contact with an HPV serotype, we recommend considering the possibility of vaccination against HPV at earlier ages.

Prevalence of human papillomavirus in oral rinse samples from healthy individuals in northern Thailand

BACKGROUND

The incidence of oral cancers associated with human papillomavirus (HPV) has been increasing in recent years. Therefore, it is necessary to elucidate HPV prevalence in oral cells and exposure to risk factors in various age groups.

METHODS

Oral rinse samples from healthy individuals in northern Thailand were investigated for HPV prevalence and genotyped using the polymerase chain reaction (GP5+/6+ primers) and DNA sequencing of the PCR products.

RESULTS

Samples were collected from 594 participants between 4 and 60 years of age. HPV was detected in 3.7% of samples. The prevalence of HPV-positive cases was 8.6% in the 31-50 age group. HPV prevalence increased with age and was the highest (9.2%) in the 41-50 age group, but decreased (to 3%) in the 51-60 age group. Risk factors significantly associated with HPV-positive cases included alcohol consumption, coffee drinking, sexual activity, and having children. HPV 16 and 18 were common genotypes, especially in the 31-50 age group, and were associated with having sexual activity (odds ratio 19.0 [95% CI: 2.5-142.5]). At follow-up of some individuals in the 4-10 age group, a 9-year-old child was found to be positive for HPV18.

CONCLUSIONS

These results suggest that HPV can be acquired at a young age and the prevalence peaks in the middle age class among healthy individuals in northern Thailand, especially in the 31-50 age group.