The DNA load of six high-risk human papillomavirus types and its association with cervical lesions.

BACKGROUND: Analysing human papillomavirus (HPV) viral load is important in determining the risk of developing cervical cancer (CC); most knowledge to date regarding HPV viral load and cervical lesions has been related to HPV-16. This study evaluated the association between the viral load of the six most prevalent high-risk viral types in Colombia and cervical intraepithelial neoplasia (CIN) frequency. METHODS: 114 women without CIN and 59 women having CIN confirmed by colposcopy, all of them positive by conventional PCR for HPV infection in the initial screening, were included in the study. Samples were tested for six high-risk HPV types to determine viral copy number by real-time PCR. Crude and adjusted odds ratios (ORa) were estimated for evaluating the association between each viral type's DNA load and the risk of cervical lesions occurring. RESULTS: The highest viral loads were identified for HPV-33 in CIN patients and for HPV-31 in patients without lesions (9.33 HPV copies, 2.95 interquartile range (IQR); 9.41 HPV copies, 2.58 IQR). Lesions were more frequent in HPV-16 patients having a low viral load (3.53 ORa, 1.16-10.74 95%CI) compared to those having high HPV-16 load (2.62 ORa, 1.08-6.35 95%CI). High viral load in HPV-31 patients was associated with lower CIN frequency (0.34 ORa, 0.15-0.78 95%CI). CONCLUSIONS: An association between HPV DNA load and CIN frequency was seen to be type-specific and may have depended on the duration of infection. This analysis has provided information for understanding the effect of HPV DNA load on cervical lesion development.

Persistence, clearance and reinfection regarding six high risk human papillomavirus types in Colombian women: a follow-up study.

BACKGROUND: The design of new healthcare schemes which involve using molecular HPV screening means that both persistence and clearance data regarding the most prevalent types of HR-HPV occurring in cities in Colombia must be ascertained. METHODS: This study involved 219 HPV positive women in all of whom 6 types of HR-HPV had been molecularly identified and quantified; they were followed-up for 2 years. The Kaplan-Meier survival function was used for calculating the time taken for the clearance of each type of HPV. The role of a group of independent variables concerning the time taken until clearance was evaluated using a Cox proportional-hazards regression model or parametric (log-logistic) methods when necessary. Regarding viral load, the Wilcoxon rank-sum test was used for measuring the difference of medians for viral load for each type, according to the state of infection (cleared or persistent). The Kruskal-Wallis test was used for evaluating the change in the women's colposcopy findings at the start of follow-up and at the end of it (whether due to clearance or the end of the follow-up period). RESULTS: It was found that HPV-18 and HPV-31 types had the lowest probability of becoming cleared (1.76 and 2.75 per 100 patients/month rate, respectively). Women from Colombian cities other than Bogotá had a greater probability of being cleared if they had HPV-16 (HR 2.58: 1.51-4.4 95% CI) or HPV-58 (1.79 time ratio: 1.33-2.39 95% CI) infection. Regarding viral load, HPV-45-infected women having 1 × 106 to 9.99 × 109 viral copies had better clearance compared to those having greater viral loads (1.61 time ratio: 1.01-2.57 95% CI). Lower HPV-31 viral load values were associated with this type's persistence and changes in colposcopy findings for HPV-16 gave the worst prognosis in women having low absolute load values. CONCLUSIONS: HPV infection clearance in this study was related to factors such as infection type, viral load and the characteristics of the cities from which the women came. Low viral load values would indicate viral persistence and a worse prognosis regarding a change in colposcopy findings.

Human papillomavirus detection in women with and without human immunodeficiency virus infection in Colombia.

BACKGROUND: HIV infection leads to a decreasing immune response, thereby facilitating the appearance of other infections, one of the most important ones being HPV. However, studies are needed for determining associations between immunodeficiency caused by HIV and/or the presence of HPV during the course of cervical lesions and their degree of malignancy. This study describes the cytological findings revealed by the Papanicolaou test, laboratory characteristics and HPV molecular profile in women with and without HIV infection. METHODS: A total of 216 HIV-positive and 1,159 HIV-negative women were invited to participate in the study; PCR was used for the molecular detection of HPV in cervical samples. Statistical analysis (such as percentages, Chi-square test and Fisher's exact test when applicable) determined human papillomavirus (HPV) infection frequency (single and multiple) and the distribution of six types of high-risk-HPV in women with and without HIV infection. Likewise, a logistic regression model was run to evaluate the relationship between HIV-HPV infection and different risk factors. RESULTS: An association was found between the frequency of HPV infection and infection involving 2 or more HPV types (also known as multiple HPV infection) in HIV-positive women (69.0% and 54.2%, respectively); such frequency was greater than that found in HIV-negative women (44.3% and 22.7%, respectively). Statistically significant differences were observed between both groups (p = 0.001) regarding HPV presence (both in infection and multiple HPV infection). HPV-16 was the most prevalent type in the population being studied (p = 0.001); other viral types had variable distribution in both groups (HIV-positive and HIV-negative). HPV detection was associated with <500 cell/mm(3) CD4-count (p = 0.004) and higher HIV-viral-load (p = 0.001). HPV-DNA detection, <200 cell/mm(3) CD4-count (p = 0.001), and higher HIV-viral-load (p = 0.001) were associated with abnormal cytological findings. CONCLUSIONS: The HIV-1 positive population in this study had high multiple HPV infection prevalence. The results for this population group also suggested a greater association between HPV-DNA presence and cytological findings. HPV detection, together with low CD4 count, could represent useful tools for identifying HIV-positive women at risk of developing cervical lesions.

Classical molecular tests using urine samples as a potential screening tool for human papillomavirus detection in human immunodeficiency virus-infected women.

Human papillomavirus (HPV) is the main risk factor associated with the development of cervical cancer (CC); however, there are other factors, such as immunosuppression caused by the human immunodeficiency virus (HIV), that favor progression of the illness. This study was thus aimed at evaluating the functionality of classical PCR-based molecular tests for the generic identification of HPV DNA (GP5+/GP6+, MY09/MY11, and pU1M/2R primers, individually or in combination) using cervical and urine samples from 194 HIV-positive women. Infected samples were tested with type-specific primers for six high-risk types (HPV-16, -18, -31, -33, -45, and -58) and two low-risk types (HPV-6 and -11). HPV infection prevalence rates were 70.1% for the cervical samples and 63.9% for the urine samples. HPV-16 was the most prevalent viral type in the cervical and urine samples, with higher rates of multiple infections than single infections detected in such samples. HPV DNA detection by PCR (mainly with the pU1M/2R primer set) in urine samples was positively associated with abnormal cytological findings (atypical squamous cells of undetermined significance/squamous intraepithelial lesions [ASCUS/SIL]). It was determined that the operative characteristics for detection of cytological abnormalities were similar for cervical and urine samples. This suggested using PCR for the detection of HPV DNA in urine samples as a potential screening strategy for CC prevention in future prevention and control programs along with currently implemented strategies for reducing the impact of the disease, i.e., urine samples are economical, are easy to collect, have wide acceptability among women, and have operative characteristics similar to those of cervical samples.

Human papillomavirus detection from human immunodeficiency virus-infected Colombian women's paired urine and cervical samples.

Infection, coinfection and type-specific human papillomavirus (HPV) distribution was evaluated in human immunodeficiency virus (HIV)-positive women from paired cervical and urine samples. Paired cervical and urine samples (n = 204) were taken from HIV-positive women for identifying HPV-DNA presence by using polymerase chain reaction (PCR) with three generic primer sets (GP5+/6+, MY09/11 and pU1M/2R). HPV-positive samples were typed for six high-risk HPV (HR-HPV) (HPV-16, -18, -31, -33, -45 and -58) and two low-risk (LR-HPV) (HPV-6/11) types. Agreement between paired sample results and diagnostic performance was evaluated. HPV infection prevalence was 70.6% in cervical and 63.2% in urine samples. HPV-16 was the most prevalent HPV type in both types of sample (66.7% in cervical samples and 62.0% in urine) followed by HPV-31(47.2%) in cervical samples and HPV-58 (35.7%) in urine samples. There was 55.4% coinfection (infection by more than one type of HPV) in cervical samples and 40.2% in urine samples. Abnormal Papanicolau smears were observed in 25.3% of the women, presenting significant association with HPV-DNA being identified in urine samples. There was poor agreement of cervical and urine sample results in generic and type-specific detection of HPV. Urine samples provided the best diagnosis when taking cytological findings as reference. In conclusion including urine samples could be a good strategy for ensuring adherence to screening programs aimed at reducing the impact of cervical cancer, since this sample is easy to obtain and showed good diagnostic performance.

The diagnostic performance of classical molecular tests used for detecting human papillomavirus.

Cervical samples were evaluated for human papillomavirus (HPV) presence using the hybrid capture-2 (HC2) assay and the polymerase chain reaction (PCR) with three different primer sets (GP5+/6+, MY09/11 and pU1M/2R). PCR results were compared to HC2 and results of all assays were compared to cytological and colposcopy findings. Post-test probability was assessed in individual assays and test combinations. HPV-DNA prevalence was 36.5% with HC2 and 55.2% with PCR. MY09/11 detected HPV-DNA in 38% of samples, GP5+/6+ in 19.1% and pU1M/2R in 16.4%. pU1M/2R and HC2 had the highest concordance (75.31%, k=0.39 in the whole population; 74.1%, k=0.5 in women with abnormal cytology). pU1M/2R had the best diagnostic performance, including optimal post-test probabilities and cervical abnormality detection (individually or in a panel of tests). Women positive for pU1M/2R may be at higher risk of disease progression; the assay performance when combined with a Pap smear in cervical cancer screening programs should be evaluated.

Detection by PCR of human papillomavirus in Colombia: Comparison of GP5+/6+ and MY09/11 primer sets.

The aims of this study were to determine the prevalence of HPV infection and evaluate the concordance and performance of two primer sets for detecting single and multiple viral infections. A total of 1810 Colombian women were enrolled in the study, and molecular, cytological and epidemiological analyses were performed. Both concordance and performance of two different PCR amplification primer sets (GP5+/6+ and MY09/11) were assessed. The results showed that 60.2% of females with positive HPV DNA were infected by more than one viral type. The OR for multiple infections was 18.2 when using the MY09/11 primer set and 6.52 with the GP5+/6+ primer set. The results also showed an association between GP5+/6+ positivity and the severity of the disease regarding the cytological findings. It was also found that using a single primer set led to underestimating the prevalence for HPV infection. The simultaneous use of these primer sets is an important tool for the detection of HPV DNA, being equally relevant for identifying multiple infections and low viral DNA copies. This study highlights the importance of suitable assessment of HPV epidemiological profiles; screening programs must also be strengthened to broaden the coverage of the most vulnerable populations.

Distribution patterns of infection with multiple types of human papillomaviruses and their association with risk factors.

BACKGROUND: Infection with multiple types of human papillomavirus (HPV) is one of the main risk factors associated with the development of cervical lesions. In this study, cervical samples collected from 1,810 women with diverse sociocultural backgrounds, who attended to their cervical screening program in different geographical regions of Colombia, were examined for the presence of cervical lesions and HPV by Papanicolau testing and DNA PCR detection, respectively. PRINCIPAL FINDINGS: The negative binomial distribution model used in this study showed differences between the observed and expected values within some risk factor categories analyzed. Particularly in the case of single infection and coinfection with more than 4 HPV types, observed frequencies were smaller than expected, while the number of women infected with 2 to 4 viral types were higher than expected. Data analysis according to a negative binomial regression showed an increase in the risk of acquiring more HPV types in women who were of indigenous ethnicity (+37.8%), while this risk decreased in women who had given birth more than 4 times (-31.1%), or were of mestizo (-24.6%) or black (-40.9%) ethnicity. CONCLUSIONS: According to a theoretical probability distribution, the observed number of women having either a single infection or more than 4 viral types was smaller than expected, while for those infected with 2-4 HPV types it was larger than expected. Taking into account that this study showed a higher HPV coinfection rate in the indigenous ethnicity, the role of underlying factors should be assessed in detail in future studies.

Frequency of human papillomavirus infection, coinfection, and association with different risk factors in Colombia.

PURPOSE: The aims of this study were to provide new insights into infection patterns of six high-risk human papillomaviruses (HR-HPV-16, -18, -31, -33, -45, and -58) and two low-risk HPV types (LR-HPV-6 and -11), their association with risk factors and coinfection. METHODS: Cervical samples of 2110 women were tested for the presence of HPV-DNA by polymerase chain reaction. Statistical analyses were performed to determine viral-type frequencies in single and multiple infections and association between infection and different risk factors. RESULTS: HPV-16 was the most prevalent type among the studied population, followed by HPV-31. This last viral type showed a variable distribution between the different cities evaluated. The results showed distinct type-specific distributions among regions and a high association between absence of pregnancies, cities as Girardot and Leticia, the indigenous ethnicity, and coinfection. CONCLUSIONS: The results showed a variable distribution of HPV types according to the geographical region analyzed. In addition, data suggest that some sociodemographic-factors such as ethnicity, number of pregnancies, lifetime number of sexual partners, and geographic region were significantly associated, and our results showed little differences between single and multiple infections by HPV with regard to risk factors. Furthermore, these results provide relevant information that will allow assessing in further studies the impact that vaccination programs on these populations and the selective pressure would have on the distribution of HPV types.