Comparison of the SPF ₁₀ -LiPA System to the Hybrid Capture 2 Assay for Detection of Carcinogenic Human Papillomavirus Genotypes among 5,683 Young Women in Guanacaste, Costa Rica

Abstract

The objective of this analysis was to compare the performance characteristics of two human papillomavirus (HPV) DNA detections assays, the Hybrid Capture 2 assay (HC2) and the SPF 10 assay, for the detection of carcinogenic HPV. Data are from the enrollment visits of women who participated in the randomized, double-blind, placebo-controlled phase III HPV16/18 Vaccine Trial in Guanacaste, Costa Rica. We compared the results of HC2 and SPF 10 testing of cervical specimens. Since the line probe assay (LiPA) detection system does not distinguish between HPV type 68 (HPV68; which is targeted by HC2) and HPV73 (which is not targeted by HC2), for SPF 10 In the 1990s, data from multiple, international epidemiologic studies established infection with a group of ϳ15 human papillomavirus (HPV) types as a necessary cause of cervical cancer (2, 27). The steady increase in the fraction of cervical cancers attributable to HPV infection from the low estimates reported in epidemiologic studies from a decade earlier was achieved by a reduction in misclassification due to the measurement errors caused by suboptimal HPV DNA tests (3,8,9,23). Now that the causal relationship between HPV infection and cervical cancer is certain, HPV-based prevention strategies are becoming increasingly important. In some countries HPV DNA assays are used as an adjunct to cytology to identify women at risk of cervical cancer who require preventive treatment. Recently, trials of prophylactic HPV vaccines have shown that these vaccines have high degrees of efficacy in preventing new and persistent infections with the HPV types in the vaccine formulation (most notably, HPV type 16 [HPV16] and HPV18, which together cause ϳ70% cases of cervical cancer worldwide) (11,26). Thus, the study of cervical cancer prevention within the context of vaccines requires accurate detection of type-specific incidence and persistent HPV infections associated with cancer and precancerous lesions. Beyond the detection of HPV16 and HPV18, other types must be identified accurately as well. Important secondary aims of ongoing clinical trials of vaccines are whether they confer protection against HPV types besides those in the formulations and whether reducing the frequencies of the two most carcinogenic genotypes as a result of vaccination could lead to increased frequencies of other HPV types.At present there is no "gold standard" for HPV detection; however, there is one FDA-approved molecular assay, the Hybrid Capture 2 assay (HC2; Digene Corporation, Gaithersburg, MD), which collectively targets 13 carcinogenic HPV types, with the limitation that it does not provide information about type-specific HPV genotypes. On the other hand, PCRbased assays are able to amplify most genital HPV genotypes in a single PCR and have the added benefit of providing HPV type discrimination following amplification. Commonly used PCR primers are consensus primers GP5ϩ/GP6ϩ, MY9/ MY11, and PGMY9/PGMY11, which amplify 150-bp (primer GP5ϩ/GP6ϩ) and 450-bp (primers PGMY and MY9/MY11)

A Comparison of Linear Array and Hybrid Capture 2 for Detection of Carcinogenic Human Papillomavirus and Cervical Precancer in ASCUS-LSIL Triage Study

“…Per the manufacturer's instructions, a protocol for converting the liquid cytology samples into a STM equivalent was used. In addition, hc2 cross-reacts strongly with a 14th carcinogenic HPV genotype, HPV66 (25)(26)(27), as well as other untargeted, noncarcinogenic HPV genotypes, including HPV53. hc2 signal strength [relative light units per positive control (RLU/CO)] was used as semiquantitative measure of HPV viral load (''HPV semiquantitative viral load''; ref.…”

“…We included HPV66 in our definition because it was recently reclassified as a carcinogenic HPV genotype (32), and it is well known that hc2 strongly detects HPV66, although it is not one of the 13 genotypes directly targeted by hc2 (25,26,27). In fact, in a previous analysis, we found hc2 to be more likely to be positive in the presence of HPV66 than in the presence of HPV68, one of the hc2-targeted HPV genotypes.…”

Human Papillomavirus Genotype Specificity of Hybrid Capture 2

“…However, hc2 has exhibited cross-reactivity with untargeted, noncarcinogenic HPV genotypes (12,28,29,33,41,42,45,49), which further reduces the already suboptimal clinical specificity and positive predictive value of HPV testing (12). Its cross-reactivity is most pronounced in women with cytologic changes who often harbor multiple, noncarcinogenic HPV genotypes concurrently and/or have higher viral loads (12).…”

“…The HPV genotypes most commonly found to cause hc2 cross-reactivity are HPV genotype 53 (HPV53) and HPV66, the latter of which has recently been deemed to be a carcinogenic HPV genotype (15) and therefore probably increased the clinical sensitivity of hc2. Earlier studies of hc2 (12,28,29,33,41,42,45,49) were based on single tests by research and prototype HPV genotyping assays, raising the possibility that some of the cross-reactivity resulted from misclassification by the HPV genotyping assay related to: (i) single testing of small aliquots for genotyping; (ii) modest analytic sensitivity; (iii) testing errors; and (iv) "drop out" of genotypes in multigenotype HPV infections due to PCR primer competition. Thus, the ability to describe the cross-reactivity of hc2 has been limited by the imperfections of referent standards used to detect HPV genotypes present in cervical specimens.…”

Study Comparing Human Papillomavirus (HPV) Real-Time Multiplex PCR and Hybrid Capture II INNO-LiPA v2 HPV Genotyping PCR Assays

“…Several PCR-based methodologies have been developed to amplify and detect HPV DNA (1,4,7,8,9,12,13). Many of these methodologies exploit the high homology found within specific open reading frames (ORFs) across different HPV types through the use of consensus or degenerate primer pairs that are capable of PCR amplifying numerous HPV types present in a sample.…”