The aim of this study is to evaluate the discordant results between Cobas 4800 HPV test and E6/E7 mRNA Aptima HPV Assay.
We have studied 736 cervical samples, which were obtained from women attending gynecology practitioners, in the cervical pathology unit from our hospital, in a routine cervical cancer screening program.
All specimens were collected with PreservCyt transport medium.
Each sample was analyzed with Cobas 4800 HPV (Roche Molecular System, Inc ), E6/E7 mRNA-based Aptima® HPV (AHPV; Hologic, Inc) and the discordant results between them, were analyzed by Linear Array HPV Genotyping test (Roche Molecular System Inc)
In each patient we made Pap smears, and byopsy and p16 when the patient required it.
Statistics analyses was done with SPSS 18 for windows.
The average age was 38.02 (19-90).
The prevalence of HPV in each test is shown in Table 1
| HPV | DNA Cobas 4800 | mRNA AHPV |
| Positive | 50.1% (369) p=0.032 | 41.0% (302) |
| Negative | 49.9% (367) | 59.0% (434) |
Kappa value DNA Cobas 4800 = 0.834 ; Kappa value mRNA AHPV =0.805
We calculated the sensitivity and specificity for both techniques:
mRNA E6/E7 AHPV sensitivity = 0.83 [95% CI: 0.79-0.87] specificity = 0.99 [95% CI: 0.94-0.99]
Cobas 4800 DNA sensitivity = 0.94 [95% CI: 0.91-0.96] specificity = 0.90 [0.95% CI: 86-0.92]
Our Pap smear distribution, and the frequency of HPV in each category is shown in Table 2
| Cytology | % Cobas 4800 Positive | % APTIMA Positive |
| Negative (n=450) | 28.4 | 20.4 |
| ASCUS (n=56) | 75.0 | 62.5 |
| LSIL (n=108) | 85.1 | 74.1 |
| HSIL (n=112) | 91.9 | 84.0 |
10 samples were AHPVpositive/Cobas 4800 Negative. Eight of them were negative in the Linear Array Genotyping test. Regarding the two remaining samples, one was positive for HPVs 42+51 and the other was positive for HPVs 16+35+42+51
74 samples were AHPV negative/Cobas 4800 positive:
- 2 cases out of 74 were negative in Linear Array Genotyping test.
- In the remaining 72 cases: HPV 16 was present in 27% of these cases, HPV 18: 1.7%, HPV 31: 5.4%, HPV 33: 2.7%. All the remaining samples were positives for other HPV genotipes.
50% of them were coinfected with two or more viruses.
According to our data, the sensitivity of Cobas 4800 HPV test was higher (p=0.032).
Almost 30% of the samples with discordant result, E6/E7 mRNA-based Aptima HPV negative and Cobas 4800 HPV positive, had HPV 16/18.
In the screening programs of general population, we need to get more data, as E6/E7 mRNA-based Aptima HPV we are going to loose women with high risk HPV 16/18.
[1. Basu P, Banerjee D, Mittal S, Dutta S, Ghosh I, Chowdhury N, Abraham P, Chandna P, Ratnam S. Sensitivity of APTIMA HPV E6/E7 mRNA test in comparison with hybrid capture 2 HPV DNA test for detection of high risk oncogenic human papillomavirus in 396 biopsy confirmed cervical cancers. J Med Virol. 2015 Dec 22.doi:10.1002/jmv.24453]