Disagreement in high-grade/low-grade intraepithelial neoplasia and high-risk/low-risk HPV infection: clinical implications for anal cancer precursor lesions in HIV-positive and HIV-negative MSM.

Anal condylomata are common in HIV-positive individuals and among men who have sex with men (MSM). Generally attributable to infection by low-risk human papillomaviruses (HPVs), condylomata are considered benign low-grade squamous intraepithelial lesions (SILs). However, anal condylomata have occasionally been linked to high-grade SIL and to oncogenic, high-risk HPVs. Here we describe the range of intraepithelial lesions and of the associated HPVs in heterosexual men and women and MSM. Perianal and anal condylomata were collected from 243 patients (56 heterosexual women, 61 heterosexual men and 126 MSM, including 41 HIV-positive MSM). We assessed lesion histology and HPV genotype. Prevalence estimates and Poisson models were used. Irrespective of HIV infection status, MSM showed a higher proportion of condylomata as high-grade SILs compared to heterosexual men/women. High-grade SILs were also more prevalent in anal than in perianal lesions in all patient groups. HIV-positive MSM exhibited increased prevalence ratio (4.6; 95% confidence interval 2.1-10.0) of perianal low-grade SILs containing only high-risk HPVs compared to HIV-negative MSM. In addition, more than 64% of anal SILs with a high-grade component, regardless of HIV infection, were exclusively associated with low-risk HPVs. In anal condylomata, both high-grade and low-grade SILs can be associated with high-risk and/or low-risk HPVs. Particularly, low-grade perianal SILs associated with high-risk HPVs were common in HIV-positive MSM, while presence of only low-risk HPVs in high-grade SILs were common in both MSM groups. Our findings sound a note of caution for the common clinical practice for the treatment of anal condylomata as benign lesions in MSM and HIV-positive patients.

Interlaboratory reproducibility and proficiency testing within the human papillomavirus cervical cancer screening program in Catalonia, Spain.

In Catalonia, a screening protocol for cervical cancer, including human papillomavirus (HPV) DNA testing using the Digene Hybrid Capture 2 (HC2) assay, was implemented in 2006. In order to monitor interlaboratory reproducibility, a proficiency testing (PT) survey of the HPV samples was launched in 2008. The aim of this study was to explore the repeatability of the HC2 assay's performance. Participating laboratories provided 20 samples annually, 5 randomly chosen samples from each of the following relative light unit (RLU) intervals: <0.5, 0.5 to 0.99, 1 to 9.99, and ≥10. Kappa statistics were used to determine the agreement levels between the original and the PT readings. The nature and origin of the discrepant results were calculated by bootstrapping. A total of 946 specimens were retested. The kappa values were 0.91 for positive/negative categorical classification and 0.79 for the four RLU intervals studied. Sample retesting yielded systematically lower RLU values than the original test (P<0.005), independently of the time elapsed between the two determinations (median, 53 days), possibly due to freeze-thaw cycles. The probability for a sample to show clinically discrepant results upon retesting was a function of the RLU value; samples with RLU values in the 0.5 to 5 interval showed 10.80% probability to yield discrepant results (95% confidence interval [CI], 7.86 to 14.33) compared to 0.85% probability for samples outside this interval (95% CI, 0.17 to 1.69). Globally, the HC2 assay shows high interlaboratory concordance. We have identified differential confidence thresholds and suggested the guidelines for interlaboratory PT in the future, as analytical quality assessment of HPV DNA detection remains a central component of the screening program for cervical cancer prevention.