Women who receive a kidney transplant have a higher risk of developing HPV-related premalignant lesions of the genital tract, according to a new study published in the American Journal of Transplantation.
Chronic immune suppression in renal transplant patients increases the risk of viral infections, which puts recipients at increased risk of viral-associated cancers. Previous research shows male renal transplant recipients were at increased risk of infection with the human papillomavirus, or HPV. The new study shows women are at risk as well.
About 79 million people in the United States have HPV, according to the Centers for Disease Control and Prevention (CDC). HPV is so common that most people get an HPV infection at some time in life, which can cause genital warts and cancer.
Human papillomaviruses are small viruses that contain a double-stranded, circular DNA genome of approximately 7,900 base pairs. HPVs are a group of about 200 viruses, according to the National Cancer Institute.
Sexually transmitted HPVs can be low-risk HPVs that can cause skin warts or high-risk HPVs that can cause cancer. Researchers have identified about a dozen high-risk HPVs. Two of these, HPV types 16 and 18, are the cause of most HPV-related cancers.
High-risk HPVs (hrHPVs) cause several types of cancer. Nearly all cases of cervical cancer are the result of hrHPVs and just two types, 16 and 18, cause about 70 percent of all cervical cancers. HPV causes about 95 percent of all cases of anal cancer, 70 percent of all oropharyngeal cancers, 65 percent of vaginal cancers, 50 percent of vulvar cancers and 35 percent of penile cancers.
Researchers from the Radboud University Medical Center in the Netherlands and colleagues created the study to assess the prevalence of genital HPV in female renal transplant recipients before and after transplantation.
The scientists enrolled female patients receiving counseling for renal transplantation (RT) at Radboud University Medical Center. The researchers performed gynecological examinations at the first visit, and again at one and two years later. The participants participated in HPV self-sampling and answered questionnaires of sexual behavior every three months during the study. HPV self-sampling is an at-home testing alternative to clinical sampling.
The researchers used the highly sensitive SPF10-LiPA25 test, an in vitro reverse hybridization strip assay for the qualitative identification of DNA from several HPV genotypes, to assess prevalence of 13 individual hrHPV types and 22 low-risk HPV types. They also used the clinically validated cobas HPV Test that identifies 14 high-risk HPV types.
In 65 patients who underwent RT, SPF10-LiPA25 showed that hrHPV prevalence increased significantly from 19 percent before renal transplantation to 31 percent after the procedure. The cobas HPV test results showed hrHPV prevalence increased from 10 percent before to 14 percent after renal transplantation.
Thirty-three participants did not undergo renal transplantation. Participants in this group had an hrHPV prevalence of 21 percent at the beginning of the study and of 27 percent after 12 months with the sensitive SPF10-LiPA25 test. They also had a stable prevalence of 16 percent with the clinically validated cobas test.
The participants reported no changes in sexual behavior during follow-up, which rules out new infection and indicates reactivation of latent HPV.
The results of the study suggest activation of latent HPV infections might contribute to an increased risk of HPV-related pre-malignant lesions in female renal transplant recipients.
