A More Complete HPV Test

Saturday, June 1, 2013

HealthEast Medical Laboratory (HML) is dedicated to providing physicians the most comprehensive, sensitive human papillomavirus (HPV) testing on the market.

In 2007, HML tapped the Access Genetics HPV L1 platform as its HPV test methodology of choice. The test, which follows rigid standards set forth by the Clinical Laboratory Improvement Amendments of 1988 (CLIA 88), is more sensitive and identifies more HPV types than the four U.S. Food and Drug Administration (FDA) approved tests, which only identify the presence of a limited number of HPV types — a problematic limitation, as more than 40 types of HPV are transmittable, according to the National Cancer Institute.

Casting a Larger Net

Jessica Sedivy Gunderson, CT/MB (ASCP), cytologist/molecular pathology technical specialist, anatomic pathology at St. Joseph’s Hospital, reports that the Access Genetics HPV L1 platform detects nearly double the amount of HPV strains than other tests.

“There are more than 100 different types of HPV, and more types are continually being discovered,” Sedivy Gunderson says. “Many of the commercial tests on the market test for a cocktail of about 13 to 14 different types of HPV. The Access Genetics HPV L1 platform allows us to catch 14 to 15 additional types of HPV that are believed to be of intermediate to high risk for the development of cervical cancer. Because we’re able to capture more types of HPV, we get a more complete picture.”

Carl McGary, M.D., Ph.D., anatomic pathologist, Medical Director of the histology lab, and Medical Director of the histopathology and cytology lab at St. Joseph’s Hospital, says one of the Access Genetics HPV L1 platform’s strengths is its initial evaluation for any HPV presence.

“Most other HPV platforms have probes for many of the common HPV types but not for all of the HPV types,” Dr. McGary explains. “The Access Genetics test doesn’t rely on a cocktail of probes to look for the common HPV types or sequences to decide if there’s an HPV infection. Instead, it does an initial screen looking for any HPV sequences. If any are detected, then we perform further work to identify which type of HPV it is and classify it as high, low or unidentified risk. This way, other HPV types are not excluded in the identification process.”

Sedivy Gunderson notes that the HPV L1 platform also enables physicians to track individual types of HPV over time.

“The test can be used as a great tool for physicians,” Sedivy Gunderson explains. “By identifying the specific type of HPV, physicians can track whether patients have persistent HPV that lasts year to year, or if they’re clearing transient HPV infections.”

According to the Centers for Disease Control and Prevention, most women infected with HPV clear the infection (approximately 44% in two years to 80% or more within 10 years), but it becomes persistent in some. However, patients with compromised immune systems have a higher risk of the infection progressing to cancer, so the ability to track the infection’s transience is important, Dr. McGary notes.

“The Access Genetics HPV L1 platform enables us to distinguish whether or not a patient’s HPV infection is the same type from one year to the next,” Dr. McGary says. “Identifying an HPV infection that has persisted for several years is more significant because persistent infections entail a greater risk for progression to cancer, and preventing invasive cancer is what this is all about.”

Tracking all types of HPV is beneficial, as the infection can evolve and its carcinogenicity can change. In fact, HPV experts recently reclassified several types of HPV that were previously considered low risk as having probable high risk for cancer, Dr. McGary notes.

“There’s value in classifying the low-risk types because we’re not sure how the virus will continue to evolve,” Sedivy Gunderson says. “This platform allows us to track how patients do in the long term.”

Dr. McGary adds that, for this reason, HML has a policy of reporting low-risk HPV rather than not including its discovery on test results.

Preventing Contamination

HML controls personnel access, ventilation and workflow to its two polymerase chain reaction labs, enabling technologists to maintain quality-assured practices that prevent sample contamination. The two labs also allow HML to meet the increasing demand for simultaneous Pap and HPV testing, Sedivy Gunderson explains.

“Running Pap tests and HPV tests concurrently allows us to keep both tests together throughout the entire process, from the time we receive the specimens to the time they’re signed out, whether it be by a pathologist or cytotechnologist,” she says. “Keeping both tests together gives us a good picture of the results, and we feel that’s better for the patient.”

Professional Integrity

In addition to adhering to CLIA 88 standards, HML undergoes an inspection by the College of American Pathologists every two to three years, according to Dr. McGary.

Sedivy Gunderson adds that professional rectitude guides HML’s decision to provide the best HPV test available.

“We would not run a test if we did not believe in its integrity,” Sedivy Gunderson notes. “We take this very seriously.”

For more information about HPV and other testing at HealthEast Medical Laboratory, please visit www.healtheast.org/hml or call (651) 232-3500.