Late Breaking News
- Categorized in: April 2009 Issue
DNA Test for Two Types of HPV Approved
The ﬁrst DNA test that identiﬁes the two types of human papillomavirus that cause the majority of cervical cancers among women in the United States was approved last month by the Food and Drug Administration. The test, called Cervista HPV 16/18, detects the DNA sequences for HPV type 16 and HPV type 18 in cervical cells. Differentiating these HPV types gives healthcare professionals more information on a patient’s risk of subsequently developing cervical cancer. A positive Cervista 16/18 test result indicates whether HPV type 16, 18 or both types are present in the cervical sample.
The FDA also approved the Cervista HPV HR test, which is the second DNA test that detects essentially all of the high-risk HPV types in cervical cell samples. The Cervista HPV HR test uses a method similar to the Cervista HPV 16/18 test to detect the DNA sequences of these HPV types. In women age 30 and older or women with borderline cytology, the Cervista HPV 16/18 test can be used together with cytology and the Cervista HPV HR test to assess risk of cervical disease.
HPV is the most common sexually transmitted infection in the United States. The U.S. Centers for Disease Control and Prevention estimates that more than 6 million Americans become infected with genital HPV each year and that more than half of all sexually active women and men become infected at some time in their lives.
For most women, the body’s own defense system clears the virus and infected women do not develop related health problems. However, some HPV types can cause cell abnormalities on the lining of the cervix that later can become malignant. While there are many different types of HPV, types 16 and 18 cause about 70 percent of all cervical cancers.
Cervista HPV 16/18 and Cervista HPV HR are manufactured by Madison, Wis.-based Third Wave Technologies.
FDA Assesses Anthrax-Detecting Nanotech
The Food and Drug Administration has completed a “proof-of-concept” study of a test that quickly and accurately detects the presence of even the smallest amount of the deadly anthrax toxin. The proof-of-concept study developed by FDA researchers relies on a nanotechnology-based test platform built from tiny molecular-sized particles. This assay, the europium nanoparticle-based immunoassay (ENIA), was able to detect the presence of a protein made by the anthrax bacteria known as protective antigen (PA). PA combines with another protein called lethal factor to form anthrax lethal factor toxin, the protein that enters cells and causes toxic effects.
The researchers showed that ENIA is capable of detecting PA in quantities that are 100 times lower than current tests, such as the enzyme-linked immunosorbent assay (ELISA). Both the ELISA and ENIA rely on antibodies that have an afﬁnity for the anthrax protein of interest.
The FDA test is a modiﬁ ed version of ELISA, which is already commonly used to detect anthrax and other infections. The researchers call their new test “europium nanoparticle-based immunoassay,” because atoms of europium are key to the assay’s sensitivity.
The ENIA uses molecular spheres (called nanospheres) covered with thousands of light-emitting atoms of europium, which acts as a signal that PA is present. The CBER team further enhanced the signal by modifying the nanospheres so they held additional atoms of europium, making the test more sensitive.
The ENIA detected PA in 100% of samples of mouse plasma compared to 36.4% through ELISA.