FDA approves test for early diagnosis of AIDS from HIV antigen

14 July 2010

The US FDA has approved an innovative new diagnostic tool from Abbott that can detect the AIDS antigen and give a diagnosis of AIDS earlier than ever before.

Abbott's Architect HIV Ag/Ab Combo assay is the first test approved in the United States that can simultaneously detect both HIV antigen and antibodies.

HIV antigen is a protein produced by the virus immediately after infection, whereas antibodies are developed days later as the body works to fight off the infection. Studies have demonstrated that Abbott's new test may detect HIV days earlier than antibody-only tests, which is important in controlling the spread of the virus.

Every nine and a half minutes, someone in the United States is infected with HIV, and one out of every five of these individuals doesn't know it. So an early diagnosis can help stem the spread of this disease.

"Since individuals are most infectious to others shortly after infection, detecting HIV earlier is critical and life saving," said Peter Leone, M.D., medical director, North Carolina HIV/STD Prevention and Control Branch, University of North Carolina, Chapel Hill.

"A significant percentage of new HIV infections are transmitted by someone with an undetected acute infection, so identifying more people earlier offers a significant opportunity for counselling, which can reduce high-risk behaviours and also initiate antiretroviral treatment for early-stage infection, if appropriate."

Studies conducted by the US Centers for Disease Control and Prevention (CDC) show that current antibody-only tests miss up to 10 percent of HIV infections in some high- risk populations because they do not detect antigens. However, Abbott's new assay detects the HIV p24 antigen, or the direct presence of HIV, allowing for diagnosis of early infections days before antibodies emerge.

"Abbott has long been a pioneer in HIV testing — from the world's first test to detect HIV antibodies in 1985 — to second and third generation immunoassay and molecular tests, and now the development of the country's first antigen and antibody combination test," said Brian Blaser, senior vice president, Diagnostics, Abbott. "Abbott is committed to fighting HIV and to bringing novel tests to physicians in order to help patients get the care they need as soon as possible."

This new test will run on Abbott's Architect family of diagnostic testing instruments. It is already approved for use outside the United States. In Europe, HIV antigen-antibody combination testing is routine in public health settings and HIV testing guidelines in the United Kingdom now direct clinicians to use the HIV combination test as the first-line test.