New addition to herpes family.

New addition to herpes family

The herpesvirus family may have gained a new member last month. Researchers from the National Cancer Institute and five other institutions isolated a novel herpesvirus from six patients who had unusually high levels of a type of white blood cell known as a B lymphocyte.

Electron microscopy of the patients' blood revealed large, short-lived cells containing a virus that by size and shape belongs to the herpes family. Unlike its relatives, the virus in vitro infects only fresh B cells. Antibodies against the other herpesviruses didn't attach to the new one.

In the Oct. 31 SCIENCE, the discoverers describe isolating the virus from two people who had also been infected with the AIDS virus and four people who had not. They also report finding no evidence of the new virus in 12 other AIDS patients, indicating it is not a necessary factor in AIDS.

Just what sort of problems the virus causes remains to be seen. The four non-AIDS patients in the study had lymph node abnormalities or white-cell cancers. But the virus can also infect with no outward signs--the researchers found it in four of 220 healthy people tested.

Because of its association with high levels of B cells, its discoverers, S. Zaki Salahuddin, Robert C. Gallo and others, have named it human B-lymphotropic virus (HBLV). If that name sounds familiar, it's because of its similarity to HTLV-III (for human T-lymphotropic virus type III), the AIDS virus discovered by Gallo's laboratory.

As the first new herpesvirus in more than 20 years, the virus is likely to receive a lot of attention. It may be responsible for one or more of the many apparently infectious illnesses whose agents have not yet been identified, says Stephen E. Straus of the National Institute of Allergy and Infections Diseases. And it may shed light on other members of the herpes family, he says.

Henry H. Balfour Jr., a herpes expert at the University of Minnesota in Minneapolis, says he was impressed with the research. But he was not impressed with the name, since there already is a B-lymphotropic herpesvirus, the Epstein-Barr virus. Time will tell whether HBLV will go through the name changes of HTLV-III (SN: 4/26/86, p.265; 5/25/85, p.328).