HTLV-II common among drug abusers.

HTLV-II common among drug abusers

Using a sensitive genetic technique that distinguishes one HTLV virus from the other, scientists have found a surprisingly high percentage of a sample of New Orleans intravenous drug abusers infected with a retrovirus known as HTLV-II, or human T-cell leukemia virus type II. By studying the effects of HTLV-II infection on this newly identified group of asumptomatic individuals, scientists should be able to learn for the first time whether this virus is associated with a human disease, says study coauthor Irvin S.Y. Chen, a molecular biologist at the University of California, Los Angeles, School of Medicine.

"The identification of HTLV-II in drug abusers in this country raises the possibiliby that it might cause disease. It's another virus that blood banks and organizations that work with blood need to be aware of," Chen says. Among 121 people screened, 23 were confirmed to carry some form of HTLV. Of those carriers, 21 were positive for HTLV-II and 2 for HTLV-I, suggesting HTLV-II is the predominant form among New Orleans intravenous drug abusers, report Chen and his co-workers in the April 28 SCIENCE. Intravenous drug abusers frequently harbor some form of HTLV, which can be transmitted through blood products.

In contrast to HTLV-I, known to cause adult T-cell leukemia, HTLV-II previously had been isolated in fewer than half a dozen people and cannot be definitively blamed for any ailment. The antibody tests most commonly used to identify HTLV distinguish poorly between the two HTLV types. In fact, these tests indicated that all the screened individuals in the study were infected with HTLV-I, says study coauthor Joseph D. Rosenblatt.

The team's technique rapidly and unambiguously discriminates between HTLV-I and HTLV-II, Chen says. It is a modified version of the polymerase chain reaction, which involves the amplification of small bits of viral DNA.