Virulent New HIV Strain Identified

A virulent, multi-drug resistant strain of HIV was recently identified in a patient in New York (NY, USA) who rapidly progressed to AIDS.

Following initial evaluation at the Aaron Diamond AIDS Research Center (ADARC) in New York, an isolate was sent to ViroLogic, Inc. (South San Francisco, CA, USA), which used the company's PhenoSense, GeneSeq, and Entry assays to assess resistance. Additional testing was performed by Virologic using several newer assays. ViroLogic's analysis confirmed the data from ADARC and revealed therapeutic options that informed the selection of a drug regimen for the patient.

ViroLogic's Entry assay demonstrated that the virus was susceptible to enfuvirtide (Fuzeon), the only commercially available entry-inhibitor drug. Analysis also identified the cellular receptors that this virus uses to enter CD4 cells, the targets of viral infection. Test results showed that the virus uses a receptor that has been linked to accelerated immune destruction and rapid progression to clinical AIDS. Viruses with significant resistance often replicate less well than wild-type viruses. In this case, however, the ViraLogic replication capacity (RC) assay indicated that the virus replication was comparable to most wild-type strains.

"This episode serves as a sobering reminder of the potential danger of transmitted resistant viruses,” said David HO, M.D., scientific director and CEO of ADARC and a professor at The Rockefeller University (NY, NY, USA). "While we see triple-class resistance fairly commonly in patients with a long history of antiretroviral drug experience, this case is noteworthy in that a single virus harbors triple-class resistance, a high RC, and CXCR4 receptor tropism in the setting of recent infection.”

"This case reinforces the importance of resistance testing in the management of HIV patients,” commented Michael Bates, M.D., vice president of clinical research at ViroLogic.




Related Links:
ViroLogic