PhenoSense assay bests Antivirogram in HIV analysis

NEW YORK (Reuters Health) - The PhenoSense assay (ViroLogic) shows advantages over the Antivirogram assay (Virco) in gauging HIV susceptibility to certain nucleoside reverse transcriptase inhibitors, researchers report in the April 1st issue of the Journal of Acquired Immunodeficiency Syndromes.

Senior investigator Dr. Robert W. Shafer told Reuters Health that the data "unequivocally show that the PhenoSense assay is superior to the Antivirogram assay for detecting drug resistance to those nucleoside reverse transcriptase inhibitor that have a narrow drug susceptibility range -- that is -- a small decrease in susceptibility is clinically significant."

Dr. Shafer and colleagues at Stanford University in California note that although these two assays are widely used, their precision and sensitivity have not been assessed.

To do so, initially using about 300 isolates, the researchers analyzed susceptibility results obtained by the assays. There were no significant differences between the two assays in detecting protease inhibitor and non-nucleoside reverse transcriptase inhibitor drug resistance.

However, the team found that the PhenoSense assay was significantly better than the Antivirogram in detecting resistance to abacavir, didanosine and stavudine.

Dr. Shafer added that the findings also show the "importance of public -- nonproprietary -- databases for allowing comparisons of this sort to be made in an objective manner."

"Despite the fact that these tests have been used by thousands of patients," he concluded, "our study has been the only comparison of precision and sensitivity, because most of the data have been locked in the proprietary databases of each company."

Source: J Acquir Immune Defic Syndr 2005;38:439-444. [ Google search on this article ]

MeSH Headings: Drug Resistance, Multiple