HIV Treatment Bulletin - Vol. 5, No. 6, July 2004
Simon Collins, HIV I-Base

Two articles published last year (Blanca et al J Biol Chem. 2003 May 2;278(18):15469-72, Baldanti et al AIDS. 2003 Jul 4;17(10):1568-70) reported that resistance to d4T (stavudine) was related to the nevirapine-associated Y181C mutation. This included a report that Y181C/I should eight fold resistance to d4T in a recombinant virus assay.

Prompted by the important implications of such cross-resistance on current interpretation systems for resistance reports Klaus Korn from the University of Erlangen-Nuremberg looked for corroborative evidence from a database of 500 RT genotype samples and corresponding phenotypic data to d4T.

427/511 samples without Y181C showed a median resistance factor for d4T of 1.8 (IQR 1.0-2.9). The 84/511 samples with Y181C had a corresponding resistance factor of 2.7 (IQR 1.3-5.4). However this difference was explained by strong linked to RTI mutations in the same sequences. The 3/84 samples without RTI resistance had resistance factors of 1.0, 1.1 and 1.4. Similarly only 16/59 samples with phenotypic resistance to d4T > 8-fold had Y181C.

The study therefore failed to find an association between Y181C and d4T sensitivity and concluded that d4T should not be avoided as a treatment option on the basis of this genotypic mutation.

Ref: Korn K, Schmidt B, Walter H. No evidence for stavudine resistance due to nevirapine-selected mutation Y181C in HIV-1 reverse transcriptase in a large genotype/phenotype database. Antiviral Therapy 2004; 9:S49 (abstract 43).

040710
IB040506-07

©2004. I-BASE HIV Treatment Bulletin. Permission to reproduce courtesy of HIV i-Base, Third Floor East, Thrale House, 44-46 Southwark Street, London SE1 1UN - T: +44 (0) 20 7407 8488 F: +44 (0) 20 7407 8489

AEGiS is a 501(c)3, not-for-profit, tax-exempt, educational corporation. AEGiS is made possible through unrestricted grants from Boehringer Ingelheim, Elton John AIDS Foundation, John M. Lloyd Foundation, the National Library of Medicine, and donations from users like you. Always watch for outdated information. This article first appeared in 2004. This material is designed to support, not replace, the relationship that exists between you and your doctor.

AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.

Copyright ©1980, 2004. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content.