Genotypic resistance in HIV-1-infected patients with persistently detectable low-level viremia while receiving highly active antiretroviral therapy.
BACKGROUND
Technical limitations in the sensitivity of commercial genotyping methods may prevent clinicians from determining whether drug-resistant human immunodeficiency virus type 1 (HIV-1) is present in patients with low-level viremia. We performed ultrasensitive HIV-1 genotyping for patients with persistent plasma virus loads of 50-400 copies/mL to better define the prevalence of drug resistance and the most common resistance mutations during persistently detectable low-level viremia.


METHODS
Genotyping of HIV-1 was performed with an ultrasensitive clonal genotyping method.


RESULTS
We studied 21 patients who had persistent, detectable, low-level viremia for a median of 11 months. Nine (43%) of 21 patients had HIV-1 isolates with significant resistance mutations. The most common mutations were M184V, K65R, and M41L/T215Y.


CONCLUSIONS
The finding that clinically significant resistance mutations were present in some but not all patients with persistent viremia (range, 50-400 copies/mL) highlights the need to improve the sensitivity of current clinical assays for detection of drug resistance.
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Richard E
RE
Nettles
Tara L
TL
Kieffer
Rachel P
RP
Simmons
Joseph
J
Cofrancesco
Richard D
RD
Moore
Joel E
JE
Gallant
Deborah
D
Persaud
Robert F
RF
Siliciano
D000328:Adult; D000368:Aged; D019380:Anti-HIV Agents / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D019562:Viral Load; D014766:Viremia / Q000821:virology*
D019380:Anti-HIV Agents