Three-year clinical outcomes of resistance genotyping and expert advice: extended follow-up of the Argenta trial.
OBJECTIVE
To investigate the influence of genotypic resistance-guided HIV-treatment decisions on long-term clinical and virological outcomes in patients failing antiretroviral therapy by a prospective 30-month observation following a 6-month randomized study (Argenta trial).


METHODS
Patients (n=174) with virological failure on highly active antiretroviral therapy (HAART) were initially randomized (1:1) to receive empirical therapy or guidance by genotypic resistance results. After month 6, all patients with HIV RNA >1,000 copies/ml received genotypic resistance tests and expert advice. Predictors of virological and clinical outcomes were analysed by logistic regression and Cox's regression models.


RESULTS
There was a gradual increase in the proportion of patients with HIV RNA <400 copies/ml with 29.3% at 36 months (intent-to-treat) without differences between initial randomization arms. Independent predictors of 36-month virological response were the use of a salvage therapy with less daily doses and a more pronounced 3-month viral load drop. At 36 months, 84% survived without new AIDS events/death. Independent predictors of new AIDS events/death were previous AIDS events, higher baseline viral load, less pronounced 3-month viral load drop and, in a separate model, baseline protease substitutions K20M/R and 184V.


CONCLUSIONS
The virological benefit of genotype-guided treatment decisions was continuously appreciable over time. Short-term virological response and viral cross-resistance were independent predictors of long-term outcomes.
De Luca
Andrea
A
Istituto di Clinica delle Malattie Infettive, Università Cattolica del Sacro Cuore, Rome, Italy. andrea.deluca@rm.unicatt.it
Di Giambenedetto
Simona
S
Cingolani
Antonella
A
Bacarelli
Alessandra
A
Ammassari
Adriana
A
Cauda
Roberto
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D023241:Antiretroviral Therapy, Highly Active; D024882:Drug Resistance, Viral / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology / Q000821:virology; D016333:HIV Protease / Q000235:genetics; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood; D017211:Treatment Failure; D016896:Treatment Outcome
D012367:RNA, Viral; D016333:HIV Protease