Supersensitive Viral Load Assay in Predicting CD4-Guided Treatment Failure

Abstract

Abstract:In HIV patients who discontinue highly active antiretroviral therapy (HAART), the degree of HIV RNA suppression at the time of treatment interruption may predict success of re-treatment after the interruption (STI). A casecontrol substudy of the Staccato trial in Thailand included CD4-guided STI subjects with HIV RNA > 50 copies /ml (virological failure cases, n=11) and HIV RNA < 50 copies/ml (controls, n=22) after 12-24 weeks of HAART re-treatment following a median of 2 STI cycles. Controls were matched for age, gender and pre-ART CD4 count. HIV RNA with 5 copies/ml detection limit was determined on pre-virological failure samples. HIV RNA increased in cases compared to controls with each successive STI cycle (p-trend across time-points 0.004). The last HIV RNA below 50 copies/ml was significantly higher among cases compared to controls (p=.004). Measuring HIV RNA below 50 copies/ml may be useful in predicting virological failure to STI.

Standardization and performance evaluation of “modified” and “ultrasensitive” versions of the Abbott RealTime HIV-1 assay, adapted to quantify minimal residual viremia

“…maintaining viral load suppression below detectable levels of methods more sensitive than routine HIV RNA tests is predictive of more durable response to ART 29,30 ; v. when intermittent interruption of treatment or simplification of treatment are considered, the levels of MRV at the time of treatment interruption may predict virological failure. 18,31 Therefore, in some instances, when a treatment interruption regimen is being considered, evaluation of MRV may help to take a decision. 32 Different lines of evidence support that, in patients with long lasting suppression of viremia due to ART, ongoing replication of HIV occurs, 11,22 and that cells different from CD4 T cells harbor replication-competent provirus and may be the source of low level viremia.…”

“…Then, virologists are faced with increasing demands for dosing MRV. To meet this requirement, different methods have been currently described, based either on modified commercial systems, 31,34,35 or on home-made methods. 6,15,16 However, the results obtained with these methods are not directly comparable, for general lack of standardization.…”

Predicting Time to Achieving Viral Load Less Than 50 Copies/ml in HIV Infected Patients on Antiretroviral Therapy: a Cohort Study

“…The effect of HAART is to suppress VL below the level of detection and this occurs in the first weeks after start of therapy [9]. Increases in CD4 cell counts during treatment with HAART and reaching undetectable level of VL are also significantly associated with a better prognosis [10]. In another study VL concentration declined quickly in many, but not all, HIV patients with substantial increases in CD4 counts within months of starting HAART [6].…”