At this time, the Writing Group does not recommend the use of CD4 T-cell percentage to monitor disease progression in adult patients with HIV-1 infection. There are exceptions to this rule: individuals with splenectomy and patients with Human T-lymphotropic virus Type 1 (HTLV-1) coinfection [9, 10] may have a CD4 lymphocytosis and, in this instance, CD4 T-cell counts may give a misleading impression as to the true extent of

immune deficiency. Patients with these conditions should be monitored using CD4 T-cell percentage and ART should be offered to individuals with values of 21% or lower. A significant discrepancy between CD4 T-cell count and percentage should alert clinicians to potentially reversible causes of immune deficiency such as steroid and/or cytotoxic therapies, and intercurrent sepsis. Primary HIV infection is associated with a high plasma viral load. This declines about 4–6 months after infection BIBW2992 solubility dmso to a nearly steady level, with a small but appreciable increase observed over time during the asymptomatic phase of the infection [1, 2]. The viral load increases sharply again

in advanced disease, coinciding with the onset of AIDS. It has been long established that the set-point viral load is a strong predictor of the rate of disease progression [3-5]. While viral load results are generally highly reproducible, at least two values are required for patients with chronic Panobinostat infection to establish a firm set point [6]. Subsequent measurements can be taken every 6 months in asymptomatic stable

patients not receiving ART. A further measurement should be taken prior to initiation of therapy if a recent value is not available. While the CD4 T-cell count is the main driver for initiation of ART, the viral load provides additional guiding information, especially in patients with a relatively high CD4 T-cell count. In addition, the viral load may influence Tryptophan synthase the choice of antiretroviral agents [7]. The goal of ART is restoration of CD4 T-cell count and suppression of viral load below the quantification limit of commercial viral load assays, until recently 50 copies/mL. Newly introduced viral load assays, typically based on real-time polymerase chain reaction (PCR) technology, have a lower limit of quantification of 40 copies/mL (e.g. Abbott RealTime, Abbott Molecular, Abbott Park, Illinois, USA) or 20 copies/mL (e.g. Roche TaqMan v.2, Roche, Basel, Switzerland) and can report qualitative RNA detection below these thresholds. The interpretation of RNA detection below 50 copies/mL remains difficult in the absence of published evidence. While lack of RNA detection during ART may be regarded as a desirable outcome, evidence indicates that HIV-1 RNA persists at a low level in the plasma of treated patients who maintain suppression <50 copies/mL for several years [8].