Genotypic susceptibility score (GSS) and CD4+ T cell recovery in HIV-1 patients with suppressed viral load

• Published in: Journal of antimicrobial chemotherapy Vol. 72; no. 2; pp. 496 - 503
• Main Authors: Gonzalez-Serna, Alejandro, Glas, Arie C, Brumme, C J, Poon, Art F Y, Nohpal De La Rosa, Adriana, Mudrikova, Tania, Dias Lima, Viviane, Wensing, Annemarie M J, Harrigan, Richard
• Format: Journal Article
• Language: English
• Published: England 01.02.2017
• Subjects: Adult; Anti-HIV Agents - therapeutic use; Antiretroviral Therapy, Highly Active; CD4 Lymphocyte Count; CD4-Positive T-Lymphocytes - immunology; Drug Resistance, Viral; Female; Genetic Predisposition to Disease - genetics; HIV Infections - drug therapy; HIV Infections - virology; HIV-1 - drug effects; HIV-1 - immunology; Humans; Male; Middle Aged; Viral Load - immunology; Viremia - immunology; Viremia - virology
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkw455

HIV drug resistance, measured by the genotypic susceptibility score (GSS), has a deleterious effect on the virological outcome of HIV-1-infected patients. However, it is not known if GSS retains any predictive value for CD4 recovery in patients with suppressed viral load. Four hundred and six patients on virological failure (>500 copies/mL) with GSS  : <6 months prior to switch therapy who achieved undetectable plasma viral load (<50 copies/mL) within 1 year, remained undetectable >1 year on an unchanged regimen and had CD4 data available during entire follow-up were included. Adjusted and unadjusted analyses of all characteristics at switch related to CD4 recovery were made for three time frames: (i) 'switch-suppression'; (ii) 'suppression-1 year'; and (iii) 'switch-1 year'. Higher GSS was associated with a greater CD4 recovery between 'switch' and '1 year' in the unadjusted analysis (P = 0.010); however, the effect of GSS was no longer statistically significant after adjusting for pre-switch clinical (CD4 count and plasma viral load) and demographic variables. Furthermore, only a lower pre-switch CD4 count was associated with increased CD4 recovery in the 'suppression-1 year' period in both unadjusted and adjusted models. The main CD4 recovery occurred in 'switch-suppression' and the variables associated, both unadjusted and adjusted, were CD4 and plasma viral load at switch, maintaining a trend for GSS (P = 0.06). In individuals who re-suppressed HIV viraemia after switching therapy, regimens having a higher GSS were associated with improved CD4 recovery only during the period from switch to virological suppression, but, once viral load is re-suppressed, the GSS of the new regimen has no further effect on subsequent CD4 recovery.