Carlo Mengoli1, Samantha Andreis1, Renzo Scaggiante2, Mario Cruciani3, Oliviero Bosco4, Roberto Ferretto5, Davide Leoni6, Gaetano Maffongelli7, Monica Basso1, Carlo Torti8, Loredana Sarmati6, Massimo Andreoni6, Giorgio Palù1, Saverio Giuseppe Parisi9. 1. Department of Molecular Medicine, University of Padova, Padova, Italy. 2. Infectious Disease Unit, Padova Hospital, Padova, Italy. 3. Center of Diffusive Diseases, Verona, Italy. 4. ULSS-20, Verona, Italy. 5. Clinical Infectious Diseases, Schio Hospital, Schio, Italy. 6. Clinical Infectious Diseases, Tor Vergata University, Rome, Italy. 7. Department of Systems Medicine, Tor Vergata University, Rome, Italy. 8. Unit of Infectious Diseases, University 'Magna Graecia', Catanzaro, Italy. 9. Department of Molecular Medicine, University of Padova, Padova, Italy saverio.parisi@unipd.it.
Abstract
OBJECTIVES: To evaluate the role of pre-treatment co-receptor tropism of plasma HIV on the achievement of viral suppression (plasma HIV RNA 1.69 log10 copies/mL) at the sixth month of combination antiretroviral therapy (cART) in a cohort of naive patients using, for the first time in this context, a path analysis (PA) approach. PATIENTS AND METHODS: Adult patients with chronic infection by subtype B HIV-1 were consecutively enrolled from the start of first-line cART (T0). Genotypic analysis of viral tropism was performed on plasma and interpreted using the bioinformatic tool Geno2pheno, with a false positive rate of 10%. A Bayesian network starting from the viro-immunological data at T0 and at the sixth month of treatment (T1) was set up and this model was evaluated using a PA approach. RESULTS: A total of 262 patients (22.1% bearing an X4 virus) were included; 178 subjects (67.9%) achieved viral suppression. A significant positive indirect effect of bearing X4 virus in plasma at T0 on log10 HIV RNA at T1 was detected (P = 0.009), the magnitude of this effect was, however, over 10-fold lower than the direct effect of log10 HIV RNA at T0 on log10 HIV RNA at T1 (P = 0.000). Moreover, a significant positive indirect effect of bearing an X4 virus on log10 HIV RNA at T0 (P = 0.003) was apparent. CONCLUSIONS: PA overcame the limitations implicit in common multiple regression analysis and showed the possible role of pre-treatment viral tropism at the recommended threshold on the outcome of plasma viraemia in naive patients after 6 months of therapy.
OBJECTIVES: To evaluate the role of pre-treatment co-receptor tropism of plasma HIV on the achievement of viral suppression (plasma HIV RNA 1.69 log10 copies/mL) at the sixth month of combination antiretroviral therapy (cART) in a cohort of naive patients using, for the first time in this context, a path analysis (PA) approach. PATIENTS AND METHODS: Adult patients with chronic infection by subtype B HIV-1 were consecutively enrolled from the start of first-line cART (T0). Genotypic analysis of viral tropism was performed on plasma and interpreted using the bioinformatic tool Geno2pheno, with a false positive rate of 10%. A Bayesian network starting from the viro-immunological data at T0 and at the sixth month of treatment (T1) was set up and this model was evaluated using a PA approach. RESULTS: A total of 262 patients (22.1% bearing an X4 virus) were included; 178 subjects (67.9%) achieved viral suppression. A significant positive indirect effect of bearing X4 virus in plasma at T0 on log10 HIV RNA at T1 was detected (P = 0.009), the magnitude of this effect was, however, over 10-fold lower than the direct effect of log10 HIV RNA at T0 on log10 HIV RNA at T1 (P = 0.000). Moreover, a significant positive indirect effect of bearing an X4 virus on log10 HIV RNA at T0 (P = 0.003) was apparent. CONCLUSIONS: PA overcame the limitations implicit in common multiple regression analysis and showed the possible role of pre-treatment viral tropism at the recommended threshold on the outcome of plasma viraemia in naive patients after 6 months of therapy.