Different Degrees of Immune Recovery Using Antiretroviral Regimens with Vonavir or Zidovudine/Lamivudine/Efavirenz in HIV-Positive Patients Receiving First Line Treatment in Iran

Background: The initial antiretroviral therapy (ART) regimens recommended by most national treatment guidelines in resource-limited settings consist of two Nucleoside Reverse-Transcriptase Inhibitors (NRTIs) and one Non-Nucleoside Reverse- Transcriptase Inhibitor (NNRTI). The NRTIs are Zidovudine (AZT) or Stavudine (d4T) with Lamivudine (3TC); the NNRTI components are either Nevirapine (NVP) or Efavirenz (EFV). Existing data regarding the effectiveness of Vonavir compared to other first-line ART regimens in increasing CD4+ T cell counts are unsatisfactory. Methods: Immunological outcomes of 134 individuals who were on initial stage of antiretroviral therapy with Vonavir or a combination of Zidovudine/Lamivudine and Efavirenz were analyzed. The immunological response was then assessed during 28 weeks. Results: Both groups demonstrated a significant increase in their CD4+ T cell count which was greater in Zidovudine/Lamivudine and Efavirenz treated group. We observed a noticeable increase in CD4+ T cells rates in the first three months of therapy; however, our results indicated a greater increase of cell counts in individuals with baseline CD4 lower than 100 cells/mm3 treated with Vonavir in first 12 weeks of treatment compared to those with higher baseline CD4. Conclusion: A rapid CD4+ Tcell increase occurred shortly after beginning ART consisting either Vonavir or combination of Zidovudine, Lamivudine and Efavirenz. Late increases in CD4+ T cell counts were more pronounced in therapy using Zidovudine/ Lamivudine and Efavirenz.