Raltegravir intensification therapy in two human immunodeficiency virus-infected patients with undetectable viremia and discordant CD4⁺ response

Immunologic failure is characterized by the inability to maintain an adequate CD4+ cell count despite human immunodeficiency virus (HIV) suppression below standard limits of detection. With no consensus on the most efficacious treatment for poor immunologic response, intensification of a given antiretroviral therapy regimen with an additional antiretroviral agent has been proposed. We describe the responses to intensification therapy with raltegravir to increase CD4+ cell count in two HIV-infected patients who were receiving optimized antiretroviral therapy but experienced discordant immunologic response. In both patients, HIV RNA remained undetectable for at least 70 weeks. The first patient demonstrated no clinically significant change in absolute CD4+ count over baseline (-2 cells/mm3) as well as a net decrease in CD4+ percentage (-3%). The second patient demonstrated a robust increase in absolute CD4+ count over baseline (+61 cells/mm3) and a clinically significant increase in CD4+ percentage (+3%). Therefore, conflicting immunologic responses to raltegravir intensification occurred in these two patients with undetectable HIV RNA who were receiving optimized background therapy. Management strategies for immunologic failure and results of the few studies on intensification with antiretrovirals in virologically suppressed patients are discussed. Further prospective trials confirming the immunologic benefits of raltegravir intensification are required before this strategy can be routinely recommended.