Incomplete functional T-cell reconstitution in immunological non-responders at one year after initiation of antiretroviral therapy possibly predisposes them to infectious diseases

Abstract Background Immunological non-responders (INR) represent a unique category of HIV-infected patients on antiretroviral therapy. These patients have suppressed viremia but a suboptimal increase in CD4 cell count, which might have opposing effects on functional immune reconstitution. Hence, the extent of immune reconstitution in INR patients was investigated in order to determine their susceptibility to opportunistic infections. Methods Twenty-three INR patients (CD4 increase 3 , viral load 100 cells/mm 3 , viral load Results A higher percentage of INR patients had clinically symptomatic infections than the responders. CD8 + activation and innate immune parameters, including the absolute neutrophil count and natural killer (NK) cell frequency and functionality, were restored in the INR patients. They had significantly higher non-HIV antigen-specific T-cell responses and activated CD4 + cells, but significantly compromised T-cell functionality, as assessed after anti-CD3 stimulation, and lower CD31 + and CD62L + CD4 + cells. Conclusions INR patients showed lower thymic output, incomplete functional T-cell reconstitution, higher responses to HIV co-pathogens, and higher symptomatic events, indicating the need for close monitoring and intervention strategies to overcome their continuing immunocompromised status.