CD4 and lymphopenia: It has been suggested that microbial translocation is a potent factor in the maintenance of chronic immune activation/inflammation [9], along with viral persistence, CD4+ T cell lymphopenia, Th17 loss, a change in the regulatory T cell balance, disruption of the lymph node architecture, viral co-infection, accelerated ageing, the side effects of some antiretroviral drugs, and individual susceptibility [2,10,11]).