Figure 3

Typical course of HIV-1 disease in relation to HIV-1 coreceptor usage. (A) Individual infected with pure R5 variants: constant rate of CD4 decline and viral load incline. (B) Individual with emergence of CXCR4-using variants in the course of infection: accelerated CD4 decline, viral load incline and disease progression upon emergence of CXCR4-using variants. While CXCR4-using variants can emerge at any stage of infection, untreated individuals who develop such variants progress to AIDS within an average of 2 years after their first detection.