CD8+ cell noncytotoxic antiviral response in long-term HIV-1 infected former blood donors in China.

Most of the HIV-infected long term survivors show strong CD8+ cell noncytotoxic antiviral response (CNAR) that plays as an important factor for maintaining the relative healthy state of infected individuals. HIV infected former blood donors (FBDs) in Anhui, China are the unique population that considered infected by the same or a related HIV strain by the same exposure route, and is better to be studied for viral and host immunological factors associated with disease progression, such as CNAR. We examined CNAR in 63 asymptomatic untreated HIV infected FBDs with different CD4+ cell counts and plasma viral loads. The average CD8+ : CD4+ cell ratio to reach 90% suppression of HIV replication in the groups with CD4+ cell counts of >500, 300-500 and <300 cells/microl were 0.85 : 1, 1.47 : 1 and 1.88 : 1 respectively (P<0.0001). The average CD8+ : CD4+ cell ratio to reach 90% suppression of HIV replication was 1.07 : 1 and 1.66 : 1 in the group with plasma viral load of <30,000 and >30,000 RNA copy/ml respectively (P=0.0002). The results indicated that CNAR activity in long-term HIV-1 infected FBDs correlates directly with CD4+ cell counts, and correlates reversely with plasma viral loads. Our findings in long term infected FBDs confirm the clinical relevancy of CNAR and suggest that CNAR could be an additional marker to help determine the optimal time for starting therapy in HIV infected person.