Control of a superinfecting virus in an elite controller
22 September 2008. Related: Basic science.
Richard Jefferys, TAG
A free access article in the journal Clinical Infectious Diseases describes the case of an individual controlling HIV to below 50 copies/ml in the absence of treatment (classified as an “elite controller”) who became superinfected with another virus. 
The researchers were able to document the source of the superinfecting HIV strain and report that after a brief increase in viral load to a maximum of 25,000 copies, the elite controller was able to regain his unusual degree of control of viral replication and has since shown viral loads consistently around 2,000 copies/ml over two years of follow-up. CD4 counts have remained in the normal range throughout.
In contrast, the individual’s previously uninfected partner who was infected with the same virus showed high viral loads and decreasing CD4 counts, as did the individual who was the source of both infections. The researchers note that the elite controller possesses the HLA B*57 allele, which has been consistently associated with immunological control of HIV replication, and conclude that at least in some cases “host mechanisms seem to be able to repeatedly control HIV-1 replication, halting disease progression.”
However, it’s perhaps worth noting that the implications of the somewhat higher viral load levels observed after superinfection for the individual’s clinical course remain to be determined.
TAG Basic Science Blog (28 October 2008).
Ref: Rachinger A et al. Recovery of Viremic Control after Superinfection with Pathogenic HIV Type 1 in a Long-Term Elite Controller of HIV Type 1 Infection. Clinical Infectious Diseases 2008;47 DOI: 10.1086/592978 (free access to full text).