CDC HIV/AIDS/Viral Hepatitis/STD/TB Prevention News Update Virologic and Immunologic Characterization of Long-Term
Cao, Yunzhen; Qin, Limo; Zhang, Linqi et al.
January 27, 1995
New England Journal of Medicine (01/26/95) Vol. 332, No. 4, P.
Although most HIV-infected people develop clinical or
laboratory evidence of immunodeficiency with 10 years of
seroconversion, a few infected people remain healthy and
immunologically normal for more than a decade. Cao et al.
studied 10 seropositive people who were asymptomatic and had
normal and stable CD4 lymphocyte counts despite 12 to 15 years
of HIV-1 infection. Plasma cultures were uniformly negative
for infectious virus, but particle-associated HIV-1 RNA was
detected in four subjects. Standard limiting-dilution cultures
detected infectious HIV-1 in peripheral-blood mononuclear
cells (PBMCs) in three patients, while CD8-depleted culture
found infectious virus in another. A quantitative polymerase-
chain-reaction showed that all 10 subjects had detectable, but
low, titers of viral DNA in PBMC. While there was no in vitro
evidence of host CD4 lymphocyte resistance to HIV-1 infection,
long-term survivors had a vigorous, virus-inhibitory CD8
lymphocyte response and a strong neutralizing-antibody
response. Cao et al. concluded that those people who remain
asymptomatic for many years despite infection with HIV-1 have
low levels of HIV-1 and a combination of strong virus-specific
immune responses with some degree of attenuation of the virus.