In the present study, we have studied the level of oxidative DNA base damag
e in lymphocytes of HIV-infected intravenous drug users (IDUs) and a serone
gative control group. Chromatin was isolated from the lymphocytes and then
analyzed by gas chromatography/isotope-dilution mass spectrometry with sele
cted-ion monitoring (GC/IDMS-SIM). Significantly greater levels of four oxi
datively modified DNA bases were observed in chromatin samples from the sym
ptomatic HIV-infected patients than in those from the seronegative patients
. These were 5-hydroxyuracil, 5-hydroxycytosine, 8-hydroxyadenine and 8-hyd
roxyguanine. In the case of 5-hydroxyuracil and 8-hydroxyguanine, a statist
ically significant difference was also found between the control group and
the asymptomatic HIV-positive patients. These results suggest that oxidativ
e stress may play an important role in the pathogenesis of acquired immune
deficiency syndrome (AIDS), and that administration of antioxidant drugs to
HIV-infected patients may offer protection against AIDS-related carcinogen
esis.