PROVIRUS LOAD CHANGES IN UNTREATED AND ZIDOVUDINE-TREATED HUMAN-IMMUNODEFICIENCY-VIRUS TYPE 1-INFECTED PATIENTS

Human immunodeficiency virus type 1 (HIV-1) provirus burden was quanti fied during followup of untreated patients and mathematically analyzed by a parameter called intrinsic rate of increase (r). There was an in crease in provirus burden in patients at early stages of the infection , and the increase occurred at a similar rate in later stages of the d isease. Antiviral response to zidovudine was evaluated using r. Nearly 50% of patients responded with strong decreases of r, and the rest be haved as nonresponders. Parameter r is valuable in disease prognosis, as the mean r was higher in disease progressors than in nonprogressors , and this difference was significant and more pronounced in treated p atients. The zidovudine resistance mutation at codon 215 of reverse tr anscriptase was associated with a worse response to therapy. Absence o f antiviral response and resistance mutations were more frequent in pa tients with lower CD4(+) cell counts and higher provirus loads. These findings support a more beneficial effect of early than late therapy.