[Measurements of plasma HIV-1 RNA in Iceland.]

First to measure plasma HIV-1 RNA in Icelandic HIV infected individuals and second to evaluate the initial effects of new combination regimens on viral load and CD4+ cell counts in HIV infected patients in Iceland.

The cohort studied consis notted of all HIV infected individuals we received samples from during the period September 1995 to November 1996. HIV-1 RNA and CD4+ cells were measured initially and subsequently every three to six months except when a change was made in the antiretroviral regimen, when samples were measured before the change, three to four weeks later and then every three to six months. The quantitative measurement of viral RNA was performed using the Amplicor HIV Monitor Test (Roche Diagnostic Sys nottems). CD4+ cell counts were measured by flow cytometry.

A total of 44 patients were evaluated. The initial RNA ranged from %lt; 2.6 logio to 6.13 logio with a mean of 5.02 log. CD4+ cell counts ranged from 2 to 641 per mm3 (mean 230 cells/mm3). Eleven patients had never been treated with antiretroviral drugs and had greater than 10 000 viral copies per mL of plasma. Twenty five of the patients were evaluated following a change in or initiation of a new treatment. The initial change in treatment led to a +0.7 to -2.88 log change in plasma RNA (mean -0.9 log) and a mean of 6.9 cells per mm3 increase in CD4+ cells. Saquinavir was added to two reverse transcriptase (RT) inhibitors in 11 patients with a resulting mean of 0.23 log fall in RNA levels (range +0.70 log to -0.78 log). Saquinavir plus one RT inhibitor were added to one RT inhibitor in six patients with a subsequent mean of 0.65 log reduction in viral load (range +0.24 to -2.26 log). Saquinavir plus two RT inhibitors were given to four antiretroviral naive patients with a resulting mean of 2.37 log reduction in viral load (range -1.8 log to -2.67 log).

1. In a mixed cohort of RT inhibitor naive and treated patients, the viral RNA ranged throughout the range of the RNA assay. 2. Changes in viral load following changes in treatment were quite variable. 3. Saquinavir alone added to two RT inhibitors did not lead to a significant reduction in viral load. 4. In antiretroviral naive patients the viral load was reduced 100 fold following treatment with saquinavir and two RT inhibitors.