Introduction: This retrospective study analyses causes as well as clinical, immunological and virological consequences of antiretroviral treatment interruptions (Ti) of more than 30 days in HIV-1 infected adults.
Methods: This causes were classified as related to drug toxicity, therapeutic or adherence failure. We studied therapeutic regimens before Ti and after treatment reinitiation (TR), clinical events related to Ti, CD4 cells and viral loads before Ti and at months 3, 6, 9, and 12 after TR.
Results: Out of 188 Ti analysed, 42.6% were related to therapeutic failure, 33.5% to drug toxicity, and 23.9% to adherence failure. Eight Aids defining clinical events were reported during Ti, in patients with low CD4 cells and high viral load (P < 0.05). Viral loads evolution after TR was better if Ti was related to treatment failure (P < 0.05), was prolonged (P < 0.05), and if CD4 cells were high before Ti and at TR (P < 0.05). Median CD4 cells was of 296/mm(3) at month 12 after TR vs 382 before Ti.
Conclusions: Ti consequences are strongly related to CD4 cells, which decrease sharply during Ti, increasing Aids defining events probability. Prospective randomised clinical studies are needed to define usefulness of Ti.