Immunovirologic consequences and safety of short, non-structured interruptions of successful antiretroviral treatment.

OBJECTIVES

The aim was to evaluate the safety of short antiretroviral treatment interruptions and their virologic and immunologic consequences in HIV-infected adults on highly active antiretroviral treatment (HAART) with suppressed viral replication. The viral efficacy upon reintroduction was also evaluated.

PATIENTS AND METHODS

All patients with undetectable viral load while on HAART were prospectively followed to detect any treatment interruption. We analysed viral and cellular kinetics, incidence of resistance mutations, clinical outcome and results after therapy resumption.

RESULTS

Twenty patients were included, mean time since HIV diagnosis was 95 months and time with undetectable viral load 16 months. Treatment was interrupted because of adverse effects, cancer, tuberculosis or patient will. Treatment was reintroduced after 4 weeks using, if possible, the same combination. HIV viral load was detectable on day 28 after interruption in 18 patients (90%). Median of CD4 cell count (p25-p75) decreased from 478/mm3 (96-716) to 257/mm3 (118-663) (p=0.5). Resistance mutations were found in 9 patients (45%) after interruptions. Treatment was reintroduced in 14 patients; all of them achieved viral suppression.

CONCLUSIONS

In patients receiving HAART who have undetectable viral load, an interruption, no longer than 4 weeks, due to any intercurrent problem seems to be safe. Response to resumption can usually be achieved. Due to the frequent development of resistance, a genotypic test during interruption might be helpful.