Avascular necrosis in HIV infection

Protease-based, highly active antiretroviral therapy (HAART) has had a major beneficial impact on both the survival and the short-term outcomes of HIV-infected patients. This has led to the rapid acceptance of HAART into widespread clinical practice, supported by safety data generated over a relatively short time. With both an increasing number of patients on HAART and a longer period of observation, additional data on a variety of adverse effects potentially related to protease inhibitors are being reported. Lipodystrophy, dyslipidaemia, hyperglycaemia and nephrolithiasis have been proposed as some of the side-effects from protease inhibitors. More recently, avascular necrosis (AVN) of the bone has been noted at a higher than predicted prevalence of eight per 600 in patients on protease inhibitors. In the past, AVN has only rarely been reported in HIV-positive patients. We wish to report three cases of AVN in a population of 700 patients that do not appear to be related to protease therapy and which may reflect background disease prevalence.