Begin treatment as early as possible: this general common sense rule seems to apply to most diseases except HIV-AIDS, which is only treated once a certain number of immune cells called "CD4+" cells have disappeared. The results of a North American study, which involved the team of Dr. Marina Klein of the Research Institute of the MUHC, run contrary to this consensus. The findings show that the risk of death in seropositive patients decreases by 69% to 94% if they start treatment earlier than officially recommended.