Diagnose HIV infection as early as possible, treat as quickly as possible. A study published Jan. 11 in the journal Nature Communications This provides a strong argument in favor of the strategy. Because, beyond the collective interest – stopping the chain of contamination – benefit It is also personal. Early antiretroviral treatment, this work shows, promotes a lasting immune response, capable of neutralizing the virus even after treatment is stopped. Conducted on macaques, the study was conducted by teams from the Institut Pasteur (Paris), CEA and Inserm (University of Paris-Seclay).
Enough to better understand the phenomenon observed in the 2000s in a small group of patients, “post-treatment controls”. In France, 31 of them are followed in the Visconti group. They initially benefited from a combination of antiretrovirals, the famous triple therapy (for 80%, within three months after primary infection), which they followed for several years (three or four years, average duration). Even though they stopped taking their medications, the virus remained undetectable in their blood for 23 years after stopping, a median follow-up of 14 years. A very rare phenomenon: in most cases, as the patient interrupts their antiretroviral therapy, HIV multiplies again and the disease progresses.
How to explain this control of the virus? In 2013, the importance of starting treatment – triple therapy – arose very early. It was yet to be formally proven. The authors compared three groups of macaques infected with SIV, the simian immunodeficiency virus. This model allows controlling other parameters (gender, age, genetic background, virus strain, etc.) likely to modify immune responses and disease progression.
Educate the immune response
The first group (11 animals) received standard triple therapy four weeks after infection (acute phase). Another (11 animals) started the same treatment six months after infection (chronic phase). In both cases, treatment was discontinued after two years. For the third group (17 animals), it was not treated.
Results: 9 of 11 monkeys treated early controlled virus multiplication in the blood, whereas only 2 of 11 monkeys treated late and 2 of 17 untreated monkeys. “Early treatment greatly increases the likelihood of viral control after treatment interruption”, from the Pasteur Institute in Paris, summarizes Assier Sez-Sirian, who coordinated the study with Roger Le Grand of the University of Paris-Saclay (CEA, Inserm). If treatment is started after five months “window of opportunity” has passed.
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