HIV seroreversion possible when treatment started early

[Guest guest]

http://www.aidsmeds.com/news/20060222clin004.html

HIV seroreversion possible when treatment started early

Last Updated: 2006-02-22 15:24:00 -0400 (Reuters Health)

NEW YORK (Reuters Health) - HIV antibody seroreversion is possible

when patients are started on antiretroviral therapy (ART) early in

the course of their infection, US researchers report in the March 1st

issue of Clinical Infectious Diseases. However, such patients still

remain infected and capable of transmitting the virus.

There has been concern that immune responses could diminish if ART is

started too early, lead author Dr. C. Bradley Hare, from the

University of California, San Francisco, and his colleagues note.

To determine the effects of early ART on the immune system, the

researchers started ART in 12 patients with acute seronegative HIV

infection and in 75 with early HIV infection, who had a positive HIV-

1 antibody test result preceded by a negative test result within the

same year. The patients maintained undetectable HIV-1 RNA levels for

at least 24 weeks while receiving continuous ART.

All 12 subjects with acute infection developed antibodies to HIV-1,

although one patient had negative result on second-generation enzyme

immunoassays (EIA). However, one of these patients and five who

started ART during early infection demonstrated negative HIV antibody

results on at least one diagnostic test during median follow-up of 90

weeks.

The third-generation EIA test -- Bio-Rad/Genetic Systems HIV-1/HIV-2

PLUS O EIA -- was more sensitive than the other three second-

generation tests used, with results reverting to negative on this

test in only one subject.

Of five seroreverters that could be tested, four developed cytotoxic

T lymphocyte responses to HIV Gag peptides, the investigators note,

suggesting that cellular responses are maintained.

The authors also point out that five subjects who tested negative for

antibodies discontinued ART, after which they developed detectable

levels of HIV and positive EIA responses, reinforcing the fact that

they were still infected and infectious.

Dr. Hare's group indicates that these findings have implications for

the safety of blood and tissue donation, since a patient with an

undetectable viral load and negative antibody test results while

receiving ART could be misidentified as being HIV negative.

" This possibility does emphasize the importance of using the most

sensitive donor-screening techniques, such as third-generation HIV-

1/HIV-2 EIAs, as well as sensitive testing for HIV-1 RNA with nucleic

acid amplification technology, " they write.

Clin Infect Dis 2006;42:700-708.