NOTE :

We are currently translating the 2009-2010 "Medical Management of HIV Infection" into a web-ready format. We will post each chapter as it is completed. To make any comments or suggestions click here

  HOME
Previous         27         Next
dkfhkd

Discussion Thread

  • the absolute CD4 count (JID 1994;169:28). Data from a large observational database suggested that the CD4 count is the most useful predictor of the risk for development of opportunistic infections (JAIDS 2004;36:1028). More recent analyses based on cohort studies suggest that the CD4 percentage may be better for predicting disease progression with a CD4 count >350/mm3 (JID 2005;192:950), and for determiniing the time to initiate HAART (JID 2007;195:425). Others conclude that the absolute count may be preferred for levels below the 350/mm3 threshold (JID 2005;192: 945; 2004;36:1028). Corresponding CD4 cell counts and percentages are provided in the table below.

TABLE 2-6:

Approximate CD4/CD4% Equivalents
CD4 Cell Count % CD4
>500/mm3 >29%
200 to 500/mm3 14% to 28%
<200/mm3 <14%

 

  • Response to HAART: The CD4 count typically increases ≥50 cells/ mm3 at 4 to 8 weeks after viral suppression with HAART and then increases at a rate that correlates with time, baseline. CD4 count, and viral load suppression. With good virologic response the increase at one year averages 100-150 cells/mm3, at 3-5 years it averages 20- 50 cells/mm3/yr and at ≥ 5 years it averages 20-30 cells/mm3/yr. (Lancet 2007;370:407). Some cohort studies show sustained incremental gains to normal levels (Lancet 2007;370:366). However, others have found that only patients with baseline counts >350/mm3 had nearly normal CD4 counts after 6 years of HAART with good viral suppression (CID 2008;46:149) beyond 4-5 years suggesting limited immunologic reserve (CID 2007; 44:441; AIDS 2003;17:1707; AIDS 2003;13:963). The CD4 response generally correlates with virologic control, but viral loads <10,000 c/mL are generally associated with CD4 stability or modest increases and protection from opportunistic infections (NEJM 2003; 2175; JAIDS 2005; 40:404; Lancet 2007; 369:1169; Lancet 2006; 368:466). Despite good virological response, there may be an initial delay in CD4 response that cannot be explained (JAMA 2002;288:222). The CD4 response generally correlates with viral load suppression, but discordant results are common in both directions (Antivir Ther 1999;4(Suppl 3):7; JID 2001;183:1328). Nevertheless, population-based studies have found that most important predictor of CD4 response to HAART is the duration of virologic control (JID 2004;190:148). The CD4 count usually declines rapidly, up to 100-150 cells/mm3 in 3 to 4 months, when antiretroviral therapy is discontinued (CID 2001;33:344; CID 2001;32:1231; NEJM 2003;349:837).
2007 © John G. Bartlett, M.D. All rights reserved.27

Chapter 2: Laboratory Tests

Page 27 of 58 (0 Posts)

Add Thread | View All Threads

 

ImagesThreadsNamePostsDate

No Threads...