Prognostic value of plasma HIV RNA among highly active antiretroviral therapy users.
BACKGROUND
The study objective was to compare the prognostic value of plasma HIV RNA and CD4 cell count at baseline and as time-updated variables in highly active antiretroviral therapy (HAART) users for two outcomes: development of AIDS and change in CD4 cell count.


METHODS
The study population comprised 387 men enrolled in the Multicenter AIDS Cohort Study who were AIDS-free and initiated HAART between 1996 and 2001. Follow-up until AIDS diagnosis (n=36, 9%) or the last AIDS-free visit was included. To determine the predictive value of combining HIV RNA and CD4 cell count, regression tree methods using recursive partitioning at pre-specified cut points for both variables were used.


RESULTS
Low CD4 cell count was a strong predictor of AIDS among HAART users. However, HIV RNA showed strong prognostic value for AIDS development among those with CD4 cell counts > 250 x 10(6) cells/l, in whom an HIV RNA level > 1000 copies/ml carried a 4.6-fold greater risk of developing AIDS. HIV RNA < 5000 copies/ml was also predictive of subsequent increase in CD4 cell count with significantly higher increases among those with initial CD4 counts > 300 x 10(6) cells/l.


CONCLUSIONS
Although, in HAART users, CD4 cell count was the primordial prognostic marker, an HIV RNA > 1000 copies/ml attained after HAART initiation was a strong predictor of the rate of subsequent CD4 cell count increase and of developing AIDS in patients whose CD4 cell counts were > 250 x 10(6) cells/l.
Tarwater
Patrick M
PM
School of Public Health, University of Texas Health Science Center, 1100 N. Stanton, Suite 110, El Paso, TX 79902, USA.
Gallant
Joel E
JE
Mellors
John W
JW
Gore
Mary E
ME
Phair
John P
JP
Detels
Roger
R
Margolick
Joseph B
JB
Muñoz
Alvaro
A
D000163:Acquired Immunodeficiency Syndrome / Q000097:blood / Q000276:immunology; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D015331:Cohort Studies; D018450:Disease Progression; D005500:Follow-Up Studies; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D015497:HIV-1; D006801:Humans; D008297:Male; D011379:Prognosis; D012367:RNA, Viral / Q000097:blood*
D012367:RNA, Viral