Clinical Manual > Testing and Assessment > HIV Progression

Determining Risk of HIV Progression

July 2006; updated July 2007

Chapter Contents

Background

References

Table 1. Relationship between CD4 Count or Viral Load and AIDS Progression

Table 2. Predicted 6-Month Risk of AIDS according to Age and Current CD4 Cell Count and Viral Load, Based on a Poisson Regression Model

Figure 1. Prognosis according to CD4 Cell Count and Viral Load in the Pre-HAART and HAART Eras

Background

The absolute CD4 cell count and CD4 percentage are used for disease staging, and to determine when to start antiretroviral therapy (ART) and prophylaxis against opportunistic infections. The HIV RNA level (viral load), when used in conjunction with the CD4 count, also provides prognostic information in patients who are naive to ART.

Data from various cohort studies have demonstrated the strong relationship between lower CD4 count or higher viral load and the risk of progression to AIDS. Tables 1 and 2 and Figure 1 below show the risk of disease progression and death in patients who have not been treated with ART and in patients starting ART in several North American, European, and Australian cohorts. The data consistently indicate the importance of initiating ART before the CD4 count declines to <200 cells/µL, if possible.

Table 1. Relationship between CD4 Count or Viral Load and AIDS Progression

CD4 Count (cells/µL)	Viral Load (copies/mL)	AIDS Progression in Men (%)
CD4 Count (cells/µL)	Viral Load (copies/mL)	Over 3 Years	Over 9 Years
<200	<10,000	14%	64%
	10,000-30,000	50%	90%
	>30,000	86%	100%
200-350	<10,000	7%	66%
	10,000-30,000	36%	85%
	>30,000	64%	93%
>350	<10,000	7%	54%
	10,000-30,000	15%	74%
	>30,000	40%	85%

Adapted from: Mellors JW, Rinaldo CR Jr, Gupta P, et al. Prognosis in HIV-1 infection predicted by the quantity of virus in plasma. Science. 1996 May 24;272(5265):1167-70.

Figure 1. Prognosis according to CD4 Cell Count and Viral Load in the Pre-HAART and HAART Eras

Figure shows Kaplan-Meier estimates of the probability of AIDS at 3 years.

HAART = highly active antiretroviral therapy

Reprinted with permission from Elsevier (Egger M,May M, Chene G, Phillips AN, Ledergerber B, Dabis F, Costagliola D, D'Arminio Monforte A, de Wolf F, Reiss P, Lundgren JD, Justice AC, Staszewski S, Leport C, Hogg RS, Sabin CA, Gill MJ, Salzberger B, Sterne JA; ART Cohort Collaboration. Prognosis of HIV-1-infected patients starting highly active antiretroviral therapy: a collaborative analysis of prospective studies. Lancet. 2002 Jul 13;360(9327):119-29.)

Table 2. Predicted 6-Month Risk of AIDS according to Age and Current CD4 Cell Count and Viral Load, Based on a Poisson Regression Model

	Predicted Risk (%) at Current CD4 cell Count (x 10 ⁶ cells/L)*
Viral Load (copies/ml)	50	100	150	200	250	300	350	400	450	500
Age 25 years
3,000	6.8	3.7	2.3	1.6	1.1	0.8	0.6	0.5	0.4	0.3
10,000	9.6	5.3	3.4	2.3	1.6	1.2	0.9	0.7	0.5	0.4
30,000	13.3	7.4	4.7	3.2	2.2	1.6	1.2	0.9	0.7	0.6
100,000	18.6	10.6	6.7	4.6	3.2	2.4	1.8	1.4	1.1	0.8
300,000	25.1	14.5	9.3	6.3	4.5	3.3	2.5	1.9	1.5	1.2
Age 35 years
3,000	8.5	4.7	3.0	2.0	1.4	1.0	0.8	0.6	0.5	0.4
10,000	12.1	6.7	4.3	2.9	2.0	1.5	1.1	0.9	0.7	0.5
30,000	16.6	9.3	5.9	4.0	2.8	2.1	1.6	1.2	0.9	0.7
100,000	23.1	13.2	8.5	5.8	4.1	3.0	2.3	1.7	1.3	1.1
300,000	30.8	18	11.7	8.0	5.7	4.2	3.1	2.4	1.9	1.5
Age 45 years
3,000	10.7	5.9	3.7	2.5	1.8	1.3	1.0	0.7	0.6	0.5
10,000	15.1	8.5	5.4	3.6	2.6	1.9	1.4	1.1	0.8	0.7
30,000	20.6	11.7	7.5	5.1	3.6	2.6	2.0	1.5	1.2	0.9
100,000	28.4	16.5	10.6	7.3	5.2	3.8	2.9	2.2	1.7	1.3
300,000	37.4	22.4	14.6	10.1	7.2	5.3	4.0	3.1	2.4	1.9
Age 55 years
3,000	13.4	7.5	4.7	3.2	2.3	1.7	1.2	0.9	0.7	0.6
10,000	18.8	10.7	6.8	4.6	3.3	2.4	1.8	1.4	1.1	0.8
30,000	25.4	14.6	9.4	6.4	4.6	3.3	2.5	1.9	1.5	1.2
100,000	34.6	20.5	13.3	9.2	6.5	4.8	3.6	2.8	2.2	1.7
300,000	44.8	27.5	18.2	12.6	9.1	6.7	5.0	3.9	3.0	2.4

*Shading distinguishes risk: <2%, no shading; 2-9.9%, light gray; 10-19.9%, mid-gray; > 20%, darkest gray.

Reprinted with permission from Lippincott, Williams & Wilkins [Phillips A; CASCADE Collaboration. Short-term risk of AIDS according to current CD4 cell count and viral load in antiretroviral drug-naïve individuals and those treated in the monotherapy era. AIDS 2004; 18 (1):51-8]. Lippincott, Williams & Wilkins home page: http://lww.com

References

Egger M, May M, Chene G, et al. Prognosis of HIV-1-infected patients starting highly active antiretroviral therapy: a collaborative analysis of prospective studies . Lancet. 2002 Jul 13;360(9327):119-29.

Hare CB. Clinical Overview of HIV Disease . In: Peiperl L, Coffey S, Volberding PA, eds. HIV InSite Knowledge Base [textbook online]; San Francisco: UCSF Center for HIV Information; 2004. Accessed February 7, 2006. Available online at hivinsite.ucsf.edu/InSite?page=kb-03-01-01.

Mellors JW, Rinaldo CR Jr, Gupta P, et al. Prognosis in HIV-1 infection predicted by the quantity of virus in plasma . Science. 1996;272:1167-70.

Phillips A. CASCADE Collaboration. Short-term risk of AIDS according to current CD4 cell count and viral load in antiretroviral drug-naïve individuals and those treated in the monotherapy era . AIDS. 2004;18(1):51-8.

U.S. Department of Health and Human Services. Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents . October 10, 2006. Available online at aidsinfo.nih.gov/Guidelines/GuidelineDetail.aspx?GuidelineID=7. Accessed July 3, 2007.

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