Guidelines for the Use of Antiretroviral Agents in
HIV-1-Infected Adults and Adolescents CD4 T-Cell Count (Last
updated:2/12/2013; last reviewed:2/12/2013) The CD4 T-cell count
(CD4 count) serves as the major laboratory indicator of immune
function in patients who have HIV infection. It is one of the
key factors in determining both the urgency of antiretroviral
therapy (ART) initiation and the need for prophylaxis for
opportunistic infections. It is also the strongest predictor of
subsequent disease progression and survival according to
findings from clinical trials and cohort studies.1,2 CD4 counts
are highly variable; a significant change (2 standard
deviations) between 2 tests is approximately a 30% change in the
absolute count, or an increase or decrease in CD4 percentage by
3 percentage points. - Use of CD4 Count for Initial Assessment.
The CD4 count is one of the most important factors in
determining the urgency of ART initiation and the need for
prophylaxis for opportunistic infections. All patients at