Definition of Absolute CD4 count

Absolute CD4 count: The number of 'helper' T-lymphocytes in a cubic millimeter of blood. The absolute CD4 count is frequently used to monitor the extent of immune suppression in persons with HIV because with HIV, this number declines as the infection progresses. Also known as T4 count.

Source: MedTerms™ Medical Dictionary
http://www.medterms.com/script/main/art.asp?articlekey=2100
Last Editorial Review: 3/19/2012