Laboratory guidelines for enumeration CD4 T lymphocytes in the context of HIV/AIDS (‎revised version 2009)‎

Overview

The human immunodeficiency virus selectively invades a subpopulation of lymphocytes (‎CD4 T lymphocytes)‎. The progressive loss of CD4 T lymphocytes eventually results in the loss of an ability to mount desirable immune response to any pathogen and results in vulnerability to opportunistic pathogens characteristic of AIDS. The establishment of peripheral CD4 T lymphocyte counts is used as a tool to take an informed decision for initiation of antiretroviral treatment, monitoring disease progression and the effectiveness of antiretroviral treatment. Several technologies for determining the number of CD4 T lymphocytes are now available. The technologies are either flow cytometric or non-flow cytometric. This document describes the technologies as well as the infrastructure required for these in developing countries.