Quantifying CD4+ cells has been useful in staging human immunodeficiency virus (HIV) disease and, therefore, in deciding when to recommend HIV treatment or prophylactic antibiotics. Much more controversial, however, has been using CD4+ cell counts as an acquired immunodeficiency syndrome (AIDS)—qualifying diagnosis, and CD4+ cell number has been disappointing as a surrogate marker of the clinical benefits of antiretroviral drugs.1 Of particular concern is that CD4+ depletion is a rather distal effect of HIV infection and may be influenced by other cofactors. Indeed, most clinicians appreciate that various acute infections, including HIV itself, may cause a temporary decrease in peripheral CD4+ cell numbers. Less often are we concerned about factors that may cause CD4+ cell counts to be unexpectedly elevated.
Volberding PA. HIV, HTLV-I, and CD4+ LymphocytesTroubles in the Relationship. JAMA. 1994;271(5):392-393. doi:10.1001/jama.1994.03510290074041