CD4-Count Recovery from a Nadir <100 Cells/mm³ — How High, How Quickly?

Because diagnosis at a late stage of HIV infection is common, antiretroviral therapy (ART) is often initiated in patients with very low CD4 counts (<100 cells/mm³). Virologic suppression is frequently achieved in this setting, but the recovery of CD4 lymphocytes may be attenuated following lengthy, substantial depletion, especially in older individuals.

To investigate this phenomenon, researchers reviewed data on CD4-cell–count response for 400 patients who were followed consistently in the UK Collaborative HIV Cohort Study. All started ART after 1999 with CD4 counts <100 cells/mm³ (median, 38 cells/mm³), achieved and sustained virologic suppression (HIV RNA ≤50 copies), and had ≥2 years of follow-up after ART initiation.

Kaplan-Meier estimat…