From the Guidelines
Lymphocyte percentages, particularly CD4+ T lymphocytes, typically decrease during HIV infection, with a decline from a normal range of 500-1500 cells/mm³ to below 200 cells/mm³, which defines AIDS, as noted in the 2009 update by the HIV Medicine Association of the Infectious Diseases Society of America 1.
Changes in Lymphocyte Percentage
The primary target of the virus is CD4+ T lymphocytes, and their depletion is a major clinical finding in progressive infection.
- In early HIV infection, the CD4+ T cell count may remain relatively normal.
- As the disease progresses without treatment, these cells steadily decline.
- The CD4:CD8 ratio, normally greater than 1, becomes inverted as CD8+ T cells increase in response to the infection while CD4+ cells decrease.
Mechanism of Depletion
This lymphocyte depletion occurs through:
- Direct viral killing
- Chronic immune activation leading to cell exhaustion
- Disruption of lymphoid tissues
Treatment and Management
Antiretroviral therapy (ART) can halt and often reverse this decline by suppressing viral replication, allowing immune reconstitution with gradual increases in CD4+ counts.
- Modern ART regimens typically include three active drugs, such as two nucleoside reverse transcriptase inhibitors (like tenofovir and emtricitabine) plus an integrase inhibitor (like dolutegravir).
- Treatment should begin immediately upon diagnosis regardless of CD4 count, as earlier treatment leads to better immune recovery and prevents AIDS-related complications, as supported by guidelines from the HIV Medicine Association of the Infectious Diseases Society of America 1.
From the Research
Changes in Lymphocyte Percentage in HIV Infection
- The provided studies do not directly address the changes in lymphocyte (white blood cell) percentage in Human Immunodeficiency Virus (HIV) infection 2, 3, 4, 5, 6.
- However, some studies discuss the recovery of CD4+ T-cell counts, which are a type of lymphocyte, in HIV-infected individuals 5.
- One study found that initiation of antiretroviral therapy (ART) earlier (≤4 months after the estimated date of HIV infection) was associated with an enhanced likelihood of recovery of CD4+ counts to 900 or more cells per cubic millimeter compared to later initiation (>4 months) 5.
- Another study discussed the importance of CD4 cell count in determining the optimal time for initiation of ART in asymptomatic, HIV-infected, treatment-naive adults 3.
- The studies primarily focus on the optimal time for initiation of ART, the choice of regimen, and the monitoring of patients on therapy, rather than the changes in lymphocyte percentage 2, 3, 4, 6.