What is the significance of CD4 count trends in a patient on ART?

• A. CD4 count is irrelevant when on ART.
• B. Increasing CD4 count indicates immune reconstitution; persistently low CD4 counts with suppressed viral load may require opportunistic infection prophylaxis.
• C. CD4 count only matters if viral load is high.
• D. CD4 should always be zero.

Answer: (B)

Tracking CD4 count trends during ART shows whether the immune system is recovering as HIV replication is suppressed. When ART lowers the viral load and immune restoration occurs, CD4 counts rise, signaling improved immune function and a reduced risk of opportunistic infections. If the viral load is well controlled but CD4 counts stay low, the person remains immunocompromised despite effective treatment, so clinicians may continue or start prophylaxis against opportunistic infections and monitor CD4 closely. This is why a rising CD4 count is a sign of immune reconstitution, while a persistently low CD4 count with suppressed viral load indicates ongoing risk and the potential need for prophylaxis.