What does a CD4 count greater than 400 in an HIV patient on antiretroviral treatment indicate?

A CD4 count greater than 400 in an HIV patient on antiretroviral treatment is indicative of a robust immune system response. In the context of HIV infection, CD4 cells, which are a type of white blood cell, play a crucial role in maintaining the immune system's function. When a patient with HIV is on effective antiretroviral therapy, an increase in CD4 count suggests that the treatment is working, leading to improved immune function and a lower risk of opportunistic infections.

A CD4 count above this threshold generally implies that the immune system is not severely compromised, and the patient is doing well in managing their HIV infection. Monitoring CD4 counts helps healthcare providers assess how well a patient's treatment is working and adjust care accordingly, but counts above 400 are typically seen as a positive clinical outcome. Hence, it reflects good health status in the context of HIV management.