What are the management steps for a CD4 (Cluster of Differentiation 4) count of 475 cells per cubic millimeter?

Management of a CD4 Count of 475 cells/mm³

For a patient with a CD4 count of 475 cells/mm³, no antiretroviral therapy initiation is required based solely on this CD4 count value, as it indicates preserved immune function without immediate risk for opportunistic infections. 1, 2

Interpretation of CD4 Count of 475 cells/mm³

• A CD4 count of 475 cells/mm³ represents normal immune function and is well above the threshold that would indicate significant immunosuppression 2
• This CD4 count falls within the range of >350 cells/mm³, which historically has been considered a level at which immune function is relatively preserved 1
• At this CD4 level, the risk for progression to AIDS and opportunistic infections is significantly lower compared to counts below 200 cells/mm³ 1
• This CD4 count corresponds to a CD4 percentage of approximately 29%, which also indicates preserved immune function 2

Clinical Management Recommendations

• Current guidelines recommend antiretroviral therapy (ART) for all HIV-infected individuals regardless of CD4 count, so treatment should be initiated even with this preserved CD4 count 1
• Prophylaxis against opportunistic infections like Pneumocystis jirovecii pneumonia (PcP) is not indicated at this CD4 count, as it would typically be recommended only when CD4 counts fall below 200 cells/mm³ 1
• Regular monitoring of both CD4 count and viral load is essential to track disease progression and treatment response 2, 3
• With a CD4 count of 475 cells/mm³, the patient is not at immediate risk for AIDS-defining illnesses, as most serious opportunistic infections occur at CD4 counts below 200 cells/mm³ 1, 2

Monitoring Recommendations

• Obtain HIV viral load measurement to determine virologic control, as viral load is a more sensitive predictor of disease progression than CD4 count 3, 4
• For patients not on ART, CD4 count should be monitored regularly as the median decline in untreated HIV infection is approximately 35 cells/μL per year 5
• If initiating ART, both CD4 count and viral load should be monitored at regular intervals (typically every 3-6 months) 2
• Viral load monitoring is superior to CD4 count monitoring for predicting mortality and disease progression in patients on ART 3, 4, 6

Important Considerations

• The CD4 count of 475 cells/mm³ suggests the patient has relatively preserved immune function with low immediate risk for opportunistic infections 1, 2
• If this is a newly diagnosed patient, baseline laboratory studies including HIV resistance testing should be performed before initiating ART 2
• For patients considering structured treatment interruptions, a CD4 count of 475 cells/mm³ is above the threshold where treatment interruption might be considered in specific research contexts, though continuous therapy is generally recommended 7
• The specificity of CD4 criteria for predicting virologic failure is high (97%), but sensitivity is low (12-17%), meaning CD4 count alone may not accurately identify treatment failure 4, 6

Treatment Approach

• Initiate or continue ART regardless of this CD4 count level, as current guidelines recommend treatment for all HIV-infected individuals 1
• The choice of ART regimen should be based on resistance testing, comorbidities, potential drug interactions, and patient preferences 1, 8, 9
• Monitor for immune reconstitution inflammatory syndrome (IRIS) after ART initiation, particularly if there are underlying opportunistic infections 1
• Assess and address any barriers to medication adherence to ensure optimal treatment outcomes 1