What are the recommended surveillance labs and frequency for checking HIV (Human Immunodeficiency Virus) RNA (viral load) and CD4 (Cluster of Differentiation 4) cell count in a patient on Genvoya (elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide)?

Surveillance Labs and Monitoring Schedule for HIV Patients on Genvoya

For patients on Genvoya (elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide), HIV viral load and CD4 cell counts should be monitored every 3-4 months initially, then can be reduced to every 6 months after viral suppression has been maintained for at least 1 year in clinically stable patients.

Initial Laboratory Assessment

Before starting Genvoya, the following baseline tests should be performed:

• HIV RNA viral load
• CD4 cell count
• Complete blood count (CBC)
• Chemistry panel (renal and liver function)
• Lipid profile
• Urinalysis for glucose and protein
• Genotypic resistance testing (reverse transcriptase and protease)
• Serologies for hepatitis A, B, and C
• Screening for sexually transmitted infections (STIs)
• Tuberculosis screening

Monitoring Schedule for Patients on Genvoya

HIV Viral Load Monitoring

• 4-6 weeks after starting therapy 1
• Every 3-4 months until suppression for at least 1 year 1
• Every 6 months after viral suppression for >1 year 1
• Can be reduced to once yearly after 5 years of stable suppression 1

CD4 Cell Count Monitoring

• Every 3-4 months initially 1
• Every 6 months after viral suppression until consistently >250 cells/μL for at least 1 year 1
• No further monitoring needed after stable counts above 250 cells/μL unless virologic failure occurs or patient develops immunosuppressive condition 1

Renal Function Monitoring

• Creatinine and estimated glomerular filtration rate (eGFR) every 3-6 months
• Urinalysis for glucose and protein at least annually 1
• More frequent monitoring may be needed for patients with risk factors for kidney disease

Bone Health Monitoring

• Consider baseline bone mineral density (BMD) in patients with risk factors for osteoporosis
• Genvoya (containing tenofovir alafenamide) has shown significantly less impact on BMD compared to tenofovir disoproxil fumarate regimens 2

Metabolic Parameters

• Lipid profile every 6-12 months
• Weight and BMI at baseline and every 6 months 1
• Blood pressure at each clinical visit 1

Additional Monitoring

• STI screening based on risk factors and exposures 1
• Tuberculosis screening based on risk factors 1
• Depression screening annually 1

Special Considerations for Monitoring

Virologic Failure

If viral load is >50 copies/mL after previous suppression:

1. Repeat measurement in 2-4 weeks
2. Assess adherence and medication tolerability
3. If confirmed >200 copies/mL, obtain genotypic resistance testing 1

Renal Safety Advantage

Genvoya contains tenofovir alafenamide (TAF), which has demonstrated improved renal safety compared to tenofovir disoproxil fumarate (TDF) regimens, with:

• Smaller increases in serum creatinine
• Significant reductions in proteinuria and albuminuria 2, 3

Monitoring Frequency Adjustments

The monitoring schedule can be adjusted based on:

• Duration of viral suppression
• Baseline CD4 count
• Presence of comorbidities
• Medication adherence

Common Pitfalls to Avoid

1. Premature reduction in monitoring frequency: Don't decrease monitoring frequency until viral suppression has been maintained for at least 1 year.

2. Overlooking renal function: Even though Genvoya has improved renal safety compared to TDF-containing regimens, renal function should still be monitored regularly.

3. Ignoring metabolic parameters: Weight gain has been associated with integrase inhibitor-based regimens like Genvoya, so regular monitoring of weight and metabolic parameters is important.

4. Missing drug interactions: Cobicistat in Genvoya can interact with many medications, requiring careful medication review at each visit.

5. Inadequate STI screening: Regular STI screening should be performed based on risk factors and exposures, not just at baseline.