What test should be ordered for HIV RNA?

HIV RNA Testing: Ordering Information

Order the test as "HIV RNA quantitative" or "HIV viral load" or "plasma HIV RNA level"—these are the standard nomenclatures used in clinical practice for quantitative HIV RNA testing. 1

Standard Test Names and Ordering

The test can be ordered using several equivalent terms:

• Plasma HIV RNA level (most commonly used in guidelines) 1
• HIV viral load (widely recognized clinical term) 1
• Quantitative HIV RNA 1
• HIV-1 RNA quantitative assay 1

FDA-Approved Testing Platforms

Several FDA-approved assays are available for clinical use, and you should specify one of these platforms when ordering 1:

• HIV RNA PCR (Amplicor HIV-1 Monitor, Roche Laboratories; or RealTime HIV-1 Assay, Abbott; or Cobas AmpliPrep/Cobas Taqman HIV-1 Test, Roche) 1
• Nucleic acid amplification test (NASBA) (NucliSens HIV-1 QT, bioMerieux) 1
• Branched DNA assay (bDNA) (VERSANT HIV-1 RNA 3.0 assay, Bayer) 1

Critical Ordering Considerations

Always use the same assay method and laboratory throughout a patient's care to ensure consistent results, as different assays can yield values that differ by more than 2-fold even when testing the same sample. 1

When to Order HIV RNA Testing

Order HIV RNA testing in these specific clinical scenarios:

• At initial diagnosis of HIV infection (baseline measurement) 1
• Every 3-4 months in untreated patients 1
• Immediately before starting antiretroviral therapy 1
• 4-8 weeks after initiating or changing therapy to assess treatment response 1
• Every 3-4 months while on therapy to monitor ongoing effectiveness 1
• When acute HIV infection is suspected (use in conjunction with HIV antibody test, as antibody tests may be negative during acute infection) 1, 2, 3

Special Circumstances Requiring HIV RNA (Not Standard Antibody Testing)

Order HIV RNA specifically (not just antibody testing) when:

• Patient presents with acute retroviral syndrome symptoms and recent high-risk exposure—antibody tests will miss acute infections 1, 2, 3
• Patient has recent antiretroviral exposure (including PrEP), which can suppress viral load and delay seroconversion 2
• Diagnosing acute HIV infection where HIV RNA can detect infection 10-14 days post-exposure versus 18-45 days for antigen/antibody tests 2

Result Reporting Standards

Results should be reported in both copies/mL and log10 transformation for optimal clinical utility 1. The assay method and manufacturer must be documented on all reports 1.

Detection Thresholds

• Standard assays: 200-400 copies/mL 1
• Ultra-sensitive assays: 20-80 copies/mL 1
• Current clinical threshold for "undetectable": <500 copies/mL (older guidelines) or <50 copies/mL (newer assays) 1

Common Pitfalls to Avoid

Do not order HIV RNA testing during or within 4 weeks after:

• Acute intercurrent infections 1
• Vaccinations 1
• Symptomatic illness 1

These conditions can transiently elevate HIV RNA levels and give misleading results. 1

Important limitation: HIV viral load tests are not FDA-approved for diagnosing HIV infection—they are approved only for monitoring disease status after diagnosis has been established by serology. 1 The exception is using HIV RNA specifically for diagnosing acute HIV infection when used in conjunction with antibody testing. 1, 2, 3