HIV‑1 RNA Quantitative Real‑Time PCR with Reflex to Co‑receptor Tropism UDS
Use
This test quantifies HIV‑1 RNA and, if indicated, reflexes to co‑receptor tropism ultradeep sequencing (UDS) to determine viral coreceptor usage (CCR5, CXCR4, or dual‑mixed), aiding therapeutic decisions such as eligibility for CCR5 antagonist agents.
Special Instructions
Reflex to UDS occurs only when indicated (e.g., need to determine tropism if initial result suggests R5-only virus) — reflex testing adds time and additional charge.
Limitations
UDS reflex performed only when initial tropism assay indicates predominantly R5 virus; minority variant detection limited by assay sensitivity; not all patient specimens may reflex depending on viral load or quality. Analytical constraints for detecting low‑level X4 variants.
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 20447-9
Result Turnaround Time
7-10 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
Not provided
Minimum Volume
Not provided
Container
EDTA (lavender-top) plasma tube
Collection Instructions
Collect plasma in EDTA (lavender‑top) tube; separate plasma from cells within 24 hours; do not freeze whole blood in primary tube
Causes for Rejection
Serum, heparinized plasma, non‑centrifuged specimens
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 6 days (refrigerated) |
| Frozen | 30 days (frozen preferred) |