The use of CCR5 antagonists in patients harboring CXCR4(X4) or dual-mixed (DM) viruses has proven to be ineffective and leads to the emergence of X4 viruses as the predominant species in DM patients. In clinical trials, X4 virus was found in 55% of patients failing maraviroc therapy vs. only 9% of patients who experienced treatment failure in the placebo arm. The use of CCR5 antagonists, therefore, requires screening for viral tropism to exclude patients harboring X4 or DM virus. Detection of X4 virus prior to the initiation of therapy has been associated with a reduced response to maraviroc. http://www.accessdata.fda.gov/drugsatfda_docs/label/2007/022128lbl.pdf
Collect blood in sterile tubes containing EDTA
anticoagulant (lavender-top) or PPT (white-top) tube.
Separate plasma from the cells by centrifugation within 24
hours after collection, transfer the plasma to a separate
plastic screw-cap vial, and ship frozen.
Reported (Analytical Time)
The CPT codes provided are based on AMA guidelines and are for informational purposes only.
CPT coding is the sole responsibility of the billing party.
Please direct any questions regarding coding to the payer being billed.