Cytomegalovirus Drug Resistance by Next Generation Sequencing, Ganciclovir, Foscarnet, Cidofovir, Maribavir, and Letermovir

Casandra

Casandra Test Code AR73012Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 3004615CPT Codes 87900, 87910

Cytomegalovirus Drug Resistance by Next Generation Sequencing, Ganciclovir, Foscarnet, Cidofovir, Maribavir, and Letermovir

Also known as: CMVNGS5

Clinical Use

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Use

This test provides antiviral susceptibility information for multiple drugs including ganciclovir, foscarnet, cidofovir, maribavir, and letermovir, intended for patients with a cytomegalovirus (CMV) viral load greater than 2.6 log IU/mL. It is used to assess resistance to these drugs by identifying mutations associated with drug resistance in CMV. The assay sequences the UL97, UL54, UL27, and UL56 genes using next generation sequencing, with interpretations based on an ARUP-developed database of published resistance mutations. It detects mutations that may account for resistance interpretation differences between methods, even identifying mutations in as little as 10% of the viral population.

Special Instructions

Patients should have a viral load greater than 2.6 log IU/mL for this test to be effective. It is important to submit the most recent viral load and test date and provide information on current or past drug therapy, if available. The test may not succeed if the CMV DNA viral load is below the specified threshold.

Limitations

This test may not detect some insertions or deletions due to software limitations and may not succeed if the viral load is below 2.6 log IU/mL. Indeterminate results can occur if there is incomplete sequence coverage, and some mutation sites may not be called if they have inadequate sequence reads. Resistance interpretation may vary based on population differences detected down to 10%.

Test Details

New York Approved