Chimerism, Posttransplant, Sorted Cells (Granulocytes)

Casandra

Casandra Test Code AR14539Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 3005417CPT Code 81268

Chimerism, Posttransplant, Sorted Cells (Granulocytes)

Clinical Use

Use

This test is used to monitor the engraftment of donor cells following an allogeneic stem cell transplant. It provides critical insights for managing patients undergoing bone marrow transplantation by correlating chimeric status with clinical outcomes. The detection and quantification of donor cells versus recipient cells help in assessing the success of the transplant and guiding clinical decisions regarding treatment modifications. It aids in identifying potential graft failures or complications by analyzing the presence and proportion of donor cells in the granulocyte population.

Special Instructions

Each posttransplant specimen must have a unique ARUP accession number. Donor and recipient specimens must be obtained and genotyped before the transplant. Include the results and date of the patient's most recent WBC and differential counts. If submitting bone marrow specimens for cell sorting, provide information on the patient's bone marrow cellularity. Use the Cell Isolation Request for Chimerism, Posttransplant, Sorted Cells for processing.

Limitations

The test's accuracy can be impacted by rare sequence variations, which may lead to diagnostic errors. The assay has a limit of detection at 2 percent of the minor cell population, meaning that the test might not detect very low levels of chimerism. The interpretive value of the test also depends on the timing post-transplant and correlation with clinical status. As the test is classified as a Laboratory Developed Test (LDT), it might not hold the same regulatory clearances as FDA-approved tests.

Test Details

New York Approved

Methodology

PCR-based (Fragment Analysis)

Biomarkers

No genes

Gene

Result Turnaround Time

5-10 days

Specimen

Whole Blood

Volume

2 mL

Minimum Volume

2 mL

Container

Lavender (EDTA), pink (K2EDTA), or yellow (ACD solution A or B)

Collection Instructions

Transport 2 mL whole blood. Ship overnight. Ensure specimens are received within 24 hours of collection for optimal isolation of the requested cell line(s).