Dihydrorhodamine Flow Cytometric Test, Blood

Casandra

Casandra Test Code MC67086Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID DHRCPT Code 86352

Dihydrorhodamine Flow Cytometric Test, Blood

Clinical Use

Use

The Dihydrorhodamine Flow Cytometric Test is primarily used for the evaluation of chronic granulomatous disease (CGD), both X-linked and autosomal recessive forms. It can identify Rac2 deficiency, monitor nicotinamide adenine dinucleotide phosphate oxidase (NOX) function post-hematopoietic cell transplantation, assess residual NOX activity pretransplant, and help identify female carriers of X-linked CGD. It also evaluates changes in lyonization with age in female carriers. Approximately 70% of CGD cases are due to mutations in the CYBB gene, while other cases involve mutations in genes like NCF1, NCF2, and CYBA.

Special Instructions

Testing is not performed on weekends or observed holidays and specimens should arrive within 24 hours of collection. Two whole-blood sodium heparin specimens are needed, one from the patient and a second from a healthy donor as a control. Use of the Ambient Shipping Box-Critical Specimens Only (T668) is recommended for specimen shipping.

Limitations

Specimens should be tested within 24 hours of collection for optimal results; however, stability is maintained for 48 hours. Some NCF4 variants might not be detected by this assay. Complete myeloperoxidase deficiency and severe glucose-6-phosphate dehydrogenase deficiency can cause false-positive results. Specimens with an absolute neutrophil count below 200 are unacceptable.

Test Details

New York Approved