Paroxysmal Nocturnal Hemoglobinuria, High Sensitivity, RBC

Casandra

Casandra Test Code AR64247Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 2004366CPT Code 86356

Paroxysmal Nocturnal Hemoglobinuria, High Sensitivity, RBC

Also known as: PNH RBC

Clinical Use

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Use

This test is used to monitor subclinical paroxysmal nocturnal hemoglobinuria (PNH) and eculizumab treatment. It is designed to quantify CD59 expression on erythrocytes using flow cytometry, specifically to identify high-sensitivity PNH RBCs. The test can detect PNH clone size and assist in therapeutic decisions, especially beneficial for evaluating treatment in myelodysplastic bone marrow disorders with subclinical PNH populations. It also helps to accurately measure PNH RBC clone sizes beyond the initial diagnostic contexts.

Special Instructions

This assay is performed using quantitative flow cytometry and developed according to published guidelines. Testing requires whole blood specimens collected in lavender (EDTA), pink (K2EDTA), or green (sodium or lithium heparin) tubes, and must be refrigerated during transport. Repeat testing may be necessary upon any change in clinical or laboratory parameters.

Limitations

The test is not FDA-approved and is not suitable for use in New York. The assay results may be affected by recent RBC transfusions, which could decrease the percentage of PNH cells measured. The assay is specifically developed to determine CD59 expression and quantify RBC Type II and III clones when PNH RBCs exceed 1% of the total. It is essential to note that incorrect clinical diagnosis can result from improper sample collection or handling. Clotted or hemolyzed specimens are unacceptable and can result in erroneous results.

Test Details