Donath-Landsteiner (Sendout)

Indications: This test may be ordered in a patient suspected of having paroxysmal cold hemoglobinuria (PCH). This entity is more common in children, and may be characterized by episodes of hemolysis upon exposure to cold temperatures.

Test Information: As PCH is classically due to an IgG antibody, preliminary tests such as a direct antiglobulin test using polyspecific Coombs reagent may be performed prior to proceeding with the Donath-Landsteiner test; this is to help differentiate PCH from cold agglutinin syndrome (CAS), when an IgM antibody is causing hemolysis.

Note: Special collection procedures are required. To arrange for testing, contact the Laboratory Medicine Resident on-call via the paging operator. The Bloodworks NW Immunohematology Reference Laboratory (206-689-6534) should be notified prior to sample collection.

15 mL blood in a RED TOP tube kept warm after collection.

• Maintain sample temperature at 37°C with heel warmer pad and walk sample to the lab immediately (NW220 at UW-MT or GWH-47 at HMC).
• Upon arrival, notify the lab that the sample must be kept warm.

Unacceptable: Serum separator gel tube.

If unable to centrifuge immediately, specimen can be held in a 37°C water bath for up to 15 minutes. Once sample is clotted, centrifuge and transfer serum to a separate, plastic aliquot.

Send serum sample at ambient temperature with a completed Bloodworks Northwest requisition or Epic requisition.

Note: A fresh source of complement is needed for the test. The LMR should call Platelet Immunology Lab at 206-689-6534 if a quick turnaround is desired.