Post Tx Purpura Workup (Sendout)

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General Information

Lab Name
Post Tx Purpura Workup (Sendout)
Lab Code
RPSAB
Epic Name
Post Tx Purpura Workup (Sendout)
External Test Id
3660-00
Description

Test Information: Strong positive antibody results against platelets from random donors and the absence of common platelet antigens in the patient are indicative of PTP.

Additional Test Information: Post-transfusion Purpura (PTP) can occur in patients who have been previously sensitized to platelets by transfusion or through pregnancy. Transfusion of cellular blood products containing any platelets (e.g., platelets, granulocytes or red blood cell transfusions) induce a recall of a previously formed alloantibody against platelet specific antigen(s) between 5-10 days post-transfusion. In the process of recalling the alloantibody, the patient apparently also develops a transient autoantibody that leads to the destruction of the patient’s own platelets often resulting in severe thrombocytopenia.

Ordering Requirements:

  • Contact Platelet Immunology Lab at (206) 689-6543 prior to testing to alert them to an incoming order.
  • Limited specimen stability. Time collections appropriately to ensure that specimens arrive within 25 hours of collection.
Forms & Requisitions
Synonyms
3660-00, Post Transfusion Purpura Workup, PTP
Components
Code Name
RPSABR Post Tx Purpura Workup Result (Sendout)
S2PSAB Post Tx Purpura Workup Testing Lab

Interpretation

Method

Flow Cytometry, Polymerase Chain Reaction (PCR), Enzyme Linked Immunosorbant Assay (ELISA)

Reference Range
See individual components

Ordering & Collection

Specimen Type
Blood
Collection

Collect 10 mL Lavender EDTA, 10 mL BLUE (citrate), and 10 mL RED TOP (clot) tube

Collection Timing: Specimens must be received by Bloodworks Northwest within 24 hours of collection. Time collections appropriately.

  • Collect Monday through Friday only (see additional restrictions for Friday collections below). Do not draw samples on or before a holiday.
  • Samples collected on a Friday must be received in UWML or HMC lab by 8:30 am so that they arrive at Bloodworks by the 10:00 am cutoff. Samples received after the cutoff on Friday or over the weekend will need to be re-drawn.

Expedite transport to the lab.

Forms & Requisitions
Handling Instructions

Outside Laboratories: Due to the limited specimen stability for this test, outside laboratories should arrange for testing directly with Bloodworks Northwest.

Quantity
Requested: 10 mL EDTA + 10 mL citrate + 10 mL clot whole blood
Minimum: 10 mL EDTA + 10 mL citrate + 10 mL clot whole blood

Processing

Receiving Instructions

Store and transport whole blood specimens at ambient temperature.

  • Specimens should arrive at the Platelet Immunology Lab within 24 hours of collection.
  • Samples collected on Friday must arrive at the Bloodworks Platelet Immunology Lab prior to the 10 am cutoff.
  • Package sample(s) with the associated Epic or Bloodworks requisition in a biohazard bag (one patient per bag).
    • Orders received with multiple patient samples/requisitions in the same biozard bag will be rejected.
  • Send samples as received by DLMP courier or Delivery Express.
  • Samples to be sent by: UWML Cross Hospital Sendouts, HMC Sendouts, or FHCC SPS depending on draw site. UWNW: Expedite transport of samples to UWML for sendout to Bloodworks Northwest. If nearing the time cutoff, send to Bloodworks Northwest directly.

Stability: Ambient (required): 24 hours.

Misc Sendout

Performance

Lab Department
Sendouts(SO)
Frequency
Performed: As requested. TAT: 1 business day for antibody screen, 5 business days for additional testing.
Available STAT?
No
Performing Location(s)
Sendout Bloodworks Northwest Platelet Immunology/Genomics Laboratory (Central HPG)

921 Terry Ave
6th Floor - SDL
Seattle, WA 98104

Genomics Testing Laboratory (for RBC genotyping): (206) 689-6269

Platelet Immunology Laboratory: (206) 689-6543

Laboratory staffed for questions Monday through Friday, 08:00 am to 04:30 pm.

Billing & Coding

CPT Codes
86022, 86023x2
LOINC
30896-5