Cystine, Leukocyte - Collect Mon-Thurs only. Must be delivered to UMMC Labs by 1500.

Abbrev Code:WBCYS   
Order Code:LAB3879Order Name:Cystine, Leukocyte
Synonyms:White Blood Cell Cystine; 1/2 Cystine; Leukocyte Cystine
Methodology:Tandem mass spectrometry; granulocyte half-cystine
CPT Codes: 82131 x1
Turnaround Time:Specimens are sent to reference laboratory Mon-Thur; results are reported within 2 weeks.
Special Instructions:
This test must be shipped the same day it is collected. Include a completed UCSD Biochemical Genetics Request form (see Associated Links) with each sample including the exact collection time and the time of the patient's last medication.

Diagnostic specimens require a control sample from an unrelated normal individual collected, processed and shipped in parallel.

Patient and control sample must be refrigerated within 1 hour. Collect specimen on wet ice. Do not use chemical ice packs or allow to freeze.  
Associated Links:

UCSD Biochemical Genetics Request Form

Collection Instructions

Optimal Volume:5 mL
Minimum\Peds Volume:3 mL
Container:Yellow (ACD, Solution A) tube available from laboratory
Collection Instructions:
Collect specimen on wet ice. Do not use chemical ice packs or allow to freeze.

Optimal collection time is immediately prior to the next dose (trough level).

Collect Mon-Thurs only and deliver to UMMC labs by 1500.

West Bank: Send to Sendouts Bench STAT with STAT sticker, or hand-deliver directly to Sendouts Bench for prompt refrigeration.

A control sample from an unrelated normal individual must be obtained at the same time as the patient sample for diagnostic specimens.
Causes for Rejection:Clotted or frozen specimens or specimens not refrigerated within 1 hour of collection. Diagnostic specimens arriving without a control sample.

Processing and Shipping

Specimen Processing:Refrigerate patient sample and control within 1 hour of collection. Do not process.
Shipping Instructions:Ship in a STAT bag on wet ice. Samples must arrive in East Bank Core Lab/Sendouts or ACL West Bank, Mon-Thur 0700-1500, to be sent to UCSD the same day.
Test Performed at or Referral Lab Lab Sendouts  (University of California, San Diego)


Reference Range:When blood is collected immediately prior to the medication dose, a value of <1.9 nmol/mg protein in granulocytes is found in >99% (the "3 sigma value") of samples from (asymptomatic) cystinosis carriers.
Use:To monitor cystinotic patients taking medication for cystinosis.

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