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Test Code CD45RA RO T Cells CD45 RA and RO

Important Note

Note: limited specimen stability - see Sample Requirements Info below - do NOT refrigerate.

Children's Outpatient Blood Draw areas and Community Services - order "T&B Community Service" (specific tests will be ordered in Cell Markers Lab) and submit copy of requisition with specimen.

For more information call Cell Markers (206) 987-2560.

Additional Codes

Study includes: CD3, CD4, CD8, CD45 RA/RO. Panels can be ordered alone, or in combination with other T and B Panels - Duplicate tests will not be charged.

Clinical System Name

T and B CD3, Subsets, CD45RA and RO

Synonyms

CD45 RA/RO
RA/RO

45 RA/RO

45RA/RO

RA RO

Description

The CD45RA/RO assay is used in the evaluation of immunodeficiency.  CD45RA and CD45RO are isoforms of the CD45 antigen that are typically expressed on T Cells in identifiable patterns using flow cytometry.

Sample Requirements

Specimen:  Whole Blood

Container(s):  Lavender/EDTA; Dk Green/Heparin also acceptable from referring labs if CBC & differential results submitted

Preferred Vol:  2-3 mL

Minimum Vol:  2 mL; no microtainers

 

Note:  Specimens received after 1430 will be held and testing will be performed the next working day. 

 

 

  Collected in-house at Seattle Children's Collected off-site (including SCH Bellevue)
M-Th collect any time collect any time
Friday collect any time ok if received at SCH main lab same day, if not do not collect
Saturday ok if collected before 12 noon do not collect
day before a holiday ok if collected before 12 noon must be received at SCH main lab before 12 noon
Sunday ok if collected after 12 noon (to be tested next morning)

ok if collected after 12 noon (to be tested next morning)

Sunday before a holiday Monday do not collect do not collect
Holiday ok if collected after 12 noon (to be tested next morning) ok if collected after 12 noon (to be tested next morning)

 

Children's Outpatient Blood Draw areas and Community Services - order "T&B Community Services" (specific tests will be ordered in Cell Markers Lab) and submit copy of requisition with specimen.

Processing Instructions

Reject due to:  clotted specimen, Microtainers, Refrigerated

Spin: N

Aliquot: N

Temp:  RT - DO NOT REFRIGERATE

Note:  Have Core Lab run specimen through hematology analyzer and send a copy of the results and community services requisition (if applicable) with specimen to Cell Markers.

Storage location: Days:  Transport specimen, copy of community services requisition (if applicable), and labels to 10th floor Cell Markers (station #280).    Eves/Nights:  Store specimen, copy of community services requisition (if applicable), and labels in the Cell Markers RT box in CPA.

 

Off-site collection: Keep whole blood at room temperature. Referring labs may send CBC w/differential results from the same collection along with the sample.

Stability

Temperature Time
Room temp EDTA - 30 hours; Heparin - 48 hours
Refrigerated N
Frozen N

 

Availability

STAT Performed TAT
N M-F, Sa (0730-1200) 2-3 days

Note: limited specimen stability - see Sample Requirements

Performing Laboratory

Seattle Children's Laboratory    

Department

Department:  Cell Markers

Phone Number: 206-987-2560

 

Reference Range

Reference values accompany patient report.
 

Methodology

Method:  Flow Cytometry

Analytical Volume:  dependent on patient's white count and testing requested

Limitations:

CPT Codes

contact Laboratory Client Services at (206)-987-2617

Clinical Utility

CD45RA and CD45RO are isoforms of the CD45 antigen that are typically expressed on T Cells in identifiable patterns using flow cytometry.  Typically CD45RA and CD45RO are run against each other and against CD3 and CD4 or CD8.  This is a 5-color flow cytometry study.

 

CD45RA is the long isoform of CD45 and is expressed on naive T cells.  CD45RO is the shorter isoform, and is expressed on T cells that have encountered antigens.  In clinical immunology, this distinction between CD45RA+ versus CD45RO+ T-cell subsets is particularly  useful to determine the status of the naive T-cell compartment relative to their thymus origin.  Primary immunodeficiency disorders characterized by decreased/absent thymic output often show decreased CD45RA+ (naive) T cells.