Ordering Recommendation

Monitor engraftment of maternal T cells in patients with severe combined immunodeficiency (SCID) prior to allogenic stem cell transplantation.

Mnemonic
STR-SCID
Methodology

Polymerase Chain Reaction/Fragment Analysis

Performed

Sun-Sat

Reported

5-9 days

New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA), Pink (K2EDTA), or Yellow (ACD Solution A).

Specimen Preparation

Transport 3 mL whole blood. (Min: 3 mL) Increase the amount of blood submitted for patients with low cell counts.

Storage/Transport Temperature

Room temperature. Ship overnight. Specimens should be received within 24 hours of collection for optimal isolation of T cells.

Unacceptable Conditions

Clotted or hemolyzed specimens.

Remarks

Please provide the results and date of the patient's most recent WBC and differential counts.

Stability

Ambient: 48 hours; Refrigerated: 48 hours; Frozen: Unacceptable

Reference Interval
Type Maternal Maternal cells only.
Type Patient Patient cells only.
Mixed Patient and Maternalt cells present.  Semi-quantitative results of percentage of patient and maternal cells will be reported.

Interpretive Data

Background Information for Maternal T Cell Engraftment in SCID:
Indication:
Severe combined immunodeficiency (SCID) patients lack T cells and cannot recognize and reject maternal T cells from maternal-fetal transfusion. Maternal T cell can proliferate in the absence of host T cells, leading to difficulty in determining the host T cell numbers required for the diagnosis of SCID and/or can cause graft-versus-host disease-line (GVHD) presentation. 
Methodology:
PCR followed by capillary electrophoresis. Specimens are analyzed using 15 autosomal markers (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, THO1, D13S317, D16S539, D2S1338, D19S433, vWa, TPOX, D18S51, D5S818, and FGA) and one gender marker (amelogenin).
Kit Used:
AmpFLSTR Identifiler PCR Amplification Kit, Applied Biosystems.
Limit of Detection:
2 percent of minor cell population. 

Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Note

To complete Maternal T Cell Engraftment in SCID testing, samples should be collected to perform the following three tests: (1) A buccal swab or brush collected from the patient for Maternal T Cell Engraftment in SCID, Pre-Engraftment Specimen (ARUP test code 2014694), used as a genetic baseline for the patient. (2) A peripheral blood sample from the biological mother for Maternal T Cell Engraftment in SCID, Maternal Specimen (ARUP test code 2014704), used as a genetic baseline for the mother. (3) A peripheral blood sample collected from the patient for Maternal T Cell Engraftment in SCID, (ARUP test code 2014699). T cells isolated from the blood sample will be genotyped for comparison to the patient and biological mother baseline genotypes. If T cell sorting is not completed on the blood sample before submission, BMT Cell Isolation (ARUP test code 2005498) will be added. Additional charges apply.

Hotline History
N/A
CPT Codes

81268; If cell sorting is performed, add 88184

Components
Component Test Code* Component Chart Name LOINC
2014700 Specimen, Maternal Engraftment
2014701 Mat Engraftment, Informative Loci
2014702 Maternal Engraftment, Interpretation
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • Maternal engraftment
  • SCID engraftment
Maternal T Cell Engraftment in SCID