Test Code ALPS Alpha Beta Double-Negative T Cells for Autoimmune Lymphoproliferative Syndrome, Blood
Reporting Name
ALPS ScreenPerforming Laboratory
Mayo Clinic Laboratories in RochesterUseful For
Diagnosing autoimmune lymphoproliferative syndrome, primarily in patients younger than 45 years
Method Name
Flow Cytometry
Shipping Instructions
Testing is performed Monday through Friday. Specimens not received by 4pm (CST) on Friday may be canceled.
Collect and package specimen as close to shipping time as possible. It is recommended that specimens arrive within 24 hours of collection.
Samples arriving on the weekend and observed holidays may be canceled.
Necessary Information
Ordering healthcare professional name and phone number are required.
Specimen Required
Container/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Additional Information: For serial monitoring, it is recommended that specimens are collected at the same time of day.
Specimen Type
Whole Blood EDTASpecimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole Blood EDTA | Ambient | 72 hours | PURPLE OR PINK TOP/EDTA |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Reference Values
Alpha beta TCR+DNT cells
2-18 years: <2% CD3 T cells
19-70+ years: <3% CD3 T cells
Reference values have not been established for patients that are younger than 24 months of age.
Alpha beta TCR+DNT cells
2-18 years: <35 cells/mcL
19-70+ years: <35 cells/mcL
Reference values have not been established for patients that are younger than 24 months of age.
Alpha beta TCR+DNT B220+ cells
2-18 years: <0.4% CD3 T cells
19-70+ years: <0.3% CD3 T cells
Reference values have not been established for patients that are younger than 24 months of age.
Alpha beta TCR+DNT B220+ cells
2-18 years: <7 cells/mcL
19-70+ years: <6 cells/mcL
Reference values have not been established for patients that are younger than 24 months of age.
TCR = T-cell receptor
DNT = Double negative T cell
Interpretation
The presence of increased circulating T cells (CD3+) that are negative for CD4 and CD8 (double-negative T cells: DNT) and positive for the alpha/beta T-cell receptor (TCR) is required for the diagnosis of autoimmune lymphoproliferative syndrome (ALPS).
The laboratory finding of increased alpha beta TCR+DNT cells is consistent with ALPS only with the appropriate clinical picture (nonmalignant lymphadenopathy, splenomegaly, and autoimmune cytopenias). Conversely, there are other immunological disorders, including common variable immunodeficiency (CVID), which have subsets for patients with this clinical picture, but no increase in alpha beta TCR+DNT cells.
If the percent of the absolute count of either the alpha beta TCR+DNT cells or alpha beta TCR+DNT B220+ cells is abnormal, additional testing is indicated. All abnormal alpha beta TCR+DNT cell results should be confirmed (for ALPS) with additional testing for defective in vitro lymphocyte apoptosis followed by confirmatory genetic testing (ALPSG / Autoimmune Lymphoproliferative Syndrome [ALPS] Gene Panel, Varies).
Day(s) Performed
Monday through Friday
Report Available
3 to 4 daysTest Classification
This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
86356 x2
86359
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
ALPS | ALPS Screen | 101414-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
23973 | %alpha/beta-TCR DNT | 34962-1 |
23974 | alpha/beta-TCR DNT | 34963-9 |
28904 | % TCR+DNT B220+ | 88052-6 |
28905 | Absolute TCR+DNT B220+ | 88053-4 |
23975 | Interpretation | 69052-9 |
Forms
If not ordering electronically, complete, print, and send a Benign Hematology Test Request Form (T755) with the specimen.