Test Catalog

Test Id : ALPS

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Alpha Beta Double-Negative T Cells for Autoimmune Lymphoproliferative Syndrome, Blood

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosing autoimmune lymphoproliferative syndrome, primarily in patients <45 years of age

Method Name
A short description of the method used to perform the test

Flow Cytometry

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

ALPS Screen

Aliases
Lists additional common names for a test, as an aid in searching

Canale-Smith syndrome

CD4/CD8 negative

DNT (Double Negative T-Cells)

Double negative T cells (DNT)

Alpha/Beta positive

Specimen Type
Describes the specimen type validated for testing

Whole Blood EDTA

Shipping Instructions

Specimens are required to be received in the laboratory weekdays and by 4 p.m. on Friday. Draw and package specimen as close to shipping time as possible.

 

It is recommended that specimens arrive within 24 hours of draw.

 

Samples arriving on the weekend and observed holidays may be canceled.

Necessary Information

Ordering physician name and phone number are required.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

For serial monitoring, we recommend that specimen draws be performed at the same time of day.

 

Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions: Send specimen in original tube. Do not aliquot.

Forms

If not ordering electronically, complete, print, and send a Benign Hematology Test Request Form (T755) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.5 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Whole Blood EDTA Ambient (preferred) 72 hours PURPLE OR PINK TOP/EDTA

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosing autoimmune lymphoproliferative syndrome, primarily in patients <45 years of age

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Autoimmune lymphoproliferative syndrome (ALPS) (also known as Canale-Smith syndrome) is a complex clinical disorder of dysregulated lymphocyte homeostasis that is characterized by lymphoproliferative disease, autoimmune cytopenias, splenomegaly, and lymphadenopathy with an increased susceptibility to malignancy.(1) Typically, ALPS is diagnosed by childhood or young adulthood.

 

Genetic defects in the apoptosis (programmed cell death) pathway have been determined for most cases of ALPS. Apoptosis plays a role in normal immune homeostasis by limiting lymphocyte accumulation and autoimmune reactivity. The interaction of the surface receptor CD95 (FAS) and its ligand (CD95L;FASL) triggers the apoptotic pathway in lymphocytes.

 

The following molecular ALPS classification has been established:

 

ALPS Classification

 

Molecular/Genetic Defect in Apoptosis

Type Ia

CD95 (FAS) mutations(1)

Type Ib

Heterozygous CD95L (FASLG) mutations(1)

Type Ic

Homozygous CD95L (FASLG) mutation(2)

Type II

CASP8 or CASP10 mutations(1,3)

Type III

Unknown(1,3)

 

Patients with ALPS have an increase in a normally rare population of T cells (typically <1%) that are alpha beta T-cell receptor (TCR)-positive, as well as negative for both CD4 and CD8 coreceptors (double-negative T cells: DNT).(1) The alpha beta TCR+DNT cells from ALPS patients also express an unusual B-cell-specific CD45R isoform, called B220.(4,5) B220 expression on alpha beta TCR+DNT cells has been demonstrated to be a sensitive and specific marker for ALPS and is associated with FAS mutations.(4)

 

Several other diseases can present with an ALPS-like phenotype, including independent conditions like Evans syndrome (a combination of autoimmune hemolytic anemia and autoimmune thrombocytopenic purpura), Rosai-Dorfman disease (massive painless cervical lymphadenopathy that may be accompanied by leukocytosis, elevated erythrocyte sedimentation rate, and hypergammaglobulinemia), and nodular lymphocyte-predominant Hodgkin disease.(1)

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

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 less 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 less 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 less 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 less than 24 months of age.

Interpretation
Provides information to assist in interpretation of the test results

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 for FAS mutations (call 800-533-1710 for test forwarding information).

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test is typically not indicated in older adults. For questions about appropriate test selection, call 800-533-1710.

 

The sole presence of increased alpha beta TCR+DNT B220+ cells is not sufficient for a diagnosis of autoimmune lymphoproliferative syndrome (ALPS); additional testing is required to confirm a diagnosis of ALPS.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Worth A, Thrasher AJ, Gaspar HB: Autoimmune lymphoproliferative syndrome: molecular basis of disease and clinical phenotype. Brit J Hematol 2006;133:124-140

2. Del-Rey M, Ruiz-Contreras J, Bosque A, et al: A homozygous Fas ligand gene mutation in a patient causes a new type of autoimmune lymphoproliferative syndrome. Blood 2006;108:1306-1312

3. Salmena L, Hakem R: Caspase-8 deficiency in T-cells leads to a lethal lymphinfiltrative immune disorder. J Exp Med 2005;202:727-732

4. Blessing JJH, Brown MR, Dale JK, et al: TCR alpha beta+ CD4-CD8-T-cells in humans with the autoimmune lymphoproliferative syndrome express a novel CD45 isoform that is analogous to urine B220 and represents a marker of altered O-glycan biosynthesis. Clin Immunol 2001;100(3):314-324

5. Bleesing JJH, Janik JE, Fleisher TA: Common expression of an unusual CD45 isoform on T-cells from patients with large granular lymphocyte leukemia and autoimmune lymphoproliferative syndrome. Brit J Hematol 2003;120:93-96

Method Description
Describes how the test is performed and provides a method-specific reference

This assay uses a 5-color, single-platform method with a 2-tube panel stained for the following antibodies: CD3, CD4, CD8, CD45, alpha beta TCR, and B220. The sample is stained with the antibody cocktail and incubated in the dark at room temperature for 20 minutes. Following incubation, the samples are treated with BD lysing solution to lyse the RBCs, followed with a wash step using BD FACS wash buffer. The cells are resuspended in 1% paraformaldehyde and analyzed by flow cytometry. The different subsets are expressed as a percent of CD3 T cells, and the absolute counts of all subsets are expressed as cells/mcL.(Unpublished Mayo method; Bleesing JJH, Brown MR, Dale JK, et al: TCR alpha beta + CD4-CD8- T-cells in humans with the autoimmune lymphoproliferative syndrome express a novel CD45 isoform that is analogous to murine B220 and represents a marker of altered O-glycan biosynthesis. Clin Immunol 2001;100[3]:314-324)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

3 to 4 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

4 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

86356 x2

86359

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
ALPS ALPS Screen In Process
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
28905 Absolute TCR+DNT B220+ 88053-4
23974 alpha/beta-TCR DNT 34963-9
28904 % TCR+DNT B220+ 88052-6
23973 %alpha/beta-TCR DNT 34962-1
23975 Interpretation 69052-9

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Create a PDF

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports