Test ID: ADA
Adenosine Deaminase, Blood
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Evaluation of hemolytic anemia of obscure cause
Evaluation of severe combined immunodeficiency syndrome
Method Name A short description of the method used to perform the test
Kinetic Spectrophotometry (KS)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube:
Preferred: Yellow top (ACD solution B)
Acceptable: EDTA
Specimen Volume: 4 mL
Forms: If not ordering electronically, please submit a Hematopathology/Molecular Oncology Request Form (Supply T241) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross reject |
| Lipemia | NA |
| Icterus | NA |
| Other | Green-top (heparin) tube |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole blood | Refrigerated | 20 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Adenosine deaminase (ADA) catalyzes the deamination of adenosine to inosine, an important mechanism for regulating the quantity of adenosine nucleotides (eg, adenosine triphosphate [ATP]) within the red cell. Some congenital hemolytic anemias with markedly elevated (50-70 x normal) ADA activity are associated with reduced concentrations of ATP. This hemolytic disorder is inherited in an autosomal dominant pattern, in contrast to most erythrocyte enzymopathies. Elevated ADA is also seen in Diamond Blackfan anemia (DBA) and may be used as supportive evidence in the differential diagnosis of transient erythroblastopenia of childhood. Approximately 20% of severe combined immunodeficiency disease (SCID) patients are associated with ADA deficiency. This test can be used in combination with clinical features and corroborative laboratory testing to support a diagnosis subtype for suspected SCID patients.
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.
0.5-1.7 U/g Hb
Interpretation Provides information to assist in interpretation of the test results
In hemolytic anemia due to adenosine deaminase (ADA) excess, ADA concentrations are 48 U/g hemoglobin to 100 U/g hemoglobin.
In severe combined immunodeficiency syndrome, ADA concentrations are <0.3 U/g hemoglobin.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test should not be used for monitoring patients receiving PEG-adenosine deaminase (ADA) therapy.
The limit of detection of this assay is such that the result of this test should not be used as an independent diagnostic test for adenosine deaminase deficiency. If clinical or family history or presentation is suggestive of a severe combined immunodeficiency syndrome or variant severe combined immunodeficiency disease, consultation with a clinical immunologist is recommended along with additional testing for lymphocyte subset quantitation (TBBS/9336 T- and B-Cell Quantitation by Flow Cytometry) to determine the immune phenotype. As the diagnostic window is very narrow for this test, some normal healthy individuals can have values below the limit of detection.
Mayo Medical Laboratories does not offer ADA testing on pleural fluid. If looking to rule-out tuberculosis, we recommend MTBRP/88807 Mycobacterium tuberculosis Complex, Molecular Detection, PCR assay. That test is FDA-approved for respiratory specimens only, but can be performed on other specimen types.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Fairbanks VF, Klee GG: Biochemical aspects of hematology. In Tietz Textbook of Clinical Chemistry. Third edition. Edited by CA Burtis, ER Ashwood, Philadelphia, WB Saunders Company, 1999, pp 1642-1646
2. Hirschhorn R: Adenosine deaminase deficiency and immunodeficiencies. Fed Proc 1979;36:2167-2170
3. Hirschhorn R: Overview of biochemical abnormalities and molecular genetics of adenosine deaminase deficiency. Pediatr Res 1993 Jan;33(1 Suppl):S35-41
Method Description Describes how the test is performed and provides a method-specific reference
The ADA assay is also based on the enzymatic deamination of adenosine to inosine. Inosine is converted to hypoxanthine by purine nucleoside phosphorylase (PNP). Hypoxanthine is then converted to uric acid and hydrogen peroxide (H2O2) by xanthine oxidase (XOD). H2O2 is further reacted with N-Ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline (EHSPT) and 4-aminoantipyrine (4-AA) in the presence of peroxidase (POD) to generate quinone dye which is monitored in a kinetic manner. The entire enzymatic reaction scheme is shown below.
|
| ADA |
|
| adenosine + H2O | -----> | inosine + NH3 |
|
| PNP |
|
| inosine + Pi | -----> | hypoxanthine + ribose-1-phosphate |
|
| XOD |
|
| hypoxanthine + 2H2O + 2O2 | -----> | uric acid + 2H2O2 |
|
| POD |
|
| 4H2O2 + 4-AA + EHSPT | -----> | 4H2O + quinone dye (lamda max 556 nm) |
One unit of ADA is defined as the amount of ADA that generates 1 micromole of inosine from adenosine per minute at 37 degrees C.(Beutler E: Red cell metabolism. In A Manual of Biochemical Methods. Second edition. Grune and Stratton, 1984, pp 99-100)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
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's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
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 Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
82657
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| ADA_ | Adenosine Deaminase, B | 47549-1 |
External
link
PDF
document
Excel
document
Word
document