Test Catalog

Test Id : ST2S

This test is temporarily unavailable.  For additional details, see test update here.

ST2, Serum

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

Aiding in prognosis for patients diagnosed with chronic heart failure

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

Enzyme-Linked Immunosorbent Assay (ELISA)

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


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

ST2, S

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

Cardiac Fibrosis

Cardiac Remodeling

Heart Failure


Soluble ST2

Suppression of Tumorigenicity 2


IL-33 Receptor

Specimen Type
Describes the specimen type validated for testing

Serum Red

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

Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.


If not ordering electronically, complete, print, and send a Cardiovascular Test Request Form (T724) with the specimen.

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

0.2 mL

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

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

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
Serum Red Frozen (preferred) 90 days
Refrigerated 7 days
Ambient 72 hours

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

Aiding in prognosis for patients diagnosed with chronic heart failure

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

Heart failure is a chronic, progressive, complex cardiovascular disorder with a variety of etiologies and heterogeneity with respect to the clinical presentation of the patient. Heart failure is significantly increasing in prevalence with an aging population and is associated with high short- and long-term mortality rate. Over 80% of patients diagnosed and treated for acute heart failure syndromes in the emergency department are readmitted within the forthcoming year, incurring costly treatments and therapies.(1)


The development and progression of heart failure is a clinically silent process until manifestation of the disorder, which typically occurs late and irreversibly into its progression. Mechanistically heart failure, whether due to systolic or diastolic dysfunction, is thought to progress primarily through adverse cardiac remodeling and fibrosis in response to cardiac injury or stress.(2) Soluble ST2 (sST2) is a biomarker that appears to be actively involved with interleukin (IL)-33 in modulating cardiac remodeling and ventricular function via effects in the inflammatory and apoptosis pathways.(3)


ST2 is a member of the IL-1 receptor family and has 2 isoforms that are directly implicated in progression of cardiac disease: sST2 and a transmembrane-bound form, ST2 ligand (ST2L). IL-33 is the hormone that interacts with ST2L, protecting against left ventricular hypertrophy and myocardial fibrosis to effectively preserve cardiac function. Therefore, when sST2 concentrations are high, IL-33 is unavailable for cardioprotective signaling, leaving the heart vulnerable to the effects of sST2. High concentrations of sST2 result in cellular death, tissue fibrosis, reduced cardiac function, and an increase in the rate of disease progression.

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.


<24 months: not established

2-17 years: < or =43.0 ng/mL

> or =18 years: < or = 52.0 ng/mL



<24 months: not established

2-17 years: < or =43.0 ng/mL

> or =18 years: < or =38.7 ng/mL

Provides information to assist in interpretation of the test results

Clinically, ST2 concentrations in the HF-ACTION heart failure study were a significant predictor of mortality, all-cause hospitalization, mortality due to cardiovascular disease, and hospitalization due to cardiovascular disease using a cut point of 35 ng/mL. In addition, mortality risk was significantly higher in patients with ST2 greater than 35 ng/mL.(4) The risk appears early and persists throughout the follow-up period.


Clinical risk categories are substantiated by results from several large chronic heart failure studies:

-Low risk: < or =35.0 ng/mL

-High risk: >35.0 ng/mL (high risk)


Results should be interpreted in the context of the individual patient presentation. Elevated ST2 results indicate an increased risk for adverse outcomes and signal the adverse remodeling and progression of disease.


The reference interval was derived from normal donors without a history of cardiovascular disease, stroke, diabetes, renal disease, liver disease, or autoimmune diseases. The reference range is gender dependent; however, it is the clinical cut point that is recognized as providing the most utility.


Knowledge of ST2 results in a heart failure patient may assist in cardiovascular risk stratification and lead to more aggressive management. There are no specific ST2 inhibitors available at this time and heart failure patients with elevated ST2 concentrations should be treated and monitored according to established guidelines. Angiotensin receptor blockers and aldosterone antagonists are thought to be particularly effective.

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

ST2 has not been shown to be useful in the acute diagnosis of heart failure; natriuretic peptides (BNP or NT-proBNP) should be utilized for this purpose in the context of appropriate clinical suspicion of acute heart failure. ST2 and natriuretic peptides are measures of separate and distinct biological processes, providing independent and complimentary prognostic information.


There are no significant analytical interferences reported for ST2 from bilirubin, hemoglobin, triglycerides, cholesterol, or total protein. Forty-nine therapeutic substances were tested for analytical interference and none had significant interference with the ST2 assay.(5)

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

1. Weintraub NL, Collins SP, Pang PS, et al: Acute heart failure syndromes: emergency department presentation, treatment, and disposition: Current approaches and future aims: a scientific statement from the American Heart Association. Circulation. 2010;122:1975-1996. doi: 10.1161/CIR.0b013e3181f9a223

2. Kakkar R, Lee R: The IL-33/ST2 Pathway: therapeutic target and novel biomarker. Nat Rev Drug Discov. 2008;7:827-840. doi: 10.1038/nrd2660

3. Seki K, Sanada S, Kudinova AY, et al: Interleukin-33 prevents apoptosis and improves survival after experimental myocardial infarction through ST2 signaling. Circ Heart Fail. 2009;2(6):684-691. doi: 10.1161/CIRCHEARTFAILURE.109.873240

4. Whellan DJ, O'Connor CM, Lee, KL, et al: HF-ACTION Trial Investigators. Heart failure and a controlled trial investigating outcomes of exercise training (HF-ACTION): design and rationale. Am Heart J. 2007;153(2):201-211

5. Dieplinger B, Januzzi J, Steinmair M, et al: Analytical and clinical evaluation of a novel high-sensitivity assay for measurement of soluble ST2 in human plasma - The Presage ST2 Assay. Clin Chim Acta. 2009;409:33-40. doi: 10.1016/j.cca.2009.08.010

6. Meeusen JW, Johnson JN, Gray A, et al: Soluble ST2 and galectin-3 in pediatric patients without heart failure. Clin Biochem. 2015;Dec;48(18):1337-1340. doi: 10.1016/j.clinbiochem.2015.08.007

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

The ST2 assay is an FDA 510K-cleared in vitro diagnostic device. It is a quantitative 2-site manual enzyme-linked immunosorbent assay (ELISA) validated for use in human sera. The capture monoclonal antibody (mouse antihuman ST2) is immobilized on 96-well plates, while the second mouse monoclonal antihuman capture antibody functions as the tracer antibody for detecting ST2, which is bound to the capture antibody. The tracer antibody is biotinylated and bound with streptavidin-horseradish peroxidase during incubation and detection occurs following addition of tetramethylbenzidine substrate.(Package insert: Presage ST2 Assay, Critical Diagnostics Inc.; 03/2018)

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


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.


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.

1 to 8 days

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

14 days

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


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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 has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

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.


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
ST2S ST2, S 90239-5
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.
61723 ST2, S 90239-5

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 | 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

Test Update Resources

Change Type Effective Date
Test Status - Test Down 2023-01-18