Archive for April, 2013

Cardiac ELISA kits | Cardiac RapidTests

Cardiac Elisa Kits | Cardiac Rapid Tests

Background:

Our daily aim includes saving patients and helping people around the world by providing new and advanced diagnostic products.  In one hand growing demand for highly effective and impactful medicines is being driven by an aging population and economic pressures.  On the other hand the availability of genomic and proteomic tools and system biology approaches to identify novel biomarkers have permitted additional disease biomarkers to emerge.  At DIAGNOSTIC AUTOMATION (focusing on ELISA Kits and rapid tests) standing at the leading edge of scientific innovations, we take advantage of an influx of new technologies and information incorporating them into novel tests which enables us to offer innovative diagnostic tests every day.

Despite the amazing scientific advances in the physical and biological sciences, the number of effective cardiovascular therapies and viable therapeutic targets remains surprisingly limited. The number of useful cardiovascular biomarkers is even fewer. To gain an insight into the disease processes in individual patients, their unique response to etiological risk factors, and their stages of disease progression, an array of diagnostic biomarkers are needed.  We believe that most useful or specific diagnostic/prognostic/efficacy biomarkers eventually will be shown to have biological relevance to the disease.  In our team we have a member who has experience in using systems biology tools such as microarray and proteomics in discovering novel biomarkers related to cardiovascular disease [1].  The general principle employed involves the convergence of well-defined models, together with validation in clinical samples, to provide unique opportunities of early diagnosis.  Three new patents for detection of early cardiovascular remodeling and heart failure using systems biology approach have been filed using this approach.

Cardiovascular diseases are the most prominent circulation disorders around the world.  In 2008, there were an estimated 57 million global deaths, of which 30.5% were attributed to cardiovascular disease [2]. This fraction is greater than combined deaths stemming from other diseases such as cancer, diabetes mellitus, nutritional/endocrine disorders, respiratory diseases, and digestive diseases.  Moreover, Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in the United States.  By 2030 approximately 116 million people in the United States (40.5 percent) will have some form of cardiovascular disease and the cost to treat them will triple [3].  The social, economic, and human costs of cardiovascular disease continue to escalate as a result.  However, death from cardiovascular diseases is preventable with accurate early-stage diagnosis and subsequent proper treatment.  Correct diagnosis is dependent upon cardiac biomarkers.  Cardiac biomarkers are proteins that are released into the blood following a myocardial infarction and are a valuable tool for assessing the pathogenesis and diagnosis of cardiovascular diseases.  We believe that most useful or specific diagnostic biomarkers are the ones with biological relevance to the disease.  To gain an insight into the disease processes in individual patients, their stages of disease progression, and to achieve an in-depth evaluation we have offer 6 different marker ELISA kits in our cardiac elisa kits in addition to our rapid tests.  The integration of these tests will provide robust clinical phenotypes with high level of sensitivity and specificity which is pivotal for a successful diagnostic program.  Used in conjunction with clinical information the rapid and accurate testing of cardiac markers is crucial especially in acute cases where every minute counts.  Moreover, the insight from these tests will assist physician to make both an easier and more informed decision on their choice of medication to treat their patients more effectively in a timely manner.

Myocardial infarction (MI) or acute myocardial infarction (AMI),

Commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die. WHO criteria formulated in 1979 has classically been used to diagnose MI; a patient is diagnosed with myocardial infarction if two (probable) or three (definite) of the following criteria are satisfied:
1.    Clinical history of ischemic type chest pain lasting for more than 20 minutes
2.    Changes in serial ECG tracings
3.    Rise and fall of serum cardiac biomarkers such as creatine kinase-MB fraction and troponin.

The WHO criteria were refined in 2000 to give more prominence to cardiac biomarkers.  According to the new guidelines, a cardiac troponin rise accompanied by either typical symptoms, pathological Q waves, ST elevation or depression, or coronary intervention is diagnostic of MI [4].

Presently, Muscle creatine kinase (CK) and brain subunits (CK-MB) and troponin T, are known as The standard biochemical metrics of myocardial injury.  Therefore to achieve an in-depth evaluation we have combined 3 tests to have robust clinical phenotypes to provide adequate sensitivity or specificity.  At DIAGNOSTIC AUTOMATION our integrated 3 in 1 cardiac rapid test includes Troponin I/Myoglobin/CK-MB both in human serum and in whole blood.

These 3 in 1 Cardiac Markers rapid tests are to be used as aids in the diagnosis of Acute Myocardial Infarction (AMI). In recent years, point-of-care 3 in 1cardiac rapid tests have emerged to play a vital role in the rapid diagnosis and treatment of acute chest pain patients. By combining three cardiac marker tests into one device, the test is able to identify multiple release profiles for improved sensitivity and thus, not only able to identify myocardial infarctions, but also to identify at-risk patients with a possible life-threatening cardiac event in the near future.

3 in 1CARDIAC MARKERS TEST

http://rapidtest.com/blog/3-in-1-cardiac-markers-rapid-test-troponin-ckmb-myoglobin

Los Angeles-based Diagnostic Automation is pleased to offer two  Cardiac Markers Rapid Tests to customers around the world. Both 3 in 1 Cardiac Markers Rapid Tests are available in cassette format. These convenient 3-panel rapid tests are immunochromatography assays for the qualitative and quantitative determination of three biochemical markers (Troponin I, CK-MB, and Myoglobin) simultaneously in human serum or whole blood. The cardiac markers tests are point-of-care testing devices.

Troponin I/CKMB/Myoglobin Serum, (#166778-1) 

3 in 1 Troponin I/CK-MB/Myoglobin Serum/Whole Blood (#166779-1)

3 in 1 rapid test is for the qualitative assessment of cardiac Troponin I, CK-MB, and Myoglobin in human serum and whole blood.

HIGHLIGHTS OF 3 IN 1 CARDIAC MARKERS RAPID TESTS

These 3 in 1 Cardiac Markers rapid tests are to be used as aids in the diagnosis of Acute Myocardial Infarction (AMI). In recent years, point-of-care 3 in 1 cardiac elisa kits have emerged to play a vital role in the rapid diagnosis and treatment of acute chest pain patients. By combining three cardiac marker tests into one device, the test is able to identify multiple release profiles for improved sensitivity and thus, not only able to identify myocardial infarctions, but also to identify at-risk patients with a possible life-threatening cardiac event in the near future [5].

In addition to 3 in 1 rapid test at Diagnostic Automation,  three ELISA kits are offered individually as well as:
1.    Troponin I ELISA kit

http://www.rapidtest.com/index.php?i=Troponin-I-ELISA-kit&id=45&cat=10

1.    Myoglobin ELISA kit

http://www.rapidtest.com/index.php?i=Myoglobin-ELISA-kit&id=46&cat=10

1.    CK-MB ELISA kit

http://www.rapidtest.com/index.php?i=CK-MB-ELISA-kit&id=44&cat=10
Here are brief description of each marker and its biological function:
1. Troponin is a complex of three regulatory proteins (troponin C, troponin I and troponin T) that is integral to muscle contraction in skeletal and cardiac muscle, but not smooth muscle.

Model of Troponin molecular structure [1]
For those more interested in the mechanism of contraction: Troponin is attached to Tropomyosin and lies within the groove between actin filaments in muscle tissue.  In a relaxed muscle, Tropomyosin blocks the attachment site for the myosin cross-bridge, thus preventing contraction. When the muscle cell is stimulated to contract by an action potential, calcium channels open in the sarcoplasmic membrane and release calcium into the sarcoplasm. Some of this calcium attaches to troponin which causes it to change shape, exposing binding sites for myosin (active sites) on the actin filaments. Myosin binding to actin forms cross-bridges and contraction (cross bridge cycling) of the muscle begins.  Both cardiac and skeletal muscles are controlled by changes in the intracellular calcium concentration. When calcium raises, the muscles contract, and when calcium falls, the muscles relax [6].

Diagnostic applications
In medicine, Troponin levels can be used as a test for several different heart disorders, including myocardial infarction.  From the 3 subunits of Troponin, Troponin-I is highly specific for cardiac muscle necrosis. Serum levels rise 3-6 hours after onset of chest pains, peak at 12–16 hours and return to baseline within 5–9 days.

The high specificity and sensitivity of this marker make it extremely useful to either take action against or rule out with confidence any risk of heart attack in patients presenting clinical symptoms such as chest pain, breathing difficulties or left arm pain.
Troponin I elisa kit is also offered at DIAGNOSTIC AUTOMATION

2. Myoglobin is Myoglobin is a heme (an iron- and oxygen-binding) protein found in skeletal and cardiac muscle that has attracted considerable interest as an early marker of MI. Its low molecular weight accounts for its early release profile: myoglobin typically rises 2-4 hours after onset of infarction, peaks at 6-12 hours, and returns to normal within 24-36 hours.

High concentrations of myoglobin in muscle cells allow organisms to hold their breaths longer.  Diving mammals such as whales and seals have muscles with particularly high myoglobin abundance.  Myoglobin is the primary oxygen-carrying pigment of muscle tissues which is responsible for making meat red. The color that meat takes is partly determined by the oxidation states of the iron atom in myoglobin and the oxygen species attached to it.  When meat is in its raw state, the iron atom is in the +2 oxidation state, and is bound to a dioxygen molecule (O2).  Cooked meat is brown because the iron atom is now in the +3 oxidation state, having lost an electron.  Myoglobin is found in Type I muscle, Type II A and Type II B, but most consider myoglobin not to be found in smooth muscle.

Model of myoglobin molecular structure[1]
Myoglobin is released from damaged muscle tissue, which has very high concentrations of myoglobin.  The released myoglobin is filtered by the kidneys but is toxic to the renal tubular epithelium and so may cause acute renal failure.  It is not the myoglobin itself that is toxic, but the portion that is dissociated from myoglobin in acidic environments (e.g., acidic urine).

Diagnostic applications
Levels of myoglobin start to rise within 2-3 hours of MI or other muscle injury, reach their highest levels within 8-12 hours, and generally fall back to normal within one day. An increase in myoglobin is detectable sooner than troponin, but it is not as specific for heart damage and it will not stay elevated as long as troponin.  Serial sampling of blood every 1-2 hours can increase the sensitivity and specificity; a rise of 25-40% over 1-2 hours is strongly suggestive of acute MI.  If myoglobin does not increase within 12 hours following the onset of chest pain, a heart attack is very unlikely.  Blood samples are drawn on admission and every 2-3 hours for up to 12 hours in those who come to the emergency room with a possible MI.  An increase in blood myoglobin means that there has been very recent injury to the heart or skeletal muscle tissue.  Additional tests, such as Troponin, are necessary to determine where the damage has occurred.  Because myoglobin is also found in skeletal muscles, increased levels can occur in people who have accidents, seizures, surgery, or any muscle disease, such as muscular dystrophy.  If myoglobin does not increase within 12 hours following the onset of chest pain, a heart attack is very unlikely.

Although a negative myoglobin result effectively rules out an MI, a positive result must be confirmed by testing for troponin.  This is why at DIAGNOSTIC AUTOMATION we offer the 3 tests together as a cardiac elisa kits which increases both sensitivity and specificity of our diagnosis of AMI.  By combining three cardiac marker tests into one device, the test is able to identify multiple release profiles for improved sensitivity and thus, not only able to identify myocardial infarctions, but also to identify at-risk patients with a possible life-threatening cardiac event in the near future.  An increase in blood myoglobin means that there has been very recent injury to the heart or skeletal muscle tissue.  Additional tests, such as Troponin, are necessary to determine where the damage has occurred.  Because myoglobin is also found in skeletal muscles, increased levels can occur in people who have accidents, seizures, surgery, or any muscle disease, such as muscular dystrophy.  Increased myoglobin levels can occur after muscle injections or strenuous exercise.  Because the kidneys remove myoglobin from the blood, myoglobin levels may be high in people whose kidneys are failing. Heavy alcohol consumption and certain drugs can also cause muscle injury and increase myoglobin in blood [8].

Myoglobin levels are normally very low or not detectable in the urine.  High levels of urine myoglobin indicate an increased risk for kidney damage and failure.  Additional tests, (which we offer at DIAGNOSTIC AUTOMATION) as cardiac elisa kits, are done to monitor kidney function in these patients.

Myoglobin elisa kit is also offered at DIAGNOSTIC AUTOMATION .

3. Creatine Kinase–MB
Prior to the introduction of cardiac troponins, the biochemical marker of choice for the diagnosis of acute MI was the CK-MB isoenzyme. The criterion most commonly used for the diagnosis of acute MI was 2 serial elevations above the diagnostic cutoff level or a single result more than twice the upper limit of normal. Although CK-MB is more concentrated in the myocardium, it also exists in skeletal muscle and false-positive elevations occur in a number of clinical settings, including trauma, heavy exertion, and myopathy [9].

Model of CK-MB molecular structure [1]

Diagnostic applications
CK-MB first appears 4-6 hours after symptom onset, peaks at 24 hours, and returns to normal in 48-72 hours. Its value in the early and late (>72 h) diagnosis of acute MI is limited. However, its release kinetics can assist in diagnosing subsequent infarction if levels rise after initially declining following acute MI.

The CK-MB isoenzyme exists as 2 isoforms: CK-MB1 and CK-MB2. Laboratory determination of CK-MB actually represents the simple sum of the isoforms CK-MB1 and CK-MB2. CK-MB2 is the tissue form and initially is released from the myocardium after MI. It is converted peripherally in serum to the CK-MB1 isoform rapidly after symptom onset.  Normally, the tissue CK-MB1 isoform predominates; thus, the CK-MB2/CK-MB1 ratio is typically less than 1. A result is positive if the CK-MB2 is elevated and the ratio is greater than 1.7 [10 &11].
CK-MB  ELISA Kit is also offered at DIAGNOSTIC AUTOMATION

Additional Cardiac Markers ELISA Kits offered at DIAGNOSTIC AUTOMATION :


1.    Digoxin ELISA Kit
http://www.rapidtest.com/index.php?i=Digoxin-ELISA-kit&id=43&cat=10

2.    Lp(a) ELISA Kit

http://www.rapidtest.com/index.php?i=Lp(a)-ELISA-test-kit&id=198&cat=10

3.    C-Reactive Protein (CRP) which is a Serum Rapid Test (Cassette) RapiCard™ InstaTest
http://www.rapidtest.com/index.php?i=C-Reactive-Protein-(CRP)-ELISA-kit&id=47&cat=10

 

Test limitations
Since these markers appear hours after the first symptoms, they are not fully sensitive to be used for an early detection of any heart problems.  Moreover, because these markers remain high for up to two weeks, a positive test may not distinguish between an ongoing MI with the earlier one.

References:
1. Arab S. et al. Cardiovascular proteomics: tools to develop novel biomarkers and potential applications. J Am Coll Cardiol.  2006 Nov 7;48(9):1733-41.
2. WHO. Cause-specific mortality, 2008. World Health Organization. Accessed on March, 2013.   from:http://www.who.int/gho/mortality_burden_disease/global_burden_disease_DTH6_2008.xls
3. U.S. department of health and human resources Feb 2011.       http://www.hhs.gov/news/press/2011pres/2011.html.
4. Alpert JS, et al. (2000). Myocardial infarction redefined—a consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the redefinition of myocardial infarction. J Am Coll Cardiol 36 (3): 959–69.  PMID 10987628 .
5. Rao SP, et al. (August 1999). Cardiac troponin I and cardiac enzymes after electrophysiologic studies, ablations, and defibrillator implantations. Am. J. Cardiol. 84 (4): 470, A9; PMID 10468091.
6. Nelson, D. L.; Cox, M. M. (2000). Lehninger Principles of Biochemistry (3rd ed.). New York: Worth Publishers. p. 206. ISBN 0-7167-6203-X
7. [Takano T (March 1977). Structure of myoglobin refined at 2.0 Å resolution. II. Structure of deoxymyoglobin from sperm whale. J. Mol. Biol. 110 (3): 569–84 ; PMID14871135.
8. [ Naka T, et al. (April 2005). Myoglobin clearance by super high-flux hemofiltration in a case of severe rhabdomyolysis: a case repor Crit Care 9 (2): R90–5; PMID 15774055.
9. Guzy PM (December 1977). Creatine phosphokinase-MB (CPK-MB) and the diagnosis of myocardial infarction. West. J. Med. 127 (6): 455–60; PMID 339548.
10. Puleo PR, et al. Use of a rapid assay of subforms of creatine kinase-MB to diagnose or rule out acute myocardial infarction. N Engl J Med. Sep 1 1994;331(9):561-6.
11. Newby LK, et al. Frequency and clinical implications of discordant creatine kinase-MB and troponin measurements in acute coronary syndromes. J Am Coll Cardiol.  2006;47(2):312-8.