After a blood clot, tests can be run to determine if you have a condition that makes your blood clot more easily than the majority of the population.  These conditions are often referred to as clotting conditions, thrombophilia, or hypercoagulable states.  Testing for these conditions will not be able to predict who will and will not have a clot.  About half of the people who have a clot will have no known cause.  This means that the blood work would show no clotting conditions.

Testing for thrombophilia is useful when deciding the length of time a patient will be on anticoagulants.  The problem with anticoagulants is that they are risky.  You only want to be on anticoagulants if the risk of clotting is larger than the risk of a life threatening bleed.  Testing for thrombophilia will give you more information so that you and your doctor can determine which risk is more acceptable for you.

To determine if thrombophilia testing is right for you, you should:

• Ask your doctor if having thrombophilia would change his or her recommendations about the amount of time that you will take anticoagulant medications.  If the test will not change treatment, the test is not needed.
• Talk with your doctor and insurance agents about the impact the findings may have on your ability to obtain life insurance.
• Consider your age.  Many recommendations state that individuals under the age of 50 that had a DVT or PE without a significantly large risk factor (abdominal surgery, bed ridden, cancer, or other major risks) have tests run to see what may have caused the clot.
• Consider your risks.  Can you and your doctor identify any MAJOR risks?  A major risk may be able to be eliminated so that the clot doesn't repeat.  If you only had a minor risk (weight and birth control are examples) there is a good chance that something else contributed to your clot.
• Ask your medical team what they feel are typical, minor, and major risks for blood clots and figure out where you fit into that list.
• Consider what risks will be in your future.  Are you thinking about birth control, infertility treatments, cancer, hormone replacement, frequent long haul airplane trips, or any other big risks?  You may want to know if you have a clotting condition that will put you at further risk.
• Is there a family history of clotting or miscarriage?  If there is, let your doctors know!
  

Think about your history, the costs, risks, and benefits.  Medical testing seems harmless but it can have unwanted effects.  If you need help deciding about testing please talk to your primary care provider and consider requesting a hematology consult.  Feel free to get a second opinion.  Many times doctors will write off a clot as a simple case of birth control pills, weight, or travel when there might be more to the story.  If you haven't experienced a recent major risk factor there is a good chance that there is more to your clot's story.

MTHFR is a genetic mutation that will sometimes increase the risk of blood clots.  MTHFR is caused by a change in the methylenetetrahydrofolate reductase (NAD(P)H) gene.  This gene is also known simply as MTHFR.  MTHFR carries the instructions for making an enzyme called methylenetetrahydrofolate reductase.  One of the most important things that this enzyme does is to convert an amino acid homocysteine into another amino acid, methionine.  The body then uses the new amino acid to make a number of different proteins in the body.

HOW DOES MTHFR AFFECT CLOTTING?
Some individuals who have the MTHFR gene mutation develop elevated levels of homocysteine.  Elevated levels of homocysteine have been associated with an increased risk of blood clots.  Individuals who have a MTHFR mutation and have normal levels of homocysteine are not at an increased risk of clotting.  It is the elevated homocysteine that raises the risk of clots, not the MTHFR mutation.

HOW IS MTHFR DIAGNOSED?
MTHFR is diagnosed by measuring the levels of homocysteine in the blood.  MTHFR is not a large risk factor for blood clots.  For this reason, some doctors will limit homocysteine testing to individuals who are under 30 years of age who have a blood clot or have a history of repeated blood clots.

TREATMENT
The best way to prevent clots is always to use good clotting hygiene.  Make sure to keep moving, be careful on long car rides and flights, stay hydrated, and to speak with a doctor for extended illnesses or surgeries.  If blood clots are a problem, anticoagulation therapy may be useful.  Vitamins B12 and B6 are involved in lowering homocysteine levels in the body.  Studies haven't clearly shown a decrease in blood clotting risk when patients take B6 and B12.  If you have elevated homocysteine levels, it would be worth asking your doctor how he or she feels about using B vitamins to prevent clots.

REFERENCES
How MTHFR Testing Works. (n.d.). CEPMED. Retrieved October 22, 2013, from https://cepmed.dnadirect.com/grc/patient-site/mthfr-pregnancy-complications/how-mthfr-testing-works.html

Moll, S. (2010, November 19). Thrombophilia Testing – Who Should be Tested? Clot Connect. Retrieved October 22, 2013, from http://patientblog.clotconnect.org/2010/11/19/thrombophilia-testing-%E2%80%93-who-should-be-tested/

Treating High Homocysteine. (n.d.). CEPMED. Retrieved October 22, 2013, from https://cepmed.dnadirect.com/grc/patient-site/mthfr-pregnancy-complications/treating-high-homocysteine.html

Varga, E. A., Sturm, A. C., Misita, C. P., & Moll, S. (2005). Homocysteine and MTHFR Mutations Relation to Thrombosis and Coronary Artery Disease. Circulation, 111(19), e289–e293. doi:10.1161/01.CIR.0000165142.37711.E7, from http://circ.ahajournals.org/content/111/19/e289.full

What Is MTHFR? (n.d.). CEPMED. Retrieved October 22, 2013, from https://cepmed.dnadirect.com/grc/patient-site/mthfr-pregnancy-complications/index.html

Who Should Consider MTHFR Testing? (n.d.). CEPMED. Retrieved October 22, 2013, from https://cepmed.dnadirect.com/grc/patient-site/mthfr-pregnancy-complications/who-should-consider-mthfr-testing.html

This week, doctors have shared another risk factor for pulmonary embolisms, DVTs, and other types of venous thrombosis.  The good news is that we now have another risk factor that we can avoid.  The bad news is that the risk factor is a critical treatment for many patients.  Glucosteroids, one of which is cortisone, have been found to increase the risk of having a venous blood clot by two to three times.  Even more problematic is that the form of the steroid doesn't matter.  Inhaled, injected, or swallowed, all glucosteroids increase the risk of a clot (although some forms are more risky than other forms).  

Doctors are already cautious about using glucosteroids due to their lengthly list of frequent, serious side effects.  This caution should continue.  The risk of clots is the highest after beginning a new steroid regimen.  The risk continues throughout the steroid use and then for at least a year after the steroid is discontinued.

The important thing to learn from this study is that every patient needs to discuss this risk with his or her doctor.  It would be a good idea to discuss the risk of the steroid, other risks that the patient has, and possible ways to lower the risk of clotting.

To read more about the study see http://ow.ly/jYWTF 

Picture By Kevin Dufendach [CC-BY-3.0)], via Wikimedia Commons