Essential Thrombocythemia~medical terms made simple

You've been through the CBC's. You've seen the hematologist. You've possibly been sent for a bone marrow biopsy. And now it's been confirmed that you have a Myeloproliferative Neoplasm called Essential Throbocythemia. But what in the world does that mean?

A Rare Disorder

You have a rare disorder. How rare is rare? Well in this case it means that only about 2.3/100,000 people in the U.S. have this disorder. It also means that it is difficult to find other people with this disorder that you can talk to and get advice from. One more thing it means is that not many people will have ever even heard of it. It leaves a lot to learn. It leaves a lot to explain. Your best bet is to get as much information about it as possible since you likely will be the one explaining it to all those who are curious about your health.

Is it Cancer?

'Essential Throbocythemia is closely related to and considered by many to be a type of cancer.' Those words are hard to hear and it seems that the imagination can take that one statement and make it play out a hundred different ways in your mind in a matter of a few minutes. It is considered by some to be a chronic leukemia. It is considered by some to be a preleukemic disorder. The disorder closely mimics what happens in cancer or leukemia with the copying and spreading of damaged or immature cells. Let's look further to understand.

Myeloproliferative Neoplasm or MPN for short

The hematologist rolls those words right off his or her tongue and it may as well be another language. It is a bit difficult to even pronounce. There are a few disorders within this category. Polycythemia Vera (PV), Essential Thrombocythemia (ET), Chronic Myeloid Leukemia (CML), and Primary Myelofibrosis (PMF) or (MF) are all MPNs. All of the MPNs are a disorder originating in the bone marrow. In your bone marrow there are stem cells. The best way to picture it is that these cells come about ready to work. They line up ready to be turned into either a red blood cell, a white blood cell, or a platelet. These blood cells then go out throughout your body to do their intended jobs. When enough of a particular blood cell has been made, a signal switches letting the bone marrow know that there are enough and hold off on making that type for a little bit. In 3 of the MPNs, something within the bone marrow is not doing it's signaling job to let the marrow know that enough of a particular cell has been made. Therefore, it continues to make more and more unneeded cells of that type. In PV, there are too many red blood cells. In CML, there are too many white blood cells. And in ET, there are too many platelets. Often times, not only is there too many of these cells going out but the cells are immature or a mature but not fully functional form. In MF, the bone marrow isn't doing the job it needs to anymore because the marrow has become hardened to a fiber state.

What does this mean with ET?

It means that you are making too many platelets. Think of it as if your signaling switch for making platelets is 'stuck' in the 'on' position. In 2005, a gene mutation called the JAK2 mutation was discovered. This was found in at least 95% of all PV cases, 50% of MF cases, and at least 60% of all ET cases. Many studies are being done to realize the full scope of how this gene mutation affects the signaling pathways and what medications directed toward this gene will do to help with these disorders. In 1960, the Philadelphia chromosome was discovered. This is a fusion between the BCR and ABL genes. This is found in at least 95% of all CML cases. That sets CML apart from the other disorders in the group where this chromosome is not found.

Symptoms of ET

Symptoms of ET include:

• elevated platelet level
• headaches
• minor vision changes
• dizziness
• weakness or fatigue
• numbness, freezing, burning, or tingling in hands and/or feet
• red or purplish color in extremities
• a slightly enlarged spleen

occasionally some notice:

• nosebleeds
• bruising
• blood in the stools
• bleeding gums and teeth
• TIAs (minor strokes caused by clots temporarily blocking blood flow to the brain)
• other serious bleeding or clotting events (heart attacks, deep vein thrombosis, miscarriages, strokes, etc.)

Many people have no symptoms before they are diagnosed. Most diagnosis' happen when a CBC is done for another reason or at a routine check up. Then an elevated platelet level is noticed. Usually another CBC will be done a week or two later to see if the platelet level is still elevated. If so you will likely be sent to a hematologist. Often times a bone marrow biopsy (BMB) is done then to see the bone marrow itself and confirm the disorder.

Medications

The most important thing to take care of in Essential Thrombocythemia (ET) is the platelet level. Though all doctors view this differently, in general, If you have not had a thrombotic or bleeding event, you are not over the age of 55, and have a platelet count under 1 million, you will likely only be told to take an Asprin a day. If you have had clotting issues, bleeding issues, are older than 55, or have a platelet count over 1 million, then you will likely be put on one of 3 medications. Hydrea (Hydroxyurea), Anagrelide, or Interferon. There are other medications also available, especially recently, to target the JAK 2 mutation directly (if you are JAK 2 positive). The point of all of these drugs is to bring down cell counts to a normal level. Getting the dosage correct can be tricky as you have to find what works to keep your blood levels in a good range without lowering them too far or causing too many side effects from a high dosage. Each of these medications have worked without causing any side effects (or a few minor ones) in some people but in others can cause harsh side effects that make it imperative to try a different medication. It is different person to person.

Summarized in easier terms

Essential Thrombocythemia (ET for short) is one of 4 Myeloproliferative Neoplasms (MPNs for short). It is a problem in the bone marrow that allows the marrow to keep making more and more platelets. Platelets are the blood cells responsible for clotting. These are the cells that cling to a cut and begin to harden and create a scab over top of it. But when there are too many of them, you could have clots within your blood flow that do not belong. It can also cause your blood to be very thick. These clots can cause dangerous things like stroke, heart attack, pulmonary embolism, or deep vein thrombosis, along with other health concerns. But don't let that scare you too much. Only 20% of people diagnosed with ET have a thrombotic event sometime in their life. As long as the platelets are kept in a controlled range, bleeding and clotting issues should also be kept under control. Thankfully, ET is not a disorder that is known to shorten your life span. Most people with ET live a normal life span, however, your platelet levels will have to be monitored and though you may not need medicated at first, chances are that at some point in time you will need to be. As with everything though, there is always the smaller chance that things could go wrong. When you have an MPN, you have an increased risk of developing Myelofibrosis (MF) or Acute Myeloid Leukemia (AML) of which the outlook is not so good. The increased risk is slight (around 5% with ET progress to one of these). Regular blood tests and bone marrow biopsies will help watch for any progression. At this point in time there is no cure for ET but there are drugs to control it. In short, with ET, you may need to be a bit of a pincushion and take pills everyday but your life will most likely not be dramatically affected other than that.

Best advice

The best advice I have heard is to keep a notebook or spreadsheet of your information. I've included an example chart. This spreadsheet should include, dates of CBC's, bone marrow biopsies or any other scans needing done to check for a clot, platelet count, red blood cell count, white blood cell count, spleen size, medication start dates, and dates and dosage changes of any medications. It is also important to keep a log of your symptoms as it is sometimes difficult to know if a symptom is due to the disorder or a medication you are on.

One more bit of advice I have... since this is a rare disorder, read and be knowledgeable. Join a support group. Don't just go by what your hematologist knows as they may or may not really know a whole lot about this condition. Ask questions, insist on answers, and be on top of your health. But on the flip side, do not read so much that you allow it to over take you or fill you with fear or stress. As with most health conditions, stress makes it worse. So be informed but not consumed by it all.

For more information check out these links:

http://www.mpnresearchfoundation.org/

http://www.youtube.com/watch?v=yms9hPKYS7Q

I am not a medical professional. Please check all information with your doctor.