ET Diagnostic Criteria

[gvibes]

Hi, I have polycythemia vera- diagnosed about a year and half ago and being treated with pegasys. My brother in law is seeing a hematologist for rising platelet levels (presently >900) and was determined to be JAK2 negative. While I understand the p-vera criteria pretty well, I really only have a general idea about ET diagnosis.

So my questions are: What are the criteria to determine an ET diagnosis? I realize that about 50% are JAK2 positive. Are there other mutations that determine a diagnosis? Are there other tests that indicate ET?

thanks so much!

[hunter5582]

Here is some basic information

Essential thrombocythemia is a diagnosis of exclusion. The 2017 World Health Organization (WHO) diagnostic criteria for essential thrombocythemia include 4 major and 1 minor criteria. [4] Diagnosis requires meeting all 4 major criteria or the first 3 major criteria and the minor criterion. The major criteria are as follows::

1. Platelet count ≥450 × 109/L

2. Bone marrow biopsy showing megakaryocyte lineage with increased numbers of enlarged, mature megakaryocytes with no significant increase in neutrophil granulopoiesis or erythropoiesis and, rarely, minor reticulin fibers.

3. Not meeting WHO criteria for CML, polycythemia vera (PV), primary myelofibrosis, myelodysplastic syndromes, or other myeloid neoplasms.

4. Presence of JAK2, CALR or MPL mutation

The minor criterion is the presence of a clonal marker or absence of evidence of reactive thrombocytosis (eg, infection, inflammation, iron deficiency anemia).

medscape.com/answers/206811...

[gvibes in reply to hunter5582]

Thanks hunter. That helps.

[Jennytheb in reply to hunter5582]

Another clear and helpful post Hunter, thanks.

[Hopetohelp]

Rising platelets and jak2 positive was all they needed to diagnose me with et

[Notdiagnosed]

Calr and mpn are the most common aren't they. I had others and waiting results. I am in the UK though.

[Janis12]

Hi, I have ET and triple negative however I do have a Tet2 mutation which is considered to be my driver mutation other than that just an increased platelet count. I must admit I find it all rather confusing so I try not to do too much research otherwise I feel I would scare myself to death.

[gvibes in reply to Janis12]

I also have a tet2 mutation although I guess it is secondary to the exon 12. What does triple negative mean? Thx.

[Janis12 in reply to gvibes]

As I understand triple negative means that the three main mutations that they would normally find with ET are not present.

[EPguy]

If it's available to him, he should get more allele tests. If they find CALR or MPL it's almost certainly ET as Hunter noted.

Any MPN patient should also get nex gen mutation study to look for other "non-driver" mutations as a baseline starting condition. This info is just starting to become useful and very likely will be more so in the future.

[gvibes in reply to EPguy]

Thanks. They just got labs and positive for CALR so it seems to be ET.