[Jacqueline]

NT-proBNP testing - what is it used for?

by Jacqueline on Thu Sep 10, 2015 6:21 pm

Hello,

My hematologist prescribed me an analysis with measurement of NT-proBNP (inter alia).

This is the first time I do this, and I do not understand why (this analysis concerns the heart). The doctor told me nothing at all.

I will have the result within 10 days, but I found this on the internet:

Patients with NT-proBNP >50,000 pg/mL had only hematologic malignancies, primarily multiple myeloma. There was no association between M-spike proteins and NT-proBNP"

Source: J Popat et al, "What is causing extremely elevated amino terminal brain natriuretic peptide in cancer patients?", Congestive Heart Failure, May-June 2013 (full text of article)

Is "NT-proBNP" an aid to prognosis? Furthermore, I have never had kappa / lambda testing, nor B2 microglobulin testing (for the B2, I just now requested with an extra cost because it was not pre­scribed).

Thanks.
Jacqueline

[Multibilly]

Re: NT-proBNP testing - what is it used for?

by Multibilly on Thu Sep 10, 2015 7:24 pm

Jacqueline,

Forum member Blessthischick had the NT-proBNP test done to check for the possibility of amyloid deposits in the heart, which can be caused by amyloidosis. Amyloidosis can occur in 10-15% of patients with multiple myeloma, so it's a good thing for your doctor to be on the lookout for. See this posting:

https://myelomabeacon.org/forum/t-14-16-as-indicator-for-high-risk-disease-t3004.html#p16698

Has your doctor mentioned any suspicion of amyloidosis, or did you have a recent biopsy that showed the presence of amyloid fibrils? Common symptoms of amyloidosis can be found here:

http://www.mayoclinic.org/diseases-conditions/amyloidosis/basics/symptoms/con-20024354

However, my understanding is that myeloma can also cause cardiac issues that show up via the NT-proBNP test as a result of the excess monoclonal protein in one's blood. So amyloidosis isn't the only thing that might be suspected by your doctor.

I hope your doc takes the time to explain things to you in more detail when you see him next.

[Jacqueline]

Re: NT-proBNP testing - what is it used for?

by Jacqueline on Fri Sep 11, 2015 7:17 am

Thank you so much Multibilly,

My doctor looked at my tongue. He asked me if I thought it was enlarged, because I have my teeth marks on it. But my tongue did not grow as much as I can judge ... I hope at least, because my teeth mark a lot.

And to finish the picture, my ankles are still swollen (but not after waking up).

I will stop getting worried and expected results of analysis ...

Thanks again!

[Tracy J]

Re: NT-proBNP testing - what is it used for?

by Tracy J on Fri Sep 11, 2015 10:28 am

ER doctor here. BNP (as it's called for short) is traditionally used to track a patient with classic congestive heart failure. It can rise and fall in a matter of one or two days. It's a protein found in the heart muscle cells that is released into the blood in excess when the cells are under stress. The normal range is 0-100, but it can go way up into the tens or even hundreds of thousands. It doesn't become significant or important until you get above 200 or 300, and there is a lot of variability in the test. So some people can have a lot of symptoms from heart failure with a BNP of just 200, while other people can feel fine with BNP up in the 400s. That makes it not a fantastic test. Even so, if a patient with a history of CHF comes into the ED with shortness of breath, BNP is one of the routine tests we get, along with EKG and an xray of the chest and other labs.

However, there are many other situations in which BNP can be helpful, most of which are far less well known. Multiple myeloma and especially amyloidosis are two of those. Amyloid fibrils are known for depositing in the kidney and heart. In the heart they stress the cells, make them less efficient and can cause a particular type of heart failure. The BNP will rise accordingly. In fact, BNP, along with another heart lab test, the troponin, have been found to be prognostic in AL amyloidosis. There are easy tests to get, and the stakes are high, so it's worthwhile check­ing if there's any question.

Reference:

S Kumar, "Revised Prognostic Staging System for Light Chain Amyloidosis Incorporating Cardiac Biomarkers and Serum Free Light Chain Measurements," Journal of Clinical On­col­ogy, March 2013 (full text of article)

[blessthischick]

Re: NT-proBNP testing - what is it used for?

by blessthischick on Sun Sep 13, 2015 2:39 pm

Hi Jacqueline

My serum NT proBNP is checked every 3 months. This is done as it is the best indicator of heart failure in relation to amyloid deposition on my heart. Thankfully my results have been fine thus far.

It was an amyloid deposit that was found in a skin biopsy near my eye that prompted a check of my protien levels. These were fine but 6 months later for completion the pathologists asked for a Bence Jones protein check that shockingly was posative. FLC's were ordered and a BMB. Both were abnormal. I have lambda light chain MGUS therefore I don't have an M spike therefore my initial blood check had been fine.

In the UK anyone with amyloid in their body plus a plasma cell dyscrasia plus abnormal flcs are sent to our national centre in London. Lots of checks are done and a SAP scan is carried out. You are given the result right away after your 2 days of tests. I was told that I did not have Al Amyloidosis but I had SMM. It was the 10th October 2013 at 16:20...I will never forget.

However, when the report arrived the following month after my case had been discussed at a Multi-disciplinary meeting as is normal where all the experts get together and decide the best way forward for patients, it had been decided that although I did not have Al Amy at that time, I needed to be watched closely for it in the future. Apparently my biopsy was so small they could not type it. But because I had a plasma cell dyscrasia and a predominance of Lambda light chain (which I am told is amyloidogenic) there is a possibility I will develop Al Amy in the future. Apparently, amyloid deposition should it occur can occur rapidly that's why my serum NT pro BNP is checked regularly plus all my other bloods are done monthly which monitors my other organs for signs of amyloidosis related failure.

The main worry that I have with developing Al Amy is that if organs are failing, it will obviously be more difficult to treat Myeloma as the amount of chemo I could tolerate would be much less and overall patients who have both diseases tend to have an even poorer outlook.

I have no idea if this has helped but that is my NT proBNP story. I hope your doc can clarify things further for your case and the reasons he did this test on you. My best wishes to you.

[mdszj]

Re: NT-proBNP testing - what is it used for?

by mdszj on Sun Sep 20, 2015 4:14 pm

This is an interesting thread. I have IgA smm and was just reviewing some lab results from a visit at Sloan Kettering I had back in March 2015. I noticed that my troponin test result was < 0.06 ng/mL; and BNP was 177 pg/mL (> 100 pg/mL suggests CHF). THis was never brought up at my consult at the time.

I also have tingly/numb fingers often when I wake up.

Is this something I should be concerned about as far as possibility of amyloidosis?

[Sister In Law]

Re: NT-proBNP testing - what is it used for?

by Sister In Law on Tue Sep 22, 2015 10:57 am

Hi

So there is a MGUS that has a component of amyloidosis? Does the amyloidosis do damage during the MGUS stage? Or is it sort of dormant?

My sister-in-law had multiple myeloma and amyloidosis. Her kidneys were her downfall, darn it. But she had pretty bad symptoms for well over a year before her kidneys actually failed and she then found out about the myeloma and the amyloidosis. If she would have sought help a good year or two before she did, she probably would have done much better. No M-spike for her, so it was harder to find I guess.

Now my husband has a monoclonal protein in his urine. Waiting for the immunofixation part of things to find out what on earth is going on now!

[Tracy J]

Re: NT-proBNP testing - what is it used for?

by Tracy J on Tue Sep 22, 2015 5:18 pm

Mdszj,

The only way to test for amyloidosis is for biopsy samples to have the "Congo Red Stain" in the pathology laboratory. Congo Red Stain obviously means nothing to us, but to the pathologists, it's a certain technique. Amyloid fibrils can't really be seen with other common procedures that biopsy samples undergo. You'll have to check to see if this have ever been done to any of your samples.

The samples could be bone marrow, kidney, skin, abdominal subcutaneous tissue, even heart or lung. Typically it would be wherever there are symptoms or abnormal findings + bone marrow. However, none of these is 100% sensitive for amyloidosis, so if the suspicion is high enough, the doctor just has to keep going with the biopsies until satisfied, which is undefined. This is where the "art" of medicine comes in. The oncologist has to assimilate the risk of amyloid, the symptoms you are having, the physical exam findings, all the other labs, images and pathology reports to decide when to stop collecting tissue samples!

For example, when I was diagnosed in 2012, my bone marrow biopsy was negative for amyloidosis, but I was showing A LOT of kidney symptoms and my light chains were through the roof, so we proceeded to kidney biopsy, which was positive for amyloid.

FYI amyloid is known for causing neuropathy, as well as carpal tunnel syndrome, so your numbness and tingling does ring a bell for me. However, the list of other things that can also cause numbness and tingling is LONG.

[mdszj]

Re: NT-proBNP testing - what is it used for?

by mdszj on Wed Sep 23, 2015 8:17 pm

Tracy,

Thanks for responding to my post. After searching through more posts in here and searching the Internet, from what I can tell, it looks like the tingly fingers could also just be from the smoIdering myeloma I have.

I looked at one of your previous posts in this thread where you discuss the importance of different BNP levels but I did not notice any units. Were you expressing your BNP numbers using units of pg per mL?

Thanks, Mike