[Kas]

Test shows some Bence-Jones protein - progression sign?

by Kas on Sat Aug 09, 2014 10:23 pm

I have had MGUS for the past 18 months that I know of. I also have sarcoidosis with anemia and renal involvement. eGFR is 39 at present.

Up until now I have had a very low M spike of 1, all globulins in range and a kappa / lambda free light chain ratio of 3.93. My MGUS is IgG kappa. I had a bone marrow biopsy a year ago, which showed no plasma cells, and I have been monitored every 6 months.

My last 24 hour urine test, which has always been normal (no Bence Jones seen) came back this time with the following: "A small amount of free kappa light chain (BJ protein) is detected). The clinical significance at this level is unknown. A repeat in 6 months is suggested."

Of course, I am very concerned. Does this mean I am progressing to multiple myeloma, or could it be due to my autoimmune renal dysfunction. Is it OK to wait 6 months for next testing?

[Carol Anne]

Re: Test shows some Bence-Jones protein - progression sign?

by Carol Anne on Sat Aug 09, 2014 10:56 pm

Hi Kas,

I wish I knew how to answer your questions and I hope someone with knowledge will respond to help you, but I did want to ask you something as I am confused by the fact you wrote your bone marrow biopsy from 1 year ago did not show any plasma cells. If your bone marrow biopsy did not show or find any plasma cells, what is your doctor explaining to you about what is causing your abnormal free light chains, your low M-spike or your Bence Jones proteins?

I thought each of these were a result of having abnormal plasma cells in your bone marrow. I am wondering if perhaps they missed them in the sample they took.

Or could their be another reason for your abnormal proteins?

Sincerely,
Carol Ann

[Dr. Heather Landau]

Re: Test shows some Bence-Jones protein - progression sign?

by Dr. Heather Landau on Mon Aug 11, 2014 12:56 am

Hi Kas,

Please be reassured that when patients have MGUS or even multple myeloma (asymptomatic or symptomatic and low level serum light chains and Bence-Jones proteins), the 24 hour urine quantification (measurement of BJ proteins) can fluctuate between "not detected" and "low level detected" simply because it is not a great test.

So, no, I do not think this indicates progression and I suspect your next test may continue to show low level detected or even revert back to negative - if all your other disease markers (IgG level, M-spike, free kappa level) remain stable.

As for Carol Anne's comment about the plasma cells not being detected, there could be a few reasons for this:

1. MGUS is commonly associated with a low burden of abnormal plasma cells, so if our most sensitive testing (immunophenotyping, flow cytometry) is not done (or not done well), it could be missed
2. Abnormal plasma cells tend to hang out in clusters and are often found in "patches" in the bone marrow, so, indeed, one can aspirate the bone marrow in a location where there are minimal abnormal plasma cells and "miss" an area where there are more.

Hope that answers both of your questions!

[Kas]

Re: Test shows some Bence-Jones protein - progression sign?

by Kas on Mon Aug 11, 2014 9:17 am

Dear Dr. Landau,

Thank you so much for your most reassuring response. I am sure the family doctor who is following me will be relieved, too! She suggested re-testing the urine in three months, although the lab recommended my usual 6 monthly testing. My multiple myeloma specialist only wants to see me again if things change to the extent she has informed my doctor. I had my BMB last July at Sunnybrook Cancer Centre in Toronto, and I do have the full report of that.

Your rapid response is much appreciated.

Best wishes,

Kas

[Kas]

Re: Test shows some Bence-Jones protein - progression sign?

by Kas on Tue Oct 07, 2014 5:27 pm

Based on the small amount of BJ protein found in my last 24 hour test mentioned here, I have been told I have an appointment with the multiple myeloma specialist at Sunnybrook on November 6. My family doctor had sent my results there with a letter.

I am quite shocked that I need to go again, and I hope I do not have to have another BMB done (last one was 15 months ago).

Decreased renal function and anemia were all stable at last testing at end of August - nothing new.

Only thing I have had is a pain for the last three months in my lower leg predominantly (also down the side and front of upper left leg), which has been diagnosed as sciatica for L4-5 nerve impingement, as seen on MRI of September 3. No bone marrow involvement seen. Some improvement with physical therapy and chiropractic, but it lingers.

Otherwise, well with good energy levels, despite the very long-standing anemia, which was there before MGUS was diagnosed, as were the renal issues - most likely due to my sarcoid.