[Rooikop]

Can it still be MGUS with a kappa-lambda ratio over 20?

by Rooikop on Thu Dec 06, 2018 3:30 pm

Hello all,

I am a a 63 year old woman, who was diagnosed with IgG kappa MGUS in 2013.

At that time, my M protein was very small ( 0.1) and my light chain ratio about 4.

A bone marrow biopsy showed 2-5% plasma cells.

I was found to have anemia and stage 3 chronic kidney disease after being diagnosed with sarcoidosis in 2003, so both are assumed to be unrelated to my MGUS status. My kidneys have improved and are stable, and the anemia remains in the same range as at diagnosis. My immunoglobulins are in range, with IgM slightly low at 0.37 g/L.

Over the years, my kappa light chain level has continued to rise. When the ratio got to around 8.5, in 2016, another bone marrow biopsy was carried out, which again showed plasma cells of 2-5%.

Then the ratio jumped from 10- 12.91, and the M-protein went slowly up to 0.2 and now is holding stable at 0.3 for the last few tests.

I was shocked, though, to see my kappa light chain level is now 173.5mg\L, my lambda 8.5, and my kappa-lambda free light chain ratio a whopping 20.41

That's a huge jump is 6 months, and I see my specialist on December 14, when she will probably want to repeat my bone marrow biopsy again.

So, my M protein has stayed stable and low, my other results are all stable and very much the same as they have been for five years, but this ratio keeps climbing, with a large jump this time.

Two weeks before the testing, I was really ill with suspected diverticulitis . An MRI of my pelvic bones and lower back (all normal), showed a trace free fluid and possible thickening of the sigmoid. The fever went down and the pain vanished. I am waiting on a colonoscopy, but feel well again. An ultrasound showed a fallopian tube filled with fluid, which I am following up next week.

I know that my abnormal free light chain level and ratio put me at higher risk for progression, and I am really worried that I am no longer MGUS.

Is it possible to still be classified with MGUS with a kappa-lambda ratio of 20.41?

[TerryH]

Re: Can it still be MGUS with a kappa-lambda ratio over 20?

by TerryH on Thu Dec 06, 2018 9:13 pm

Hello Rooikop,

Since your M-spike is still very low, it is the clonal plasma cell percentage from your bone marrow biopsy that is going to determine whether you are still classified as having MGUS. If it stays below 10 percent, and assuming your kappa-lambda ratio stays below 100, you'll still be considered to have MGUS. It appears that your MGUS is light chain predominant, although it wouldn't be considered light chain MGUS since you are showing a (low) M-spike.

It sounds like your doctors are being very thorough, but I wonder if you have been tested for amyloidosis. Bone marrow plasma cell percentages in amyloidosis patients are usually not that high, but free light chain levels are "out of whack", similar to what you are experiencing. A simple "fat pad biopsy" can help determine whether or not you have amyloidosis.

Good luck, and keep us posted about what you find out.

[Rooikop]

Re: Can it still be MGUS with a kappa-lambda ratio over 20?

by Rooikop on Fri Dec 07, 2018 12:20 pm

Hello Terry,

Thanks for your rapid response.

I will certainly ask my oncologist about having a fat pad biopsy and another bone marrow biopsy when I see her next Friday. I will let you know the results.

Amyloidosis scares me even more than myeloma, which is frightening enough!

My nephrologist does not feel I have renal amyloidosis, as I show no protein in my urine tests. My kidneys have actually improved , and are at the best they have been since being diagnosed with CKD six years before the arrival of MGUS.

I am feeling well and healthy again since my diverticulitis attack, and hope to have a colonoscopy within the next month. I will also ask the gastroenterologist to stain any biopsies he takes for amyloidosis.

Best wishes.