[tomsteffco]

Normal serum FLC results, but Bence Jones protein

by tomsteffco on Fri Jan 23, 2015 2:15 pm

I had a completely normal serum FLC:

Kappa free light chains 5.73
Lambda free light chains 12.12
Kappa/lambda ratio 0.47

But Bence Jones protein - 6 mg / 24 hour.

I've read that normal can be 1-10 mg and excess stress on the kidneys like heavy exercise can cause this. Is this true?

Also, serum M-spike was 0.6 g/dL.

[Dr. Heather Landau]

Re: Normal serum FLC results, but Bence Jones protein

by Dr. Heather Landau on Mon Jan 26, 2015 1:59 am

Hi tomsteffco,

It sounds like you likely have low risk MGUS, which is defined by an M-spike of less than 1.5 g/dl, normal FLC ratio, and IgG subtype (though you did not mention this?!).

Indeed, despite having a normal FLC ratio, at times low levels of protein can be detected in the urine. Are you certain that the 6 mg was referring to the Bence Jones component of the protein in the urine, or the total protein in the urine? Regardless, a low level of protein, even if it is Bence Jones, can be present in the general population; and non-specific protein excretion can increase after exercise. I suspect this value will fluctuate moving forward, i.e., sometimes it will be detected, and other times not. If it goes away and comes back, don't be alarmed. It will likely remain benign.

Hope this helps!

[tomsteffco]

Re: Normal serum FLC results, but Bence Jones protein

by tomsteffco on Mon Jan 26, 2015 2:41 pm

Thank you so very much, Dr. Landau, for your answer.

I left out the following on my first post. Again, thank you.

Thomas

Protein, Total Urine 3.2
Protein, Urine 24hr 48.0
Albumin, U 20.3
Alpha-1-Globulin, U 6.3
Alpha-2-Globulin, U 23.6
Beta Globulin, U 17.8
Gamma Globulin, U 32.0
M-Spike, % 11.7
M-Spike, mg/24 hr 6

Immunofixation result, urine:
Immunofixation shows IgG monoclonal protein with
kappa light chain specificity.