[South Dakota]

Can "false highs" of free light chain tests occur?

by South Dakota on Sun Aug 17, 2014 12:29 am

I was diagnosed with MGUS Feb 2012 and had slightly high free light chain ratio.

My last test had a ratio of 95.70 and I will be repeating this test in another week.

Does anyone get false high results? And does this mean my MGUS has progressed.

I will see my oncologist / hematologist again, but that will be after the next test.

[Dr. Prashant Kapoor]

Re: Can "false highs" of free light chain tests occur?

by Dr. Prashant Kapoor on Mon Aug 18, 2014 11:39 pm

While interpreting the results of the free light chain (FLC) assays, it is important to not only look at the FLC (ratio FLC), but also the actual levels of involved and the uninvolved FLC. A depression of the uninvolved FLC without a concomitant increase in the involved FLC, could markedly alter the FLC ratio.

Also, one should look at the trend and the degree to which the FLC levels have altered, vis-a-vis other monoclonal protein studies.

[South Dakota]

Re: Can "false highs" of free light chain tests occur?

by South Dakota on Tue Aug 19, 2014 5:36 pm

My kappa chain went from 1.32 mg/dL to 1.32 mg/dL to 9.57 mg/dL

While the lambda free light chain went from 0.75 mg/dL to 0.69 mg/dL to 0.10 mg/dL .

That ratio went from 1.76 to 1.91 to 95.70, so I had a big jump.

[Beacon Staff]

Re: Can "false highs" of free light chain tests occur?

by Beacon Staff on Tue Aug 19, 2014 5:41 pm

Hi South Dakota,

What was the time period for those tests?

[South Dakota]

Re: Can "false highs" of free light chain tests occur?

by South Dakota on Tue Aug 19, 2014 8:33 pm

Dates of tests:

March 30, 2012
November 20, 2012
July 30, 2014

[Toni]

Re: Can "false highs" of free light chain tests occur?

by Toni on Tue Aug 19, 2014 9:37 pm

So are you being tested every 1 1/2 years? Did you have any other test results which have changed? I am not terribly knowledgeable, but this is quite a jump.

Have you had an appointment with your oncologist yet or did they just ask you to have another test done first? What is your m-spike? Has it changed too?

[South Dakota]

Re: Can "false highs" of free light chain tests occur?

by South Dakota on Tue Aug 19, 2014 11:11 pm

I saw the oncologist before the light chain test were in. I had good kidney and liver values and he didn't think I needed to come back for another 1 1/2 or 2 years. When the light chain values came in he wanted to repeat the blood work in one month.

My IgA has always been a little high 869 mg/dL 885 mg/dL 986mg/dL
IgG low 528 mg/dL 554 mg/dL 488 mg/dL
IgM normal 53 mg/dL 43 mg/dL 47 mg/dL

[Toni]

Re: Can "false highs" of free light chain tests occur?

by Toni on Tue Aug 19, 2014 11:32 pm

So how was your diagnosis of MGUS determined? Do you have a monoclonal gammopathy? (I would assume of the IgM? If so, what was the result? I am out of my realm here as I don't understand such a huge leap in your FLC, but I'm just trrying to get some more history from you so I can get a better understanding.

[South Dakota]

Re: Can "false highs" of free light chain tests occur?

by South Dakota on Tue Aug 19, 2014 11:38 pm

I was diagnosed with MGUS at the Mayo Clinic in Arizona February of 2012. I had (and still have) high levels of inflammation and pain. I am having a fairly good day if my CRP levels are under 30.

[Toni]

Re: Can "false highs" of free light chain tests occur?

by Toni on Tue Aug 19, 2014 11:51 pm

I am so sorry for your pain. I do hope you can find the answers you seek and that the results will come back differently. Please do keep posting.