[gracefullily]

Different reference ranges for FLC results?

by gracefullily on Sat Jan 11, 2014 4:11 pm

Are there different types of FLC serum labs? I have a new result & the reference ranges are completely different than a previous result so I'm not certain what the correlation between the 2 are.

[Multibilly]

Re: Different reference ranges for FLC results?

by Multibilly on Sat Jan 11, 2014 6:21 pm

Are you in the USA? My understanding is the Freelite(R) chain assay is the only FDA-approved serum free light chain assay on the US market. The patented Freelite assay technique runs on different lab analysis machines and it was my understanding that the all of the different machines are normalized to the same Freelite reference ranges. Sometimes you will see a difference in the units of measure (i.e. mg/dL versus mg/L), but this just requires multiplying or dividing the results by 10 to make them match up. What are the different reference ranges you are seeing?

Last edited by Multibilly on Sat Jan 11, 2014 7:03 pm, edited 1 time in total.

[Wayne K]

Re: Different reference ranges for FLC results?

by Wayne K on Sat Jan 11, 2014 10:12 pm

The decimals on my report are generally different from what I see on here, but the numbers are the same for the ranges.

[rocco24]

Re: Different reference ranges for FLC results?

by rocco24 on Sun Jan 12, 2014 1:25 am

Hi gracefullily,

I can only speak with what my lab has tested me for, but I found that this range was in my lab's report:

The Serum Free Light Chain Assays:
Normal Versus Abnormal
Normal levels of serum free light chains are*:
• Kappa: 3.3–19.4 mg/L*
• Lambda: 5.71–26.3 mg/L*
• Kappa/lambda ratio: 0.26–1.65
*Note: The units here are mg/L; different laboratories use different units. It is important
to double-check the units used when comparing numbers in lab values.

There may be cases where the numbers are off by a factor of 10 or so, which could be due to the conversion of units.

The above reference is from a .pdf entitled "Understanding Serum Free Light Chain Assays" by the International Myeloma Foundation in North Hollywood, CA.