First I'm not a doc, so please verify with your doc.
Based on the reference values you provided, these are not from a standard serum free light chain (FLC) assay test (aka Freelite assay). However, the reference ranges you mentioned are "sort of" close to the ranges of a Freelite assay test. The Freelite assay is the standard test one uses to monitor free light chains.
But, to try to answer your question, it is possible to have a serum kappa free light value as high as 4610 mg/L (assuming for the moment this value was from a Freelite assay).
Note that the "H" and the "L" on a lab result usually means either a value that is higher or lower than the normal range, respectively.
Also, if a person has a high kappa FLC value, coupled with a low lambda FLC value and a high kappa/lambda ratio, this could signify that your mom was also experiencing bone marrow suppression in addition to a monoclonal gammopathy when she got her first test. See this site for an explanation of bone marrow suppression:
http://www.cancer.ca/en/cancer-information/diagnosis-and-treatment/managing-side-effects/bone-marrow-suppression/?region=onIn any case, this was a pretty remarkable change in the FLC numbers in such a short period of time. Others will need to comment if they have seen such a rapid improvement in such a short amount of time.
The other thing I notice is that your mom's IgG was high, while her IgA and IgM were suppressed. This can often happen with multiple myeloma patients and is a phenomemon known as "immunoparesis".
Lastly, it would be good to go back and look at the serum protein electrophoresis test (SPEP) and see if you can find her "M-spike". This may be listed as an M-protein, monoclonal protein, paraprotein, abnormal protein band, etc (assuming she has an M-spike). You also want to track the M-spike and not just the FLCs (again, assuming she had an M-spike to begin with).
This is very high, is it possible?
