Rajkumar et al identified risk factors associated with progression in patients with monoclonal gammopathy of undetermined significance (MGUS). The authors are from the Mayo Clinic and the University of Birmingham in England.
Parameters:
(1) free light chain ratio in the serum (ratio of kappa to lambda light chains)
(2) immunoglobulin class for the monoclonal protein
(3) serum concentration of the monoclonal protein
free light chain ratio in the serum =
= (serum concentration of kappa light chains) / (serum concentration of lambda light chains)
|
Parameter |
Finding |
Points |
|
serum free light chain ratio |
< 0.26 |
1 |
|
|
0.26 to 1.65 |
0 |
|
|
> 1.65 |
1 |
|
immunoglobulin class involved |
includes IgG |
0 |
|
|
does not include IgG |
1 |
|
serum concentration of the monoclonal protein |
< 1.5 g/dL (< 15 g/L) |
0 |
|
|
>= 1.5 g/dL (>= 15 g/L) |
1 |
where:
• The reference range for free light chain ratio is 0.26 to 1.65. A ratio < 0.26 indicates excess lambda light chains. A ratio > 1.65 indicates excess kappa light chains.
• The immunoglobulin class patterns that did not include IgG were IgA, IgM and biclonal IgA and IgM.
total score =
= SUM(points for all 3 parameters)
Interpretation:
• minimum score: 0
• maximum score: 3
• The higher the score the greater the risk of progression to multiple myeloma.
|
Total Score |
Risk of Progression |
Probability of Progression at 20 Years |
|
0 |
low |
5% |
|
1 |
low to intermediate |
21% |
|
2 |
intermediate to high |
37% |
|
3 |
high |
58% |
Specialty: Hematology Oncology
ICD-10: ,
