Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

RMPSU
60069
MPSS
0.57-2.63 mg/dL
KAPPA/LAMBDA-FREE LIGHT-CHAIN RATIO
0.26-1.65
Clinical References: 1. Kyle RA, Katzmann JA, Lust JA, Dispenzieri A: Clinical indications and
applications of electrophoresis and immunofixation. In Manual of Clinical Laboratory Immunology. 6th
edition. Edited by NR Rose, et al. Washington DC. ASM Press, 2002, p 66-70 2. Rajkumar SV, Kyle
RA, Therneau TM, et al: Serum free light chain ratio is an independent risk factor for progression in
monoclonal gammopathy of undetermined significance. Blood 2005;106:812-817 3. Katzmann JA,
Dispenzieri A, Kyle RA, et al: Elimination of the need for urine studies in the screening algorithm for
monoclonal gammopathies by using serum immunofixation and free light chain assays. Mayo Clin Proc
2006;81(12):1575-1578
Monoclonal Protein Study, Random, Urine
Clinical Information: Urine proteins can be grouped into 5 fractions by protein electrophoresis:
-Albumin -Alpha-1 -Alpha-2 -Beta-globulin -Gamma globulin The urine total protein concentration, the
electrophoretic pattern, and the presence of a monoclonal immunoglobulin light chain may be
characteristic of monoclonal gammopathies such as multiple myeloma, primary systemic amyloidosis,
and light-chain deposition disease. The use of a random urine specimen is sufficient for identifying the
presence or absence of a monoclonal immunoglobulin, but a 24 hour specimen is preferred for
quantitating and monitoring the abnormality. See An Expanded Algorithm for the Laboratory
Evaluation of Suspected Multiple Myeloma in Special Instructions and the Laboratory Approach to the
Diagnosis of Amyloidosis algorithm in Special Instructions. Also see Diagnosis and Monitoring of
Multiple Myeloma in Publications.
Useful For: Diagnosing monoclonal gammopathies
Interpretation: A characteristic monoclonal band (M-spike) is often found in the urine of patients
with monoclonal gammopathies. The initial identification of an M-spike or an area of restricted
migration is followed by immunofixation to identify the immunoglobulin heavy chain and/or light
chain. Immunoglobulin free light chains as well as heavy chain fragments may be seen in the urine of
patients with monoclonal gammopathies. The presence of a monoclonal light-chain M-spike of >1 g/24
hours is consistent with a diagnosis of multiple myeloma or macroglobulinemia. The presence of a
small amount of monoclonal light chain and proteinuria (total protein >3 g/24 hrs) that is predominantly
albumin is consistent with primary systemic amyloidosis (AL) or light-chain deposition disease
(LCDD). Because patients with AL or LCDD may have elevated urinary protein without an identifiable
M-spike, urine protein electrophoresis is not considered an adequate screen for these disorders and
immunofixation is also performed.
Reference Values:
ELECTROPHORESIS, PROTEIN
The following fractions, if present, will be reported as a percent of the total protein:
Albumin
Alpha-1-globulin
Alpha-2-globulin
Beta-globulin
Gamma-globulin
No reference values apply to random urine.
Clinical References: Kyle RA, Katzmann JA, Lust JA, Dispenzieri A: Clinical indications and
applications of electrophoresis and immunofixation. In Manual of Clinical Laboratory Immunology. 6th
edition. Edited by NR Rose, et al. Washington, DC, ASM Press, 2002, pp 66-67
Monoclonal Protein Study, Serum
81756
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