Sign in →

Test Code RSMPU Monoclonal Protein Screen, Random, Urine


Ordering Guidance


The use of a random urine specimen is sufficient for identifying the presence or absence of monoclonal proteins, but a 24-hour specimen is preferred for quantitating and monitoring the abnormality. See SMPU / Monoclonal Protein Screen, 24 Hour, Urine.



Shipping Instructions


Refrigerate specimen after collection and send refrigerated.



Specimen Required


Supplies: Urine Container, 60 mL (T313)

Submission Container/Tube: Plastic, 60-mL urine bottle

Specimen Volume: 50 mL

Collection Instructions:

1. Collect random urine specimen.

2. Aliquot between 30 mL and 50 mL of urine into a plastic, 60 mL urine bottle.


Useful For

Identifying monoclonal gammopathies using random urine specimens

Profile Information

Test ID Reporting Name Available Separately Always Performed
MPTRU M-protein Mass-Fix, Random, U No Yes
RPTU2 Protein/Creatinine Ratio, Random, U Yes, (RPTU1) Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
RPEU Protein Electrophoresis, Random, U No No

Testing Algorithm

Urine M-protein mass-fix alone is not considered adequate screening for monoclonal gammopathies.

 

The laboratory will evaluate the urine for M-proteins with the mass-fix method, and if positive for M-protein, protein electrophoresis will be performed at an additional charge.

 

The following algorithms are available:

-Amyloidosis: Laboratory Approach to Diagnosis

-Multiple Myeloma: Laboratory Screening

Method Name

RPTU2: Turbidimetry/Enzymatic Colorimetric Assay

RPEU: Agarose Gel Electrophoresis

MPTRU: Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS)

Reporting Name

M-protein Screen, Random, U

Specimen Type

Urine

Specimen Minimum Volume

30 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 14 days
  Frozen  5 days
  Ambient  24 hours

Reject Due To

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Urine proteins can be grouped into 5 fractions by protein electrophoresis:

-Albumin

-Alpha-1-globulin

-Alpha-2-globulin

-Beta-globulin

-Gamma-globulin

One or more quantifiable monoclonal proteins may be present and reported as M spike

 

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 following algorithms are available:

-Amyloidosis: Laboratory Approach to Diagnosis

-Multiple Myeloma: Laboratory Screening

Reference Values

CREATININE:

≥18 years old: 16-326 mg/dL

Reference values have not been established for patients younger than 18 years of age.

 

PROTEIN/CREATININE RATIO:

≥18 years: <0.18 mg/mg creatinine

Reference values have not been established for patients younger than 18 years of age.

 

ELECTROPHORESIS, PROTEIN

The following fractions, if present, will be reported as mg/dL:

-Albumin

-Alpha-1-globulin

-Alpha-2-globulin

-Beta-globulin

-Gamma-globulin

No reference values apply to random urines.

 

MASS-FIX M-PROTEIN ISOTYPE

M-protein Isotype MS:

No monoclonal protein detected

 

Flag M-protein Isotype MS:

Negative

Interpretation

The presence of a monoclonal immunoglobulin light chain in the urine is seen in multiple myeloma, macroglobulinemia, primary systemic amyloidosis and light-chain deposition disease, monoclonal gammopathy of undetermined significance, and idiopathic Bence-Jones proteinuria. The presence of a monoclonal light chain can produce renal insufficiency, may be deposited as amyloid fibrils, may damage the proximal tubes producing Fanconi syndrome, or light chains may deposit in the glomerulus and cause light-chain deposition disease.

 

Heavy chain fragments as well as light chains may be seen in the urine of patients with multiple myeloma or amyloidosis.

Day(s) Performed

Monday through Friday

Report Available

4 to 6 days

Specimen Retention Time

See Individual Test IDs

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

84156

82570

84166 Electrophoresis, protein (if appropriate)

0077U

LOINC Code Information

Test ID Test Order Name Order LOINC Value
RSMPU M-protein Screen, Random, U In Process

 

Result ID Test Result Name Result LOINC Value
617119 M-protein Isotype MS, Random, U In Process
PTCN1 Protein, Total, Random, U 2888-6
617120 Flag M-protein Isotype MS, Random, U No LOINC Needed
CRTR1 Creatinine, Random, U 2161-8
PCRT1 Protein/Creatinine Ratio 2890-2