Test Code RATO2 Protein/Creatinine, Random, Urine
Specimen Required
Only orderable as part of a profile. For more information see ORTHP / Orthostatic Proteinuria, Random, Urine.
Useful For
Calculation of total protein concentration per creatinine concentration
Method Name
Only orderable as part of a profile. For more information see ORTHP / Orthostatic Proteinuria, Random, Urine.
Calculation
Reporting Name
Protein/Creatinine RatioSpecimen Type
UrineSpecimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 14 days | |
Frozen | 30 days | ||
Ambient | 24 hours |
Clinical Information
Orthostatic proteinuria refers to the development of increased proteinuria that develops only when the person is upright and resolves when recumbent or supine. This condition is usually seen in children, adolescents, or young adults, and accounts for the majority of cases of proteinuria in childhood.
Orthostatic proteinuria usually does not indicate significant underlying renal pathology, and is usually not associated with other urine abnormalities such as hypoalbuminemia, hematuria, red blood cell casts, fatty casts, etc. Orthostatic proteinuria typically resolves over time.
This test evaluates for this condition by demonstrating either significant proteinuria, even while supine, or normal protein excretion. Significant proteinuria, even while supine, suggests that the patient does not have orthostatic proteinuria while normal protein excretion supports the diagnosis. This test is typically done on three consecutive mornings to provide more robust support for the diagnosis.
Reference Values
Only orderable as part of a profile. For more information see ORTHP / Orthostatic Proteinuria, Random, Urine.
≥18 years: <0.18 mg/mg creatinine
Reference values have not been established for patients younger than 18 years of age.
Interpretation
First-morning urine protein-to-creatinine ratio below 0.20 mg/mg creatinine supports the diagnosis of orthostatic proteinuria, while a result above 0.20 mg/mg creatinine does not support this diagnosis.
Further investigation into other etiologies for proteinuria may be warranted.
Day(s) Performed
Monday through Sunday
Report Available
Same day/1 dayPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
RATO2 | Protein/Creatinine Ratio | 2890-2 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
RATO2 | Protein/Creatinine Ratio | 2890-2 |