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Test Code RA1U Alpha-1-Microglobulin, Random, Urine


Specimen Required


Container/Tube: Plastic, 5-mL tube

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.


Useful For

Assessment of renal tubular injury or dysfunction using random urine specimens

 

Screening for tubular abnormalities

 

Detecting chronic asymptomatic renal tubular dysfunction (2)

Profile Information

Test ID Reporting Name Available Separately Always Performed
AIMR Alpha-1-Microglobulin, Random, U No Yes
CRETR Creatinine, Random, U Yes, (Order RCTUR) Yes

Method Name

AIMR: Immunonephelometry

CRETR: Enzymatic Colorimetric Assay

Reporting Name

Alpha-1-Microglobulin, Random, U

Specimen Type

Urine

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 7 days
  Frozen  7 days

Reference Values

≥18 years: <35 mg/g creatinine

Reference values have not been established for patients who are less than 18 years of age.

Interpretation

Alpha-1-microglobulin above the reference values may indicate a proximal tubular dysfunction. As suggested in the literature, 7 mg/g creatinine is an upper reference limit for pediatric patients of 1 month to 15 years of age.(3)

Clinical Reference

1. Akerstrom B, Logdberg L, Berggard T, Osmark P, Lindqvist A: Alpha(1)-microglobulin: a yellow-brown lipocalin. Biochim Biophys Acta. 2000 Oct 18;1482(1-2):172-184

2. Yu H, Yanagisawa Y, Forbes M, Cooper EH, Crockson RA, MacLennan RC: Alpha-1-microglobulin: an indicator protein for renal tubular function. J Clin Pathol. 1983 Mar;36(3):253-259

3. Hjorth L, Helin I, Grubb A: Age-related reference limits for urine levels of albumin, orosomucoid, immunoglobulin G, and protein HC in children. Scand J Clin Lab Invest. 2000 Feb;60(1):65-73

4. Pagana K, Pagana T, Papana T, eds: Mosby’s Diagnostic and Laboratory Test Reference. Mosby; 2020:632

Day(s) Performed

Varies

Report Available

1 to 7 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83883

LOINC Code Information

Test ID Test Order Name Order LOINC Value
RA1U Alpha-1-Microglobulin, Random, U 48415-4

 

Result ID Test Result Name Result LOINC Value
A1M_U Alpha-1-Microglobulin, Random, U 46723-3
CRETR Creatinine, Random, U 2161-8
A1M_R A1M/Creat Ratio 48415-4

Forms

If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.