Specimen Collection
Specimen: Casual/Spot urine.
Avoid first void urine in the morning. Ensure adequate hydration. Collect a random, fresh, mid-stream urine.
Note:
As beta-2 microglobulin is unstable at pH<7.0,
urine must be collected in Tris-Cl buffer.
Request form needs to be marked as
"URGENT"
.
Call the laboratory Automation section via LabLINK ext 22000
prior to sample collection
:
1. To alert them that a urine beta-2 microglobulin sample will be coming (provide patient details).
2. To obtain a urine pot containing 1mL Tris-CI buffer from the laboratory via Lamson tube.
Once urine sample collected:
3.
IMMEDIATELY pour at least 20mls of urine into the Tris-Cl buffer containing pot.
4. Hand-deliver the urine directly to Specimen Services Reception (level 3, LabPLUS) AS SOON AS IT IS PASSED. Make the Specimen Services Reception staff aware of the sample's arrival.
Note: Additional urine tests
If additional urine tests are required, a separate plain urine collection (no additives) is NECESSARY. Any tests, other than beta-2 microglobulin, requested on a urine collected in Tris-Cl buffer will be REJECTED.
Sample stability:
(When pH is adjusted to 7-9)
-
5 days at 15-25
o
C
-
14 days at 2-8
o
C
-
12 weeks at -20
o
C
Reference Intervals
Units: mg/L| Age Range | Male | Female |
|---|
| All | < 0.3[1] | < 0.19 |
[1]
For both male and female (children and adult): <=0.03mg/mmol creatinine
Uncertainty of Measurement
: 0.1 mg/L at the level of 0.3 mg/L
Turnaround Time:
Same day
Diagnostic Use and Interpretation
Urinary beta-2 microglobulin concentration is a sensitive test of
renal tubular damage.
Beta-2 microglobulin is filtered by the glomerulus and catabolised by the renal tubule.
Increased urinary concentrations are seen in renal tubular dysfunction, e.g. acute tubular necrosis, nephrotoxic drugs, Fanconi syndrome.and Cadmium toxicity.
Contact Information
Emails to
chemicalpathologist@adhb.govt.nz
will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via
Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours
: contact
Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Samarina Musaad
(Clinical Lead)
:
SamarinaM@adhb.govt.nz
ext. 22402
Dr Cam Kyle:
CampbellK@adhb.govt.nz
ext 22052
Dr Weldon Chiu:
WeldonC@adhb.govt.nz
ext. 23427
Dr Campbell Heron:
CHeron@adhb.govt.nz
ext. 23427
Specimen Transport Instructions for Referring Laboratories
Clinician to organise with their local laboratory:
Aim to deliver to laboratory as soon as the fresh urine sample is passed (after prior emptying of the bladder).
Referral Laboratory staff:
Immediately adjust the pH of the urine to 7-8 by adding drop-wise 1M NaOH within 2 hours post collection. Freeze specimen and send frozen to LabPLUS.