Citric Acid (Citrate):Creatinine Ratio, Random Urine
Synonyms
- Citrate Excretion, Urine
Special Instructions
pH must be 1 to 3 or the sample frozen without the addition of acid.
Expected Turnaround Time
3 - 7 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Documents
Specimen Requirements
Specimen
Urine (random), acidified or frozen
Volume
2 mL
Minimum Volume
1 mL (Note: This volume does not allow for repeat testing.)
Container
Use random urine transport tube or urine Monovette® with pH stabilizer (Labcorp No. 56015). Monovette® instructions accompany units.
Collection
Collect urine and transfer to a random urine transport tube or urine Monovette® with pH stabilizer (Labcorp No. 56015). Alternatively, the sample may be frozen without added acid.
Storage Instructions
Refrigerate at 2°C to 8°C.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 29 days |
Refrigerated | 29 days |
Frozen | 49 days |
Freeze/thaw cycles | Stable x5 |
Causes for Rejection
Citrate: Boric Acid used as a preservative (Boric acid ≥1250 mg/dL may cause citrate results to be reduced by approximately 30%); multivitamin ≥397.5 mg/dL (estimated as 1 pill per day) may cause citrate results to be unmeasurable. Results of interference testing may not be representative of in-vivo characteristics of multivitamin consumption.
|
Citrate: Boric Acid used as a preservative (Boric acid ≥1250 mg/dL may cause citrate results to be reduced by approximately 30%); multivitamin ≥397.5 mg/dL (estimated as 1 pill per day) may cause citrate results to be unmeasurable. Results of interference testing may not be representative of in-vivo characteristics of multivitamin consumption. Citrate: Boric Acid used as a preservative (Boric acid ≥1250 mg/dL may cause citrate results to be reduced by approximately 30%); multivitamin ≥397.5 mg/dL (estimated as 1 pill per day) may cause citrate results to be unmeasurable. Results of interference testing may not be representative of in-vivo characteristics of multivitamin consumption. |
|
Citrate: Boric Acid used as a preservative (Boric acid ≥1250 mg/dL may cause citrate results to be reduced by approximately 30%); multivitamin ≥397.5 mg/dL (estimated as 1 pill per day) may cause citrate results to be unmeasurable. Results of interference testing may not be representative of in-vivo characteristics of multivitamin consumption. Citrate: Boric Acid used as a preservative (Boric acid ≥1250 mg/dL may cause citrate results to be reduced by approximately 30%); multivitamin ≥397.5 mg/dL (estimated as 1 pill per day) may cause citrate results to be unmeasurable. Results of interference testing may not be representative of in-vivo characteristics of multivitamin consumption. |
Test Details
Use
A timed 24-hour urine collection is the preferred specimen for measuring and interpreting this urinary analyte. Random collections normalized to urinary creatinine may be of some clinical use in patients who cannot collect a 24-hour specimen, typically small children. The mean urinary citrate excretion rate in patients with idiopathic calcium urolithiasis has been found to be significantly lower than that of control groups. Hypocitraturia is common in patients with urolithiasis resulting from renal tubular acidosis and in patients with enteric hyperoxaluria. Citrate excretion is low in renal insufficiency.
Methodology
Nuclear magnetic resonance (NMR) or Enzymatic
|
Nuclear magnetic resonance (NMR) |
|
Nuclear magnetic resonance (NMR) or Enzymatic |
Reference Interval
• Male: 3−72 mg/g creatinine
• Female: 5−96 mg/g creatinine
References
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 123880 | Citric Acid/Creat Ratio, Rand | 016869 | Citric Acid, Random Urine | mg/L | 2128-7 | |
| 123880 | Citric Acid/Creat Ratio, Rand | 016870 | Creatinine,Ur | mg/dL | 2161-8 | |
| 123880 | Citric Acid/Creat Ratio, Rand | 016876 | Citric/Creat Ratio | mg/g creat | 13722-4 |
© 2021 Laboratory Corporation of America® Holdings and Lexi-Comp Inc. All Rights Reserved.
CPT Statement/Profile Statement
The LOINC® codes are copyright © 1994-2021, Regenstrief Institute, Inc. and the Logical Observation Identifiers Names and Codes (LOINC) Committee. Permission is granted in perpetuity, without payment of license fees or royalties, to use, copy, or distribute the LOINC® codes for any commercial or non-commercial purpose, subject to the terms under the license agreement found at https://loinc.org/license/. Additional information regarding LOINC® codes can be found at LOINC.org, including the LOINC Manual, which can be downloaded at LOINC.org/downloads/files/LOINCManual.pdf