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Thiosulfate/Creatinine Ratio, Urine

Published: August 9, 2026Updated: August 16, 2026

Measures urine thiosulfate relative to creatinine to help evaluate sulfur metabolism while accounting for urine concentration.

Quick summary

["This urine test can help identify disorders that affect sulfur metabolism, particularly when symptoms suggest sulfite oxidase deficiency."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
32274-3
Short code
Thiosulfate/Creat Ur-Rto
Synonyms
Thiosulfate/Creat Ur-Rto
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test measures thiosulfate, a sulfur-containing compound, in urine and compares its amount with urine creatinine. The ratio helps account for variations in urine concentration.

Why might I need this test?

It may be used to evaluate suspected problems with sulfur metabolism, including sulfite oxidase or molybdenum cofactor deficiency. It is most relevant when an infant or child has unexplained neurologic symptoms, seizures, or developmental concerns.

How is the test performed?

A urine sample is collected and tested to determine the amounts of thiosulfate and creatinine. The laboratory then calculates the thiosulfate-to-creatinine ratio.

How do I prepare for the test?

Collect the urine sample as instructed by your healthcare professional, using a clean container and the collection method provided. Tell the laboratory if you are taking medications or supplements that contain sulfur, because they may affect the result.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated thiosulfate-to-creatinine ratio may indicate reduced breakdown of sulfur-containing compounds, as can occur with sulfite oxidase deficiency or related disorders. The result is interpreted with symptoms, other laboratory findings, and sometimes genetic testing because an elevated ratio alone does not establish a diagnosis.

Short name

Urine thiosulfate-to-creatinine ratio

Frequently asked questions

Does the test require a blood sample?
No. This test uses a urine sample, which is collected and sent to the laboratory for analysis.
Why is creatinine included in the result?
Urine concentration can vary widely. Comparing thiosulfate with creatinine helps reduce the effect of differences in urine concentration.
Can supplements or medicines affect the result?
Yes. Sulfur-containing products and some medications may alter urine thiosulfate levels, so supplements and medicines should be reported to the healthcare professional ordering the test.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy