Alpintest3cfrserpl
This test measures the proportion of intestinal alkaline phosphatase (IAP) relative to total alkaline phosphatase (ALP) in your blood, helping doctors determine the source of elevated ALP levels.
{"Measures intestinal ALP as a percentage of total ALP","Helps distinguish between liver, bone, and intestinal sources of elevated ALP","Useful in diagnosing digestive tract conditions","Performed on a blood sample (serum)","Results are reported as a ratio or percentage"}
Key facts at a glance
- LOINC
- 53579-9
- Short code
- ALP-I/ALP-T ratio
- Synonyms
- ALP Intest 3 CFr SerPl
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or plain red top tube
- Units
- not specified
- Ref low
- 0
- Ref high
- 0.2
- Critical range
- 20 not specified – 400 not specified
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 18 years
- Method
- Enzymatic assay with isoform separation using selective inhibition or electrophoretic technique
- CPT
- 82050
- SNOMED
- 27080006
- Specimen volume
- 1-2 mL of serum
- Stability
- Room temperature: 24-48 hours; Refrigerated (2-8°C): 5-7 days; Frozen (-20°C): 2-3 months
- Hemolysis max
- 50
- Lipemia max
- 100
- Icterus max
- 20
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The intestinal alkaline phosphatase ratio test measures how much of the total alkaline phosphatase in your blood comes specifically from the intestines. Alkaline phosphatase is an enzyme found in various tissues throughout the body, including the liver, bones, and intestines. This test helps doctors understand whether an elevated total ALP level is due to intestinal issues or other causes.
How is the test performed?
A healthcare professional will draw a small blood sample from a vein in your arm. The blood is collected in a tube, allowed to clot, and then the serum is separated for analysis. No special preparation is typically required, though your doctor may ask you to fast for a short period before the test.
Why might I need this test?
Your doctor may order this test if your routine blood work shows elevated total alkaline phosphatase levels. Since ALP can come from different organs, this test helps pinpoint whether the intestine is the source. It is particularly useful in evaluating digestive disorders, intestinal inflammation, or when liver and bone causes have been ruled out.
Reference range
0-0.2 (fraction) or 0-20%not specified
Fasting 8-12 hours preferred; fatty meals increase intestinal fraction
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Is fasting required before this test?
What does a high intestinal ALP ratio mean?
Can medications affect the test results?
Is this test painful?
How long does it take to get results?
Sources
- 1
- 2
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.
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 17, 2026. · Read our editorial policy