DPD (Dihydrofolate Reductase) Activity in Plasma
This test measures the activity level of the enzyme dihydrofolate reductase (DPD) in your blood plasma. It helps assess folate metabolism and is sometimes used to monitor treatment for certain cancers or genetic conditions.
["DPD activity helps track enzyme function linked to folate metabolism and potential cancer therapies."]
Key facts at a glance
- LOINC
- 104173-0
- Short code
- DPYD gene.c.1905+1G>A Geno Bld/T
- Synonyms
- DPYD gene.c.1905+1G>A Geno Bld/T
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test if you’re undergoing treatment for conditions like colorectal cancer, where DPD levels can be affected by chemotherapy. It may also be used in research or specialized diagnostic scenarios to evaluate enzyme function in blood.
What to Expect Before the Test
No special preparation is needed for this test. You’ll have a small needle inserted into your arm to draw a blood sample. The process is quick and typically painless. If you’re on blood-thinning medication, let your provider know before the test.
What the Results Mean
DPD activity results are not typically provided as a single reference range in standard clinical practice. Instead, they’re often used in relative comparisons (e.g., before/after treatment) or in research settings. Your provider will interpret the results in the context of your medical history and treatment plan.
Common Reasons for Abnormal Results
Elevated or reduced DPD activity may indicate underlying conditions like certain cancers, genetic disorders affecting folate metabolism, or side effects from medications. Your provider will discuss these findings with you based on your clinical picture.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
DPD activity testing is primarily used in specialized clinical or research settings. In colorectal cancer treatment, monitoring DPD levels can help assess how well chemotherapy is working by measuring enzyme activity that’s influenced by the treatment. It’s not a routine screening test for most patients.
Short name
DPD Activity
Frequently asked questions
What does a DPD test measure?
Why might my doctor order a DPD test?
Can I eat or drink anything before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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 16, 2026. · Read our editorial policy