Which prostaglandin D2 test did you have?
The label 'prostaglandin D2 test' can mean several different tests. Mayo measures urine 2,3-dinor-11beta-PGF2 alpha. Sheffield measures urine 11beta-PGF2 alpha. Labcorp offers a direct urine PGD2-to-creatinine ratio, and some labs test direct PGD2 in blood. These tests measure different chemicals or samples. Find the exact test and sample before comparing results or using a high value to support MCAS. A normal result does not rule out MCAS. Keep the test name, timing, handling, symptoms, medicines, baseline, other mast-cell tests, and clinical question together.
Stable urine metabolite
Mayo 2,3-dinor-11beta-PGF2 alpha
A creatinine-normalized LC-MS/MS urine test, usually collected over 24 hours. This is not direct PGD2 and it has its own pg/mg creatinine interval.
Different urine metabolite
Sheffield 11beta-PGF2 alpha
A UK urine pathway with a different analyte name and ng/mmol creatinine unit. Its 825 number doesn't apply to a Mayo report.
Direct PGD2
Serum or random urine PGD2
A shorter-lived measurement with strict freezing or handling instructions. Direct serum and urine values use their own method-specific reports.
It doesn't tell you which chemical the test measured, which range applies, whether the sample survived handling, or whether MCAS is present. It also cannot prove food histamine caused symptoms, explain brain fog alone, select treatment, or make a current severe reaction safe.
Save this test
Save the analyte, sample type, collection time, and result
Store the number beside the analyte, specimen, unit, method, interval, event timing, handling, medicines, symptoms, baseline, other mediators, and clinician interpretation. That way, no one compares a later serum or urine result with the wrong test.
My Fog keeps the record.
How do age, sex, pregnancy, medicines, and collection ability change the result?
The current cited clinical catalogs do not provide one validated universal age, sex, pregnancy, or postpartum cutoff for every PGD2-related test. Life stage still matters because the likely diagnosis, medicine safety, urine collection, creatinine correction, and emergency plan can change.
Babies and young children
Adult ranges from the internet don't apply to children. Mast-cell disease in childhood often presents differently from adult systemic disease, and a 24-hour collection may be difficult to complete. A pediatric allergy or hematology service should choose the test, collection method, and performing laboratory.
Children and teenagers
Use the interval printed by the pediatric performing laboratory and keep age, urine creatinine, total collection quality, symptoms, and medicines with the result. A school-age child or teenager with breathing trouble, swelling, fainting, or a severe multi-system reaction needs urgent care now. Collecting urine can wait.
Adult women and men
Mayo's current urine metabolite catalog prints one reference value for men and women alike. This doesn't prove sex has no biological effect. It means a separate universal male or female MCAS cutoff is not established by this catalog. Use symptoms, event timing, the exact assay, and the wider assessment in every adult.
Pregnancy, postpartum, and breastfeeding
The cited lab catalogs and MCAS guidance don't set a pregnancy-specific cutoff. Record pregnancy or time since birth, symptoms, blood pressure, bleeding, medicines, and obstetric context. Do not stop prescribed aspirin, an NSAID, antihistamine, or another treatment for testing without the obstetric or prescribing clinician. Severe breathing trouble, swelling, fainting, or collapse is an emergency.
Older adults and people taking several medicines
Several things can change what the result means: aspirin and NSAID use, kidney function, urine creatinine, your ability to collect the sample, urticaria, angioedema, and myeloproliferative disease. Keep the full medicine list and clinical differential with the number instead of treating a high result as one diagnosis.
How do you prepare for a prostaglandin D2 or urine metabolite test?
Ask for the full test name before collecting anything. Check whether the lab will measure direct PGD2 or a urine breakdown product. The breakdown product may be 11beta-PGF2 alpha or 2,3-dinor-11beta-PGF2 alpha. Ask whether the test needs blood serum, one urine sample, or all urine collected over 24 hours.
Get the performing laboratory's container, storage, return, and timing instructions in writing. Mayo prefers a refrigerated 24-hour urine collection with no preservative for its stable metabolite. Labcorp says its direct random urine PGD2 sample and its direct serum PGD2 sample must be frozen immediately. Sheffield advises a 24-hour urine collection for MCAS questions and may require freezing before dispatch from another hospital.
Go over these with the clinician who ordered the test and the laboratory: aspirin, ibuprofen, naproxen, indomethacin, other NSAIDs, prescriptions, over-the-counter medicines, supplements, and recent emergency treatment. Mayo says aspirin and NSAIDs can lower its urine metabolite and gives a possible two-week aspirin and 72-hour NSAID hold when medically feasible. Keep taking every medicine a prescriber hasn't stopped. A prescriber must decide whether a change is safe or whether the test should document usual treatment.
If the question is an episodic reaction, agree on an event and baseline plan before another episode. Ask which symptoms count, when to collect, whether the plan also includes serum tryptase and other urine mediators, and when to collect a baseline sample. Never provoke symptoms to produce a sample.
For a 24-hour collection, empty the bladder into the toilet at the start and record that time. Collect every urine passage after it, including the final urine at the same time the next day. Follow the kit's refrigeration or other storage instruction, and record total volume, duration, and every missed, spilled, or contaminated sample.
For a random or post-event sample, record symptom start, body systems involved, treatment, collection time, sample type, and when the sample reached a fridge or freezer. A sample collected during ordinary symptoms and one collected soon after a sudden systemic reaction answer different questions.
Emergency care comes before sample collection. Follow the emergency plan for trouble breathing, throat or tongue swelling, fainting, collapse, or severe wheezing. Fast-worsening symptoms in more than one body system also need immediate medical help. Do not delay epinephrine or emergency services to save urine.
Name the exact test
Copy the analyte, specimen, method, laboratory, and unit from the order. 'PGD2' alone is not enough to choose a range or collection method.
Set the medicine and timing plan
Ask the prescriber and lab which medicines should stay the same and what may change the result. Confirm whether the aim is a 24-hour total, a sample after an event, or a baseline for comparison.
Collect every required sample correctly
Complete the whole 24 hours when ordered, or collect the planned random sample at the agreed time. Record any collection problem rather than hiding it.
Protect the sample
Refrigerate or freeze exactly as the performing laboratory requires. Direct PGD2 is especially handling-sensitive, so the wrong tube or a warm delay can make the number hard to trust.
Compare like with like
Use the range printed for that test. Compare event with baseline only when analyte, specimen, method, unit, and handling are comparable.
What do prostaglandin D2 test results mean?
Start with the full analyte name, specimen, unit, method, and laboratory interval. Then check event timing, medicine effects, collection quality, storage, and baseline comparability. Finish with symptoms, tryptase, other urine mediators, allergy questions, and any mastocytosis assessment.
The test identity or sample quality is unclear
The analyte, specimen, unit, timing, or handling is unclear
Pause before reading the number. Get the original report and find whether it measured direct PGD2 or a named breakdown product. Check blood versus urine, one sample versus 24-hour collection, creatinine correction, method, lab range, storage, medicines, and collection time.
Inside the exact laboratory interval
Inside the exact performing laboratory's interval
The measured analyte was not above that laboratory's interval in this specimen. This is useful but does not exclude MCAS, systemic mastocytosis, anaphylaxis, allergy, or another cause of symptoms. Check whether collection happened during the intended event and whether treatment or handling could have lowered the level.
Above the interval or higher than baseline
Above the exact interval or higher than a comparable baseline
The named PGD2-related result was higher in that sample. The number cannot tell which cells released it or which condition is present. Read the size and timing with symptoms, serum tryptase, N-methylhistamine, leukotriene E4, medicines, allergy history, and any mastocytosis check.
A severe systemic reaction is happening now
A severe systemic reaction is happening now, whatever the result
Use the person's emergency plan and get immediate help for breathing trouble, throat or tongue swelling, fainting, collapse, severe wheeze, or rapidly worsening multi-system symptoms. A past normal result or a pending urine collection does not make the current event safe.
The numbers 1802, 1820, 825, and 115 belong to different reports
Mayo's 1802 and 1820 values concern one urine breakdown product corrected for creatinine. Sheffield's 825 concerns another urine breakdown product and unit. ARUP's 35 to 115 concerns direct PGD2 in serum or plasma. None is a universal MCAS cutoff.
See research details
These checks separate the analytes, current ranges, collection methods, medicine effects, country differences, specificity limits, and recent assay research.
Copy the full test name and unit from the original report. Compare results only when the analyte, specimen, and method match. Mayo's current LC-MS/MS urine test measures 2,3-dinor-11beta-prostaglandin F2 alpha. Its reference value is below 1802 pg/mg creatinine. Its interpretation section separately discusses values above 1820 pg/mg creatinine.
Keep the number and printed interval exactly as reported. Do not invent a value for the small gap, and do not use either number as a universal MCAS threshold.
Use the ordered collection, complete it accurately, and record whether an incomplete 24-hour collection became a random test.
This is a laboratory interference instruction, not permission to stop treatment. The prescriber and laboratory should make and document the plan.
Use the result as one part of the event record and specialist assessment. Do not use it as a screening label for chronic, nonspecific symptoms alone.
A high result needs a differential diagnosis. A normal result needs the same event, treatment, timing, and handling review before it is used to lower concern.
The reported 90 percent figure applies to the study's combined testing approach and must not be treated as universal MCAS accuracy or as the performance of PGD2 testing alone.
Use the Sheffield report and referral pathway as written. Read its number only against the Sheffield range. Sheffield and Mayo measure different chemicals.
In Australia or New Zealand, ask an allergist or immunologist what's validated and available locally. A US lab range doesn't apply to an unrelated private test.
Read direct serum PGD2 only against its own current report. A public web page without a range is not a reason to borrow a number from another laboratory.
Keep the performing method and laboratory with the result. A more exact measurement doesn't make the diagnosis more certain.
Use paired samples only through a planned specialist pathway and compare like with like. The 1.3 acute-to-baseline ratio from this selected study isn't a cutoff for diagnosis at home.
Make the next sample and event easier to understand
The safest useful work is to make the next event, sample, and clinical question easier to interpret. There is no evidence-based food, supplement, or home-treatment plan that should be chosen from one PGD2-related result.
Make a one-page event record
For each sudden episode, record the start time and symptoms in the skin, breathing, stomach, heart, blood pressure, or nervous system. Add the possible exposure, medicine, response, emergency care, and exact sample times. A short fact list is more useful than a long list of possible triggers.
Prepare the kit and instructions before an event
Keep the correct container, written storage steps, laboratory contact, collection window, and emergency plan together. Confirm whether to refrigerate or freeze the sample and where you can return it after hours.
Keep ordinary food and fluid habits unless told otherwise
Do not fast, dehydrate, overdrink, or begin a broad low-histamine or anti-inflammatory diet to alter the result. Record ordinary meals, alcohol, illness, exercise, heat, and suspected exposures so the clinician can see the real context.
Review medicines without changing them alone
Make one list of aspirin, NSAIDs, antihistamines, mast-cell medicines, inhalers, supplements, and recent emergency treatment. Ask which should remain unchanged, which may affect the assay, and which are medically unsafe to hold.
Ask what answer would change care
Ask which problem the clinician is checking. It may be anaphylaxis, MCAS, systemic mastocytosis, hives, swelling, aspirin-related breathing disease, or another problem. Ask how a high, normal, or unusable result would change what happens next.
Do not change aspirin, NSAIDs, antihistamines, mast-cell medicines, supplements, diets, or doses from this result. Do not trigger a reaction on purpose. Follow the emergency plan and call 911 for trouble breathing, throat or tongue swelling, fainting, collapse, or severe wheezing. Call for fast-worsening symptoms in more than one body system too.
What should you keep with a prostaglandin D2 result?
Keep these together
- Full analyte name, direct PGD2 or named urine metabolite
- Serum or urine, random or 24-hour collection, and event or baseline purpose
- Value, unit, printed laboratory interval, method, and performing laboratory
- Urine creatinine, duration, total volume, container, storage, and return time
- Every missed, spilled, contaminated, warm, delayed, or rejected specimen detail
- Symptom start, body systems involved, severity, suspected exposure, and emergency treatment
- Aspirin, NSAIDs, antihistamines, mast-cell medicines, supplements, and any agreed hold
- Acute and baseline tryptase, N-methylhistamine, leukotriene E4, and other ordered results
- Allergy, urticaria, angioedema, respiratory, blood-count, KIT, and mastocytosis findings when relevant
- Clinician interpretation, criteria met and missing, next action, and reason for any repeat
Question for the visit
“Were the sample and handling usable? Which range applies? Did the result change from a comparable baseline? Which diagnosis can it support, and which can't it confirm? What will it change in my care?”
Sources for Prostaglandin D2 Urine Test: Collection and Results
Current 2026 analyte, method, collection, storage, medicine effects, range, interpretation, specificity limits, and internal three-marker sensitivity
Current random-sample alternative, collection, method, creatinine normalization, and report context
Current direct serum assay, SPE with LC-MS/MS, red-top tube, immediate freezing, and specimen rejection
Current direct random urine assay, immediate freezing, ratio and direct-result units, and specimen requirements
Current example 35 to 115 pg/mL direct-serum interval and explicit warning against method interchangeability
Current US diagnostic framework, systemic event pattern, tryptase, urine mediators, and specialist assessment
Emergency symptoms and immediate-care boundary
Adult and child disease context and specialist evaluation
Current UK analyte, local range, sample, stability, 24-hour MCAS and post-reaction pathway, and turnaround
UK public information on child and adult presentation, blood counts, tryptase, and clinical diagnosis
Current Australia and New Zealand criteria, tryptase preference, PGD2 non-recommendation, and cutoff limits
AAAAI workgroup MCAS criteria and mediator limitations
Urine mediator review for systemic mastocytosis and mast-cell activation
Selected acute-to-baseline urine mediator ratios paired with a qualifying tryptase rise
Current review of emerging urine mediator use alongside tryptase
Updated biomarker review, paired sampling, and unsettled urine-mediator thresholds
Analytical interference and differential-mobility improvement in urine 2,3-dinor-11beta-PGF2 alpha measurement
Urinary PGD2-metabolite elevation in aspirin-exacerbated respiratory disease and specificity limits
Small early urinary metabolite timing and aspirin-challenge study, with limited generalizability
See each claim's sources
range
Mayo's current LC-MS/MS urine test measures 2,3-dinor-11beta-prostaglandin F2 alpha. Its reference value is below 1802 pg/mg creatinine. Its interpretation section separately discusses values above 1820 pg/mg creatinine.procedure
Mayo prefers a complete refrigerated 24-hour urine collection with no preservative for this metabolite, requires duration and volume, and accepts a separate random test.procedure
Mayo states that aspirin and NSAIDs can lower the urine metabolite and gives a two-week aspirin and 72-hour NSAID hold only when medically feasible.limitation
Mayo states that high urine 2,3-dinor-11beta-PGF2 alpha is not specific for systemic mast-cell disease and that some affected patients do not have an elevated result.interpretation
AAAAI places urine 11beta-PGF2 alpha within a wider MCAS assessment that also requires a compatible recurrent systemic event pattern, objective mediator evidence, and response to appropriate treatment.range
Sheffield's current UK service measures urine 11beta-PGF2 alpha, prints a local interval below 825 ng/mmol creatinine, and advises a 24-hour collection for MCAS questions.limitation
ASCIA's current position paper does not recommend blood PGD2 or 11beta-PGF2 alpha for MCAS investigation in Australia and New Zealand because clinical validation and diagnostic cutoffs are insufficient.procedure
Labcorp's current direct serum PGD2 assay uses SPE with LC-MS/MS and requires red-top serum to be transferred and frozen immediately.procedure
Labcorp's current direct random urine PGD2 test reports a creatinine ratio in ng/g and direct PGD2 in pg/mL and requires immediate freezing without preservative.limitation
Moehnke 2024 found analytical interferences in targeted urine 2,3-dinor-11beta-PGF2 alpha measurement and showed that added differential mobility separation reduced them without creating a new clinical cutoff.interpretation
Butterfield 2023 reported acute-to-baseline urine mediator changes in selected cases with a qualifying tryptase rise, but the approximately 1.3 lowest PGD2-metabolite ratio is not a universal diagnostic threshold.limitation
Urine PGD2 metabolites can rise in aspirin-exacerbated respiratory disease, so an elevated result is not specific to MCAS or systemic mastocytosis.safety
Suspected anaphylaxis needs immediate treatment and emergency care; collecting urine must not delay the emergency plan.