White mulberry IgE

Measures IgE antibodies to white mulberry tree pollen, one of several tree pollens that can cause hay fever symptoms in spring.

AI-verified against cited sources. Awaiting expert reviewAlso called t70LOINC 6281-0

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Your White mulberry IgE result

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What it is

This test measures IgE antibodies to pollen from the white mulberry tree (Morus alba), also called silkworm mulberry (ImmunoCAP t70). White mulberry is a small to medium tree that grows in warm and mild regions around the world, including North America. In many places its pollen season runs from about April to May. In people who are sensitized, the pollen can cause hay fever symptoms and can make asthma worse.

Why it matters

A result above your lab's range shows your immune system has made IgE to mulberry pollen. Whether it causes your symptoms depends on your exposure and on when your symptoms happen. IgE to mulberry pollen can show up alongside IgE to some grass and tree pollens, so a clinician usually reads this result with your symptom timing and other allergy tests.

If it’s high

A level above your lab's range means your body has made more IgE to mulberry pollen. It shows sensitization, which can happen with or without symptoms. The class number describes how much IgE was found, not how bad your symptoms will be.

Common causes

Seasonal hay fever (allergic rhinitis) from tree pollen
Sensitization to mulberry pollen without any symptoms
IgE to mulberry showing up alongside IgE to grass, olive or alder pollen, which can share similar proteins
IgE that also reacts with related plants in the mulberry family, such as paper mulberry, fig, jackfruit and breadfruit

What can help

Ask your clinician about ways to lower pollen exposure, such as keeping windows closed on high-pollen days and showering after time outdoors
Check local pollen reports to see when mulberry pollen is in season where you live
Ask whether testing other tree or grass pollens, or seeing an allergist, would help sort out which pollens matter for you
Tell your clinician about any itching or swelling after handling mulberry leaves or eating fig, jackfruit or breadfruit

Usual ranges

What labs print as the reference range, by who was tested. Ranges differ a little between labs, so the range on your own report is the one your result is judged against.

For adults: 0–0.09 kU/L. Source: ARUP Laboratories, Mayo Clinic Laboratories, U.S. Food and Drug Administration.

Adults (this one applies)0–0.09 kU/L
Sources: ARUP Laboratories, Mayo Clinic Laboratories, U.S. Food and Drug Administration

ImmunoCAP IgE classes (ARUP Laboratories)

Class 0: no significant level foundbelow 0.1 kU/L
Class 0/1: clinical relevance undetermined0.1 to under 0.35 kU/L
Class 1: low0.35 to under 0.71 kU/L
Class 2: moderate0.71 to under 3.51 kU/L
Class 3: high3.51 to under 17.51 kU/L
Class 4: very high17.51 to under 50.01 kU/L
Class 5: very high50.01 to under 100.01 kU/L
Class 6: very high100.01 and above kU/L

What can affect your result

Where you live: mulberry trees grow in many warm and mild regions, and pollen timing depends on the region
Overlap with other pollens: tree and grass seasons can overlap, so symptoms may not point to one pollen
Sensitization to other pollens, such as grass, olive or alder, which can appear alongside mulberry
The lab and test brand, because results from different systems are not directly comparable
Where a lab draws its cutoff (0.10 or 0.35 kU/L)
Different labs and test brands give different numbers for the same blood sample, so compare results from the same lab and system.
Some labs reject hemolyzed, icteric or lipemic samples (ARUP).

Slow. It usually shifts over months to years, not weeks.

When to talk to a clinician

Talk with a clinician soon if wheezing, chest tightness or shortness of breath come with your pollen symptoms. Call 911 or your local emergency number for severe trouble breathing. For hay fever that stays hard to control, bring this result to your next visit.

Questions you could ask

How should I read this result together with my other allergy tests?
Do my symptoms line up with when mulberry and other trees pollinate where I live?
Would testing other tree or grass pollens help?
What are my options for managing hay fever?

Questions people ask

I tested positive to mulberry, grass and olive. Am I allergic to all of them?

Not necessarily. Some pollens share similar proteins, so IgE made against one can show up alongside IgE to others. Your clinician looks at which results fit your symptoms, such as when they start in the spring.

When is mulberry pollen season?

It depends on where you live. In many places white mulberry pollinates from about April to May. Check local pollen reports for your area.

Show the science and sources

For clinicians and researchers

Quantitative IgE to an extract of white mulberry pollen (Morus alba, family Moraceae; ImmunoCAP t70). ARUP lists it as Allergen, Tree, White Mulberry Tree and reports it in kU/L with LOINC 6281-0. Reported as allergen-specific IgE by ImmunoCAP fluoroenzyme immunoassay in kUA/L, with calibrators traceable to the WHO IgE reference (IRP 75/502 or the 3rd International Standard 11/234). The FDA-reviewed system has a limit of quantitation of 0.1 kUA/L and reports up to 100 kUA/L; its maker recommends a 0.35 kUA/L cutoff and tells each lab to set its own range (FDA review K173726). Thermo Fisher notes that sensitization to the pollen extract has been shown by skin prick or specific IgE testing, but patient sensitivity to individual allergens is not yet characterized, and it lists no separate ImmunoCAP component for white mulberry. Reported allergenic proteins include Mor a 2 (a cobalamin-independent methionine synthase, 80 to 85 kDa, listed in the IUIS database), a profilin (14 to 15 kDa) and a nonspecific lipid transfer protein (about 10 kDa). Cross-reactivity has been described with other Moraceae (paper mulberry, fig, jackfruit, breadfruit) and with grass, olive and alder pollen. A positive result shows sensitization, not clinical allergy; ARUP notes that results may not correlate with the degree of clinical response or skin testing and that a negative test may not rule out clinical allergy.

LOINC 6281-0 (primary). Specimen: serum.

Sources

Allergen, Tree, White Mulberry Tree (ARUP test 0099554), ARUP Laboratories
t70 Mulberry Pollen (Allergen Encyclopedia), Thermo Fisher Scientific (Phadia)
ImmunoCAP Specific IgE (allergen component f447) 510(k) decision memorandum K173726, U.S. Food and Drug Administration
Mulberry, IgE, Serum (test ID MULB), Mayo Clinic Laboratories
Mulberry, White (test 602569), Labcorp
Guidelines for the Diagnosis and Management of Food Allergy in the United States: Report of the NIAID-Sponsored Expert Panel, Journal of Allergy and Clinical Immunology (2010)

AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. How we build and check these pages.