Sensitization to the native Tree-of-Heaven (Ailanthus altissima [Mill.] Swingle) in Beijing, China

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References:
1. Ballero M., Ariu, A., Falagiani, P. (2003). Allergy to Ailanthus altissima (tree of heaven) pollen. Allergy 58(6):532-3.
2. Majd, A., Rezanejad, F., Irian, S. et al. (2013). Hypersensitivity to Ailanthus altissima (tree of heaven) pollen: identification of major IgE-binding component. Aerobiologia 29(3): 407-12. https://doi.org/10.1007/s10453-013-9290-6.
Sensitization to the native Tree-of-Heaven
(Ailanthus altissima [Mill.] Swingle) in Beijing,
China
Matthias Werchan*,**, Yuxiang Zhi***, Jianqing Gu***, Barbora Werchan* & Karl-Christian Bergmann**
*German Pollen Information Service Foundation, Charitéplatz 1, 10117 Berlin, Germany
**Charité –Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health,
Department of Dermatology, Venerology and Allergology, Charitéplatz 1, 10117 Berlin, Germany
***Department of Allergy, Peking Union Medical College Hospital & Chinese Academy of Medical Sciences, 100730 Beijing, China
Results
13,213 (29.4%) patients were identified as sensitized to AA
pollen (wheal diameter ≥5mm). Wheals with a diameter ≥
10 mm were detected in 13.7% of those patients. Male
patients were more frequently affected (34.5%) than female
patients (25.9%) (Fig. 3–6). Sensitization rates were highest
in patients aged 20 years and younger (47.3%–53.4%) and
lowest in patients over 60 years (11.3%–12.0%) (Fig. 7 and
8). Additional provocation tests for diagnosing AR have not
yet been conducted.
Introduction
Tree-of-Heaven (Ailanthus altissima [Mill.] Swingle) (AA) has
become a problematic invasive species and noxious weed
since it was imported from China and introduced as a popular
ornamental plant (Fig. 1) used in gardens, parks and as a
street tree in many countries around the world. The size of its
pollen (Fig. 2) ranges between 24 and 29 μm and it mainly
occurs in the air in the Northern hemisphere between May
and July. AA pollen is regarded a potential threat for people
with pollen allergies.1,2 Very few is know on the number of
patients with allergic rhinitis (AR) sensitized to and affected
by AA pollen. From a region with native occurrence of AA
trees, we provide outcomes of skin prick tests (SPT) of
patients consecutively visiting the Allergy Department at
Peking Union Medical College Hospital in Beijing, China.
Fig 1) Leaves and male flowers of Ailanthus altissima. © Matthias Werchan
Fig 3) Rate of sensitization to AA pollen in female patients of
different age groups.
Fig 4) Rate of sensitization to AA pollen in male patients of
different age groups.
Fig 5) Relative frequency of sensitization against AA in female patients
regarding the wheal diameter in SPT. “–” indicates no sensitization; the
different number plus signs indicate different diameters of the wheal:
“+” 5-9 mm;“++” 10-14 mm;“+++” 15-19 mm;“++++” ≥ 20 mm.
Fig 6) Relative frequency of sensitization against AA in male patients
regarding the wheal diameter in SPT. “–” indicates no sensitization; the
different number plus signs indicate different diameters of the wheal:
“+” 5-9 mm;“++” 10-14 mm;“+++” 15-19 mm;“++++” ≥ 20 mm.
Conclusion and Perspectives
1. A high proportion of patients with AR living in areas with a
regular exposition to certain AA pollen load may react to
its allergens, in particular children and adolescents.
2. Therefore, it is recommended to further investigate the
potential allergenic risk of AA, due to the rapid propagation
of the species outside of China.
3. In urban agglomerations an increasing exposure to
Ailanthus pollen could produce a new threat to allergy
sufferers in Europe.
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0-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 ≥81
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Male patients
Number of patients Senzitization rate in %
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Number of patients Senzitization rate in %
Fig 2) Pollen grains of Ailanthus altissima stained with Safranin under a light microscope at a magnification of 400×.
© Matthias Werchan
0.10 [%] 0.23 [%]
5.71 [%]
28.45 [%]
65.50 [%]
Male patients
++++ +++ ++ + -
0.03 [%] 0.09 [%]
2.54 [%]
23.24 [%]
74.1 [%]
Female patients
++++ +++ ++ + -
0.09 [%]
0.39 [%]
6.72 [%]
42.01 [%]
50.79 [%]
A
++++ +++ ++ + -
0.03 [%]
0.06 [%]
2.14 [%]
21.46 [%]
76.32 [%]
B
++++ +++ ++ + -
0.11 [%]
0.49 [%]
11.19 [%]
40.59 [%]
47.62 [%]
A
++++ +++ ++ + -
0.10 [%]
0.14 [%]
3.81 [%]
24.24 [%]
71.72 [%]
B
++++ +++ ++ + -
Fig 7) Relative frequency of sensitization against AA in A) female
children patient under 18 years of age and B) female adult patients
regarding the wheal diameter in SPT. “–” indicates no sensitization; the
different number plus signs indicate different diameters of the wheal:
“+” 5-9 mm;“++” 10-14 mm;“+++” 15-19 mm;“++++” ≥ 20 mm.
Fig 8) Relative frequency of sensitization against AA in A) male
children patient under 18 years of age and B) male adult patients
regarding the wheal diameter in SPT. “–” indicates no sensitization; the
different number plus signs indicate different diameters of the wheal:
“+” 5-9 mm;“++” 10-14 mm;“+++” 15-19 mm;“++++” ≥ 20 mm.
Objectives
A diagnostic workup of 44,994 patients of all age groups,
male (18,148;40.3%) and female (26,828;59.6%) with
suspected AR were carried out including SPT of non-
commercial Ailanthus extracts, highlighting the possible
relevance of this tree species in allergy diagnostics. The
proportion of patients under 18 years of age was 18.5%
(male + female), 81.5% were 18 years of age or older.