g7 Common reed

Allergens within Grass Pollens

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  • Latin name: Phragmites communis
  • Family: Poaceae (Gramineae)
  • Subfamily: Arundinoideae
  • Tribe: Arundineae
  • Common names: Common Reed, Reed Grass, Reed
  • Source material: Pollen
Synonyms: Phragmites australis, P. vulgaris, Arundo phragmites, Arundo vulgaris
 
A grass species producing pollen, which may induce hayfever, asthma and conjunctivitis in sensitised individuals.

Allergen Exposure

Geographical distribution
The Common Reed is native to Eurasia and Africa, but is now widespread through much of the world, including the United States, Mexico, the West Indies, Chile, Argentina, and Australia.
 
Common Reed is a tall, warm-season, bamboo-like, perennial sod-forming grass. The culms are erect, rigid, smooth, and hollow. They may be nearly 2.5 cm in diameter and from 2 to 4 m tall, occasionally up to 6 m, terminating in a 30 cm-long, densely flowered, tawny or purplish panicle. The plant has stout, creeping, extensive rhizomes, often also stolons. Roots grow down to a depth of about 1 m. The leaf-blades, arising from the culm, are broad, flat, 1.5 to 6 dm long, 1 to 6 cm broad, glabrous, green or glaucous, with the sheaths overlapping.
 
The flowers develop later than in most other grasses and blooming often coincides with that of common weeds such as Artemisia or other members of the Asteraceae (Compositae), in the late summer to fall. The spikelets are 10 to 17 mm long, and the florets are exceeded by the hairs of the rachilla. The seeds ripen from late to mid-fall. The flowers are hermaphrodite (have both male and female organs) and are pollinated by wind.
 
Environment
It grows in marshes, swamps and other wet wastelands, and along streams, lakes, ponds and ditches. It is often weedy and very difficult to eradicate, as the stoloniferous rhizomes may reach 10 m or more in length. But for the same reason it may be planted to stabilize stream banks.
 
Reeds are very commonly used for thatching and for making partitions, fences, coarse mats, carrying nets, baskets, rope, sandals, pens, brooms, lattices, and arrows.
 
The shoots, roots, stems, leaves and seeds have culinary uses, and are more recently harvested for cellulose. Young reeds provide animal forage and green manure. The leaves, flowers and stems are used medicinally, and in ornamental arrangements.
 
Unexpected exposure
It is converted into alcohol (for use as a fuel), fertilizer, rayon, insulation, plaster, cork substitute, upholstery filler, boards and paper. A light-green dye is obtained from the flowers.
 
Allergens
No allergens from this plant have yet been characterised.
Common Reed appears to contain Group 1, Group 2 and Group 5 allergens (1-2).  

Potential Cross-Reactivity

An extensive cross-reactivity among the different individual species of the genus could be expected, as well as to a lesser degree among members of the closely related subfamily Bambusoideae (Bamboo, Rice), and the family Poaceae (grasses) (3-4).  
 
Natural pollen extracts from Anthoxanthum odoratum (Sweet Vernal grass), Avena sativa (Cultivated Oat), Cynodon dactylon (Bermuda grass), Lolium perenne (Rye grass), Phragmites communis (Common Reed), Poa pratensis (Meadow grass), Secale cereale (Cultivated Rye grass), Triticum sativum (Cultivated Wheat), and Zea mays (Maize/Corn) were characterised regarding their allergen contents by means of specific antibodies and by IgE immunoblot inhibition with recombinant allergens from Phl p 1, Phl p 2, Phl p 5, and Bet v 2 using sera of 193 European, American, and Asian subjects. Immunologically detectable Group 5 and Group 2 allergens were found in all these species except for C. dactylon and Z. mays (1).
 
Group 1 and Group 5 allergens were shown to be present in Dactylis glomerata (Cocksfoot), Festuca rubra (similar to Meadow Fescue), Phleum pratense (Timothy), Anthoxanthum odoratum (Sweet Vernal), Secale cereale (Cultivated Rye), Zea mays (Maize/Corn), and Phragmites communis (Common Reed). Cross-reactivity of IgE antibodies against Lol p 1 or Lol p 5 to these grasses was investigated by means of RAST-inhibition, and the degree of cross-reactivity was demonstrated to be highly variable. Individual sera were not always equally cross-reactive to all pollen species. A high degree of cross-reactivity for Group 1 allergens did not necessarily imply the same for Group 5 (2).

Clinical Experience

IgE mediated reactions
Common reed pollen can induce asthma, allergic rhinitis and allergic conjunctivitis.
 
Common Reed grass is a common aeroallergen in the Western Cape, South Africa (5).
 
Compiled by Dr Harris Steinman, harris@zingsolutions.com

References:

    1. Niederberger V, Laffer S, Froschl R, Kraft D, Rumpold H, Kapiotis S, Valenta R, Spitzauer S. IgE antibodies to recombinant pollen allergens (Phl p 1, Phl p 2, Phl p 5, and Bet v 2) account for a high percentage of grass pollen-specific IgE. J Allergy Clin Immunol 1998;101(2 Pt 1):258-64 
    2. Van Ree R, Driessen MN, Van Leeuwen WA, Stapel SO, Aalberse RC. Variability of crossreactivity of IgE antibodies to group I and V allergens in eight grass pollen species. Clin Exp Allergy 1992;22(6):611-7 
    3. Yman L. Botanical relations and immunological cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09 
    4. Yman L. Pharmacia: Allergenic Plants. Systematics of common and rare allergens. Version 1.0. CD-ROM. Uppsala, Sweden: Pharmacia Diagnostics, 2000. 
    5. Potter PC, Berman D, Toerien A, Malherbe D, Weinberg EG. Clinical significance of aero-allergen identification in the western Cape. S Afr Med J 1991;79(2):80-4

2002



Further Reading