Cat Allergen Fel D1
by Michael
(London, UK)
3D rendering of the Fel d 1 dimer, the primary allergen present in cat saliva - Wikimedia commons file
This is reverse cat health. It's about human health problems caused by a cat. It is a Wikipedia article extended and reworked (and reproduced under their license) to make it a bit more readable (hopefully!) and more complete on one page.
The Fel d 1 protein, produced largely by cat saliva and sebaceous glands, is the primary allergen present on cats. Atopy is a disease characterized by a tendency to be “hyperallergic”.
Definitions for para above:
Fel D1: Believed to stand for: Felis Domesticus 1 (1 being the first allergen discovered).
protein: a class of molecule that are organic compounds made of amino acids arranged in a linear chain and folded into a globular form.
saliva: the watery and usually frothy substance produced in the mouths of humans and most other animals.
sebaceous glands: microscopic glands in the skin which secrete an oily/waxy matter, called sebum, to lubricate the skin and hair of mammals.
allergen in cats: a nonparasitic antigen capable of stimulating a type-I hypersensitivity reaction in atopic individuals.
Atopic individuals: Most humans mount significant Immunoglobulin E (IgE) responses only as a defense against parasitic infections. However, some individuals mount an IgE response against common environmental antigens. This hereditory predisposition is called atopy. In atopic individuals, non-parasitic antigens stimulate inappropriate IgE production, leading to type I hypersensitivity. Sensitivities vary from one person to another and it is possible to be allergic to an extraordinary range of substances.
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The protein is of an unknown function to the animal but causes an IgG or IgE reaction in sensitive humans (either as an allergic or asthmatic response). Removal of soft surfaces in the home (carpet, furniture), frequent washings of bed linens, HEPA filters and even washing cats have been proven to reduce the amounts of Fel d 1 present in the home. Fel d 1 is a particularly sticky protein and has been shown to cling to clothing and human hair and can be detected in environments where a cat has never been present.
Definitions for para above:
IgG antibodies: are produced for several hours/days after exposure to an allergen. They are called Type III delayed hypersensitivity reactions. IgG antibodies are predominately involved in the secondary immune response.
IgE antibodies: is a class of antibody that has only been found in mammals. It plays an important role in allergy, and is especially associated with type 1 hypersensitivity. It has also been implicated in immune system responses to most parasitic worms.
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Cats produce, on average, 2-7 µg of Fel d 1 per day. Studies have shown that intact males produce Fel d 1 in levels higher than castrated males, leading to the assumption that Fel d 1 is hormonally regulated by testosterone. Castrated males produce Fel d 1 in levels similar to females (both intact and altered females produce Fel d 1 in similar levels). Even though females and castrated males produce Fel d 1 in lower levels, they still produce enough to cause allergic symptoms in sensitive individuals.
Definitions for para above:
µg: a microgram (µg , mcg or sometimes ug) is a unit of mass equal to 1/1,000,000 of a gram.
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Fel d 1 is an 18 kDa heterodimer protein and belongs to the secretoglobin family of small disulfide linked dimeric proteins found only in mammals.
Cat Allergen Fel D1 to Cat Health Problems
