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Risk factors for allergic disease

Speaker: Allan Linneberg

29 September 2012


Capital Region of Denmark

Research Centre for Prevention and Health

Risk factors for allergic disease

Allan Linneberg Research Centre for Prevention and Health Glostrup University Hospital the Capital Region of Denmark, Copenhagen, Denmark E-mail: allan.linneberg@regionh.dk


Capital Region of Denmark

Disclosures

โ€ข Lecture Fees: ALK-Abellรณ Siemens Diagnostics

Research Centre for Prevention and Health


Capital Region of Denmark

Research Centre for Prevention and Health

Definitions In epidemiology, Risk factors are variables associated with an increased risk of disease. They are not necessarily causal. The term allergy refers to IgE-mediated allergic disease


Prevalence of allergic rhinitis confirmed by examination in adults in Copenhagen Allergic rhinitis = combination of relevant symptoms and positive allergy tests (IgE sensitisation against aeroallergens)

30 Prevalence (%)

25 1990 1998 2007

20 15 10 5

11.6%

21.2%

0 Linneberg, Allergy 2000

Allergic rhinitis


Prevalence of allergic rhinitis confirmed by examination in adults in Copenhagen Allergic rhinitis = combination of relevant symptoms and positive allergy tests (IgE sensitisation against aeroallergens)

30 Prevalence (%)

25 1990 1998 2007

20 15 10 5

11.6%

21.2%

0 Linneberg, Allergy 2000 (2007 data unpublished)

Allergic rhinitis

23.5%


Prevalence of allergic rhinitis confirmed by clinical examination in eight European countries in 2001 30

Mean prevalence 22.7% Prevalence %

25

20

15

10

5

0 France

Belgium

Bauchau, Durham, Eur Respir J 2004

Germany

Italy

Spain

Sweden

UK


Historical perspectives 1819

1873 1911

1968

2012


Historical perspectives 1819

1873 1911

1968

2012

Detailed description of a rare disease: ”hay fever”

John Bostock


Historical perspectives 1819

1873 1911

1968

2012

Detailed description of a rare disease: �hay fever�

Pollens are triggers of hay fever

Charles Blackley

John Bostock


Historical perspectives 1819

1873 1911

Detailed description of a rare disease: �hay fever�

John Bostock

Pollens are triggers of hay fever

Charles Blackley

Development of Immunotherapy

1968 Noon/Freeman

2012


Historical perspectives 1819

1873

Detailed description of a rare disease: �hay fever�

John Bostock

Pollens are triggers of hay fever

Charles Blackley

1911

Development of Immunotherapy

1968

Discovery of IgE Noon/Freeman

2012

Johansson/Ishizakas


Historical perspectives 1819

1873 1911

1968

2012


Historical perspectives 1819

1873 1911

1968

2012

Civilization modern life The educated and aristocratic Nervousness Westernization Urbanization affluence

Allergic to civilization


Historical perspectives 1819

1873 1911

1968

2012

Civilization modern life The educated and aristocratic Nervousness Westernization Urbanization affluence

Allergic to civilization

Allergic to industrialization Allergic to indoor environment

Chemicals Air-pollution Wood-stowes Plastics Fumes Pesticides VOCs Isocyanates Paints Humidity Preservatives Moulds Gas Pets Phthalates House-dust-mites


Historical perspectives 1819

1873 1911

1968

2012

Civilization modern life The educated and aristocratic Nervousness Westernization Urbanization affluence

Allergic to civilization

Allergic to industrialization Allergic to indoor environment

Chemicals Air-pollution Wood-stowes Plastics Fumes Pesticides VOCs Isocyanates Paints Humidity Preservatives Moulds Gas Pets Phthalates House-dust-mites Family-size Genetics Sedentarism Obesity Parazites Viral-infections ↓Sleep Alcohol Vitamin-D FLG Endotoxins Mycobacteria Breastfeeding VEGF TNFA Diet TLR HLA Stress DENND1B Intestinal-flora Paracetamol IL4RA ACTL9 ADRB2

Allergic to hygiene

Allergic to lifestyle

GST TGFB1 ORMDL3 STAT IL1RL1 IL2RB


We have achieved much, but are we any wiser ?


What happens when a population adopts the westernized/urban/affluent lifestyle?

Affluence

Westernization Urbanization


What happens when a population adopts the westernized/urban/affluent lifestyle?

Greenland Affluence

Westernization Urbanization

Diseases of globalisation Diabetes CVD Asthma Allergy


Increase in allergy (IgE sensitization) in Greenland between 1987 and 1998

15-19

20-29

30-39

40-49

>=50

Age (years) Krause, Lancet 2003


What factors underlie the association of allergy with westernization, affluence, and urbanization?

Westernization

? Affluence

Urbanization

Linneberg, Int Arch Allergy Immunol 2008


Prevalence of self-reported allergy to house dust mites in Denmark

Rural

Urban Danish National Institute of Public Health, 1997


Studies on levels of House Dust Mites in mattress dust in Danish homes ? Micrograms/gram

50 40 40 30 30 20 10

4

1

0 Farmers

Rural

Summer Cottages

Copenhagen Copenhagen

Urban

References: Iversen, Clin Exp Allergy 1990; Korsgaard, Allergy 2005; Sidenius, Ann Agric Enivron Med 2002; Mosbech, Clin Exp Allergy 1991


Prevalence (%)

Pets in the home and pet allergy in relation to urbanization in Greece 60 50 40 30

Urban area Rural area

20 10 0 Cat in home

Priftis, Allergy 2007

Dog in home


Prevalence (%)

Pets in the home and pet allergy in relation to urbanization in Greece 60 50 40 30

Urban area Rural area

20 10 0

5.2%

2.1%

Cat in home Priftis, Allergy 2007

Dog in home

Cat SPT+

3.2% 1.5%

Dog SPT+


Total pollen counts by increasing urbanization in France

Rural

Urban

Floriane Bosch-Cano , Environmental Research 2011


Capital Region of Denmark

Research Centre for Prevention and Health

The allergen exposure paradox

We only develop allergies to allergens that we meet

but high levels of allergen exposure, as in rural areas, do not necesarily increase risk of allergy


“How wonderful that we have met with a paradox. Now we have some hope of making progress�

Niels Bohr Awarded Nobel Prize in Physics in 1922


Dose-response curve for allergen exposure and risk of sensitization ?

Risk of Allergy

Individual A

Dose of Allergen Exposure Linneberg, Allergy 2011


Dose-response curve for allergen exposure and risk of sensitization ?

Individual B Risk of Allergy

Individual A

Dose of Allergen Exposure Linneberg, Allergy 2011


Capital Region of Denmark

Research Centre for Prevention and Health

Key points Allergy has increased in Europe More than 20% of adults in Europe suffer from Allergic rhinitis In the global perspective a continuing increase is expected – Globalisation of economy means globalisation of diseases ?

Our knowledge of risk factors has increased dramatically These impressive achievements brings hope for the future – but they have not yet resulted in a breakthrough for primary prevention of allergies

We have efficient treatments – some of which may even have potential for prevention of allergies


Capital Region of Denmark

Research Centre for Prevention and Health

Thank you


Underdiagnosis and undertreatment of Allergic Rhinitis General population studies in Europe show that persons with allergic rhinitis (confirmed by clinical examination) are frequently

Underdiagnosed: (not aware of condition)

31%

Undertreated: (no treatment past 2 yrs)

47%

Bauchau, Durham, Eur Respir J 2004

Allan Linneberg  

allergy, scientific

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