Has Decreased Infection Load Of Infants Led To Increased Diseases?

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http://www.sciencedaily.com/releases/2008/05/

080528095732.htm

 

Has Decreased Infection Load Of Infants Led To Increased Allergic And

Autoimmune Diseases?

 

ScienceDaily (May 29, 2008) — The starting point of the hygiene

hypothesis is that the decreasing infection load of infants in the

developed countries leads to an increase in allergic and autoimmune

diseases. Such development has been observed practically in all

industrialized countries after the Second World War. Now an extensive

research project begins to establish how the living environment

affects the development and maturation of a child's immune system.

 

High living standards and the life style connected to them seem to

promote the development of autoimmune diseases and allergic symptoms.

This has lead to the assumption that the immune system begins to

overreact to the organism's own structures or to exogenous non-

infectious proteins, i.e. allergens, when it does not have to work

hard enough to protect the individual from infections.

 

The European Union with its Seventh Framework Program has allocated 6

million euros to the University of Helsinki coordinated DIABIMMUNE

research project for the years 2008-2013 to establish whether the

decrease in the infection load is connected to type 1 diabetes and

the emergence of allergies.

 

The project comprises 12 partners from five countries. The study will

include 7 000 children from Finland, Estonia and Russian Karelia in

northwestern Russia. In each country the study will follow more than

300 children from birth to their 3rd birthday. In addition, the

research will focus on 2 000 children from their third to fifth

birthdays.

 

" Earlier we have studied autoimmune phenomena and allergic responses

in Finnish and Russian Karelian school children. Now we are to study

infants and toddlers in order to yield new information on the

maturation of the immune system and the interaction between the

immune system and the environment " , says Professor Mikael Knip from

the University of Helsinki.

 

Based on earlier studies it is known that the incidence of type 1

diabetes is six times higher and the prevalence of celiac disease

five times higher among Finnish children than among Russian Karelian

children. The HLA gene variants that predispose people to autoimmune

diseases are however approximately equally common in both

populations. The studies have also revealed that Russian Karelian

school children have helicobacter antibodies as signs of earlier

infections 15 times more often, Toxoplasma antibodies five times more

often, and hepatitis A antibodies 12 times more often than Finnish

children. Karelian children also have considerably more often

antibodies against the Coxsackie B4 virus, belonging to the

enterovirus group, than Finnish children have.

 

" The differences in the frequency of autoimmune phenomena and

allergic responses between Finland and Russian Karelia cannot be due

to genetic causes. High living standards and the associated life

style appear to promote the development of autoimmune diseases and

allergic responses " , Knip says.

 

The DIABIMMUNE project focuses for example on the development of the

intestinal bacterial flora after birth and the effect the living

environment has on the composition of the bacterial flora. The

research also studies the effect infections have on the maturation of

the human immune system and the operation of the white blood cells

that regulate immune responses. In addition, the researchers study

whether the protection conferred by infections against autoimmune and

allergic responses is associated with the overall infection load or

due to specific microbes. The project also examines the effect of the

child's nutrition on the maturation of the immune system, the

intestinal bacterial flora and the occurrence of infections.

 

" The diseases we are studying are the most common chronic diseases in

children and their impact, both societal and medical, is vast. We are

searching for ways to stop these diseases from becoming more frequent

and to prevent their development " , Knip says.

 

 

Adapted from materials provided by University of Helsinki, via

EurekAlert!, a service of AAAS.

 

University of Helsinki (2008, May 29).

Has Decreased Infection Load Of Infants Led To Increased Allergic And

Autoimmune Diseases?.

ScienceDaily.

Retrieved June 10, 2008,

from http://www.sciencedaily.com­ /releases/2008/05/080528095732.htm