Immune System Disorders

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The human body's immune system is a complex network of organs, cells and proteins located throughout the body that defends against infections and other invaders, whilst protecting the body’s own cells. Immune system disorders include allergic diseases, immunodeficiencies and autoimmunity.

An overview of the immune system

The body’s immune system defends against infections from germs (such as bacteria, viruses, fungi, parasites) and other invaders (such as cancer cells) whilst protecting the body’s own cells.  

The immune system involves a complex network of organs, cells and proteins located throughout the body, which include:

As well as defending the body against infections and cancer, the immune system is involved with other systems in the body, such as the endocrine system and the nervous systems.

In most people their immune system is an effective network that responds and adapts to defend the body against infections and cancer. The immune system can also protect the body from germs that infect the body more than once, using specific memory cells.   However, some people have overactive immune responses (autoimmunity or allergies) or under reactive immune systems (immunodeficiencies).

Disorders of the immune system  

Overactivity of the immune system can take many forms.  In allergic diseases the immune system makes an excessive response to proteins in substances (known as allergens).  In autoimmune diseases the immune system mounts a response against normal components of the body.

Underactivity of the immune system, also called immunodeficiency, can be inherited, acquired as a result of medical treatment or caused by another disease. Immunodeficiency predisposes people to infections and/or swellings and can be life threatening in severe cases.

Clinical immunology/allergy specialists diagnose, treat and manage patients with immune system disorders.  These specialists are listed on the ASCIA website

Research into immune system disorders has been active in recent decades. Australia and New Zealand have strong track records in these areas. This makes immunology and allergy a dynamic and constantly changing field of medicine. 

© ASCIA 2019

ASCIA is the peak professional body of clinical immunology/allergy specialists in Australia and New Zealand.

ASCIA resources are based on published literature and expert review, however, they are not intended to replace medical advice. The content of ASCIA resources is not influenced by any commercial organisations.

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