Immunoglobulins (also known as antibodies) are proteins produced by the immune system (the body’s defence system) to fight disease-causing germs, such as viruses and bacteria. They attach themselves to germs entering the body, so that the immune system can find and destroy them.

The immune system makes different immunoglobulins to fight different types of germs. For example, your body produces different immunoglobulins to fight the common cold than it makes if you get infected with chicken pox.

There are five different types of immunoglobulins. Immunoglobulin G (IgG) is the most common.

Low or high levels of immunoglobulins can be a sign that something is wrong with your immune system.

Your immunoglobulin levels may be checked to see if you have an infection or if you are protected from getting one (have immunity). A test for immunoglobulins can help to diagnose conditions where immunoglobulin products might be used, including immune deficiencies and autoimmune conditions.

Immunoglobulin products are made from the plasma of donated human blood (plasma is the clear fluid left when blood cells are removed). The plasma from several thousand donations is pooled as part of the manufacturing process. This produces a super-concentrated collection of antibodies to fight against the many possible foreign substances your immune system might get exposed to.

During the manufacturing process, most of the other immunoglobulins are removed from the pooled plasma, leaving immunoglobulin G (IgG) and small amounts of immunoglobulin A (IgA) – IgG is the key ingredient that helps to fight disease-causing substances, such as viruses and bacteria.

The IgG is made into a solution and put into small bottles (vials) for use. The solution will also contain small amounts of other ingredients to stabilise the IgG so that it stays effective for longer.

There are a number of different immunoglobulin products available in Australia. Some are made in Australia and some are imported from overseas to meet the needs of Australian patients. Plasma products used in Australia must be assessed and approved by the Therapeutic Goods Administration (TGA). The TGA is a Commonwealth Government agency that regulates blood products, medical devices, vaccines and drugs. The TGA regulates the safety, quality, and efficacy of all immunoglobulin products.

Not all immunoglobulin products registered for use by the TGA are publicly funded by the Australian government.

More about immunoglobulin products and the TGA

More about other ingredients contained in medicines

Immunoglobulin replacement therapy is one of the two ways that immunoglobulin products are used

IRT is given to people who do not make enough of their own immunoglobulins. This condition is called an immune deficiency, or immunodeficiency.

Low levels of immunoglobulins make it harder for your body to fight infections. This can happen because of a genetic problem that you were born with (primary immune deficiency) or that you acquired as a result of other illnesses or treatments. These usually happen later in life but can occur in young people (called secondary immune deficiency).

Acquired conditions are more common than genetic ones, which are rare.

Most people who are born with an immune deficiency condition will need IRT for their whole lives.

Some acquired conditions only need IRT for a short time. Others require long-term treatment. This will vary for each condition and individual.

IRT can help treat existing infections associated with immune deficiency, and prevent new infections. It can also help prevent long-term damage from repeated infections, such as chronic lung disease.

IRT is not a perfect replacement for your immune system – it won’t provide complete protection from infections. If an infection occurs, you may need other treatment such as antibiotics to help treat the problem.

Immune modulation therapy is another way that immunoglobulin products are used.

IMT (using immunoglobulin products) may be given to people with autoimmune and inflammatory conditions. This is where the immune system mistakenly attacks and destroys healthy tissue. Autoimmune and inflammatory conditions can affect nerves, blood cells, or other parts of the body.

IMT can help reduce the symptoms and change how these conditions develop, although how this works is not completely understood.

IMT can help some autoimmune and inflammatory conditions but not others, and not everyone will respond to treatment.

In Australia, government-funded immunoglobulin products are restricted to conditions where:

• use is supported by scientific and clinical evidence, and
• other treatments are less effective or can’t be used.

This is because there is a limited supply of immunoglobulin products and they are expensive to manufacture. Careful management is needed to ensure that there is an adequate, secure and affordable supply of immunoglobulin products for Australians who need them.

The conditions and circumstances under which government-funded immunoglobulin products can be considered for use are set out in the Criteria for the Clinical Use of Immunoglobulin in Australia (the Criteria).

The Criteria:

• list the conditions where evidence suggests that a person is most likely to benefit from immunoglobulin therapy
• set out the eligibility criteria for access to immunoglobulins – for example, how severe the condition is
• set out the criteria for the review of a person’s response to immunoglobulin treatment.

Your doctor may be able to arrange access to immunoglobulin products for conditions or cases that are not funded this way.

These are some examples of conditions where immunoglobulin products are used:

• immune deficiency (primary) – severe combined immunodeficiency (SCID), common variable immunodeficiency (CVID), X-linked agammaglobulinaemia (XLA).
• immune deficiency (secondary) – chronic lymphocytic leukemia, multiple myeloma, and reduced immune function following hematopoietic stem cell transplantation.
• neurological conditions – chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy, Guillain Barré syndrome, and myasthenia gravis.
• autoimmune / inflammatory conditions – immune thrombocytopenia, and autoimmune haemolytic anaemia.

Find out more about how immunoglobulin products are made available on the National Blood Authority’s Access to Intravenous Immunoglobulin (IVIg) webpage.

A full list of the conditions that are approved for government funded immunoglobulin products appears in The Criteria for the Clinical Use of Immunoglobulin in Australia

Immunoglobulin products have been used for many decades and have an excellent safety record. The plasma used to produce immunoglobulin products is thoroughly tested for blood-borne diseases such as hepatitis B, hepatitis C, and HIV.

Processes used in the manufacturing of immunoglobulin products include steps to remove viruses that might not be detected during screening tests for blood or plasma donors or stop them working (inactivation).

The risk of getting an infection from immunoglobulin products is extremely low.

All plasma products, whether manufactured here or imported from overseas, must meet strict standards for safety and effectiveness. Plasma products used in Australia must be assessed and approved by the Therapeutic Goods Administration (TGA). The TGA is an Australian Government agency that regulates blood products, medical devices, vaccines and drugs. The TGA regulates the safety, quality, and efficacy of all immunoglobulin products.

Read more about the safety of blood products

Read more about immunoglobulin side effects and how to manage them

The National Blood Authority has more information on immunoglobulin products and how they are accessed

• National Blood Authority: Immunoglobulin (Ig)
  
• National Blood Authority Immunoglobulin resources – for patients and health professionals
• The National Immunoglobulin Governance Program

Read more about managing your immune condition with immunoglobulin products

Autoimmune disorder occurs when the body's immune system attacks and destroys healthy body tissue by mistake. Examples associated with immune deficiencies include Crohn’s disease and ulcerative colitis.

Immunoglobulins, also known as antibodies, are protein molecules produced by plasma cells (white blood cells). They act as a critical part of the immune response by specifically recognising and binding to specific foreign substances, such as bacteria or viruses, and aiding in their destruction.

Immunoglobulin modulation therapy (IMT) is used to treat people with autoimmune and inflammatory conditions. This is where the immune system mistakenly attacks and destroys healthy tissue. IMT can help reduce the symptoms and change how these conditions develop, although how this works is not completely understood.

Immunoglobulin replacement therapy (IRT) is used to treat people who are unable to make enough of their own immunoglobulins, or whose immunoglobulins don’t work properly. Used in a number of primary and secondary immune deficiency disorders to help protect against infection and prevent long term damage from ongoing infections (such as chronic lung disease).

Intravenous immunoglobulin (IVIg) is a product made up of immunoglobulins (antibodies) that can be given intravenously (through a vein).

Primary immune deficiency disorders are a group of disorders caused by inherited or genetic defects in the cells and tissues of the immune system. These are grouped according to what part of the immune system is affected (such as the B cells or T cells).

Secondary immune deficiency disorders are more common than primary immune deficiency disorders. They can happen as a result of a person’s main medical condition, or because of damage to the immune system from environmental factors such as some cancer treatments. They are often resolved by treating the main medical condition.

Subcutaneous immunoglobulin therapy (SCIg) is a form of immunoglobulin treatment given by slowly injecting an immunoglobulin product into tissue just underneath the skin, usually on the abdomen or thigh.

Find out more about Immunoglobulins