Use of immunoglobulin (IgG) in antibody deficiency

This information is for patients who have been referred to receive regular replacement antibody therapy using immunoglobulin (IgG). This page tells you about the treatment, including risks and benefits, and where you can obtain further information.

What is immunoglobulin?

Immunoglobulin (IgG) is a fluid containing antibodies, (proteins produced by the immune system), that help protect against infection. It has been available for the treatment of antibody deficiency syndromes for more than 30 years. It has been proven to be a very effective and well tolerated treatment. IgG is extracted from blood derived from donor pools of at least 10,000 individual blood donors.

How safe is it?

There is an extremely small risk that some bloodborne infections may be passed on through the use of  immunoglobulin.

Immunoglobulin products have been prepared from fully tested blood and have also been treated during manufacture to destroy blood-borne agents known to cause infection. However the risk of blood-borne infection cannot be completely eliminated. No recipients of IgG have contracted HIV or CJD (the human form of mad cow disease). No proven cases of hepatitis C have been identified since the mid 1990s, when the manufacturing process was altered to include elimination of this virus.

What are the benefits?

There is very strong clinical evidence that if you are not treated with IgG you are likely to have recurrent infections, which may lead to tissue damage, including long-term chest complications. 

Are there any side effects? 

As with all medicines there is a small chance of side effects. However, immunoglobulin has a good safety record. Adverse reactions may be categorised as mild, moderate or severe.

• Mild reactions usually occur within 30 minutes of the start of the infusion and include headache, flushing, chills, backpain, or muscular aches.
  Reactions are experienced by up to 10 in 100 patients, typically lasting a few hours. These reactions can often be prevented by the use of simple medicines, paracetamol and/or anti-histamine before starting your infusion and ensuring that the infusion speed is not too rapid.
• Severe allergic reactions are very rare and typically happen within seconds or minutes of beginning the infusion. Symptoms may include itchy skin rash, swelling of the face and throat, difficulty in breathing, dizziness or fainting and even collapse. This will be discussed with you before you start treatment.

How do I receive it? 

• Your medication can be transfused into a vein like a blood transfusion over 1-3 hours, and then repeated every 2-4 weeks.
• It can also be given subcutaneously (under the skin), on a more frequent basis, usually weekly.
• Your therapy will initially be given in hospital, after which time you may choose to be trained to give your own treatment at home. This will be discussed with you on an individual basis. 

Your treatment will probably be life-long. 

Will I need any blood tests?

You will be asked to have regular blood tests to monitor your IgG levels. The dosage and frequency of treatment may then be adjusted as necessary. Failure to achieve acceptable IgG levels can lead to recurrent infections. 

It is also normal practice to store small samples of your blood at the start of your treatment and before any change of product. Should any blood-borne infections occur this will enable us to determine whether it is related to your infusion.

Where to get further information and advice

Further information is available from the manufacturers of the individual IgG product. (The name of the manufacturer can be obtained from your clinician).

Safety and adverse reactions information

© North Bristol NHS Trust. This edition published March 2024. Review due March 2027. NBT002304.