Immune Suppression - Causes of immune suppression

What causes immunosuppression?

The following can be causes of immunosuppression:

  • Age. Our immune systems become less effective when we become elderly.
  • Persisting (chronic) disease. Immune systems tend to become less effective as certain long-term illnesses progress. Examples include severe chronic kidney disease, chronic liver disease and diabetes mellitus.
  • Malnutrition.
  • Medicines for illness caused by the immune system attacking itself (autoimmune conditions). Examples include rheumatoid arthritis and Crohn's disease.
  • Medicines in the form of oral steroids for conditions which result in inflammation where treatment is needed to reduce inflammation.
  • Medicines taken to prevent rejection in people who have had organ or bone marrow transplants.
  • Chemotherapy or radiotherapy treatment for cancer
  • Cancers. Certain cancers can cause immune suppression, particularly those which involve the blood cells which are so crucial to our immune system. Lymphomas, leukaemias and myeloma are the cancers which may suppress the immune system.
  • Not having a spleen, due to it having been removed. Or having a spleen which does not work well. This can occur due to certain conditions such as sickle cell anaemia, thalassaemia major or lymphoma, or after radiotherapy.
  • HIV and AIDS. The human immunodeficiency virus (HIV) affects the immune system.
  • Rare genetic conditions which result in loss of immune function - for example, severe combined immunodeficiency syndrome (SCID), DiGeorge's syndrome, Wiskott-Aldrich syndrome.

Which specific medicines cause immune suppression?

Oral steroids are a common offender and are used in numerous conditions. When used at high doses for long periods of time they can cause immune suppression. Lower doses do not generally cause a problem. For an adult, a dose of 40 mg per day of prednisolone for more than a week may cause immune suppression, but this dose varies for other steroids and for children. See separate leaflet called Oral Steroids for more information.

Other medicines which suppress the immune system include:

These medicines are used to treat all sorts of conditions, some of the more common ones including:

Why would the spleen be removed?

Your spleen is an important part of your immune system but sometimes it has to be removed, with an operation called a splenectomy. This may need doing if you are involved in an accident, or have an injury where your spleen is ruptured. It may need removing to stop you losing vast quantities of blood.

Sometimes it has become too large and destroys too many of your blood cells. Examples where this occurs and the spleen may need to be removed include:

See separate leaflets called The Spleen and Preventing infection after a Splenectomy or if you do not have a Working Spleen for more information about the spleen.

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Dr Mary Harding
Peer Reviewer:
Dr Adrian Bonsall
Document ID:
29417 (v1)
Last Checked:
05 July 2017
Next Review:
04 July 2020

Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Patient Platform Limited has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.