This is a short summary. More detailed information is also available.
Acute interstitial nephritis (AIN) means inflammation in the tubules (the tiny tubes that take urine from the filtering units of the kidney), and the surrounding parts of the kidney. This inflammation is most commonly caused by an allergic reaction to something.
What trouble does it cause?
It causes the kidneys to work less well and can cause severe kidney failure. Like most diseases affecting the kidney, it produces very few symptoms unless the kidneys are quite severely affected. Some people may get a rash or other symptoms at the same time as the kidney disease, but many people do not get these things.
Blood tests will show abnormal kidney function. Urine tests often show only minor abnormalities, but the urine may contain white blood cells as if it was infected.
What causes AIN?
Most commonly it is an allergic reaction to something, often a medicine. Antibiotics and anti-inflammatory drugs are common causes of this. Occasionally it can even be caused by medicines that you can buy without a prescription, such as ibuprofen (nurofen or omeprazole). There is a very long list of medicines that can occasionally cause AIN.
Other causes include infections (although these are usually fairly obvious!)
Sometimes AIN can occur without any obvious cause and with inflammation of the eyes. This is called TINU Syndrome (Tubulointerstitial Nephritis and Uveitis Syndrome).
Occasionally it may be part of an autoimmune disease which causes inflammatioon in other parts of the body (e.g. Lupus, Sarcoid).
Some infections may cause AIN, but the infection is usually fairly obvious.
There are some other rare causes.
How is AIN treated?
If the cause is known, it should be removed. If it is a drug, the drug must be stopped and you must never use it again – this means for the rest of your life. AIN occuring a second time could cause more severe kidney damage.
Steroid tablets often speed recovery of AIN caused by allergic reactions to medicines. They work in some other types as well.
Will my kidneys recover?
Usually recovery from AIN is complete, expecially if it is picked up early. Sometimes there is some residual kidney damage which needs to be monitored by blood tests over years to come.
Where can I get further information?
Try our more detailed information first. That page also has information on some other diseases affecting the tubules and the ‘interstitium’ of the kidney.
Acknowledgements: The author of this page was Neil Turner. It was first published in August 2001. The date is was last modified is shown in the footer.