Diseases & Conditions

AIN - Acute Interstitial Nephritis


Overview, Causes, & Risk Factors

Acute interstitial nephritis is also called AIN. AIN is a condition in which there is damage to the tissue around the filtering unit of the kidney. This can result in a sudden decline in the kidney function.

What is going on in the body?

In AIN, different types of white blood cells invade the filtering system of the kidney. This causes it to swell. The rise in white blood cells is most often a result of an allergic reaction to a medicine. But it may also be caused by some infections. Most people who have AIN recover completely. But sometimes, scarring results. If that happens, the kidney may have irreversible damage.

What are the causes and risks of the disease?

AIN may be caused by:

  • allergic reaction to certain medicines. Examples include penicillin, cephalosporins, sulfa medicines, ibuprofen, thiazide, phenytoin, and cimetidine. A person who is exposed over and over to the medicine that caused the AIN has a higher risk of infection.
  • autoimmune disorders, such as systemic lupus erythematosus and Sjogren syndrome
  • infection, such as pyelonephritis or infection of the kidney, group A streptococcal infection, diphtheria, and mononucleosis
  • Sometimes the cause is unknown.


    Symptoms & Signs

    What are the signs and symptoms of the disease?

    Symptoms of AIN include:

  • back pain or flank pain
  • blood in the urine
  • burning or pain when passing urine
  • fever
  • joint pain
  • rash on the trunk, upper arms, and legs

  • Diagnosis & Tests

    How is the disease diagnosed?

    The doctor can usually diagnose AIN by doing the following:

  • taking a history of the medicines the person uses
  • doing a complete physical exam
  • noting the symptoms
  • Urine and blood tests are done to assess the kidney function. They can also help confirm the diagnosis. Sometimes a skin biopsy of the rash and a kidney biopsy are needed.


    Prevention & Expectations

    What can be done to prevent the disease?

    Prevention of AIN is not always possible. It helps to avoid contact with the offending medicine in the case of allergic reaction. Other prevention depends on the underlying cause of infection, such as avoiding exposure to strep.

    What are the long-term effects of the disease?

    Most cases of kidney damage can be reversed with treatment. But a few cases of AIN may lead to lasting kidney failure.

    What are the risks to others?

    AIN is not catching and cannot be spread to others. Certain underlying conditions, such as mononucleosis, may be catching.


    Treatment & Monitoring

    What are the treatments for the disease?

    Treatment will depend on what has caused the disease. If the AIN was caused by an allergic reaction to a medicine, the kidney function usually returns to normal once the medicine is stopped.

    If the kidney function does not return or if the damage is severe, steroids may be used. They can help decrease the allergic response. Sometimes short-term dialysis may be needed. This can help remove toxins until the kidney function returns. If the damage to the kidneys can't be reversed, the person may need long-term dialysis. Or, in some cases, a kidney transplant may be needed.

    What are the side effects of the treatments?

    Side effects of steroids may include:

  • feeling shaky
  • weight gain
  • insomnia
  • Side effects of surgery may include:

  • bleeding
  • infection
  • allergic reaction to anesthesia
  • What happens after treatment for the disease?

    Usually the kidney heals completely and the AIN symptoms slowly go away. If surgery is needed, recovery will depend on the extent of surgery.

    How is the disease monitored?

    The doctor will generally advise regular visits and kidney function tests. Any new or worsening symptoms should be reported to the doctor.


    Attribution

    Author:Rajnish K. Dhingra, MD
    Date Written:
    Editor:Crist, Gayle P., MS, BA
    Edit Date:04/25/02
    Reviewer:Eileen McLaughlin, RN, BSN
    Date Reviewed:07/12/01

    Sources

    Current Pediatric Diagnosis & Treatment, Hathaway, et al, 1993

    Complete Guide to Symptoms, Illness, & Surgery, H. W. Griffith, 2000

    Harrison's Principles of Internal Medicine, Fauci, et al., 2000