IgA nephropathy

Definition

Nephropathy refers to damage, disease , or other abnormalities of the kidney. IgA nephropathy is a kidney disorder in which antibodies to a protein called IgA build up in kidney tissue.

It is also called Berger’s disease.

Alternative Names

Nephropathy - IgA; Berger's disease

Causes, incidence, and risk factors

IgA is a protein that helps the body fight infections. IgA nephropathy (Berger's disease) occurs when too much of this protein is deposited in the kidneys. IgA builds up inside the small blood vessels of the kidney. Structures in the kidney called glomeruli become inflamed.

IgA nephropathy (Berger's disease) is a form of mesangial proliferative nephritis.

The disorder can appear suddenly (acute), or progress slowly over many years (chronic glomerulonephritis).

Risk factors include::

• A personal or family history of IgA nephropathy or Henoch Schonlein purpura, a form of vasculitis that affects many parts of the body
• Caucasian or Asian ethnicity

IgA nephropathy can occur in persons of all ages, but most often affects males in their teens to late 30s.

Symptoms

There may be no symptoms for many years.

Symptoms include:

• Bloody urine that starts during or soon after a respiratory infection
• Repeated episodes of dark or bloody urine
• Hand and feet swelling
• Symptoms of chronic kidney disease

Signs and tests

IgA nephropathy usually is discovered after one or more episodes of dark or bloody urine in a person with no other symptoms of kidney disorder.

There are no specific changes seen during a physical examination. Occasionally, blood pressure may be high or swelling of the body may be present.

Tests include:

• Creatinine and blood urea nitrogen (BUN) to measure kidney function
• Urinalysis will show blood and protein in the urine
• Kidney biopsy confirms the diagnosis
• Urine immunoelectrophoresis

Treatment

The goal of treatment is to relieve symptoms and prevent or delay chronic renal failure.

Medicines may be given to control high blood pressure and swelling (edema). Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) are used. Controlling blood pressure is the most important measure to delay kidney damage.

Corticosteroids, other immunosuppressive drugs, and fish oil have also been used to treat this disorder.

Salt and fluids may be restricted to control swelling. A low to moderateprotein diet may be recommended in some cases.

Some people will need to take medicines to lower their cholesterol.

Eventually, many patients must be treated for chronic kidney disease.

Support Groups

For additional information and support, see the IgA Nephropathy Support Network website (www.igansupport.org).

Expectations (prognosis)

IgA nephropathy progresses slowly. In many cases, it does not progress at all. High blood pressure, large quantities of protein in the urine, and increased BUN or creatinine levels (blood tests that reflect kidney functioning) indicate a higher risk for progression of the disorder.

About 25% of adults with IgA nephropathy develop end-stage kidney failure within about 25 years.

Complications

• Acute nephritic syndrome or nephrotic syndrome
• Chronic kidney failure
• End-stage kidney disease

Calling your health care provider

Call your health care provider if you have bloody urine or if your urine output decreases.

References

In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 122