IgA nephropathy (Berger's disease)

IgA nephropathy (Berger’s disease) is a disease of the kidneys caused by a buildup of an antibody called immunoglobulin A (IgA) in the kidneys. This buildup of immunoglobulin A causes inflammation and, if prolonged, the inflammation can impede kidney function, mainly the kidney’s ability to remove waste from the blood. IgA nephropathy is considered a form of glomerulonephritis, which is inflammation of the glomeruli of the kidneys and the most common type of glomerulonephritis across the globe. It often takes years to develop, gradually progressing before it presents visible symptoms. Progression and severity of symptoms vary from person to person. Some patients go into complete remission with treatment; others develop end-stage renal failure. The disease affects twice as many men as women, usually developing between the late teens and late thirties. It is most common in whites and Asians. Although no cure exists for IgA nephropathy, medications can slow its progress. Maintaining healthy cholesterol levels and blood pressure also help to slow the disease, as does a low fat, low sodium, low protein diet.

Background

IgA nephropathy has likely been around for several centuries, but the earliest descriptions of the disease were recorded in early nineteenth-century Europe. Doctors in England, Germany, and other parts of the continent reported cases of young patients experiencing the classic symptoms of the disease as early as 1801. The disease was later elaborated on in 1968 in an article published in the Journal of Urology and Nephrology by French nephrologist Jean Berger and his coauthor Nicole Hinglais. Berger and Hinglais were the first to examine the role of IgA deposition in contracting glomerulonephritis. Berger’s contributions to the study of the disease led to many people calling it Berger’s disease.

The kidneys are two round, bean-shaped organs located in the lower abdominal region of the torso. Each person possesses two kidneys situated on the right and left side of the body. Kidneys are full of tiny blood vessels that act as the body’s filter for waste, excess water, and other substances found in the blood. After the blood passes through the kidneys, the filtered blood re-enters the body while waste and other substances go to the bladder and exit the body during urination.

Immunoglobulin A (IgA) is an antibody that supports the body’s immune function, primarily within mucous membranes. An antibody is a protein produced by plasma cells that aids in the neutralization of pathogens that enter the body. Antibodies usually emerge during times of bacterial or viral infections in the blood. In IgA nephropathy, IgA antibodies collect in the kidney’s glomeruli, a network of tiny blood vessels found in the structural and functional units of the kidney known as nephrons. When too much IgA builds up, it causes inflammation and hampers the kidneys’ ability to filter substances.

Researchers are uncertain as to what exactly causes IgA nephropathy, but some associations have been made over the years. Genetics may play a role in the development of the disease. It may be inherited over generations and has shown to be more common in some ethnic groups than others. The condition is also associated with liver disease such as cirrhosis (scar tissue buildup in the liver) and chronic hepatitis B and hepatitis C infections. Other diseases associated with IgA nephropathy include celiac disease and certain viral and bacterial infections such as HIV, upper respiratory tract infections, and stomach viruses.

Overview

In its early stages, IgA nephropathy does not usually present any symptoms. Because of this, the disease can go undiagnosed for years. Sometimes a routine blood test will show the presence of high levels of red blood cells and protein in the urine, which alerts doctors to the existence of kidney function impairment. The medical term for blood in the urine is hematuria, and the term for protein in the urine is proteinuria. Hematuria is usually very minor during the first stages of IgA nephropathy but becomes more severe as time goes on, as does proteinuria. As the disease progresses, more symptoms may occur such as dark-colored urine, pain down the side of the back, high blood pressure, and swelling in the hands and feet.

When diagnosing IgA nephropathy, doctors will perform a physical exam and inquire about symptoms. Physicians may ask if the patient has a history of urinary tract infections. To confirm that the issue is IgA nephropathy, several tests can be performed to distinguish IgA nephropathy from other diseases. Kidney biopsies, urine analyses, serum creatinine tests, cholesterol and blood pressure tests, and determining a patient’s estimated glomerular filtration rate (GFR) can help confirm a diagnosis.

Although there is no cure for IgA nephropathy, treatments to control symptoms and maintain kidney function are available. Treatment varies on a case-by-case basis depending on the severity of the disease. Those with less severe cases may not require treatment but will need to schedule regular doctor’s visits to check on kidney function. Others with a more advanced level of the disease will require treatment tailored to their symptoms. Treatments are aimed at slowing the disease’s progress, and this is usually accomplished by managing protein levels in the urine, maintaining a healthy blood pressure, and alleviating swelling.

Medications to help manage blood pressure and cholesterol may be necessary. Immunosuppressant drugs such as steroids may be prescribed to help with swelling and inflammation. Diuretics may also be helpful to remove excess fluid from the blood. Anti-inflammatory supplements such as fish oil are also sometimes prescribed. Eating a healthy diet that limits protein, fat, and sodium intake is also helpful in managing symptoms. If symptoms continue for long periods of time, patients may enter kidney failure and need to go on dialysis, a process that manually filters the blood through a machine. In some cases, a kidney transplant will be necessary.

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