Berger's disease (IgA nephropathy): what is it, symptoms, treatment, prognosis

What is Berger's disease?

Berger's disease (or IgA nephropathy) Is a kidney disease in which IgA, a protein designed to protect the body from foreign invaders, builds up in the kidneys and damages them. This degrades their filtering function. As a result, the kidneys begin to pass substances such as blood and protein into the urine.

IgA nephropathy is most common in Caucasian and Asian men. It usually appears when people are in their teens and 30s, but can occur at any age. Many cases pass over time. However, in a subgroup of patients, the disease may not clear up and, therefore, can lead to end-stage renal failure (ESRD) after 20-25 years. Rarely, the condition can progress much faster, resulting in renal failure for several years if left untreated.

People who have IgA nephropathy most often have one or more episodes of blood in their urine (visible 

hematuria). These episodes usually occur during or immediately after an upper respiratory infection, such as colds or a gastrointestinal infection.

Treatment includes drugs that are designed to slow the progression of the disease and others that are aimed at reducing inflammation. The choice of treatment depends on many factors, including blood pressure, the amount of protein in the urine, and the expected kidney function.

- Introduction.

The kidneys are two fist-sized organs located in the back under the rib cage that filter blood. They remove excess fluid and waste in the form of urine, while at the same time absorbing the required amount of water and other chemicals needed for the body to function. The name IgA nephropathy comes from the fact that a protein deposited in the kidney has the properties of a normal circulating immunoglobulin protein called IgA. With illness, the normal protein is slightly altered, causing it to be deposited in the kidney's filters and causing blood and / or protein to leak.

Signs and symptoms

Patients with IgA nephropathy often have:

• red urine (visible hematuria);
• pain on the sides of the back;
• swelling in the ankles;
• high blood pressure (arterial hypertension).

When these symptoms are present during or immediately after a respiratory infection, such as sore throats or colds, there is a higher likelihood that a person has IgA nephropathy.

Some patients with rapidly progressive IgA nephropathy or chronic asymptomatic disease may present with end-stage renal disease (ESRD) symptoms:

• high blood pressure;
• inability to urinate;
• swelling;
• feeling tired;
• drowsiness;
• generalized itching or numbness;
• dry skin;
• headaches;
• weight loss;
• loss of appetite;
• nausea;
• vomit;
• sleep problems;
• trouble concentrating;
• hyperpigmentation of the skin;
• muscle spasms.

Causes and risk factors

As mentioned above (“see Introduction "), the kidneys serve as filters for blood. Each kidney is made up of about 1 million "mini-filters" called nephrons.

Each nephron is composed of a Bowman capsule and tubules. Bowman's capsule contains many important structures, such as the glomerulus, which is a series of tiny blood vessels in which initial filtration takes place. Once the fluid is filtered by the glomerulus, it travels along the tubules where chemicals and water is either added or removed from the filtered liquid depending on the needs organism. Once the fluid passes through the tubules, it leaves the body in the form of urine.

For some unknown reason, the body of patients with Berger's disease creates abnormal IgA proteins, which it recognizes as foreign. As a result, the body attacks them, which leads to the formation of clusters of proteins called immune complexes. These immune complexes are deposited in the kidneys and cause damage. Due to this phenomenon, IgA nephropathy can be considered autoimmune disease.

Immune complexes of the IgA protein are specifically deposited in the central part of the glomerulus in the mesangial region. Once these immune complexes are deposited, the glomerulus (filter) becomes inflamed and damaged. As a result, their filtering function is impaired, which allows substances such as red blood cells and proteins to pass through the damaged filter into the urine.

When patients have respiratory infections, such as flu, IgA immune complexes have a higher circulation. Therefore, many of them end up being deposited in the kidneys, which is when patients with IgA nephropathy usually develop symptoms such as hematuria (blood in the urine). Some patients may also experience episodes of Berger's disease when they have gastrointestinal infections, such as intestinal flu.

There is reason to believe that genetic factors play a role in the disease. It has been suggested that Berger's disease is a complex polygenic disease meaning that there are many genes and environmental factors that contribute to the development of this diseases.

Affected populations

In North America and Europe, men are twice as likely to get sick, while in Asia, women are as likely as men. In terms of ethnicity, Asians are much more likely than Caucasians, who, in turn, are much more likely than blacks to have IgA nephropathy. The disease most commonly occurs during adolescence through the late 30s, but can manifest itself at any age.

Symptomatic disorders

Symptoms of the following disorders may be similar to those of Berger's disease. Comparisons can be useful for differential diagnosis:

• Purpura Schoenlein-Henoch (currently considered a type of IgA that predominantly affects the small blood vessels of the body, including the kidneys).
• Alport syndrome (hereditary nephritis).
• Thin basement membrane disease (BMTD).
• Acute post-infectious glomerulonephritis.
• Membranoproliferative glomerulonephritis.
• Lupus nephritis (glomerulonephritis caused by systemic lupus erythematosus).

Diagnostics

IgA nephropathy can be suspected when a patient develops bloody (red) or dark urine following an illness of the respiratory tract.

Although a physician may have a high index of suspicion that his patient has Berger's disease, based on a history of physical examination, urinalysis and blood tests, the only way to really diagnose IgA nephropathy is by biopsy kidneys.

A kidney biopsy is a diagnostic test in which a thin, small needle is inserted into a person's kidney to take a tissue sample. This tissue is then examined under a microscope to detect certain characteristic markers of the disease.

- Clinical testing and examination.

In addition to a kidney biopsy, patients should have regular blood and urine tests. Patients with mild illnesses (normal blood pressure, low protein in the urine) can expect to be tested every 6 to 12 months. Patients with more severe disease may expect more regular follow-up.

Standard treatments

Unfortunately, there is still no cure for Berger's disease. However, many symptoms resolve on their own.

Treatment for Berger's disease includes:

• Non-immunosuppressive drugs are those aimed at preventing the progression of the disease.
• Immunosuppressive drugs are those that aim to reduce inflammation.

The non-immunosuppressive drugs used are angiotensin converting enzyme inhibitors (ACE inhibitors) and angiotensin receptor blockers (ARBs). They help prevent disease progression by reducing the amount of protein that filtered through the damaged glomerulus and enters the urine, as well as by reducing arterial pressure.

The immunosuppressive drugs used most often are corticosteroids (such as prednisone) and cyclophosphamide. They reduce inflammation by limiting the inflammatory response.

Some patients may also be prescribed statin, which is a cholesterol-lowering drug to lower the risk of heart disease.

Prophylaxis

- Diet and nutrition.

Although the researchers did not find that diet and nutrition played a role in the onset or prevention of the disease, healthcare professionals may recommend the following dietary changes for patients with a medical condition to maximize their health kidney:

• Limit sodium intake (such as table salt)
• Eating a diet low in saturated fat and cholesterol.

Forecast

Although IgA nephropathy is usually benign, end-stage renal disease develops in 15-20% of patients within 10 years after the onset of the disease and in about 25-30% of patients by the age of 20.

The estimated life expectancy is only 6 years, within the framework of other factors affecting the overall result. However, this metric is unique to each person, and you may find that you live longer.

Many factors lead to the progression of IgA nephropathy and limit life expectancy. These include the development of complications such as diabetes, hypertension and cardiovascular disease. They reduce the life expectancy of an individual with Berger's disease to an even shorter period.