Immunoglobulin A Nephropathy (Berger's disease)

Immunoglobulin A (IgA) nephropathy is also known as Berger's disease. This is a kidney disease that is characterized by the deposition of an antibody known as immunoglobulin A (IgA)  in the glomeruli of the kidneys.

This deposition results in local inflammation of the glomeruli, therefore, damaging the kidney.

Immunoglobulin A is an antibody responsible for maintaining the body’s immunity.

In IgA nephropathy, this antibody is lodged in the glomeruli causing an inflammation known as glomerulonephritis and with time this leads to disturbance or normal function of the kidney infiltration by destroying the membrane. This allows leakage of components such as blood cells (RBC) and proteins which normally don’t get out of the body

Etiology

The cause is unknown, but several mechanisms have been linked with Immunoglobulin A (IgA) nephropathy including

• Increased iga1 production,
• Defective iga1 glycosylation causing increased binding to mesangial cells,
• Decreased iga1 clearance,
• A defective mucosal immune system, and
• Overproduction of cytokines stimulating mesangial cell proliferation.
• Familial genetic factors.
• Liver diseases such as cirrhosis
• Celiac disease triggered by eating gluten
• Dermatitis herpetiformis and infections such as HIV

Risk factors

These factors might increase your risk of developing this IgA nephropathy:

• Sex.  IgA nephropathy affects at least twice as many men as it does women.
• Race. IgA nephropathy is more common in whites and Asians than it is in blacks.
• Age. IgA nephropathy most often develops between the late teens and late 30s.
• Family history. This indicates that genetic factors contribute to the disease.

Pathophysiology of Immunoglobulin A nephropathy

Signs and symptoms

The most common manifestation is :

• Persistent or recurrent macroscopic hematuria or
• Asymptomatic microscopic hematuria with mild proteinuria.
• Coca-Cola colored urine
• Edema of the hand and feet,
• Foamy urine from protein leaking into your urine
• High blood pressure
•  

Other symptoms are usually not prominent.

Gross hematuria usually begins 1 or 2 days after a febrile mucosal illness such as upper respiratory tract infection, therefore, mimicking acute post-infectious glomerulonephritis, except the onset of hematuria is earlier.

Rapidly progressive glomerulonephritis is the initial manifestation in of some patients

Diagnosis

Clinical findings

Gross hematuria, particularly within 2 days of febrile mucosal illness or with flank pain
Incidentally noted findings on urinalysis

Urinalysis demonstrates microscopic hematuria, usually with dysmorphic red blood cells and red blood cell casts and mild proteinuria less than 1 g/day

Renal biopsy shows granular deposition of IgA and complement (C3) on immunofluorescent staining in an expanded mesangium with foci of segmental proliferative or necrotizing lesions.

Complement concentrations are usually normal.

Plasma IgA concentration may be elevated

However, persistent hematuria invariably leads to hypertension, proteinuria, and renal insufficiency.

Risk factors for progressive deterioration in renal function include:

• Proteinuria > 500 mg/24 h for > 6 months
• Elevated creatinine
• Uncontrolled hypertension
• Microscopic hematuria for > 6 months
• Extensive fibrotic changes in the glomerulus or interstitium
• Crescents on biopsy

Treatment of Immunoglobulin A nephropathy

There is no cure for IgA nephropathy, but certain drugs can slow its course. Keeping blood pressure under control and reducing your cholesterol levels also slow the disease.

Normotensive patients with intact renal function are not treated.

Angiotensin-Converting Enzyme inhibitors or angiotensin II receptor blockers for hypertension, elevated creatinine > 1.2 mg/dL, or urinary protein more than 1 g/day

Corticosteroids and immunosuppressants can be used for progressive disease

Transplantation of the kidneys

Patients with renal insufficiency or more severe proteinuria and hematuria are usually offered treatment, which ideally should be started before significant renal insufficiency develops.

Complications of IgA Nephropathy

Patients who have this condition might develop these complications.

• Hypertension. This occurs due to the damage to your kidneys from IgA deposits.
• High cholesterol levels. This elevation can increase your risk of a heart attack.
• Acute kidney injury. If the kidneys lose their filtering ability due to IgA deposits, waste products build up quickly in the blood.
• Chronic kidney disease. IgA nephropathy can cause the kidneys to gradually stop functioning.
• Nephrotic syndrome. This is a group of disorders that can be caused by damage to the glomeruli, including high urine protein levels, low blood protein levels, high cholesterol and lipids, and edema of the eyelids, feet, and abdomen.