• IgA Nephropathy occurs when IgA antibodies that are supposed to fight infections become defective and cause your immune system to work against itself.
• That may trigger the immune system to form immune complexes that deposit in the kidneys.
• Complex deposits can activate multiple pathways, including a part of the immune system called the complement system that normally fights viruses and bacteria.
• Activation of multiple pathways, including the complement system, may result in inflammation, kidney injury, and scarring.
• The inflammation damages their glomeruli, which are tiny blood vessels that perform the first step in filtering waste products out of your blood, which eventually leave your body in your urine. Glomerular disease causes your kidneys to leak blood (hematuria) and protein (proteinuria) into your urine.
• IgA nephropathy often becomes worse slowly over years. But the course of the disease varies from person to person. Some people leak blood into their urine without having other problems. Others might have complications such as losing kidney function and spilling protein into the urine.

Membranous nephropathy (MN) is a condition that causes your immune system to attack glomeruli, the tiny filters in your kidney. Your kidneys have thousands of glomeruli. These filters clean waste products from your blood. If you have membranous nephropathy, your glomeruli become inflamed. MN can cause your kidneys to stop filtering waste as well as they should.

Types of membranous nephropathy

There are two types of membranous nephropathy:

• Primary membranous nephropathy (idiopathic): This is a condition that directly affects your kidneys. It’s usually due to an autoimmune condition. Up to 75% of people have this type.
• Secondary membranous nephropathy: This type happens when another health condition or treatment affects your kidneys. About 25% of people have this type. The most common causes of secondary MN are:

• Hepatitis B
• Non-Steroidal Anti-inflammatory Drug
• Systemic Lupus nephritis
• Cancer
• Other diseases and infections

How common is membranous nephropathy?

It’s rare. Only about 1 in every 5,000 people have this condition. It’s more common in men aged 50 to 60. Children rarely get membranous nephropathy.

Lupus nephritis (LN) is an inflammation of the kidneys caused by systemic lupus erythematosus, often called lupus.

Lupus is a disease in which the body's immune system attacks its own cells and organs, called autoimmune disease. Lupus causes the immune system to make proteins called autoantibodies. These proteins attack tissues and organs in the body, including the kidneys.

Lupus nephritis occurs when lupus autoantibodies affect parts of the kidneys that filter out waste. This causes swelling and irritation of the kidneys, called inflammation. It might lead to blood in the urine, protein in the urine, high blood pressure, or even kidney failure.

Lupus Classification

Lupus nephritis is classified into six classes based on kidney biopsy results and the extent of kidney damage:

1. Class I: Minimal mesangial lupus nephritis.
2. Class II: Mesangial proliferative lupus nephritis.
3. Class III: Focal lupus nephritis (affecting less than 50% of the glomeruli).
4. Class IV: Diffuse lupus nephritis (affecting more than 50% of the glomeruli).
5. Class V: Membranous lupus nephritis.
6. Class VI: Advanced sclerosing lupus nephritis (more than 90% glomeruli are sclerosed)

These classes help guide treatment decisions and predict outcomes for patients with lupus nephritis.

Polycystic kidney disease (also called PKD) causes numerous cysts to grow in the kidneys. These cysts are filled with fluids. If too many cysts grow or if they get too big, the kidneys can become damaged. PKD cysts can slowly replace much of the kidneys, reducing kidney function and leading to kidney failure.

In the United States about 600,000 people have PKD, which is the fourth leading cause of kidney failure. Men and women are equally at risk for the disease. It causes about 5% of all kidney failure.

Types of Polycystic Kidney Disease

Autosomal Dominant PKD/ ADPKD

This form of the disease is passed from parent to child by dominant inheritance. In other words, only one copy of the abnormal gene is needed to cause the disease. Symptoms usually begin between the ages of 30 and 40, but they can begin earlier, even in childhood. ADPKD is the most common form of PKD. In fact, about 90% of all PKD cases are ADPKD.

Infantile or autosomal recessive PKD/ ARPKD

This form of the disease is passed from parent to child by recessive inheritance. Symptoms can begin in the earliest months of life, even in the womb. It tends to be very serious, progresses rapidly, and is often fatal in the first few months of life. This form of ARPKD is extremely rare. It occurs in 1 out of 25,000 people.

Acquired cystic kidney disease/ ACKD

ACKD can happen in kidneys with long-term damage and severe scarring, so it is often associated with kidney failure and dialysis. About 90 percent of people on dialysis for 5 years develop ACKD. People with ACKD usually seek help because they notice blood in their urine. This is because the cysts bleed into the urinary system, which discolors urine.

Genetic Testing for PCK

Individuals with PKD who are concerned about passing the disease to their children may want to consult a genetics counselor to help them with family planning. Many university medical centers have this service.

PKD Affecting Other Organs

PKD can affect other organs besides the kidney. People with PKD may have cysts in their liver, pancreas, spleen, ovaries, and large bowels. Cysts in these organs usually do not cause serious problems but can in some people. PKD can also affect the brain or heart.

If PKD affects the brain, it can cause an aneurysm. An aneurysm is a bulging blood vessel that can burst, resulting in a stroke or even death.

If PKD affects the heart, the valves can become floppy, resulting in a heart murmur in some patients.

About 50% of people with PKD will have kidney failure by age 60, and about 60% will have kidney failure by age 70. People with kidney failure will need dialysis or a kidney transplant. Certain people have an increased risk of kidney failure including:

• Men
• Patients with high blood pressure
• Patients with protein or blood in their urine
• Women with high blood pressure who have had 3 or more pregnancies

Anemia means your blood does not have enough healthy red blood cells. Red blood cells carry oxygen throughout your body. When you have anemia, your body may not get the oxygen it needs to work well. This can make you feel tired and weak. It can also affect your heart and overall health. Chronic kidney disease (CKD) can increase your risk of having anemia, especially in later stages of the disease. Almost half of the people in the United States with stage 3a CKD have anemia. By stage 5 CKD (also known as kidney failure), more than 9 out of 10 people have anemia.

Causes

Anemia in CKD can happen for several reasons. These include

• Low erythropoietin Healthy kidneys make a hormone called EPO that tells the body to make red blood cells. With CKD (especially kidney failure), the kidneys are less able to make EPO. This leads to your body making fewer red blood cells.
• Low iron: Iron is needed to make healthy red blood cells. People with CKD may lose iron (during dialysis) or not absorb enough iron from food.
• Low vitamin B12 or folate: Your body also needs these to make blood. If you don’t have enough, it can make it harder for your body to make healthy red blood cells.
• Chronic inflammation: People living with CKD often have inflammation (swelling throughout the body). Obesity, diabetes, and heart failure can also cause it. Inflammation can make it harder for your body to use iron properly.
• Blood loss: This can happen from frequent lab tests, dialysis, or stomach problems.