Acquired Cystic Kidney Disease - Causes, Symptoms, Diagnosis, and Treatment

What Is Acquired Cystic Kidney Disease?

Cystic kidney diseases comprise diseases that can be hereditary, developmental, or acquired. These diseases are characterized by the formation of cysts in the renal tissues. Acquired cystic kidney disease develops as a result of end-stage renal disease or kidney failure. It is generally seen in people on hemodialysis or peritoneal dialysis.

The disease is characterized by the development of numerous cystic fluid-filled sacs that do not have a hereditary history. Cysts can be mostly bilateral. When the cyst ruptures, some amount of blood is lost in the urine, causing hematuria. It can affect both children and adults with kidney failure and on dialysis. Kidney failure causes the development of cysts in the kidneys, and the risk of developing cysts increases with the number of years a person is on dialysis. Sometimes the cysts are harmless and require no treatment, whereas in some cases, there may be associated fever and pain.

What Are the Causes of Acquired Cystic Kidney Disease?

• The pathology behind cystic development is currently unknown. According to some theories, tubular epithelial hyperplasia from the accumulation of growth factors like the epidermal growth factor can play a role. The acquired cystic kidney disease is characterized by hyperplastic renal cysts. The formation of these cysts is considered to be a source of dialysis-associated renal cell carcinoma.

• End-stage renal disease resulting in kidney failure, which triggers the development of cysts, can be caused by several triggers, such as diabetes, lupus, heart problems, and urinary tract infections.

• The chances of acquired cystic kidney disease increase with the length of time the person is on dialysis. However, dialysis does not cause the condition. The disease progression is seen as a consequence of unnaturally increasing the function of the kidneys.

• Acquired cystic kidney disease can occur in conjunction with any of the following -

1. Glomerulonephritis (injury to the small filters in the kidneys).

2. Tubulointerstitial nephritis (inflammation of the spaces between the kidney tubules).

3. Diabetes mellitus (kidney disease can occur as a complication of diabetes mellitus).

4. Nephrosclerosis (hardening of the blood vessels in the kidney).

What Are the Symptoms of Acquired Cystic Kidney Disease?

Acquired cystic kidney disease is generally asymptomatic and does not require treatment. But, in some cases, the cysts are associated with pain, fever, and complications that require treatment. The symptoms include -

• Hematuria - Loss of blood in the urine due to the rupture of cysts.

• Uremia - Increase the level of urea in the blood due to kidney impairment.

• Flank Pain - Pain in the side of the body is generally associated with the development of cysts.

• Fever - The rupture of the cyst can cause the patient to feel pain and develop a fever.

• Reduced Appetite - Reduced appetite can be due to renal insufficiency.

• Anemia - A decrease in the number of red blood cells can cause anemia.

• Weight Loss - Weight loss occurs due to reduced appetite.

What Are the Complications Associated With Acquired Cystic Kidney Disease?

1. Hemorrhage Into the Cyst - The cyst develops in the renal cortex and is present bilaterally. When the cyst bursts, it leads to loss of blood which then appears in the urine.

2. Development of Renal Carcinoma - The risk of developing renal carcinoma increases with the length of time a person experiences end-stage renal disease and is on dialysis. The frequency of occurrence is about 7% of the total cases.

How Is Acquired Cystic Kidney Disease Diagnosed?

• Blood Tests - To assess normal kidney function.

• Urine Tests - To detect the presence of blood or protein in the urine.

• Kidney Ultrasound - Ultrasound is a safe and non-invasive form of imaging that can provide structural images of the organ. Ultrasonic examination of the kidneys reveals the size of the kidneys as normal or smaller in comparison. For the condition to be classified as acquired cystic kidney disease, the least number of kidney cysts should be five. They generally appear 0.5 cm in diameter. On examination of the renal tissues, the cysts are most commonly found in the renal cortex. The renal cortex is the outer section of the kidney consisting of cortical tissues that contain nephrons. Nephrons are the filtering units of the Kidneys.

• Computed Tomography (CT) Scan - A CT scan provides more details than an ultrasound. It helps in differentiating the presence of renal tumors or cysts.

• Magnetic Resonance Imaging (MRI) - Like CT scans, MRIs help to identify cysts and tumors.

How Is Acquired Cystic Kidney Disease Treated?

1. To Treat Infections - The development of cysts can cause infection in the body. Antibiotic therapy is prescribed in order to treat the infection.

2. To Treat Large Cysts - Large cysts can be treated without the need for surgery. The physician uses a long needle to reach a certain area and drain the cyst of its liquid. If a kidney cyst ruptures and causes bleeding in the body, surgery needs to be carried out to stop the flow.

3. To Treat Cancerous Growth - Surgery needs to be done in order to remove the cancerous growth developing in the kidneys. Acquired cystic kidney disease has more chances of developing into renal cancer the longer a patient is undergoing dialysis.

4. Kidney Transplant - Renal transplant is the best method to avoid dialysis. The chances of the development of cysts in the kidneys increase with the length of time the patient is on dialysis. In order to avoid dialysis, a kidney transplant needs to be done. The treatment does not involve the removal of the original kidneys but placing the donated kidney in a lower position than normal. However, the cysts that had developed managed to shrink and disappear after a successful transplant procedure.

Conclusion :

Acquired cystic kidney disease develops in the later stages of chronic kidney disease and is commonly associated with the initiation of dialysis treatment to filter the blood. Unlike polycystic kidney disease, where the patient feels uncomfortable due to slowly increasing kidneys, an individual with acquired cystic kidney disease is unaware of the cyst developing inside them. A successful kidney transplant procedure performs the functions of a normal kidney. The transplanted kidney is placed in a new position, and the original kidneys remain inside the body. The cyst in the kidneys tends to shrink and disappear after a successful kidney transplant.