Polycystic Kidney Disease: Causes, Symptoms, And Prevention
Polycystic Kidney Disease (a.k.a Polycystic Renal Syndrome) is one of the leading causes of kidney failure. It is an inherited disease and is of two types- autosomal dominant and autosomal recessive. Of all the patients with polycystic kidney disease, 80% have Autosomal dominant type of polycystic kidney disease.
- What is Polycystic Kidney Disease?
- What Causes Polycystic Kidney Disease?
- What are the Types of Polycystic Kidney Disease?
- When to see a Doctor about Polycystic Kidney Disease?
- What are the Risk factors for Polycystic Kidney Disease?
- What are the Complications of Polycystic Kidney Disease?
- How is the Polycystic Kidney Disease Diagnosed?
- What is the Treatment for Polycystic Kidney Disease?
- How is Polycystic Kidney Disease Prevented?
What is Polycystic Kidney Disease?
Formation of many cysts within the kidney is called polycystic kidney disease. A cyst is a small, fluid-filled cavity and is non-cancerous. Cysts are generally formed from the nephrons of the kidney. Size of cysts may vary from small to large, and an abnormal increase in the size of cysts leads to massive enlargement of the kidney.
What Causes Polycystic Kidney Disease?
Polycystic kidney disease occurs due to genetic mutations. Recent research shows that genetic mutations lead to alterations in the function of primary cilia found in the kidney cells.
Primary cilia are the hair-like structures, and their main function is to end the signals of urine flow. Mutations in the genes of Polycystic kidney disease 1 (PKD 1) and Polycystic kidney disease 2 (PKD 2) affects the functions of cilia. These mutations further lead to disruptive activities like an increase in cell division, cell growth and also increase in cyst formation and decrease in the storage capacity of kidneys.
What are the Types of Polycystic Kidney Disease?
Based on the types of genes involved, polycystic kidney disease is of two types. They are:-
1. Autosomal Dominant Polycystic Kidney Disease (ADPKD):
In this type, one parent has dominant genes for the polycystic kidney disease, and the chance of inheritance of the disease is high. The autosomal dominant is the most common type of polycystic kidney disease. It is also called as adult polycystic kidney disease, as symptoms are mostly seen in the adults, at the age of 30-40 years. Cysts are formed, only in the kidneys.
2. Autosomal Recessive Polycystic Kidney Disease (ARPKD):
In this type, both the parents have recessive genes for the polycystic kidney disease and the chance of inheritance of this disease is low. The parents can be the carriers of the disease, without having any symptoms or may develop the signs of illness. It is also called as pediatric or infantile polycystic disease, as it is more commonly seen in children before their birth or as infants. Cysts are also formed in other parts of the body like liver.
When to see a Doctor about Polycystic Kidney Disease?
Signs and symptoms of polycystic kidney disease are not localised to one particular part of the body; instead, it affects the whole body. Some of the symptoms include:-
- Elevated blood pressure (high BP)
- Back pain or pain on the sides
- A headache
- Heaviness in the abdomen
- Blood in urine (hematuria)
- Regular urinary tract infections
- Generalized weakness
For people with family history of polycystic kidney disease, routine screening of kidneys is essential, irrespective of symptoms of the disease.
What are the Risk factors for Polycystic Kidney Disease?
Risk factors for polycystic kidney disease include:
- Family history
- High blood pressure
- Pregnant woman with high blood pressure
- Children of parents, who are carriers
What are the Complications of Polycystic Kidney Disease?
The complications of polycystic kidney disease can be fatal too. This disease also has an impact on other body parts like heart, kidney and brain. Some of the complications are:
- High blood pressure
- Loss of kidney function
- Seizures (Eclampsia) in the pregnant woman
- A brain aneurysm
- Cysts in liver
- Colon problems
How is the Polycystic Kidney Disease Diagnosed?
Diagnosis of polycystic kidney disease includes both physical examination and medical lab tests like complete urine examination and urine culture. The main aim of further diagnostic tests is to, find out the amount of spread of cysts in the body. The investigations include:-
Sound waves are used in this technique, to study the structure and size of the kidneys. Any enlargement of the size of kidneys can be seen.
Computed Tomography Scan (CT scan):
X-rays are used in this technique, to study the cross-sectional view of the kidney.
Magnetic Resonance Imaging (MRI):
Magnetic and radio waves are used to study the structure of the kidney.
Blood samples are collected to study the genes. Genetic screening is done in patients with a family history of the disease.
Polycystic kidney disease in children can be diagnosed even before birth. Diagnosis of the disease is by the reports of ultrasound of a pregnant woman. Large-sized kidneys and lack of amniotic fluid around the kidneys is a sign of enlarged kidneys and polycystic kidney disease.
How is Polycystic Kidney Disease Differentiated?
Differential diagnosis of polycystic kidney disease is crucial. It is different from other kidney diseases like the Acquired Polycystic Kidney Disease (APKD), renal dysplasia, renal tuberculosis and medullary cystic disease.
Most often, symptoms of acquired polycystic kidney disease occur at the later stages of life, at the age of 60-70 years. The cysts are not formed due to hereditary factors and are developed in patients with a prolonged history of chronic kidney disease or dialysis patients (but, dialysis will never cause any gene changes or cyst formations).
What is the Treatment for Polycystic Kidney Disease?
Treatment of polycystic kidney disease is mainly based upon symptoms. The main aim of treatment is to slow the progression of the disease.
Symptoms like high BP are controlled with drugs such as benazepril or ramipril (Angiotensin-converting enzyme inhibitors). Painkillers are used to control back pain or a headache. Antibiotics are used to control symptoms of urine infection.
Surgical removal of cysts is performed, if the cysts are large and their boundaries are demarcated. Surgery is mostly done with the guidance of a fibre-optic device or an ultrasound.
In patients with very poor kidney functioning or complete failure of kidney, dialysis and kidney transplantation is the mode of treatment.
Dialysis is a process to get rid of excess water, extra salts and other toxic wastes. It is of two types:
- Hemodialysis– In this method, a machine and filter are used to clean the blood. The blood is routed to the device through a vascular access in the patient’s body.
- Peritoneal Dialysis– In this method, the fluid is passed into the patient’s body, and the peritoneum of the abdomen is used to filter the blood and remove the harmful wastes.
Kidney transplantation or renal transplantation involves kidney (organ) transplant into a patient with kidney failure and it is generally performed in the end-stage kidney disease. It is not easy to find a matching donor and in most of the cases, the patient is put on dialysis, until a donor is found and transplantation is done.
In cases with cysts in liver or brain aneurysms, surgical management is the method of treatment.
How is Polycystic Kidney Disease Prevented?
Polycystic kidney disease is a hereditary disease. So, it cannot be prevented, but its progression can be delayed, by the following measures:
- Genetic counselling is advised to know about the inheritance of the disease causing genes.
- Regular health check up’s and advice on the dosage of anti-hypertensive medications.
- Diet monitoring, to avoid higher intake of sodium and salts.
- Strict avoidance of, the use of painkillers for longer time, unless suggested by the physician.
- Lifestyle modifications like avoiding regular intake of cigarettes and alcohol.
- Regular exercise and weight control are important, to avoid further load on the kidneys.
Polycystic kidney disease is dangerous only in the end-stage. So, people with a family history of this disease should go for routine screening of the kidneys. Parents who are carriers but do not have the disease have to carefully monitor the disease symptoms in their children.