Polycystic Kidney Disease: Treatment and Supportive Care

Summary

Polycystic Kidney Disease is a condition in which numerous cysts, which are small growths filled with water, develop all over the kidney, and other organs too. The condition is genetic in 90% of the cases. It carries the risk of kidney failure, and in rare cases is fatal too. There is no permanent cure for the disease, however, the condition can be managed effectively through medication and lifestyle management.

Introduction

Deoxyribonucleic acid or DNA is the building block for human bodies. These are present in every cell of the body, and carry information on how the cell should grow, multiply, divide and die out eventually. The DNA molecule is wrapped and kept in place by chromosomal proteins (or just ‘chromosomes’). Genes are fragments of chromosomes and they decide all our external or physical attributes, mental or cognitive abilities, and various health parameters. Genes are passed on from parent to child at the time of birth.

Now, DNA can undergo biochemical change, called ‘mutation’, due to environmental and man-made reasons. Repeated mutations of a particular gene can lead to either positive or negative consequence. Positive consequences include better physical or mental attributes inherited when successive generations in the family select partners with better attributes. Negative consequences of DNA mutation include innumerable health conditions, diseases, disorders or symptoms. It is also important to understand that one can have an abnormal gene (which has undergone mutation), but does not develop the disease. Such people/parents are called ‘carriers’ as they are carrying the abnormal gene that will be passed on to the child.

Polycystic Kidney Disease (PKD) is one such genetic disorder. A healthy kidney has a smooth surface and is made of millions of nephrons inside, whose function is to filter out the waste from blood. A vast network of blood-vessels supplies pure blood to, and drains impure blood from, the kidneys. In PKD, numerous cysts start developing all over the kidney (both inside and outside). These are small balls filled with fluid. As these cysts grow in size or multiply in number, they crowd out the healthy nephrons, thereby impairing kidney function. The kidney also grows in size. Sometimes the cysts burst and cause other issues.

The disease eventually leads to kidney failure, as the kidney function is progressively reduced. In such a case, the patient will need dialysis and kidney transplant thereafter. There are other causes for kidney failure too, and PKD contributes 5% of all kidney failure cases, worldwide.

Causes

As explained earlier, PKD is a genetic condition. Genetic diseases are those when a parent passes on an abnormal gene to the child. This happens in 2 ways:

1. Dominant inheritance: Here, one of the 2 parents only, has the abnormal gene and disease. Which means, the mutation has resulted in PKD in one of the parents while the other parent is fine, and also does not have the abnormal gene. Now, all the children of these parents have a 50% chance of developing PKD themselves, in their childhood.
2. Recessive inheritance: In this case, both parents have the abnormal gene but have not developed the disease, or they are just carriers. The children of these parents get 2 copies of the abnormal gene and have a 25% chance of developing PKD.

Types of PKD

• Autosomal Dominant PKD (ADPKD): This is the most common type of PKD, accounting for almost all PKD cases. In 90% of the cases of ADPKD, one of the parents has the disease caused by mutation of either PKD1 or PKD2 gene. Symptoms start showing up in childhood, although the condition develops in the 30s and 40s generally. In 10% of the cases, the parents are fine and the mutation happens in the person’s own genes, in his/her lifetime. Thereafter, it can be passed on to his/her descendants. In ADPKD, cysts grow in the kidney and liver.
• Autosomal Recessive PKD (ARPKD): In this type, both parents are carriers, that is, they both have a mutated gene PKHD1, so 2 copies of the same are passed on to the child. The symptoms are visible, right when the child is in the womb, and once born, the symptoms develop quickly. That is why the condition is also called Infantile PKD. In some cases, the child may die in its early years. In most cases, the disease progresses all through childhood and adolescence and by the time he/she is in the early 20s, kidney failure may happen. Fortunately, this type is very rare. Here too, cysts are found both in kidney and liver.
• Acquired Cystic Kidney Disease (ACKD): ACKD, is not a genetic condition and an acquired one as the name implies. This is not true PKD but the symptoms are similar. There are fluid-filled cysts, but only in the kidney and not other organs. The main cause of ACKD is chronic kidney disease or CKD.

Symptoms of PKD

Symptoms of PKD across the different types are:

• Haematuria (blood in the urine)
• Pain in the back and sides
• Swollen belly or abdomen due to enlarged kidneys
• Repeated infection in the urinary tract (bladder and kidney infections)
• Hypertension or high BP
• A pounding or fluttering sensation in the chest caused by floppy valves
• Headaches that recur
• Low birthweight in the infant
• Low levels of amniotic-fluid, which causes the infant to produce less urine in the uterus
• Breathing problems in the infant
• Infant throws up breast-milk or formula food, after being fed
• Improper growth and development of the infant’s arms, legs and face
• Varicose veins in childhood
• Lower height and weight of the growing child

Complications from PKD

• Kidney stones
• Hypertension that does not go away
• Rapid progression of the disease leading to End Stage Renal Disease (ESRD) and kidney failure
• Cysts in the liver and/or pancreas
• One or more heart conditions
• Conditions of the colon
• Aneurysms (a bulging blood-vessel) in the brain
• Preeclampsia (a type of hypertension) in pregnant women
• Liver damage that worsens progressively and can cause liver failure
• Fatality, in infants with ARPKD
• Urinary tract infections that keep recurring

Diagnosing PKD

• Imaging tests such as CT scan, MRI scan and ultrasound scan of the kidneys, which can reveal the presence of cysts
• Babies in the womb who are suspected to have PKD will go through a prenatal ultrasound of the pregnant mother
• Genetic tests: A sample of the person’s blood or saliva is taken and examined under the microscope to detect mutations or changes in the genes that cause PKD.

Treatment

PKD cannot be cured completely. However, early detection and timely treatment for the same can slow down progress of the condition. So, treatment for PKD is all about managing the symptoms and consequences, so that the patient can lead a fairly normal life.

• Growing kidney cysts: Medicines based on Tolvaptan are being given in recent times. One of the side-effects of the same is reaction with other medicines and liver failure. So, the case doctor will decide if this can be given or not.
• High blood pressure: Bringing blood-pressure under control is required to slow down the progress of PKD and kidney damage. Measures include medications such as ACE inhibitors and ARBs, a low-salt, low-fat, diet that has moderate calorie and protein content, quitting smoking, regular exercise, quitting alcohol, and stress management.
• Decline in kidney function: The person must drink plain water and fluids all through the day. He/she must consume a low-protein and low-salt diet. Both these helps slow down cyst growth and hence the decline in kidney function.
• Pain and pressure: If the cysts are quite large, a surgical procedure may be done to remove some cysts. Alternately, the fluid inside cysts may be drawn out using a needle and a sclerosing agent injected to shrink the cyst. OTC medication like acetaminophen will also be given.
• Urinary tract infections: The nature of infection, and organ affected (bladder/kidney) will be thoroughly examined. Then depending on the severity of the condition, antibiotics may be given.
• Blood in the urine: In most cases, the bleeding will stop on its own. Else, the person must drink lot of plain water and other fluids, which helps dilute the urine. This will stop or prevent clots from developing in the urinary tract.
• Kidney failure: If the kidney function is rapidly deteriorating, the doctor may advice a pre-emptive kidney transplant. Else, he/she will start dialysis, while kidney transplant is the final solution.
• Aneurysms: Having PKD and a family history of brain aneurysms increases the risk. If an aneurysm is detected, a surgical procedure to clip the aneurysm and prevent rupture, is done. Else, if the aneurysm is small, the doctor may advice measures to reduce BP, though a low-fat diet, and quitting smoking.

Living with PKD

Supportive care, or inputs on how to cope with PKD can make the patient’s journey easier and living with PKD bearable.

The patient must consume a healthy diet that is low on salt and fat, moderate on protein and heavy on fresh fruits and vegetables. He/she should exercise regularly (moderate exercise), consume plenty of fluids and maintain a healthy weight. He/she should quit smoking and alcohol. All these measures will help regulate blood-pressure.

From time to time, symptoms will get bad and that’s when one should call the doctor. This includes feeling confused, unable to urinate, being short of breath, having chest pain, and developing swelling in the legs, especially ankles and feet.

 

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