Autosomal dominant polycystic kidney disease (ADPKD) is a hereditary condition and is the most prevalent form of polycystic kidney disease (PKD). It generally develops over many years or decades, leading to damage in the kidneys and other body systems. However, with appropriate healthcare, thoughtful lifestyle decisions, and potentially ADPKD-specific medications, it’s possible to slow the disease’s progression and enhance kidney longevity.
For individuals with a family history of PKD, concerns might first arise as a question before the onset of any symptoms: “Will I develop PKD like some of my relatives?” In contrast, others may experience symptoms such as high blood pressure, often identified in early adulthood. Other symptoms may include lower back pain, the presence of bright red blood in urine, or indications from routine blood tests showing a decline in kidney function.
The manifestation and progression of ADPKD can vary significantly from person to person, with symptoms ranging broadly from mild to severe. Nevertheless, certain patterns in the disease’s progression can be observed regardless of how quickly or severely it develops. ADPKD affects individuals across various races and ethnicities worldwide, with estimates suggesting that around 240,000 people in the U.S. are impacted. While it is typically inherited, approximately 20% of people with ADPKD are the first in their family to experience the condition.
Although there is no cure for ADPKD, the disease’s advancement can be managed with treatment and healthy lifestyle choices focusing on maintaining a healthy weight and blood pressure. With consistent healthcare and monitoring, individuals with ADPKD can expect a relatively normal lifespan.
### Understanding Disease Progression
While ADPKD may not present symptoms for several decades, it is genetically encoded before birth. Mutations in specific genes lead to dysfunctional kidney cells, producing fluid that forms cysts—blister-like sacs that characterize PKD. Over the years, these cysts can proliferate, numbering in the hundreds, which results in kidney swelling, damage, and potential scarring, severely affecting the kidneys’ ability to filter waste from the blood.
Typically, adult kidneys weigh about 1/3 of a pound, but in individuals with ADPKD, kidneys may grow approximately 5% annually, sometimes weighing several pounds and exceeding the size of a large fruit. Correspondingly, kidney filtering efficiency can decline at a similar rate. Enlarged kidneys can compress surrounding organs, causing pain and discomfort, sometimes requiring targeted treatments for relief.
In advanced stages, the kidneys may reach a point of inefficiency where they can no longer adequately filter blood, leading to kidney failure, which necessitates dialysis or transplantation. About 10% of patients with kidney failure in the U.S. have ADPKD.
### Systemic Effects of ADPKD
As a genetic disorder, ADPKD impacts not just the kidneys, but can also create cysts in other organs. Notably, the liver is often affected, with nearly 90% of people with ADPKD developing polycystic liver disease by the age of 35. This may lead to symptoms like abdominal discomfort and feeling full quickly, although the liver generally continues to function well.
High blood pressure, or hypertension, affects approximately 70% of individuals with ADPKD by age 30. Genetic changes associated with ADPKD can alter blood vessel lining, raising blood pressure, and impairing the regulation of blood pressure due to reduced salt excretion by the kidneys. Furthermore, people with ADPKD face a quadrupled risk of brain aneurysms compared to those without the condition.
Additional conditions also associated with ADPKD include cysts on the pancreas, as well as potential complications affecting the intestines and heart valves.
### Progression Timeline
The rate at which ADPKD advances can differ widely among individuals. Nephrologists often use imaging tests to assess kidney size, allowing them to predict potential disease progression. The Mayo Imaging Classification system, which measures total kidney volume (TKV) through CT or MRI scans, helps estimate the future risk of rapid decline towards kidney failure.
Several factors influence progression speed, with men generally experiencing a faster decline than women, often reaching kidney failure about five years earlier. Being overweight and experiencing severe symptoms before age 35 can indicate a more rapid advancement of the disease.
The specific gene mutations involved—mainly in the PKD1 or PKD2 genes—play a significant role in determining progression severity. PKD1 mutations tend to correlate with more severe disease than PKD2 mutations, with median ages for kidney failure being 54 and 74 years, respectively.
Understanding the progression of ADPKD in familial contexts can help gauge individual risk, although personal environmental factors and lifestyle modifications can significantly impact disease course.
Ultimately, while most individuals with ADPKD will eventually require dialysis or transplantation, approximately half successfully receive kidney transplants, ideally performed before reaching kidney failure. For those opting for dialysis, hemodialysis is commonly utilized, processing blood similarly to healthy kidneys.
In conclusion, while the journey with ADPKD can be complex, proactive management strategies can greatly enhance quality of life and overall health outcomes.
