Diagnosing autosomal dominant polycystic kidney disease

ByMeyeon Park, MD, MAS

Each year, millions of Americans take charge of their health by visiting their primary care provider for a periodic “check-up” or health maintenance visit.

This measure of preventive care promotes overall wellness by capturing vital signs like weight, BP, cholesterol and other health markers.

Rare diseases pose a significant challenge for PCPs, whose time with patients is particularly limited as in all health care domains. Despite these challenges, recognizing symptoms of rare diseases may be an opportunity to make a timely diagnosis for a patient and improve opportunities for protecting health. This could be the case for those living with autosomal dominant polycystic kidney disease (ADPKD), a progressive disease that causes cysts to grow on the kidneys and enlarge over time, resulting in a gradual loss of kidney function. For patients with ADPKD, early diagnosis is an important step in effectively managing their condition and delaying disease progression. Although it is a rare disease, ADPKD is the fourth leading cause of kidney failure in the U.S. and is estimated to affect up to 140,000 Americans.

There are no formal screening guidelines for ADPKD to aid physicians in spotting the various early warning signs, such as blood in the urine, high BP and back pain. Given the severe consequences of this genetic disease, it is critical for PCPs and other health care providers to be better educated on this condition, its early indicators and the importance of seeing a nephrologist.

The importance of BP screening for ADPKD

ADPKD is the most common type of polycystic kidney disease, accounting for nearly 90% of all cases. Symptoms usually begin between the ages of 30 and 40 years but, in some instances, can begin at a younger age. Typically, the first noticeable signs of ADPKD might include high BP, frequent bladder or kidney infections, blood in the urine, kidney stones, an increase in the size of the abdomen, or back or belly pain.

High BP is the most common sign of ADPKD, affecting as many as 60% of patients with ADPKD. In fact, before an ADPKD diagnosis is made, patients may develop headaches related to elevated BP levels or their doctors may detect high BP during their physical. Aggressive treatment of high BP can help slow kidney failure for ADPKD patients, and providers must recognize the importance of this symptom with respect to making a diagnosis and appropriately treating younger patients who may have ADPKD.

In ADPKD, high BP both precedes and goes hand-in-hand with kidney enlargement and is a significant independent risk factor for progression to end-stage renal disease. Additionally, high BP is a modifiable risk factor for CVD in patients with ADPKD and should be treated to help reduce the burden of cardiovascular complications. Given these considerations, early diagnosis and proper management are critical to help prevent cardiovascular complications and delay cyst growth in these patients.

Posing questions to all patients

Providers should ask every patient about their family’s history with kidney disease, especially if they detect high BP or any other early indicators of possible kidney disease. In families with a known history of ADPKD, imaging with a kidney ultrasound is a reasonable first step for individuals above age 18 years who wish to learn if they have inherited this condition. In fact, children of a parent with the disease have a 50% chance of inheriting ADPKD. However, roughly 1 in 10 patients with ADPKD do not have a known family history of the disease, and it is important to remember that ADPKD is observed in both sexes and all ethnicities.

With greater awareness about ADPKD, referral for kidney imaging and kidney function testing may lead to expedited care even before the patient reaches a nephrologist. Earlier diagnosis may help with initiation of appropriate care before the disease progresses, so conversations are critical to ensure optimal patient outcomes.

Formal screening guidelines hold a powerful potential

Due to advances in the field, there are steps that may be taken by both patients and health care providers to help manage this disease even at early stages. Since ADPKD is a systemic disease, increased awareness in the health care community will allow for faster diagnosis and earlier implementation of effective management strategies to help slow the progression of the disease. For now, providers can take advantage of resources such as www.bigkidneybigproblem.com, which takes a more proactive approach to monitoring ADPKD progression.

Still, more needs to be done to help provide the larger health care community with the necessary tools and rules to screen and diagnose individuals at risk for ADPKD. Formal screening guidelines to be developed and implemented as part of routine care would guide providers with tangible steps to understanding this rare disease. A systematic approach all levels of the health care system could help to improve outcomes of patients with ADPKD.