PKD Biomarkers Study

In polycystic kidney disease (PKD), renal cysts form in utero and progressively enlarge due
to aberrant proliferation of the cyst-lining cells and accumulation of fluid within the
expanding cyst cavity. Over decades of unrelenting cyst growth, renal function declines due
to the loss of functional tissue, eventually leading to kidney failure and the need for renal
replacement therapy, such as dialysis or kidney transplantation.

Effective therapies for the treatment of PKD will need to be delivered as early as possible,
before a measurable decline in kidney function, to preserve functional tissue. Currently, it
is difficult to make an accurate prognosis of the progression of early-stage PKD since the
growth of microscopic cysts is difficult to detect by standard imaging modalities and changes
in total kidney volume measured within a reasonable time period are too small to be
informative. Even though early cysts may not cause detectable changes in total kidney volume,
their progressive enlargement damages the surrounding tissue and is a prelude to chronic
kidney disease.

Current blood and urine tests provide important information on the decline of kidney
function; however, these tests are not useful for monitoring early events of PKD such as
initial cyst growth and damage to neighboring tissue. Clearly, novel biomarkers of early
cystic disease need to be discovered to develop appropriate clinical tests to monitor the
progression of early stage PKD. These tests will be important to identify patients at risk of
rapid progression and of need of therapeutic intervention and to monitor the effectiveness of
the therapeutic drug. The PKD Biomarkers Repository will allow approved researchers to obtain
blood and urine samples for biomarker discovery and development of appropriate biomarker
assays for prognosis of early PKD.

This observational study is currently recruiting for three groups: 1) individuals diagnosed
with relatively early PKD as defined by total kidney volume and estimated GFR, 2) unaffected
or undiagnosed family members, preferably siblings, 3) normal volunteers with no family
history of renal disease.

Inclusion Criteria:

- Inclusion for early stage autosomal dominant polycystic kidney disease (ADPKD):

- Family history of PKD

- All races and ethnic groups

- Glomerular filtration rate (GFR) >80 ml/min per 1.73 m2

- Inclusion for Healthy Volunteers:

- Male or female with no family history of kidney disease

- All races and ethnic groups

- Normal GFR

Exclusion Criteria:

- Non-insulin or insulin-dependent diabetes mellitus

- Systemic illness (i.e.systemic lupus erythematosus, vasculitis)

- Unable to provide written informed consent

- Unavailable for magnetic resonance imaging (MRI) and blood/urine collection