6414: Role of Phosphorus and FGF 23 in Patients with Dent Disease

Status: Recruiting

 

Background

Patients with Dent disease have high calcium in the urine and can get kidney calcifications (calciumdeposits) and kidney stones. This may have an effect on kidney function. The purpose of this study is to measure all the important factors that can influence high urine calcium in Dent disease patients and in kidney stone patients who have similar findings in the urine and to find out if taking phosphorus supplements can decrease calcium in the urine in these patients.

The research questions are:

  1. What are the levels of all the important factors in the blood and urine that influence the level of calcium in urine in Dent disease and similar kidney stone patients?
  2. How does the level of calcium in the urine and tendency to form kidney stones change after taking 2 weeks of phosphorus supplements?
  3. How do the levels of factors controlling calcium and phosphorus change after 2 weeks of phosphorus supplements?

About this Study

This is an interventional study with 40 participants (10 with Dent disease, 20 with kidney stone disease) that will take phosphorus supplements and 10 Dent disease patients that will not take phosphorus supplements.

The 30 participants in the interventional study will have their blood and urine tested before and after taking phosphorus supplements.

The 10 Dent disease patients who will not receive phosphorus supplements (because of the advanced kidney disease or being younger than 18 years old) will only have blood and urine measurements once.

Patients with kidney stone disease will be seen at Mayo Clinic, NY Harbor VA Medical Center and the Children’s Hospital of Philadelphia (CHOPP). Patients with Dent disease will be seen at Mayo Clinic or at their local physician. If you are not seen in either of our participating centers, we will look at your medical records from your local doctor's office so that we can collect information about your medical history, physical exam and the laboratory tests within 3 months of the beginning of the study. You will have blood and urine collected at the local site using kits provided by and shipped back to Mayo Clinic.
All patients will be asked to:

  • Keep a log of what you eat for seven days
  • Give blood (1 to 2 teaspoons)
  • Give a 24 hour urine sample

Targeted Enrollment

To be eligible for the interventional study (receive phosphorus), you must have ONE of the following:

  • A documented diagnosis of Dent disease
  • Calcium kidney stone disease with high calcium in the urine

You are not eligible to participate if you:

  • Are less than 18 years old
  • Have low kidney function (estimated GFR <40ml/min/1.73 m2)
  • Have primary or secondary hyperparathyroidism, hyperthyroidism, chronic diarrhea
  • Take thiazide diuretic, glucocorticoid or estrogen hormones within 1 month of participating in the study

To be eligible for the non-interventional study (will NOT receive phosphorus) you must have:

  • A documented diagnosis of Dent disease
  • Less than 18 years old or low kidney function (estimated GFR <40 ml/min/1.73 m2)

You are not eligible to participate if you have either of the following:

  • Primary or secondary hyperparathyroidism, hyperthyroidism, chronic diarrhea
  • Take thiazide diuretic, glucocorticoid or estrogen hormones within 1 month of participating in the study

How to participate

In order to participate in a study, you must personally contact the study coordinator of any of the participating institutions by phone or by e-mail. Please use the information below to inquire about participation.

United States

Minnesota

Mayo Clinic College of Medicine, Rochester
Contact: Julie Olson, Barb Seide and Alicia Meek
Phone: 800-270-4637
E-mail: rarekidneystones@mayo.edu

New York

NY Harbor VA Medical Center
Contact: Lada Beara Lasic, MD
E-mail: Lada.BearaLasic@nyumc.org

Contact: Frank Modersitzki, MPH
Phone: 212-263-2922
E-mail: Frank.Modersitzki@nyumc.org

Pennsylvania

The Children's Hospital of Philadelphia, Philadelphia
Contact: Taylor Moatz
Phone: 215-425-3937
E-mail: MoatzT@email.chop.edu