Role Of Phosphorus And FGF 23 In Patients With Dent Disease

Mayo Clinic

Status and phase: Completed; Phase 2; Phase 1

Conditions: Dent Disease

Treatments: Drug: Phosphorus Supplement; Other: Observation

Study type: Interventional

Funder types: Other

Identifiers

NCT02016235

13-004774

Details and patient eligibility

About

Patients with Dent disease have suppressed levels of FGF 23 which contributes to hypercalciuria, kidney stones, nephrocalcinosis and renal failure. Supplementation with phosphorus may reduce hypercalciuria.

Enrollment: 30 patients

Sex: Male

Volunteers: No Healthy Volunteers

Inclusion criteria

Patients will be recruited from those in the RKSC Dent Registry

1. Diagnostic criteria for Dent disease Observational arm include:

   1. <18 years old
   2. LMWP (at least 5 times above the upper limit of normal) and at least 1 of the following criteria: 1. Hypercalciuria, 2. Kidney stones, 3. Nephrocalcinosis, 4. Hypophosphatemia, 5. Renal phosphate leak, 6. Aminoaciduria, 7. Glucosuria without diabetes mellitus, 8. Hematuria, 9. Renal insufficiency, 10. Family history with x-linked inheritance or
   3. 1 of the above criteria (1-9) and confirmed genetic mutation of CLCN5 or OCRL1.

2. Diagnostic criteria for Dent disease Intervention arm include:

   1. >18 years old
   2. LMWP (at least 5 times above the upper limit of normal) and at least 1 of the following criteria: 1. Hypercalciuria, 2. Kidney stones, 3. Nephrocalcinosis, 4. Hypophosphatemia, 5. Renal phosphate leak, 6. Aminoaciduria, 7. Glucosuria without diabetes mellitus, 8. Hematuria, 9. Renal insufficiency, 10. Family history with x-linked inheritance or
   3. 1 of the above criteria (1-9) and confirmed genetic mutation of CLCN5 or OCRL1.

3. Idiopathic calcium nephrolithiasis with renal phosphate leak

   1. Male patients > 18 years old
   2. History of symptomatic calcium oxalate or calcium phosphate stone, hypercalciuria (>250 mg/24 hrs), renal phosphate leak (TMP/GFR <2.07 mg/dl)

4. Idiopathic calcium nephrolithiasis without renal phosphate leak

   1. Male patients > 18 years old
   2. History of symptomatic calcium oxalate or calcium phosphate stone, hypercalciuria (>250 mg/24 hrs), renal phosphate leak (TMP/GFR <2.07 mg/dl)

Exclusion criteria

1. Exclusion for Dent disease include: primary or secondary hyperparathyroidism, hyperthyroidism, chronic diarrhea states; intake of thiazide diuretics, glucocorticoids, or estrogens within one month of the study.
2. Exclusion criteria for calcium stone formers include: primary or secondary hyperparathyroidism, hyperthyroidism, estimated GFR <40 ml/mn/1.73m2, chronic diarrhea states; intake of thiazide diuretics, glucocorticoids, or estrogens within one month of the study.
3. Exclusion criteria include history of symptomatic or asymptomatic kidney stone disease; primary or secondary hyperparathyroidism; estimated GFR <40 ml/min/1.73m2, chronic diarrhea states; intake of thiazide diuretics, glucocorticoids, or estrogens within one month of the study.

Trial design

Primary purpose: Treatment

Allocation: Non-Randomized

Interventional model: Single Group Assignment

Masking: None (Open label)

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30 participants in 3 patient groups, including a placebo group

Dent Disease Intervention

Experimental group

Description:

Dent Disease subjects will receive 2 week supplementation with phosphorus

Treatment:

Drug: Phosphorus Supplement

Kidney Stone subjects

Experimental group

Description:

Kidney stone with or without phosphate leak subjects will receive 2 week supplementation with phosphorus

Treatment:

Drug: Phosphorus Supplement

Dent Disease Observation

Placebo Comparator group

Description:

Dent disease subjects will not get phosphorus

Treatment:

Other: Observation