Clinical trial NCT01799317: How Bone is Made in Children Receiving Dialysis
Official title: Regulation of Bone Mineralization in Renal Osteodystrophy
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE4
Conditions: Bone Mineralization Defect
Lead sponsor: University of California, Los Angeles
Sponsor class: OTHER
Collaborators: name: Children's Hospital Los Angeles
name: Loma Linda University
name: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
First posted: 2013-02-26
Enrollment: 60
Sex: ALL
Minimum age (years): 6
Maximum age (years): 21
Standard ages: CHILD
ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: FACTORIAL
Primary purpose: TREATMENT

Brief summary: The study outlined is designed to measure and to determine whether the combined use of vitamin D2 (ergocalciferoI) and 1-alpha-hydroxyvitamin D2 (doxercalciferol)) or doxercalciferol alone will correct the mineralization defect in pediatric patients with established secondary hyperparathyroidism (2°HPT) undergoing regular peritoneal dialysis. Serum phosphorus levels will be controlled with a calcium¬-free-metal free phosphate binder; (obtained at baseline and after 8 months of treatment) sevelamer. Indices of bone mineralization obtained at baseline and after 8 months of treatment will be measured by quantitative histomorphometry in iliac crest bone biopsies after double tetracycline labeling. Immunohistochemistry will be done in specimens of bone biopsies from iliac crest to examine the expression for selected markers of bone turnover and mineralization such as FGF-23, DMP1, MEPE and OPG. Serum PTH levels will be measured with the 1st and 2nd generation immunometric assay (PTH-IMAs) and fibroblast growth factor-23 (FGF-23) will be determined by one assay with specific detection antibodies that are against epitopes within the C-terminus of FGF-23 and another assay that uses antibodies against epitopes within the N- and C-terminal portions of the molecule respectively. The value of non-invasive assessment of bone mass by quantitative computed tomography (QCT) and its relationship with vascular disease determined by ultrasound (US) of intimal carotid thickness (CIMT) will be correlated with bone histomorphometry and the different biochemical determinations.


Eligibility criteria: Inclusion Criteria:

* medically stable patients
* 6-21 years old
* undergoing treatment with continuous cycling peritoneal dialysis
* evidence of mineralization defect and secondary hyperparathyroidism

Exclusion Criteria:

* histopathological lesion of bone such as adynamic bone or osteomalacia
* poor compliance
* current treatment with prednisone or other immunosuppressives
* treatment with human recombinant growth hormone
* parathyroidectomy

Primary outcomes:
measure: Improvement of bone mineralization defect demonstrated by bone histomorphometry
timeFrame: 8 months
Secondary outcomes:
measure: Radiographic improvement of skeletal abnormalities associated with renal osteodystrophy
timeFrame: 8 months
Other outcomes:
Locations:
city: Loma Linda
country: United States
facility: Loma Linda University
state: California
city: Los Angeles
country: United States
facility: Childrens Hospital Los Angeles
state: California
Study officials:
affiliation: University of California, Los Angeles
name: Isidro Salusky, MD
role: PRINCIPAL_INVESTIGATOR
References: