Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT04018287 |
Other study ID # |
HPP-study |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
|
First received |
|
Last updated |
|
Start date |
August 1, 2017 |
Est. completion date |
June 1, 2023 |
Study information
Verified date |
January 2023 |
Source |
Medical University of Vienna |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
The aim of the study is to accomplish a complete bone status of patients with HPP using new
approaches to assess bone quality.
Description:
Hypophosphatasia (HPP) is a hereditary disease of bone metabolism that is not yet curable.
Clinical phenotype is variable and reaches from demineralization of bone, deformation of the
skeleton, microsomia and gait abnormality to breathing difficulties. Symptoms of the adult
form are low-traumatic fractures, hip or thigh pain and arthropathy. Cause of the disease is
a mutation in the ALPL-gene (1p36.1-p34) coding for the tissue-nonspecific isoenzyme of
alkaline phosphatase (TNAP) in liver, bone and kidney. This leads to a low activity of
alkaline phosphatase (AP) and elevated levels of phosphoethanolamine (PEA) in urine.
HPP is a very rare disease with a prevalence of ~1/100 000. The Medical Department II of the
St. Vincent Hospital Vienna, Department of the Medical University of Vienna and the Sigmund
Freud University Vienna is a department that is specialized on bone diseases and, as a member
of "Orphanet", also on In particular, (i) bone microstructure as a main component of bone
strength and (ii) circulating microRNAs (miRNAs) as promising biomarkers for bone diseases
will be analyzed in patients with HPP and age-, and gender-matched healthy controls.
Microstructural deteriorations of cortical and trabecular bone as well as volumetric bone
density (vBMD) in radius and tibia in patients with HPP will be compared to healthy
individuals using HR-pQCT (High resolution peripheral quantitative computer tomography,
Scanco Medical, Brütisellen). HR-pQCT is a high-resolution, non-invasive technique to measure
cortical and trabecular bone mircostructures as well as vBMD at a high resolution level
(82µm).
Micro-RNAs (miRNAs) are short, non-coding RNA molecules of which some have been identified as
bone specific (e.g. miR-31, miR-335, miR-155, miR-29b, miR-188, miR-550a). They play a
significant role in bone metabolism controlling synthesis and function of osteoblasts as well
as osteoclasts.
In recent studies we could show that these microRNAs can be detected in serum and that their
serum concentration correlates with the risk for osteoporotic fractures. Data for patients
with HPP do not exist yet. miRNAs will be measured by qPCR (quantitative polymerase chain
reaction) in serum of patients with HPP and respective controls.
In addition, measurements of areal BMD (aBMD) by DXA (Dual Energy X-ray Absorptiometry) and
DXL (Dual X-ray and Laser) will be performed. Vitamin D and established bone turnover markers
including PINP (N-terminal propeptide of type I collagen), CTX (collagen type 1 cross-linked
C-telopeptid) and sclerostin will be analyzed. Moreover, body composition will be determined.