NCT04018287

Circulating miRNAs and Bone Microstructure in Adults With Hypophosphatasia

• Status: Unknown
• Phase: —
• Study type: Observational
• Enrollment: 60 (estimated)
• Sponsor: Medical University of Vienna · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

The aim of the study is to accomplish a complete bone status of patients with HPP using new approaches to assess bone quality.

Detailed 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.

Conditions

• Hypophosphatasia
• Bone Diseases, Metabolic
• Bone

Interventions

Type	Name	Description
OTHER	HR-pQCT scans, BMD measurements, bone specific circulating microRNAs (miRNAs)	HR-pQCT scans (XtremeCT, SCANCO Medical, Brütisellen, Switzerland) will be performed in all patients with HPP and all CTRL at the ultradistal radius and the distal tibia, using the manufacturer's standard protocol. Volumetric bone Mineral density (vBMD) will be carried out. The peripheral trabecular density adjacent to the cortex and the central medullary trabecular density will be automatically evaluated. Bone microstructure including trabecular bone volume fraction, trabecular number, trabecular thickness inhomogeneity of the network, cortical thickness and cortical porosity will be analyzed. Measurements will be carried out by two well-trained physicians and performed with the latest available software (software version 6.0). Daily crosscalibrations with standardized control phantoms (Moehrendorf, Germany) will be conducted for validation.

Timeline

• Start date: 2017-08-01
• Primary completion: 2023-03-01
• Completion: 2023-06-01
• First posted: 2019-07-12
• Last updated: 2023-01-26

Locations

1 site across 1 country: Austria