Circulating miRNAs and Bone Microstructure in Adults With Hypophosphatasia

Active, not recruiting

• Conditions: Hypophosphatasia; Bone Diseases, Metabolic; Bone
• Interventions: Other: HR-pQCT scans, BMD measurements, bone specific circulating microRNAs (miRNAs)

• Registration Number: NCT04018287
• Lead Sponsor: Medical University of Vienna

Brief 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.

Study Timeline

• Study Start: 2017-08-01
• Study First Submitted: 2019-06-13
• Study First Submitted QC: 2019-07-10
• Study First Posted: 2019-07-12
• Status Verified: 2023-01
• Last Update Submitted: 2023-01-25
• Last Update Posted: 2023-01-26
• Primary Completion: 2023-03-01
• Study Completion: 2023-06-01

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

Not provided

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Exclusion Criteria

Not provided

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Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
HPP-Group	HR-pQCT scans, BMD measurements, bone specific circulating microRNAs (miRNAs)	1. genetical verified hypophosphatasia 2. age \>18 years 3. written informed consent 4. complete serological and radiological examinations
Control-Group	HR-pQCT scans, BMD measurements, bone specific circulating microRNAs (miRNAs)	1. healthy men and women without any history of musculoskeletal diseases 2. Alkaline phosphatase (AP) in reference range 3. written informed consent 4. complete serological and radiological examinations

Primary Outcome Measures

Name	Time	Method
microRNA pattern	Assessment once after Inclusion is completed	bone specific circulating microRNAs (miRNAs) in the serum of adult patients
HR-pQCT	Assessment once after Inclusion is completed.	non-invasively measurement of trabecular and cortical bone microstructure

Secondary Outcome Measures

Name	Time	Method
DXA Scanning	Assessment once after Inclusion is completed.	measurement of areal bone mineral density (aBMD) at the lumbar spine, radius, total body and hip by DXA • measurement of aBMD at the calcaneus by DXL
Bone Turnover Markers (BTMs)	Assessment once after Inclusion is completed.	serological analysis of established BTMs including PINP, CTX and sclerostin

Trial Locations

Locations (1)

Medical University Vienna; St. Vincent Hospital; 🇦🇹 Vienna, Austria