Bone Microarchitecture in the Transplant Patient

Study Overview
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Brief Summary
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The optimal management of calcium and phosphate metabolism regulation in chronic kidney disease (CKD) is important in preventing fracture risk and vascular calcification and thus morbidity and mortality, global and vascular. Kidney transplant in a CKD context, usually with a pre-existing underlying renal osteodystrophy, malnutrition, chronic inflammation, hypogonadism and immunosuppression protocols still often made up of high-dose corticosteroid therapy, are all theoretical factors of post-transplantation bone disease. For other solid organ transplants, even though there is generally no underlying renal osteodystrophy before the transplant, the proportion of osteoporotic patients at the time of transplant is substantial. The bone risk in the immediate post-transplant period is notable. Patients' follow-up is based on biological, radiological and histological tools. Bone densitometry (DXA) is used to measure bone mass. However, recent international recommendations do not consider DXA as a valid tool to assess bone health in CKD patients. Moreover, it is less informative than peripheral quantitative tomography resolution (HR-pQCT). This latest technique, available in Lyon and Saint-Etienne, is more precise, allowing a three-dimensional study of the trabecular microarchitecture and compartmental volumetric bone density (total, cortical, trabecular), while similar to DXA in terms of radiation (less than 5 μSv). The prevention of cardiovascular risk factors is also part of the daily care of patients with a regular cardiac monitoring (heart ultrasound) and vascular (blood pressure, Doppler of the supra-aortic trunks). TRANSOS study aims to evaluate in a prospective cohort (longitudinal follow-up of 6 months), the bone status in patients receiving solid organ transplantation in the University Hospitals of Lyon and Saint-Etienne, using DXA and HR-pQCT (at baseline and month 6), in combination with classical biological and cardiovascular monitoring. Transplantation is an important activity in these two hospitals and this protocol provides the same bone follow-up for all solid organ transplants, with a reliable, efficient, non-invasive and low-dose radiation tool. The primary objective of TRANSOS study is to evaluate changes in tibial cortical density between the baseline and the 6th month post-transplant measured by HR-pQCT.

Official Title
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Longitudinal Monitoring of Bone Microarchitecture by High Resolution Peripheral Quantitative Computed Tomography of (HR-pQCT) in the Transplant Patient

Conditions
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Organ Transplant

Intervention / Treatment
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* Procedure: Tibial cortical density evaluation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient over 10 year-old Patient receiving a first solid organ transplant within involved hospitals (Lyon, Saint Etienne): kidney, heart, kidney-pancreas, lung Informed consent signed by the patients or their parents (minors) Exclusion Criteria: No health cover Ongoing pregnancy

Ages Eligible for Study
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Minimum Age: 10 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Tibial cortical density evaluation<br> | Procedure: Tibial cortical density evaluation<br>* Bone evaluation in transplant patients will be performed by HR-pQCT at baseline (either within 6 months before surgery or within 15 days following surgery) and 6 months post-intervention in order to assess its evolution.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tibial cortical density measured by HR-pQCT |  | at 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| trabecular bone area measured by HR-pQCT |  | at 6 months | 
| total bone area measured by HR-pQCT |  | at 6 months | 
| trabecular number measured by HR-pQCT |  | at 6 months | 
| trabecular thickness measured by HR-pQCT |  | at 6 months | 
| trabecular separation measured by HR-pQCT |  | at 6 months | 
| cortical perimeter measured by HR-pQCT |  | at 6 months | 
| Evaluation of bone markers by measuring calcium |  | at 6 months | 
| Evaluation of bone markers by measuring phosphate |  | at 6 months | 
| Evaluation of bone markers by measuring alkaline reserve |  | at 6 months | 
| Evaluation of bone markers by measuring PTH |  | at 6 months | 
| Evaluation of bone markers by measuring 25OHD3 |  | at 6 months | 
| Evaluation of bone markers by measuring 1-25 OHD3 |  | at 6 months | 
| Evaluation of bone markers by measuring FGF23 |  | at 6 months | 
| Evaluation of bone markers by measuring CTX |  | at 6 months | 
| Evaluation of bone markers by measuring total alkaline phosphatase |  | at 6 months | 
| Evaluation of bone markers by measuring bone alkaline phosphatase |  | at 6 months | 
| Evaluation of bone markers by measuring osteocalcin |  | at 6 months | 
| Bone mineral density assessed by DXA |  | at 6 months | 
| Fractures onset assessed by DXA |  | at 6 months | 
| Cardiovascular events (death from cardiovascular cause, heart attack, stroke) |  | at 6 months | 
| PTH | For kidney transplant only | Baseline | 
| 1-25 OHD | For kidney transplant only | Baseline | 
| FGF 23 | For kidney transplant only | Baseline | 
| calcium | For kidney transplant only | Baseline | 
| phosphate | For kidney transplant only | Baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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HRpQCT, transplant, bone microarchitecture