Bone Microarchitecture in Men With Hemophilia (HEMOS)

Hemophilia A and B are hereditary sex-linked deficiencies of coagulation factors VIII and IX characterized by bleeding. Their modern therapy increases life expectancy and risk of age-related diseases, e.g., osteoporosis. Hemophilia-specific risk factors impair formation of peak bone mass and accelerate bone loss. Fractures are more frequent in hemophilic men vs. age-matched men and induce bleeding which is aggravated by manipulations and surgical intervention. The hypothesis of this study is that hemophilic men have poor bone microarchitecture (assessed by High-resolution peripheral quantitative computed tomography (HR-pQCT)) related to an imbalance between bone formation and resorption (assessed by bone turnover markers (BTM) and bone biomarkers). The study aims to assess the difference in low trabecular number (Tb.N) at the distal radius between hemophilic men (cases) and age- height-weight-ethnicity and smoking-matched healthy men (controls). Correlation between BTM and Tb.N will be also studied. Biologic markers of bone remodeling (C-terminal telopeptide of type I collagen (PINP), N-terminal propeptide of type I procollagen (CTX-I), periostin) will be studied.

30 patients with severe hemophilia A or B (Factor (F)VIII or Factor IX (FIX)≤ 1%) aged 20 to 60 years will be included in this study.

Data of healthy men, matching in age- height-weight-ethnicity and smoking-matched with patient will be collected. These data are already available at the "Institut national de la santé et de la recherche médicale" (INSERM) research unit associated.

Patients will have a unique blood sampling of 10 mL for the measurements of sera PINP, CTX-I, periostin levels

A dual energy X-ray absorptiometry scan of lumbar spine, hip, distal radius and whole body, body composition, lateral spine will be performed.

The number of trabecular at distal tibia will be performed and compared to the values available for the healthy control group

The number of trabecular at distal radius will be performed and compared to the values available for the healthy control group

Micro-Finite Element Analysis (µFEA) reflection of bone strength will be performed and compared to the values available for the healthy control group

Trabecular Bone Score (TBS) will be performed and compared to the values available for the healthy control group The trabecular bone score is a measure of bone texture correlated with bone microarchitecture and a marker for the risk of osteoporosis

Inclusion Criteria: Patients: Men aged 20 to 60 years Severe hemophilia A or B (FVIII or FIX<1%) Regular followed up in Lyon Hemophilia Center Ability to give free and informed consent Person capable of actively participating in radiological examinations Healthy Mens: Aged 20 to 60 years Exclusion Criteria: Women Not covered by health system Vulnerable (adults unable to consent, protected under guardianship, prisoner) Any blood coagulation abnormality other than severe hemophilia A or B Having one of the following treatments against osteoporosis of more than 6 months : bisphosphonates, denosumab, teriparatide With a chronical disease having a high impact on bone structure and no related to hemophilia disease, such as Cushing or Crohn diseases.