Osteoporosis Remains Constant in Patients with Hemophilia-Long-Term Course in Consideration of Comorbidities

The influence of severity of hemophilia on bone mineral density and fracture risk

Background

Evidence states that persons with hemophilia are frequently affected by low bone mineral density (BMD). Data assessing the relationship between severity of hemophilia and occurrence of osteoporosis are lacking.

Objectives

This prospective cohort study aimed to assess the impact of hemophilia severity on BMD and to investigate trabecular bone score (TBS) and fracture risk (FRAX).

Methods

This prospective cohort study evaluated the BMD, TBS, and FRAX in 255 persons with hemophilia using dual x-ray absorptiometry. The International Society for Clinical Densitometry guidelines were used for classification: osteoporosis (T-score <-2.5), osteopenia (T-score <-1.0), normal (T-score >-1.0). Patients younger than 50 years of age with a Z-score of <-2.0 were considered below the expected range for age.

Results

Of 255 persons with hemophilia (mild: n = 52, moderate: n = 53, severe: n = 150) aged 43 ± 15 years (mean ± SD), 63.1% showed reduced BMD. Even 11.9% of persons with hemophilia aged <50 years were classified as below the expected range for age. Neck BMD decreased linearly with severity (mild: 0.907 ± 0.229, moderate: 0.867 ± 0.131, severe: 0.799 ± 0.143; P = .01). TBS was classified as "normal" in n = 178 (81.3%) with a mean value of 1.403 ± 0.136, and there were no differences between severity levels (P = .54). The FRAX was 4.4% ± 3.0%. After adjustment of TBS, it was 2.8% ± 3.7%.

Conclusion

The present study shows that BMD is decreased in 63.1% of persons with hemophilia also depending on the severity of hemophilia. However, the largely normal TBS implies that the microarchitecture of the bone does not seem to be affected. It is recommended to include osteoporosis screening, including TBS analysis, in the comprehensive diagnostic work-up of persons with hemophilia, especially as they age.

Effects of coagulation factors on bone cells and consequences of their absence in haemophilia a patients

Haemophilia is associated with reduced bone mass and mineral density. Due to the rarity of the disease and the heterogeneity among the studies, the pathogenesis of bone loss is still under investigation. We studied the effects of coagulation factors on bone cells and characterized in a pilot study the osteoclastogenic potential of patients' osteoclast precursors. To evaluate the effect of coagulation factors on osteoclasts, we treated Healthy Donor-Peripheral Blood Mononuclear Cells (HD-PBMC) with Factor VIII (FVIII), von Willebrand Factor (VWF), FVIII/VWF complex, activated Factor IX (FIXa), activated Factor X (FXa) and Thrombin (THB). FVIII, VWF, FVIII/VWF, FXa and THB treatments reduced osteoclast differentiation of HD-PBMC and VWF affected also bone resorption. Interestingly, PBMC isolated from patients with moderate/severe haemophilia showed an increased osteoclastogenic potential due to the alteration of osteoclast precursors. Moreover, increased expression of genes involved in osteoclast differentiation/activity was revealed in osteoclasts of an adult patient with moderate haemophilia. Control osteoblasts treated with the coagulation factors showed that FVIII and VWF reduced ALP positivity; the opposite effect was observed following THB treatment. Moreover, FVIII, VWF and FVIII/VWF reduced mineralization ability. These results could be important to understand how coagulation factors deficiency influences bone remodeling activity in haemophilia.

Bone mineral density in haemophilia patients: A systematic review and meta-analysis

INTRODUCTION

With the increase in life expectancy of haemophilia patients (PWH), the risk of osteoporosis increases, but there is little research on whether haemophilia is the cause of osteoporosis.

AIM

To conduct systematically review whether bone mineral density (BMD) in PWH decreased and the factors affecting BMD.

METHODS

Two authors independently searched databases and reviewed citations from relevant articles, selecting studies published in any language and performed in humans before March 2023. Eligibility criteria were observational studies in PWH, with BMD as at least one outcome other than osteoporosis or bone loss, and analyses in a group of PWH and healthy controls.

RESULTS

Twelve studies were ultimately identified, consisting of 1210 individuals (534 PWH and 676 healthy controls), compared with the control group, BMD in PWH decreased by 0.13 g/cm2 [95% confidence interval (CI) -0.18 to -0.08, I2  = 89%]. No evidence of publication bias was detected. There was no evidence that age, BMI, level of physical activity, the types of haemophilia, haemophilia severity, a blood-borne virus (HCV) and treatment modality predicted the BMD in PWH.

CONCLUSION

The results indicate that BMD in PWH is lower than in healthy controls. Therefore, we strongly recommend PWH early measurement of BMD to prevent osteoporosis.

Haemophilia and Fragility Fractures: From Pathogenesis to Multidisciplinary Approach

Haemophilia A (HA) and haemophilia B (HB) are X-linked inherited bleeding disorders caused by the absence or deficiency of coagulation factors VIII (FVIII) and IX (FIX), respectively. Recent advances in the development of effective treatments for haemophilia have led to a significant increase in life expectancy. As a result, the incidence of some comorbidities, including fragility fractures, has increased in people with haemophilia (PWH). The aim of our research was to perform a review of the literature investigating the pathogenesis and multidisciplinary management of fractures in PWH. The PubMed, Scopus and Cochrane Library databases were searched to identify original research articles, meta-analyses, and scientific reviews on fragility fractures in PWH. The mechanism underlying bone loss in PWH is multifactorial and includes recurrent joint bleeding, reduced physical activity with consequent reduction in mechanical load, nutritional deficiencies (particularly vitamin D), and FVIII and FIX deficiency. Pharmacological treatment of fractures in PWH includes antiresorptive, anabolic and dual action drugs. When conservative management is not possible, surgery is the preferred option, particularly in severe arthropathy, and rehabilitation is a key component in restoring function and maintaining mobility. Appropriate multidisciplinary fracture management and an adapted and tailored rehabilitation pathway are essential to improve the quality of life of PWH and prevent long-term complications. Further clinical trials are needed to improve the management of fractures in PWH.