Pathogenesis and treatment of osteoporosis in patients with hemophilia

How does the Dorr classification of proximal femur affect the total hip arthroplasty of hemophilic patients: a retrospective study

Patients with hemophilia (PWH) constantly suffer hemarthrosis due to the lack of coagulation factors, resulting in progressive deformity of the hip joint. Currently, there is a dearth of understanding on the unusual morphology of proximal femur in PWH. To explore how does the Dorr classification of proximal femur affect the total hip arthroplasty (THA) of PWH, we conducted a retrospective study on PWH with different Dorr classifications who underwent THA. The retrospective study comprises data of adult patients who received THA from 2018 to 2022 in the research center. Patients with a diagnosis of hemophilic arthritis and received THA were included and divided into three groups according to Dorr classification. The X-ray images were acquired before the surgery to determine the Dorr classification. The surgical time, surgical blood loss, laboratory examinations post-operation including hemoglobin (HB), total protein (TP), activated partial thromboplastin time (APTT), D-dimer (D2), C-reactive protein level (CRP), erythrocyte sedimentation rate (ESR), and functional evaluations 1 year after surgery including visual analogue scale (VAS), Harris hip score (HHS), range of motion (ROM) were collected. Kolmogorov-Smirnov test is used to test data normality, and t-test is performed by SPSS 20. P < 0.05 is considered statistically significant. 33 PWH are included in the study and have finished follow-up. All cases are male patients. Among the 33 hips, 19 (57.6%) are classified to Dorr A, and 12 (36.4%) are Dorr B, and only 2 (6%) are Dorr C. No significant difference is found in expanse, hospital stay, surgical time and total blood loss. PWH with Dorr A requires significant less coagulation factor than Dorr B and Dorr C. All Dorr types of hips present good recovery from the surgery according to the perioperative examinations including hemoglobin (HB), total protein (TP), activated partial thromboplastin time (APTT), D-dimer (D2), C-reactive protein level (CRP), erythrocyte sedimentation rate (ESR), and thigh circumference (TC). The 2-year follow-up demonstrates favorable functional rehabilitation according to functional evaluations including visual analogue scale (VAS), Harris hip score (HHS), and range of motion (ROM). In this study, we find that PWH tend to have higher prevalence of Dorr A than the general population. PWH with Dorr A requires smaller dosage to maintain the coagulation factor activity than the Dorr B and Dorr C. Additionally, all types of hip present favorable recovery after THA. Ultimately, the study supports that THA is an effective treatment for PWH with all Dorr classifications by alleviating the pain and improve the motor function.

Could PTH/Ca Ratio Serve as a New Marker for Evaluating Bone Metabolism in Hemophilia Patients?

Background/Objectives: Low bone mineral density (BMD) is common in hemophilia patients. Identifying high-risk patients for low BMD early is essential to prevent complications and reduce morbidity. The parathyroid hormone (PTH)/calcium (Ca) ratio is a cost-effective marker for predicting BMD, highlighting the need for routine screening and early intervention in this population. Hemophilia is a hereditary bleeding disorder caused by deficiencies in clotting factors VIII (hemophilia A) and IX (hemophilia B). Patients with hemophilia are at risk of low bone mineral density (BMD). This study aimed to evaluate the prevalence of low BMD, associated risk factors, and raise awareness regarding its significance in hemophilia patients. Methods: We retrospectively assessed bone metabolism in 62 hemophilia patients followed at our center. BMD was evaluated using dual-energy X-ray absorptiometry (DEXA). Additionally, serum levels of 25-OH-D3, alkaline phosphatase, PTH, Ca, phosphor, and creatinine were measured. The PTH/Ca, PTH/25-OH-D3, and Ca×25-OH-D3/PTH ratios were calculated. Results: The median age of the 62 patients with hemophilia included in the study (hemophilia A: 87.1%, hemophilia B: 12.9%) was 37 years (range: 21-66), and all were male. Of these patients, 67.7% (n = 42) had severe, 21% (n = 13) had moderate, and 11.3% (n = 7) had mild hemophilia. A total of 85.5% of patients were on factor prophylaxis, and 75.4% had a target joint. In laboratory analysis, the median 25-OH-D3 level was 13.4 µg/L and 75% patients had 25-OH-D3 deficiency. According to DEXA results, 62.9% had lower than normal BMD. When we divided the patients into normal and low BMD groups according to DEXA results, weight (p = 0.006), height (p = 0.024), factor levels (p = 0.004), PTH (p = 0.010), AST (p = 0.029), and PTH/Ca (p = 0.011) levels were statistically significantly different between the groups. The severity of the disease and the rate of receiving prophylaxis were higher in the group with low BMD (p = 0.015, p = 0.006, respectively). In multivariate analysis, PTH/Ca ratio and weight were found to be independent risk factors for BMD. A linear relationship was found between PTH/Ca ratio and BMD. The optimal cut-off value for PTH/Ca was 6.57, with a selectivity of 65% and specificity of 82%. When we divided the patients into groups according to the cut-off value of 6.57, we found that the probability of low BMD increased approximately 7-fold in the group with PTH/Ca > 6.57 (OR 7.045, 95% CI 1.485-33.42, p = 0.014). There was an inverse association between patient weight and low BMD (p = 0.043). Conclusions: Low BMD is a critical public health concern frequently observed in patients with hemophilia. The study highlights a high rate of low BMD and 25-OH-D3 deficiency in hemophilia patients, with the PTH/Ca ratio shown to be useful in predicting BMD. The PTH/Ca ratio is suggested as an accessible, cost-effective, and practical test for evaluating BMD in hemophilia patients.

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.

Insights and implications of sexual dimorphism in osteoporosis

Osteoporosis, a metabolic bone disease characterized by low bone mineral density and deterioration of bone microarchitecture, has led to a high risk of fatal osteoporotic fractures worldwide. Accumulating evidence has revealed that sexual dimorphism is a notable feature of osteoporosis, with sex-specific differences in epidemiology and pathogenesis. Specifically, females are more susceptible than males to osteoporosis, while males are more prone to disability or death from the disease. To date, sex chromosome abnormalities and steroid hormones have been proven to contribute greatly to sexual dimorphism in osteoporosis by regulating the functions of bone cells. Understanding the sex-specific differences in osteoporosis and its related complications is essential for improving treatment strategies tailored to women and men. This literature review focuses on the mechanisms underlying sexual dimorphism in osteoporosis, mainly in a population of aging patients, chronic glucocorticoid administration, and diabetes. Moreover, we highlight the implications of sexual dimorphism for developing therapeutics and preventive strategies and screening approaches tailored to women and men. Additionally, the challenges in translating bench research to bedside treatments and future directions to overcome these obstacles will be discussed.

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.