Increased osteoclastic activity as shown by increased sRANK-L/OPG ratio in boys with hemophilia

The Profile of Markers of Bone Turnover, Inflammation and Extracellular Neutrophil Traps on Bone Mass in Haemophilia and the Development of Haemophilic Arthropathy

Background: The aim of the study is to evaluate selected biomarkers of bone turnover, inflammation, neutrophil trap and factors predisposing haemophiliacs to bone loss, and to analyse their relationship with clinical features, treatment and complications. Methods: The levels of interleukin 6 (IL-6); citrullinated histone (CH3); osteocalcin (BGLAP); bone alkaline phosphatase (BALP); N-terminal procollagen type I propeptide (P1NP); and C-terminal collagen type I telopeptide (C1CP) were examined in 60 patients with haemophilia. Results: The cut-off value for BGLAP is 26.41 ng/mL, and 929.7 pg/mL for CH3. There is a statistically significant difference between BGLAP, BALP, C1CP and CH3 concentrations, depending on the prophylaxis used. The median concentration of BGLAP in patients taking the factor on demand is 28.0 ng/mL, BALP 322.5 U/L, C1CP 191.2 ng/mL and CH3 1114.4 pg/mL. In patients taking recombinant coagulation factor VIII/IX as prophylaxis of bleeding, the median BGLAP concentrations are 35.9 ng/mL, BALP 280.9 U/L, C1CP 161.6 ng/mL and CH3 952.5 pg/mL. BGLAP and BALP concentrations are dependent on the development of haemophilic arthropathic. Conclusions: The concentrations of selected markers of bone turnover and NETs may help to identify patients at particular risk of developing haemophilic arthropathy and bone metabolic turnover abnormalities.

Potential Biochemical Markers and Radiomorphometric Indices as Predictors of Reduced Bone Mass in Patients with Congenital Hemophilia

Background: The study aimed to evaluate radiomorphometric indices derived from panoramic X-rays and selected blood markers of bone turnover and neutrophil extracellular traps, with a view to identifying hemophilic patients at risk of developing osteoporosis. Methods: The study consisted of 50 adult men with hemophilia A and B (mild, moderate, and severe). The control group consisted of 25 healthy adult men. In both groups, blood samples were collected to determine concentrations of citrullinated histone H3 (CH3) and osteocalcin (BGLAP) with ELISA tests, and panoramic X-rays were obtained. Images were imported into AudaXCeph software to calculate two radiomorphometric indices: mental index (MI) and panoramic mandibular index (PMI). Concentrations of BGLAP and CH3 were compared with MI and PMI values in patients with and without hemophilia. Results: There were statistically significant differences in BGLAP, CH3, and PMI between the study and the control group (p < 0.05). Multivariate logistic regression analysis showed a predictive value for PMI, BGLAP, and CH3.The ROC curve with cutoff point (Youden index) at 0.40—PMI was calculated. No correlation was observed for the PMI index in any particular subgroup of patients. No correlation between MI and BGLAP/CH3 was observed. Conclusions: Simultaneous use of PMI value and BGLAP and CH3 levels may allow the identification of patients with hemophilia who requirea detailed diagnosis of osteoporosis with DXA.

Pathological mechanism of joint destruction in haemophilic arthropathy

Haemophilic arthropathy (HA), caused by intra-articular haemorrhage, is one of the most common complications in patients with haemophilia. Factor replacement therapy provides missing coagulation factors to prevent children with haemophilia from joint bleeding and decreases their risk for HA. However, haemophilia patients in developing countries are still suffering from HA due to insufficient replacement therapy. Symptoms such as pain and activity limitations caused by HA seriously affect the functional abilities and quality of life of patients with HA, causing a high disability rate in the haemophilia cohort. The pathological mechanism of HA is complicated because the whole pathological mainly involves hypertrophic synovitis, osteopenia, cartilage and bone destruction, and these pathological changes occur in parallel and interact with each other. Inflammation plays an important role in the whole complex pathological process, and iron, cytokines, growth factors and other factors are involved. This review summarizes the pathological mechanism of HA to provide background for clinical and basic research.

Low bone mass and hypovitaminosis D in haemophilia: A single-centre study in patients with severe and moderate haemophilia A and B

INTRODUCTION

Haemophilia (H) is frequently associated with a multifactorial reduction in bone mineral density (BDM), but little is known about possible differences between HA and HB according to their severity.

AIM

To evaluate the association between low bone mineral density (BMD), 25-hydroxyvitamin D [25(OH)D] concentrations and bone turnover markers in patients with HA and HB younger or older than 50 years.

METHODS

In 78 patients <50 years and 33 patients >50 years with severe (S) or moderate (M) HA and HB, BMD was measured by dual-energy X-ray absorptiometry at femoral neck (FN) and lumbar spine and then correlated to annual bleeding rate (ABR), World Federation of Haemophilia orthopaedic joint scale (WFH score), 25(OH)D concentrations, parathyroid hormone (PTH), amino-terminal telopeptide of type 1 collagen (NTx), urinary pyridinolines, osteocalcin and bone-specific alkaline phosphatase.

RESULTS

Overall, a high prevalence of hypovitaminosis D was diagnosed. In patients <50 years, low FN-BMD was significantly more frequent in HA than in HB, while PTH, pyridinolines, ABR and WFH score were associated with H type and severity. In patients >50 years, similarly low FN-BMD was observed in HA and HB, while ABR and WFH score were associated with H type and severity, being milder in HB.

CONCLUSIONS

Low bone mass is a frequent comorbidity in haemophilic patients of all ages, apart from those with MHB. Clinical and laboratory assessments confirm a higher bone impairment and faster bone resorption in HA compared with HB. Looking at H type and severity, MHB seems to have a normal bone metabolism and a less severe disease.

The role of sclerostin/dickkopf-1 and receptor activator of nuclear factor kB ligand/osteoprotegerin signalling pathways in the development of osteoporosis in patients with haemophilia A and B: A cross-sectional study

AIM

Haemophilia A and B are associated with reduced bone mineral density (BMD). The aim of this study was to assess circulating sclerostin and dickkopf-1 (Dkk-1), (inhibitors of osteoblastic differentiation), as well as the receptor activator of nuclear factor kB ligand (RANKL)/osteoprotegerin (OPG) system (the major regulator of osteoclastogenesis), in patients with haemophilia (PWH), their possible correlations with clinical risk factors and the effect of ibandronate on these markers.

METHODS

Eighty-nine male PWH (mean age 45.9 ± 15.3 years) and 30 age-matched healthy male controls participated. BMD was assessed by DXA. Sclerostin, Dkk-1, RANKL and OPG were measured in serum of patients, controls, as well as in ten patients receiving oral ibandronate (150 mg/mo), at baseline and after 12 months.

RESULTS

Patients with haemophilia had lower circulating sclerostin (median ± IQR: 47.4 ± 26.93 vs 250 ± 250 pmol/L, P < .001), Dkk-1 (21.24 ± 17.18 vs 26.16 ± 15.32pg/mL, P = .04) and higher levels of RANKL (0.23 ± 0.03 vs 0.04 ± 0.03 pmol/L, P = .001), RANKL/OPG ratio (0.063 ± 0.25 vs 0.005 ± 0.11, P = .001) compared with controls. Patients with low BMD had higher OPG concentrations compared to those with normal BMD. Sclerostin and RANKL/OPG correlated positively with BMD. Patients with severe haemophilia had lower sclerostin concentrations compared with those with mild or moderate disease. The degree of arthropathy negatively correlated with sclerostin and Dkk-1 levels. PWH who received ibandronate showed a decrease in serum Dkk-1 without any significant effect on sclerostin and RANKL/OPG.

CONCLUSIONS

Patients with haemophilia present increased osteoclastic activity coupled with compensatory increased osteoblastic activity. Ibandronate did not affect RANKL/OPG ratio, but it decreased Dkk-1.

Premature changes in trabecular and cortical microarchitecture result in decreased bone strength in hemophilia

Low bone density is a growing concern in aging men with hemophilia and may result in high-morbidity fragility fractures. Using high-resolution peripheral quantitative computed tomography (HR-pQCT), we demonstrate low trabecular and cortical bone density contributing to lower volumetric bone mineral density (BMD) at both distal radius and tibia in patients with hemophilia compared with age- and sex-matched controls. The low trabecular bone density found in hemophilia is attributed to significantly decreased trabecular number and increased separation; the lower cortical bone density results from thinner cortices, whereas cortical porosity is maintained. Microfinite element analysis from three-dimensional HR-pQCT images demonstrates that these microarchitectural deficits seen in patients with hemophilia translate into significantly lower estimated failure load (biomechanical bone strength) at the distal tibia and radius when compared with controls. In addition, an inverse association of joint score with BMD and failure load suggests the negative role of hemophilic arthropathy in bone density loss.

Evaluation of bone mineral density in Turkish children with severe haemophilia A: Ankara hospital experience

This study was conducted to understand the pathogenetic mechanisms that are involved in the development of bone loss in children with severe haemophilia A (HA). Fourty-four children with severe HA and 40 age- and gender-matched healthy control subjects were enrolled in this study. Markers of bone remodelling and osteoclast regulation including serum bone specific alkaline phosphatase, parathormone, 25-hydroxy-vitamin D(3) (25HOvitD(3)), osteocalcin and calcitonin levels were studied. Bone mineral density (BMD) was also studied in all children. The measurement of markers of bone remodelling and osteoclast regulation suggested increased osteoclast-mediated resorption activity in children with severe HA. Although serum parathormone levels were significantly increased, serum 25HOvitD(3) and osteocalcin levels were significantly reduced. BMD was significantly reduced in severe haemophilics compared with healthy controls. There was also significant inverse correlation between BMD z-score and total joint scores, and insignificant inverse correlation between BMD z-score and single joint scores. There were also significant inverse correlation between 25HOvitD(3) and osteocalcin levels and total joint scores. Children with severe HA could have significantly reduced BMD, compared with gender- and age-matched healthy control subjects. Our results of the markers of bone remodelling and osteoclast regulation suggested that increased osteoclast-mediated resorption and decreased osteoblastic activity in children with severe HA. All children with severe HA should be routinely screened in terms of BMD.

Comparative study of dual energy X-ray absorptiometry and quantitative ultrasonography with the use of biochemical markers of bone turnover in boys with haemophilia

Our aim was to evaluate bone status in boys with haemophilia using dual energy X-ray absorptiometry (DXA) and quantitative ultraSonography (QUS), and in addition, to compare these two methods with the use of biochemical markers of bone turnover. Twenty-six boys with a mean decimal age of 12.08 ± 4.44 years were included in the study which included a DXA scan at lumbar spine and radial, as well as tibial QUS. Serum levels of soluble receptor activator of nuclear factor κB ligand (sRANK-L), osteoprotegerin (OPG) and osteocalcin (OC) were measured and joint evaluation was performed using the Hemophilia Joint Health Score (HJHS). With regard to the study results, only 2 of 26 patients (7.7%) had bone mineral density (BMD) Z-scores < -2, and 4 patients (15.4%) had BMD Z-scores between -1 and -2. Only one patient had radial and other two had tibial QUS Z-scores < -2. No agreement was recorded between QUS and DXA in identifying patients at risk for osteoporosis (k = 0.275, P = 0.063). Haemophiliacs had significantly higher serum levels of sRANK-L (21.04 ± 4.78 vs. 18.58 ± 2.28 ng mL(-1), P = 0.038) and of OC (5.35 ± 2.29 vs. 3.09 ± 0.61 ng mL(-1), P = 0.002) and significantly decreased levels of OPG (15.78 ± 2.53 vs. 23.79 ± 4.39 pg mL(-1), P < 0.001) compared with controls. QUS Z-scores at tibia significantly correlated with HJH Scores (r = -0.450, P = 0.040), whereas lumbar BMD Z-scores significantly correlated with body mass index Z-scores (r = 0.500, P = 0.009). More studies are warranted to identify the most accurate densitometric method for assessing bone status in haemophiliacs.