Hypercalciuria and kidney function in children with haemophilia

Prevalence of and risk factors for urolithiasis in Croatian patients with hemophilia

Urolithiasis may be more prevalent in patients with hemophilia (PWH) than in age-matched non-hemophilic males. We conducted a cross-sectional evaluation of 92 adult PWH at University Hospital Center Zagreb. The primary objective was to investigate the frequency of urolithiasis in adult PWH, and the secondary objective was to determine associated risk factors. Urolithiasis was diagnosed by ultrasound and other patient- and hemophilia-related parameters were recorded. The prevalence of urolithiasis was significantly higher among PWH than the reported prevalence in the general Croatian population (10.9% vs 5.9%; P = 0.042). Similarly, the incidence of urolithiasis during the course of the disease was significantly higher than the estimated cumulative lifetime incidence of urolithiasis in the Croatian population (25% vs 12%; P = 0.001). Multivariate analysis showed that arterial hypertension, the presence of inhibitors, hypercalciuria and hyperbilirubinemia were independent predictors of current urolithiasis (P < 0.05), and that hematuria (P = 0.051) and prior urinary infections (P = 0.059) were also relevant factors.Urolithiasis is a significant burden in adult PWH. Identifying associated risk factors might help in establishing strategies for earlier recognition and more successful prevention and treatment of urolithiasis.

Mechanisms of Bone Remodeling Disorder in Hemophilia

Hemophilia is caused by a lack of antihemophilic factor(s), for example, factor VIII (FVIII; hemophilia A) and factor IX (FIX; hemophilia B). Low bone mass is widely reported in epidemiological studies of hemophilia, and patients with hemophilia are at an increased risk of fracture. The detailed etiology of bone homeostasis imbalance in hemophilia is unclear. Clinical and experimental studies show that FVIII and FIX are involved in bone remodeling. However, it is likely that antihemophilic factors affect bone biology through thrombin pathways rather than via their own intrinsic properties. In addition, among patients with hemophilia, there are pathophysiological processes in several systems that might contribute to bone loss. This review summarizes studies on the association between hemophilia and bone remodeling, and might shed light on the challenges facing the care and prevention of osteoporosis and fracture in patients with hemophilia.

Vitamin D deficiency and osteoporosis in hemophilic children: an intermingled comorbidity

The aim of this study is to investigate bone state and factors affecting it in children with hemophilia. This is a case-control study that included 37 children with hemophilia and 37 healthy controls. The patients were selected from the outpatient pediatric hematology clinic of Fayoum University Hospital, Egypt. Bone mineral density, serum vitamin D, parathormone, calcium, phosphorus, and calcium creatinine ratio levels were evaluated. Vitamin D level and bone mineral density were significantly lower in hemophiliacs than in control group (P < 0.0001). About 43.2% of cases had moderate vitamin D deficiency, whereas 35.1% had mild deficiency. Vitamin D positively correlated with bone mineral density Z-score, whereas it negatively correlated with total joint score. Positive correlation between bone mineral density and age was also found. Serum levels of urea, urinary calcium creatinine ratio, and parathormone were found to be higher in cases than in control. Also, serum calcium level was found to be lower in patients than in controls. We concluded that vitamin D deficiency is an essential cause of decreased bone mineral density in hemophilic children. Hemophilic arthropathy with consecutive immobilization plays an important role in vitamin D deficiency and decreased bone mineral density.