Puerta del Mar University Hospital, Department of Pediatric Nephrology, Cadiz, Spain
Puerta del Mar University Hospital, Department of Pediatric Cardiology, Cadiz, Spain
J Clin Res Pediatr Endocrinol. 2022 Aug 25;14(3):344-349. doi: 10.4274/jcrpe.galenos.2021.2020.0287. Epub 2021 Mar 29.
X-linked hypophosphatemia (XLH) is a rare genetic disorder with X-linked dominant inheritance. Mutations in the gene increase fibroblast growth factor 23 (FGF23) concentrations, causing loss of phosphorus at the proximal tubule. Most pediatric patients debut in the first two years with short stature and bowed legs. Conventional treatment consists of oral supplements with phosphorus and calcitriol. Since 2018, burosumab has been approved as a novel therapeutic option for XLH, with promising results. The purpose of this study was to share our experience with two cases of XLH treated with burosumab. These patients presented with a broad phenotypical differences. One had the most severe radiological phenotype and developed left ventricular hypertrophy (LVH) and left ventricular dysfunction with preserved ejection fraction. Treatment with burosumab was well-tolerated and was followed by radiological stability and a striking improvement in both blood biochemistry and quality of life. The LVH was stable and left ventricular function normalized in the patient with cardiac involvement. In recent years many studies have been carried out to explain the role of FGF23 in cardiovascular damage, but the exact pathophysiological mechanisms are as yet unclear. The most intensively studied populations are patients with XLH or chronic kidney disease, as both are associated with high levels of FGF23. To date, cardiovascular involvement in XLH has been described in patients treated with conventional treatment, so it would be of interest to investigate if early use of burosumab at the time of diagnosis of XLH would prevent the occurrence of cardiovascular manifestations.
X 连锁低磷血症（XLH）是一种罕见的遗传性疾病，呈 X 连锁显性遗传。该基因的突变会增加成纤维细胞生长因子 23（FGF23）的浓度，导致近端肾小管磷丢失。大多数儿科患者在出生后的前两年出现身材矮小和弓形腿。传统的治疗方法包括口服磷和骨化三醇补充剂。自 2018 年以来，布罗索尤单抗已被批准为 XLH 的一种新的治疗选择，具有良好的效果。本研究旨在分享我们使用布罗索尤单抗治疗的两例 XLH 患者的经验。这些患者的表型差异广泛。其中一位患者的影像学表型最严重，出现左心室肥厚（LVH）和左心室收缩功能障碍，但射血分数正常。布罗索尤单抗治疗耐受性良好，随后影像学稳定，血液生化和生活质量显著改善。有心脏受累的患者 LVH 稳定，左心室功能正常化。近年来，许多研究旨在解释 FGF23 在心血管损伤中的作用，但确切的病理生理机制尚不清楚。研究最多的人群是 XLH 或慢性肾脏病患者，因为这两种疾病都与 FGF23 水平升高有关。迄今为止，在接受传统治疗的 XLH 患者中已经描述了心血管受累，因此研究 XLH 诊断时早期使用布罗索尤单抗是否可以预防心血管表现的发生将很有意义。
