UNASSIGNED: Fibroblast growth factor 23 (FGF23)-related hypophosphatemic rickets is observed in both genetic and acquired disorders. Various reports describe FGF23-related hypophosphatemia with systemic lupus erythematosus (SLE), although FGF23-related hypophosphatemia preceding the onset of SLE has never been described. Here, we report the case of a 9-year-old female with FGF23-related hypophosphatemic rickets preceding the onset of SLE. The patient presented to us with arthralgia in the lower extremities and abnormality of gait lasting for 8 months. She was diagnosed with FGF23 hypophosphatemic rickets due to the presence of hypophosphatemic rickets symptoms and high serum levels of FGF23. Additional examination excluded hereditary diseases and tumor-induced osteomalacia. Three months after diagnosis of FGF23-related hypophosphatemic rickets, she developed nephritis and was diagnosed with SLE. She was treated with prednisolone, hemodialysis, and disease-modifying drugs, as well as oral sodium phosphate to improve hypophosphatemia. Serum anti-double-stranded DNA antibody (dsDNAab) and plasma tumor necrosis factor-α (TNF-α) were elevated at FGF23-related hypophosphatemic rickets diagnosis. During the clinical course, serum FGF23 correlated with dsDNAab and TNF-α serum levels, which are involved in SLE disease activity. In this case, FGF23-related hypophosphatemic rickets without hereditary diseases or tumor-induced osteomalacia occurred before the appearance of juvenile SLE symptoms, and serum FGF23 represented disease activity in SLE.
■成纤维细胞生长因子23(FGF23)相关的低磷血症性病在遗传和获得性疾病中均有观察。各种报告描述了FGF23相关的低磷酸盐血症伴系统性红斑狼疮(SLE),尽管从未描述过SLE发作前FGF23相关的低磷酸盐血症。这里,我们报道了1例9岁女性在SLE发病前出现FGF23相关的低磷血症病的病例.患者表现为下肢关节痛和步态异常,持续8个月。她被诊断为FGF23低磷酸盐血症病,原因是存在低磷酸盐血症病症状和血清FGF23水平高。额外的检查排除了遗传性疾病和肿瘤诱导的骨软化症。诊断FGF23相关的低磷血症病三个月后,她出现肾炎并被诊断为SLE.她接受了强的松龙治疗,血液透析,和改善疾病的药物,以及口服磷酸钠改善低磷血症。血清抗双链DNA抗体(dsDNAab)和血浆肿瘤坏死因子-α(TNF-α)在FGF23相关的低磷酸盐血症病诊断中升高。在临床过程中,血清FGF23与dsDNAab和TNF-α血清水平相关,与SLE疾病活动有关。在这种情况下,FGF23相关的低磷血症病没有遗传性疾病或肿瘤诱导的骨软化发生在青少年SLE症状出现之前,血清FGF23代表SLE的疾病活动。