%0 Case Reports
%T FGF23-related hypophosphatemic rickets preceding the onset of systemic lupus erythematosus: A juvenile case.
%A Tabei Y
%A Ohtsu Y
%A Shimada M
%A Wada A
%A Hamajima E
%A Osawa Y
%A Takizawa T
%J Clin Case Rep
%V 12
%N 1
%D 2024 Jan
%M 38223518
暂无%R 10.1002/ccr3.8420
%X <B>UNASSIGNED: </B>This case report describes the clinical course of a juvenile female with FGF23-related hypophosphatemic rickets preceding the onset of SLE. Our study demonstrates the possibility of hypophosphatemic rickets as an early symptom of SLE.<BR><B>UNASSIGNED: </B>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.