Urinary prostaglandin D₂ and E₂ metabolites are elevated with disease severity in patients with Fukuyama congenital muscular dystrophy

Treatment approaches are lacking for Fukuyama congenital muscular dystrophy (FCMD), the second most common type of pediatric muscular dystrophy after Duchenne muscular dystrophy (DMD) in the Japanese population. Recent studies demonstrating the involvement of prostaglandin (PG) D₂ in DMD progression has led to the development of novel inhibitors targeting hematopoietic PGD₂ synthase. This study aimed to determine the role of PGD₂ in FCMD etiology in 42 patients with FCMD and 77 healthy age-matched individuals. Concentrations of tetranor-PGDM and tetranor-PGEM, the metabolites of PGD₂ and PGE₂, respectively, and creatinine were measured in spot urine samples. Mean tetranor-PGDM/creatinine and tetranor-PGEM/creatinine concentrations and tetranor-PGEM/tetranor-PGDM ratio were significantly higher in patients with FCMD than the healthy controls (5.3 ± 2.1 and 30.9 ± 52.3 ng/mg creatinine and 6.8 ± 2.0 vs. 3.4 ± 0.3 and 9.5 ± 0.9 ng/mg creatinine and 3.2 ± 0.3, respectively; p = 0.0011, p < 0.0001 and p < 0.0001, respectively). These metabolites were increased in patients with typical and severe FCMD phenotypes than in those with the mild FCMD phenotype, indicating their correlation with disease severity. These results implicate that PGD₂ and PGE₂ play important roles in FCMD pathogenesis and that novel hematopoietic PGD₂ synthase inhibitors and steroids used in DMD may also have therapeutic utility in FCMD.