Use of dexamethasone in acute rhabdomyolysis in LPIN1 deficiency

Introduction: LPIN1 deficiency is an autosomal recessive form of early childhood recurrent severe rhabdomyol-ysis. Although not completely lucid yet, LPIN1 has been shown to modulate endosomal-related pro-inflammatory responses via peroxisome proliferator-activated receptor alpha (PPAR alpha) and PPAR gamma coactivator 1 alpha (PGC-1 alpha). Treatment with anti-inflammatory agents such as dexamethasone has been proposed to improve the outcome. Case: We report a male toddler with recurrent episodes of complicated rhabdomyolysis, requiring prolonged intensive care unit admissions. Whole exome sequencing revealed a common homozygous 1.7 kb intragenic deletion in LPIN1. Despite optimal metabolic cares, the patient presented with an extremely high CK level where he benefited from intravenous dexamethasone (0.6 mg/Kg/day) for a period of 6 days. Results: Dexamethasone administration shortened the course of active rhabdomyolysis, intensive care admission and rehabilitation. It also prevented rhabdomyolysis-related complications such as kidney injury and compart-ment syndrome. Conclusion: Our patient showed a favorable response to parenteral dexamethasone, in addition to hyperhydration with IV fluids, sufficient calorie intake, and restricted dietary fat. The improvement with corticosteroids suggests an uncontrolled inflammatory response as the pathophysiology of LPIN1 deficiency.