Toxic Storm Defused: Successful Use of Plasmapheresis and Continuous Renal Replacement Therapy in Propionic Acidemia

Propionic acidemia is a disorder of branched-chain amino acid metabolism, characterized by the accumulation of propionyl-CoA and its metabolites, leading to toxic effects on various systems, particularly the central nervous system. Acute metabolic decompensation – such as metabolic acidosis, hyperammonemic crises, or metabolic strokes – is often triggered by infection, fasting, or stress and can cause severe, irreversible neurological damage if untreated. Non-biochemical metabolic stroke, a rare complication, damages basal ganglia without acidosis or hyperammonemia. Another rare complication, secondary hemophagocytic lymphohistiocytosis (HLH), is a life-threatening systemic inflammatory hyperactivation. This case report describes an eight-year-old patient with propionic acidemia who developed both complications and was successfully treated.