A Rare Cause of Elevated Chitotriosidase Activity: Glycogen Storage Disease Type IV.

Human chitinolytic enzyme named "chitotriosidase" takes part in the defense mechanism against pathogens and the homeostasis of innate immunity. Chitotriosidase was firstly reported to be markedly high in plasma of patients with Gaucher disease. Abnormal lipid laden macrophages are thought to be responsible for stimulating the secretion of chitotriosidase in Gaucher disease. Subsequently, various disorders have also been found to be associated with elevated levels of chitotriosidase. Chronic liver diseases that are also related with macrophage activation may have elevated chitotriosidase activity. We report the second case of the literature with glycogen storage disease (GSD) type IV that presented with high chitotriosidase levels. GSD type IV should be taken into consideration in case of elevated chitotriosidase levels, stigmas of chronic liver disease, and inconsistency of lysosomal storage diseases.