[Molecular basis of hyperammonemia secondary to asparaginase: from therapeutic efficacity to toxicity]

Asparaginase is a key molecule in the treatment of acute lymphoblastic leukemia. It has improved response rates to chemotherapy. However, this is not without consequences. Therapeutic efficacy is sometimes achieved at the expense of toxicities that can lead to treatment discontinuation. Among them, patients can develop hyperammonemia which can sometimes be symptomatic leading to neurological disorders that can go as far as hyperammonemic coma or even death. Through a review of the current state of the literature, the objective is to understand the disparity of ammonia values as well as the clinical heterogeneity for a given ammonia concentration. A review of the literature including more than eighty publications was performed. The glutaminase activity of asparaginase seems to play an important role in the development of hyperammonia. At present, no risk factors have been identified for the development of hyperammonemia. On the other hand, the question of the impact of pre-analysis phase arises. Indeed, asparaginase continues to exert its activity in vitro, which leads to an artefactual increase in ammonia.