Drop of Butyrylcholinesterase Activity after Cyclophosphamide Conditioning as a Predictive Marker of Liver Transplant-Related Complications and Its Correlation with Transplant-Related Mortality in Pediatric Hematopoietic Stem Cell Recipients

Transplant-related liver complications are a potentially fatal condition of hematopoietic stem cell transplantation (HSCT) in pediatric patients, actually representing one of the main factors involved in transplant-related mortality (TRM). The search for a specific marker capable of predicting the development of this condition is a relevant clinical issue. We have observed a variable reduction in serum butyrylcholinesterase (BChE) activity after a cyclophosphamide-containing conditioning regimen. This study aims to determine the cutoff of BChE activity reduction that might be a specific prognostic marker for liver complications after HSCT. Our results show that the reduction of BChE values below 2000 U/L the day before the transplantation is an indicator strongly associated with the transplant-related liver complications (p < 0.0001). The incidence of overall survival at 1 year was significantly higher in the BChE > 2000 U/L group compared to the BChE < 2000 U/L group (84.7% versus 58.5%, p < 0.001), while the TRM rate was significantly lower (8.1% versus 23.1%, p < 0.05). None of the patients undergoing prophylaxis with defibrotide developed severe liver complications. Starting defibrotide treatment at the first signs of hepatic dysfunction in patients with particularly low BChE activity levels reduces severe liver transplant-related complications.