Plasma nitric oxide is associated with the occurrence of moderate to severe acute graft-versus-host disease in hemopoietic stem cell transplant recipients

Background and Objectives. Nitric oxide (NO) has been implicated as one of the mediators of acute graft-versus-host disease (GVHD) but reports on its measurement during hemopoietic stem cell transplantation (HSCT) in humans a re scarce. The present study was conducted to measure the plasma NO in HSCT recipients in order to delineate its relationships with acute GVHD. Design and Methods. Thirty-nine randomly selected patients undergoing HSCT were recruited. Thirty-one patients received an allogeneic transplant (ALLO ) from HLA-identical siblings (n=20), a haploidentical parent (n=1) or matc hed unrelated donors (n=10). Eight patients received an autologous (AUTO) H SCT Plasma levels of nitrite/nitrate (NO2-/NO3-), the end-product of NO, we re measured by chemiluminescence and the results were correlated with the o ccurrence and severity of acute GVHD. Results. Baseline NO2-/NO3- levels before HSCT were similar in the ALLO and AUTO patients (17.4 vs 21.1 mu mol/L, p >0.05). Significant increases in p lasma NO2-/NO3- (> 2 times the baseline level) were found in all 13 patient s with acute GVHD greater than or equal to grade 2, in 15 out of 18 patient s with acute GVHD grade less than or equal to 1 and 3 out of 8 patients rec eiving autologous HSCT. The increase in NO2-/NO3- among the three groups of patients was significantly different (135.5 vs 56.3 vs 36.6 mu mol/L, p < 0.001). The average NO production, calculated as the area under the curve, was also significantly differently among the three groups of patients (44.5 vs 30.0 Vs 23.8 mu mol/L, p < 0.001). Interpretation and Conclusions. Plasma NO in HSCT recipients is quantitativ ely associated with the occurrence of acute GVHD; its role remains to be de termined. (C) 2001, Ferrata Storti Foundation.