Uric acid is a danger signal contributing to
inflammation. Its relevance to allogeneic
stem cell transplantation (alloSCT) derives from preclinical models where the depletion of
uric acid led to improved survival and reduced
graft-versus-host disease (GvHD). In a clinical pilot trial, peri-transplant
uric acid depletion reduced acute GvHD incidence. This prospective international multicenter study aimed to investigate the association of
uric acid serum levels before start of conditioning with alloSCT outcome. We included patients with acute
leukemia,
lymphoma or
myelodysplastic syndrome receiving a first matched sibling alloSCT from peripheral blood, regardless of conditioning. We compared outcomes between patients with high and low
uric acid levels with univariate- and multivariate analysis using a cause-specific Cox model. Twenty centers from 10 countries reported data on 366 alloSCT recipients. There were no significant differences in terms of baseline comorbidity and disease stage between the high- and low
uric acid group. Patients with
uric acid levels above median measured before start of conditioning did not significantly differ from the remaining in terms of acute GvHD grades II-IV incidence (Hazard ratio [HR] 1.5, 95% Confidence interval [CI]: 1.0-2.4, P=0.08). However, they had significantly shorter overall survival (HR 2.8, 95% CI: 1.7-4.7, P<0.0001) and progression free survival (HR 1.6, 95% CI: 1.1-2.4, P=0.025). Non-relapse mortality was significantly increased in alloSCT recipients with high
uric acid levels (HR 2.7, 95% CI: 1.4-5.0, P=0.003). Finally, the incidence of relapse after alloSCT was increased in patients with higher
uric acid levels (HR 1.6, 95% CI: 1.0-2.5, P=0.04). We conclude that high
uric acid levels before the start of conditioning correlate with increased mortality after alloSCT.