The rate of severe infections declined after GT. Severe infections were defined as infections leading to, or prolonging, hospitalization. The number of patients contributing to each data point and the number of severe infections reported are indicated on the graph. Severe infections in the 3 months immediately following GT were not included in the analysis. Severe infections after the reintroduction of long-term PEG-ADA treatment (patients 2, 8, and 17) were excluded from the analysis.