Hepatic toxicity associated with αCD40 monotherapy is reversed with TLR7 agonism. (A,B) Kinetic analysis of serum transaminases. Mice were treated with PBS, 100 μg αCD40, 100 μg TLR7*, or both intravenously. Serum was isolated at various time points afterward, and serum levels of alanine transaminase (A) or aspartate transaminase (B) were measured as described. Data are representative of 3 independent experiments, with n = 3 to 8 mice per group, per time point. (C-F) Histologic analysis of livers treated with PBS (C), 100 μg αCD40 (D), 100 μg TLR7* (E), or 100 μg αCD40 and 100 μg TLR7* (F) for 48 hours. (G) Semiquantitative assessment of histopathologic changes in livers from mice treated as above for 48 hours. Data are pooled from 2 independent experiments, with n = 6 mice in each treatment group. P = .026 by Mann-Whitney nonparametric test.