IL-18 treatment of donor mice reduces the acute GVHD pathologic damage of liver and GI tract in the recipient.

Donor cells from IL-18–treated or diluent-treated (control) BALB/c mice were transplanted into B6 recipients as in Figure 1. Animals that underwent transplantation (n = 4/group) were killed; liver and gut were obtained for analysis on day 7 after BMT. Histology of the liver from the recipients of control-treated (A) and IL-18–treated (B) allogeneic donors. Coded slides were scored semiquantitatively for pathologic damage, as described in “Materials and methods.” BM transplant recipients of diluent-treated (▪, n = 4) or IL-18–treated (░, n = 4) allogeneic donors and of syngeneic donors (■, n = 4) are shown (C) (*P < .05; control [▪] vs IL-18 [░] allo group). Histology of the large bowel from the recipients of control-treated (D) and IL-18–treated (E) allogeneic donors is shown. Coded slides were scored semiquantitatively, as in “Materials and methods.” BMT recipients of diluent-treated (▪, n = 4) or IL-18–treated (░, n = 4) allogeneic donors and of syngeneic donors (■, n = 4) are shown (F). Total GVHD score: mean ±SE of the sum of scores for small bowel and colon from individual animals in each group (*P < .05 vs IL-18 allo group). Original magnification × 400 (A-B, D-E).