Semiquantitative analysis of lung histopathology (A) and pulmonary function (B and C) 6 weeks after BMT. CBA mice received BMT as in Fig 1 (syngeneic □, allo TCD BM alone ▩, allo TCD BM and T cells ▪). Lungs were obtained after BMT and analyzed as described in Materials and Methods. Significant lung injury was present in animals receiving allogeneic T cells compared with syngeneic BMT recipients (**P < .01). TCD significantly reduced (#P < .01), but did not eliminate, lung injury and pathology scores after TCD BMT remained significantly increased compared with syngeneic controls (*P < .01). Pulmonary dynamic compliance (C_dyn) and airway conductance (G_L) were measured in live transplanted animals as described in Materials and Methods. Lung injury that developed in mice with GVHD was associated with significant decreases in C_dynand G_L compared with syngeneic controls (**P < .01). Mice receiving TCD BMT showed significant improvements in C_dyn (B) but not G_L (C) compared with animals with GVHD (#P = .01), but both measurements remained significantly reduced compared with syngeneic controls (*P < .01). Data are expressed as mean ± SEM. (n = 12 to 15 per group).