Comparison of the histochemical changes in organs from animals with or without the EPCR blocking mAb.

The histopathologic responses of the animals given the blocking mAb plus sublethal E coli are compared with those given sublethalE coli alone. The tissues from animals in the E colialone group were recovered after death at T + 24 hours, whereas those from the blocking mAb group were recovered at the time of impending death (7 to 54 hours). No histopathologic studies of tissues from animals in the nonblocking mAb group were performed because we wished to compare survival time and biochemical parameters between the blocking and nonblocking groups. Evaluations of the parameters were performed in a blinded fashion. PMN influx, congestion, hemorrhage, necrosis, and thrombosis were graded on a scale from 0 to 4, with 0 being normal and 4 being severe. The histopathologic changes of the tissues recovered from the blocking mAb group are significantly more severe than those of the sublethal E coli control groupP < .001, with the exception of the adrenal and hepatic congestion.