Histopathology of Lymphocytic Choriomeningitis in Mice Spared by Amethopterin

Summary Mice infected with lymphocytic choriomeningitis virus in doses which were otherwise uniformly fatal were spared by administration of amethopterin. Histological examination of spared animals at intervals ranging from 5 to 57 days revealed greatly modified objective evidence of disease in the majority of these animals. In the acute stage, 82% of the mice showed no disease or extremely modified lesions of LCM. In the chronic stage, 33% showed similarly modified LCM. The remaining mice in both groups showed lesions of active LCM, even as late as 56 days after inoculation. Practically all spared mice gave evidence of multiplication of the virus in the central nervous system.