Involvement of the Central Nervous System in Rats with Acute Leukemia L 5222

Abstract

Young adult BD-IX rats made leukemic by intravenous infusion of 2×10^τ nucleated blood cells from leukemic donors (L 5222), showed lesions in the central nervous system 6 days after transfer when their leukocyte count was between 250,000 and 350,000 cells/μl. The brain was affected in only half of the animals, whereas all showed an infiltration of the meninges. Furthermore, all animals had extensive lesions in the spinal cord. The lesions consisted of nodules of leukemic cells and hemorrhages which were predominant in the lower half of the spinal cord and more abundant in the white than in the gray matter. Paraplegia appeared in some animals shortly before death. Since there is a consistent involvement of the meninges and spinal cord, the L 5222 leukemia seems to be a useful model for the study of leukemic infiltration of the central nervous system and the reaction to chemotherapy.

Chemotherapeutic Remissions in Wistar Furth Rat Acute Myelogenous Leukemia: A Model for Human AML

“…The pathophysiology of pro gressive untreated W/Fu AML is very similar to human AML including the detection of meningeal leukemia in 8°/o of autopsied rats. Further more, postchemotherapy relapse is associated with a high 93.3% incid ence of CNS involvement [manuscript in preparation] similar in neuroanatomic site to that recently reported in BD-IX rats with the L5222 leuke mia [1], a nonmyeloid leukemia [Hoelzer, personal commun.]. The W/Fu AML is a weakly antigenic leukemia derived in an inbred strain with an LD50 of 5X102 multiply passaged cells, and demonstrates no de tectable type C virus production in vivo [12].…”