[HAM rat disease: an animal model of HTLV-I infection].

We have established a model of HTLV-I infection in the WKAH rat strain. By inoculating MT-2, an HTLV-I producing human T cell line, HAM rat disease, a demyelinating disease resembling human HAM/TSP, developed in the WKAH rat strain. The affected lesion in the HAM rat disease is distributed symmetrically in the lateral and anterior funiculi of the thoratic spinal cord similar to that of HAM/TSP, and the histological features are also mimicked except for infiltration of lymphocytes. Using this model, it is suggested that the apoptosis of oligodendrocyte appears to be the most important process implicated in the demyelinating process of the spinal cord. The pathogenesis of HAM/TSP is also discussed herein.