Human T-lymphotropic virus type I or II (HTLV-I/II) associated with recurrent longitudinally extensive transverse myelitis (LETM): two case reports.

We describe two patients with recurrent longitudinally extensive transverse myelitis (LETM) associated with human T-lymphotropic virus type I or II (HTLV-I/II) exposure, and with neuromyelitis optica (NMO) immunoglobulin G (IgG) antibody in one case. HTLV-I/II are well known retroviral agents of myelopathy and B-cell dysfunction in humans. NMO is an autoimmune, demyelinating disorder of the central nervous system (CNS), also linked to B-cell dysfunction. Therefore, the immunopathogenesis of NMO may in some cases be linked to human HTLV exposure. Awareness of a possible association with human retroviral exposure will contribute to the optimal diagnosis and management of patients presenting with LETM or NMO.