Neuropathology of HTLV‐I‐Associated Myelopathy—A Report of Two Autopsy Cases—

Abstract

A neuropathological analysis was performed in two autopsy cases of HTLV‐I‐associated myelopathy. The thoracic spinal cords were most severely affected and the histopathological findings consisted of mononuclear cell infiltration, marked destruction of myelin and axons and astrocytic gliosis. More than half the infiltrated cells were positive for pan‐T cell marker; B cells were sparse in the parenchyma and subarachnoid spaces. CD4 and CD8 positive cells were found in the early stages of the lesions. CD8, however, predominated over CD4 in the other stages. It appeared that a chronic inflammatory process had started at the middle to lower thoracic cord and had extended gradually in both directions. The middle thoracic spinal cord is known to have the poorest blood supply, and the horizontal distribution of inflammatory cells at this region correlated with the most distal supply of the anterior spinal artery.

Virus-induced dysfunction of CD4+CD25+ T cells in patients with HTLV-I–associated neuroimmunological disease

“…In some HLA-A*201 HAM/ TSP patients, the frequency of Tax11-19-specific CTLs can be as high as 30% of total CD8 + T cells in peripheral blood (10) and even higher in cerebrospinal fluid (6). Neuropathological findings have demonstrated focal infiltrates of T cells and macrophages in the CNS (11). These observations have suggested that inflammatory T cells (particularly virus-specific CD8 + CTLs) may play an immunopathologic role in this disorder.…”

Occult diffuse involvement of supratentorial white matter detected by magnetic resonance imaging in HTLV-I carriers.

“…Although cognitive impairment is included in less common neurological findings in this disease (Osame and McArthur, 1992), several necropsy studies have revealed that the critical pathological findings including mononuclear infiltration or perivascular cuffing, which is prominent in the thoracic spinal cord, are commonly seen in the cerebral white matter of HAM/TSP patients (Izumo et al, 1989). Cerebral white matter involvement detected by magnetic resonance imaging (MRI) has been reported in an HTLV-I infected symptomless individual (Mattson et al, 1987) and the incidence of cerebral MRI abnormalities is significantly higher in patients with HAM/TSP than in the controls (Kira et al, 1988;Furukawa et al, 1989).…”

Neuropathology of two Brazilian autopsied cases of tropical spastic paraparesis / HTLV-I associated myelopathy (TSP/HAM) of long evolution

“…There are around 34 autopsied TSP/HAM cases described in the world [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] . This number of cases is limited, since León et al 18 , in a world meta-analytical analysis, reported on 1261 cases of TSP/HAM.…”