[Immunohistochemistry of degenerative changes in the central nervous system in spastic paraparesis associated to human T lymphotropic virus type I (HTLV-I)].
BACKGROUND
Human T lymphotropic virus type I is associated with tropical spastic paraparesis, that is a chronic and progressive disease which damages specially the cortiespinal tracts. The pathogenesis of this degenerative process remains unknown.


OBJECTIVE
To identify histopathological aspects that could suggest a pathogenic hypothesis we studied immunohistochemical features in spinal cords obtained from patients that died due to progressive spastic paraparesis.


METHODS
Five males and five females, who died between 1990 and 2000, with a mean age of 52 years and mean disease duration of 8.6, were studied. All had a complete clinical and virological diagnosis. Samples were obtained from the frontal motor cortex and spinal cord (cervical, dorsal and lumbar segments), were fixed in formol (10%), included in paraffin, and stained with Haematoxylin and Luxol-fast-blue. Immunohistochemical study was made with anti-neurofilament antibodies 1:100 (M0762, DAKO), anti-APP 1:20 (Rabbit Pre Amyloid protein 51-2700 ZYMED), anti-tau 1:100 (A0024 DAKO) and anti-ubiquitine 1:50 (NCL UBIQm Novocastra).


RESULTS
All cases had demyelinization and axonal loss in the cortico-spinal tracts; distal and segmental demyelinization of Goll tract; axonal thickening, amyloid precursor protein deposits in the white matter; tau protein aggregation in the spinal cord oligodendrocytes; axonal ubiquitination of sensitive and motor tracts, and subcortical white matter. Neurona! injury was absent.


CONCLUSIONS
The systematic damage of motor and sensitive tracts of the spinal-cord and the absence of neurona! damage, defines a degenerative process limited to axons. This central axonopathie could be caused by a disturbance of axoplasmic transport.
Cartier R
Luis
L
Departamento de Ciencias Neurológicas, Facultad de Medicina, Universidad de Chile, Concepción, Chile. lcartier@med.uchile.cl
Vergara R
Carmen
C
Valenzuela P
María Antonieta
MA
D000328:Adult; D000368:Aged; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism; D001370:Axonal Transport / Q000502:physiology; D001369:Axons / Q000473:pathology / Q000821:virology; D005260:Female; D015368:Human T-lymphotropic virus 1; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000473:pathology* / Q000821:virology; D015493:Paraparesis, Tropical Spastic / Q000473:pathology* / Q000821:virology; D016133:Polymerase Chain Reaction; D013116:Spinal Cord / Q000473:pathology* / Q000821:virology; D013194:Staining and Labeling; D025801:Ubiquitin / Q000378:metabolism; D016875:tau Proteins / Q000378:metabolism
D016564:Amyloid beta-Protein Precursor; D025801:Ubiquitin; D016875:tau Proteins