HTLV-II infection associated with a chronic neurodegenerative disease: clinical and molecular analysis.

HTLV II is a retrovirus endemic in some Amerindian tribes and spread worldwide with a high prevalence among intravenous drug abusers. It has three different genetic subtypes a, b, and d, defined mainly by the long terminal repeat (LTR) region. HTLV II has been associated with a neurodegenerative disease in few cases. We describe the first well-documented case in Brazil where the virus is endemic in isolated ethnic groups. The patient is a 55-year-old woman with a chronic and painful syndrome characterized by spastic paraparesis, hyperactive reflexes and spastic bladder. Somatosensory evoked potential indicates a thoracic spinal cord lesion. Computer tomography showed periventricular demyelination. Enzyme-linked immunosorbent assay was positive for HTLV I/II whereas the discriminatory Western blot was indeterminate. Molecular analysis of the Tax region revealed a HTLV II pattern that was also confirmed through sequencing the LTR region. Phylogenetic analysis of the LTR sequence shows an HTLV IIa subtype that clustered with the virus isolated from Kayapo Indians and Brazilian urban intravenous drug users. Indeterminate Western blots are frequently found using commercial kits, therefore we recommend that all cases in which a myelopathy is associated with an indeterminate serological result should be evaluated by PCR to determine the actual number of HTLV II associated myelopathy cases.

Intravenous methylprednisolone in HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP)

A mielopatia associada ao protovírus T-linfotrópico humano (HTLV-1), também conhecida como paraparesia espástica tropical associada ao HTLV-I (MAH/PET), constitui enfermedade imunomediada desencadeada pela infecçäo pelo HTLV-I. Nesta condiçäo tem sido demonstrada, particularmente em pacientes japoneses, boa resposta clínica à terapêutica com corticosteróides. Este efeito benéfico todavia näo foi encontrado em todas as regiöes do mundo. Pulsoterapia com metilprednisolona endovenosa tem sido utilizada com sucesso em pacientes com esclerose múltipla, outro exemplo de doença auto-imune do sistema nervoso central, especialmente durante as fases de exacerbaçäo da doença. Objetivando testar a eficácia da pulsoterapia com metilprednisolona em pacientes com MAH/PET, conduzimos estudo aberto em 23 doentes. Näo constatamos efeito benéfico significativo desta forma de tratamento na maioria dos enfermos estudados. Apenas um dos pacientes, o qual exibia o menor tempo de duraçäo de doença (cinco meses), obteve benefício a longo prazo. Acreditamos que tratamento imunossupressivos devam ser de maior utilidade naqueles doentes com menor tempo de evoluçäo, nos quais, possivelmente, há preponderância do processo inflamatório sobre o desmielinizante