RESUMO
Human T-cell lymphotropic virus type I (HTLV-I) is associated with adult T-cell leukemia (ATL) and tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM). Other inflammatory disorders may occur in HTLV-I-infected patients, such as sicca syndrome resembling Sjogren's syndrome. The sicca syndrome may be the unique clinical manifestation of HTLV-I infection, but is associated frequently with TSP/HAM, which could suggest that sicca syndrome might be an early event in disease progression to TSP/HAM in some cases. We investigated whether peculiar pX and LTR mutations could be related to sicca syndrome, or might argue the existence of clinical progression to TSP/HAM. pX, especially pX(I), pX(II), and pX(IV) ORFs corresponding to Tax cytotoxic T-lymphocyte epitopes, and LTR regions from Caribbean patients who have sicca sydrome with or without TSP/HAM, ATL patients, and healthy carriers were sequenced. The sequences were aligned and compared with ATK-1 prototype and published sequences. LTR sequences exhibited 1.5-2.4 percent of divergence with ATK-1. pX-sequenced regions showed a lower homology within p12(I) encoding sequences. Only few mutations were found within functionally important regions, but were not associated specifically with the clinical status. Finally, no existence of clinical progression to TSP/HAM were found. It would be of interest to study the clinical evolution of HTLV-I-sicca syndrome in patients and to determine HTLV-I sequences from peripheral blood and salivary glands at different stages. Copyright 1999 Wiley-Liss, Inc.(Au)
Assuntos
Idoso , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vírus Linfotrópico T Tipo 1 Humano/genética , Infecções por HTLV-I/virologia , Paraparesia Espástica Tropical/diagnóstico , Análise de Sequência de DNA/métodos , Síndrome de Sjogren/virologia , Sequências Repetidas Terminais/genética , Idoso de 80 Anos ou mais , Sequência de Bases , Região do Caribe , Progressão da Doença , Genoma Viral , Dados de Sequência Molecular , Mutação , Fases de Leitura Aberta/genética , Paraparesia Espástica Tropical/virologia , Alinhamento de SequênciaRESUMO
Infective dermatitis (ID) of Jamaican children, a distinctive pattern of dermatitis first described in Jamaican children in 1966 was found to be associated with human T-cell lymphotropic virus type (HTLV-I) infection in 1990. Since then, ID has been reported from other HTLV-I endemic areas. Further studies have confirmed the HTLV-I association and have demonstrated immunologic abnormalities in cellular and humoral immune systems as well as at the subcellular level. Viral genome has been detected in cultured skin biopsy material, and genetic factors may predispose people to the development of ID. Transmission of HTLV-I infection in ID appears to be from mother to infant via breast milk. Present therapy is with long-term antibotics to control bacterial infection and hence the dermatitis. Complications are frequent and include crusted scabies, corneal opacities, chronic bronchiectasis, parasitic worm infestation, early death, and progression to more severe HTLV-I associated disorders such as adult T-cell leukemia/lymphoma and HTLV-I associated myelopathy/tropical spastic paraparesis. Future studies are planned to determine the precise immunologic defect, the role of socioeconomic and nutritional factors, and the natural history. Intervention studies to limit breast feeding and hence HTLV-I transmission are also planned.(AU)
