Clinical and epidemiological aspects of HTLV-II infection in São Paulo, Brazil: presence of Tropical Spastic Paraparesis/HTLV-Associated Myelopathy (TSP/HAM) simile diagnosis in HIV-1-co-infected subjects / Aspectos clínicos e epidemiológicos da infecção pelo vírus linfotrópico de células T humanas do tipo 2 (HTLV-II) em São Paulo, Brasil: presença de paraparesia espástica tropical/mielopatia associada ao HTLV em pacientes co-infectados pelo HIV-1

In this study, the epidemiological and clinical features observed in solely HTLV-II-infected individuals were compared to those in patients co-infected with HIV-1. A total of 380 subjects attended at the HTLV Out-Patient Clinic in the Institute of Infectious Diseases "Emilio Ribas" (IIER), São Paulo, Brazil, were evaluated every 3-6 months for the last seven years by infectious disease specialists and neurologists. Using a testing algorithm that employs the enzyme immuno assay, Western Blot and polymerase chain reaction, it was found that 201 (53 percent) were HTLV-I positive and 50 (13 percent) were infected with HTLV-II. Thirty-seven (74 percent) of the HTLV-II reactors were co-infected with HIV-1. Of the 13 (26 percent) solely HTLV-II-infected subjects, urinary tract infection was diagnosed in three (23 percent), one case of skin vasculitis (8 percent) and two cases of lumbar pain and erectile dysfunction (15 percent), but none myelopathy case was observed. Among 37 co-infected with HIV-1, four cases (10 percent) presented with tropical spastic paraparesis/HTLV-associated myelopathy (TSP/HAM) simile. Two patients showed paraparesis as the initial symptom, two cases first presented with vesical and erectile disturbances, peripheral neuropathies were observed in other five patients (13 percent), and seven (19 percent) patients showed some neurological signal or symptoms, most of them with lumbar pain (five cases). The results obtained suggest that neurological manifestations may be more frequent in HTLV-II/HIV-1-infected subjects than those infected with HTLV-II only.

Neste estudo, as características epidemiológicas e clínicas observadas nos indivíduos infectados pelo HTLV-II foram comparadas com os pacientes co-infectados com HIV-1. Um total de 380 indivíduos atendidos na clínica do Ambulatório HTLV do Instituto de Infectologia "Emilio Ribas" (IIER), São Paulo, Brasil, foram avaliados a cada 3-6 meses nos últimos sete anos por especialistas em doenças infecciosas e neurologistas. Usando um algoritmo que emprega ensaio imunoenzimático, Western Blot e reação em cadeia de polimerase, foram incluídos 201 (53 por cento) pacientes infectados pelo HTLV-I e 50 (13 por cento) infectados pelo HTLV-II. Trinta e sete (74 por cento) eram co-infectados pelo HTLV-II e HIV-1. Dos 13 (26 por cento) indivíduos unicamente infectados pelo HTLV-II, infecção do trato urinário foi diagnosticada em três, um com vasculite e em dois casos dor lombar e disfunção erétil mas nenhum caso de mielopatia foi observado. Entre 37 pacientes co-infectados com HIV-1, quatro (10 por cento) casos apresentaram com paraparesia espástica tropical/mielopatia associada ao HTLV similar. Dois casos mostraram paraparesia como sintoma inicial, dois outros casos se apresentaram primeiramente com distúrbios vesical e erétil e as neuropatias periféricas foram observadas em cinco pacientes (13 por cento). Outros sete (19 por cento) pacientes mostraram algum sinal ou sintoma neurológico, a maioria deles com dor lombar (cinco casos). Os resultados sugerem que as manifestações neurológicas podem ser mais freqüentes em indivíduos co-infectados pelo HTLV-II/HIV-1 do que nos indivíduos infectados somente pelo HTLV-II.

The pathogenesis of tropical spastic paraparesis/human T-cell leukemia type I-associated myelopathy

Tropical spastic paraparesis/human T-cell leukemia type I-associated myelopathy (TSP/HAM) is caused by a human T-cell leukemia virus type I (HTLV-I) after a long incubation period. TSP/HAM is characterized by a chronic progressive paraparesis with sphincter disturbances, no/mild sensory loss, the absence of spinal cord compression and seropositivity for HTLV-I antibodies. The pathogenesis of this entity is not completely known and involves a multivariable phenomenon of immune system activation against the presence of HTLV-I antigens, leading to an inflammatory process and demyelination, mainly in the thoracic spinal cord. The current hypothesis about the pathogenesis of TSP/HAM is: 1) presence of HTLV-I antigens in the lumbar spinal cord, noted by an increased DNA HTLV-I load; 2) CTL either with their lytic functions or release/production of soluble factors, such as CC-chemokines, cytokines, and adhesion molecules; 3) the presence of Tax gene expression that activates T-cell proliferation or induces an inflammatory process in the spinal cord; 4) the presence of B cells with neutralizing antibody production, or complement activation by an immune complex phenomenon, and 5) lower IL-2 and IFN-gamma production and increased IL-10, indicating drive to a cytokine type 2 pattern in the TSP/HAM subjects and the existence of a genetic background such as some HLA haplotypes. All of these factors should be implicated in TSP/HAM and further studies are necessary to investigate their role in the development of TSP/HAM

Mielopatía asociada al HTLV-1: presentación de 2 casos en Argentina / HTLV-1 associated myelopathy: report of 2 cases from Argentina

La paraparesia espástica tropical en un cuadro relativamente frecuente en algunos países de América del Sur tales como Perú, Chile y Brasil. Describimos 2 pacientes con mielopatía asociada al HTLV-1 cuyo diagnóstico fue realizado hasta 3 años luego del inicio de los síntomas por falta de conocimiento de la entidad. Ambos casos se presentaron con compromiso medular lentamente progresivo que se manifestó inicialmente en miembros inferiores y se acompañó con incontinencia urinaria. La IRM del caso 1 mostró imágenes hiperintensas en T2 en médula cervical compatibles con desmielinización, mientras que el estudio tomográfico fue normal en el caso 2. Ambos pacientes presentaron serología positiva para HTLV-1 en LCR y sangre. La serología fue también positiva en el marido de la primer paciente. La mielopatía asociada al HTLV-1 es un cuadro relativamente frecuente en algunos países, vecinos a la Argentina; el conocimiento de las manifestaciones clínicas y de las características de laboratorio así como la forma de transmisión de la entidad, podría resultar de gran utilidad para efectuar el diagnóstico precoz y evitar la diseminación del cuadro