Spontaneous neutrophil activation in HTLV-1 infected patients

Human T cell lymphotropic Virus type-1 (HTLV-1) induces lymphocyte activation and proliferation, but little is known about the innate immune response due to HTLV-1 infection. We evaluated the percentage of neutrophils that metabolize Nitroblue tetrazolium (NBT) to formazan in HTLV-1 infected subjects and the association between neutrophil activation and IFN-gamma and TNF-alpha levels. Blood was collected from 35 HTLV-1 carriers, from 8 patients with HAM/TSP (HTLV-1- associated myelopathy); 22 healthy individuals were evaluated for spontaneous and lipopolysaccharide (LPS)-stimulated neutrophil activity (reduction of NBT to formazan). The production of IFN-gamma and TNF-alpha by unstimulated mononuclear cells was determined by ELISA. Spontaneous NBT levels, as well as spontaneous IFN-gamma and TNF-alpha production, were significantly higher (p<0.001) in HTLV-1 infected subjects than in healthy individuals. A trend towards a positive correlation was noted, with increasing percentage of NBT positive neutrophils and levels of IFN-gamma. The high IFN-gamma producing HTLV-1 patient group had significantly greater NBT than healthy controls, 43±24 percent and 17±4.8 percent respectively (p< 0.001), while no significant difference was observed between healthy controls and the low IFN-gamma-producing HTLV-1 patient group (30±20 percent). Spontaneous neutrophil activation is another marker of immune perturbation resulting from HTLV-1 infection. In vivo activation of neutrophils observed in HTLV-1 infected subjects is likely to be the same process that causes spontaneous IFN-gamma production, or it may partially result from direct IFN-gamma stimulation.

Infecçäo bacteriana em pacientes portadores de Leishmaniase visceral / Bacterial infection in patients with visceral leishmaniasis

Uma análise retrospectiva de 63 casos de Leishmaniose visceral (L.V.) revelou a presença, em 33 deles, de infecçäo bacteriana associada. Infecçöes do trato respiratório foram observadas em 13 (39,3%) pacientes, comprometimento de pele em 4 (12%), do trato urinário em 4 (12%), do ouvido em 3 (9%), e de orofaringe em 2 (6%). Sete (21%) pacientes apresentaram infecçäo concomitante em múltiplos sítios. Documentaçäo bacteriológica através de isolamneto do agente etiológico foi obtida em 10, näo havendo predominância estatisticamente significante de bactérias Gram positivas ou negativas. Houve 9 casos de óbito nestes 63 pacientes, sendo que em 8 deles a infecçäo bacteriana fazia parte do quadro clínico final. A análise das taxas de globulinas séricas revelou que infecçäo esteve presente de modo significativo (p < 0.05) em 15/20 (75%) dos pacientes com níveis de globulina sérica <- 4,0g%. Näo houve diferença significativa (p > 0.05) com relaçäo ao número de neutrófilos entre os grupos com e sem infecçäo bacteriana. Concluiu-se, portanto, que infecçäo bacteriana é um achado freqüente em pacientes com L.V. e se constitui num sinal de mau prognóstico da doença