RESUMO
Human T cell lymphotropic virus type 1 (HTLV-1) infection is associated with an exacerbated type 1 immune response and secretion of high levels of proinflammatory cytokines. In contrast, helminthic infection induces a type 2 immune response. In the present study, the cytokine profile in HTLV-1 carriers coinfected with helminths (Strongyloides stercoralis and/or Schistosoma mansoni) was compared with that in HTLV-1 carriers not coinfected with helminths. Levels of interferon (IFN)- gamma were higher in HTLV-1 carriers not coinfected with helminths than in HTLV-1 carriers coinfected with helminths (P<.05). The overall frequency of IFN- gamma -expressing CD8+ and CD4+ cells was decreased in HTLV-1 carriers coinfected with helminths (P<.05). The percentage of interleukin (IL)-5- and IL-10-expressing T cells in HTLV-1 carriers coinfected with helminths was higher than that in HTLV-1 carriers not coinfected with helminths (P<.05). Moreover, we found that the prevalence of helminthic infection was 7-fold higher in HTLV-1 carriers than in patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (P<.05). These data show that helminthic infection decreases activation of type 1 cells, which may influence the clinical outcome of HTLV-1 infection.
Assuntos
Portador Sadio/imunologia , Infecções por HTLV-I/complicações , Infecções por HTLV-I/imunologia , Helmintíase/complicações , Helmintíase/imunologia , Paraparesia Espástica Tropical/complicações , Adulto , Brasil , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Células Cultivadas , Feminino , Helmintíase/epidemiologia , Humanos , Interferon gama/análise , Interleucina-10/análise , Interleucina-5/análise , Masculino , Pessoa de Meia-Idade , Paraparesia Espástica Tropical/imunologia , Esquistossomose mansoni/complicações , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/imunologia , Estrongiloidíase/complicações , Estrongiloidíase/epidemiologia , Estrongiloidíase/imunologia , Carga ViralRESUMO
The epidemiology of Strongyloides stercoralis was studied in families of clinical (reference) cases and their neighbours at endemic foci in Jamaica. Thirteen foci were studied based on the place of residence of a reference case. For each household of a reference case, the 4 most proximal neighbourhood households (spatial controls) were included in the study. Out of 312 persons contacted 244 were followed up using questionaires, stool examimation and serology. Prevalence of infection based on based on stool examination was 3.5 percent and on ELISA 24.2 percent. Prevalence increased with age but was not related to gender. Reference cases were significantly older than the general study population. The prevalence of infection based on both serology and stool examination was significantly higher in referecne than in neighbouring households (the reference cases, themselves, were not included in the analysis). Furthermore, prevalence of infection was highest among persons who shared a bedroom with a reference case and decreased significantly with increasing spatial separation. This is indicative of close contact transmission which has not been previously shown for a geohelminth, but which is common among microparasites.(AU)
Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Lactente , Pessoa de Meia-Idade , Habitação , Strongyloides stercoralis/isolamento & purificação , Estrongiloidíase/epidemiologia , Distribuição por Idade , Análise por Conglomerados , Ensaio de Imunoadsorção Enzimática , Jamaica/epidemiologia , Prevalência , Distribuição por Sexo , Estatística , Estrongiloidíase/diagnósticoRESUMO
Strongyloides sterocalis infections were examined in families of clinical cases and also in those of their most proximal neighbours. Thirteen clinical cases in Kingston, Jamaica led to the identification of thirteen endemic foci. In addition to the clinical cases, 299 persons were contacted using questionnaires, stool examination and serology. Two hundred and thirty-one persons were fully compliant. The stool prevalence of S.sterocalis was 3.5 percent, while that based on ELISA was 24.2 percent (not including the 13 clinical cases). Both estimates of infection prevalence were significantly higher in the households of the clinical cases compared with the neighbours. The clinical cases were significantly older than the general study population. Furthermore, prevalence was highest among persons who shared a bedroom with a clinical case and decreased with spatial separation. These data strongly suggest that human strongyloides is a close-contact infection. This is likely to be facilitated by the direct phase of the parasite's life cycle and has significant implications for control of infections in endemic areas (AU)_
Assuntos
Humanos , Strongyloides stercoralis , Estrongiloidíase/transmissão , JamaicaRESUMO
Epidemilogic investigations of Strongyloides stercoralis and human T lymphotropic virus type I (HTLV-I) infections were conducted. Of 312 persons contacted, 209 (67 percent) provided blood and stool samples. Prevalences of S. stercoralis and HTLV-I antibodies were 26.8 percent and 8.1 percent (n = 198), respectively, and S. stercoralis larvae were detected in 4 percent. HTLV-I antibodies were significantly more common in persons positive for S. stercoralis larvae (10 [58.8 percent] of 17) compared with seropositive larvae-negative (4 [8.9 percent] of 45) or seronegative persons (9 [6.2 percent] of145) (P< .002). IgE levels increased with age in S. stercoralis-seropositive persons who were HTLV-I negative (P, .))2). However, there was an age-related depression of serum IgE in HTLV-I-positive persons (P < .003) that was sufficient to annul the IgE level-raising effect of S stercoralis seropositivity. The data provide evidence that HTLV-I infection is associated with increased frequency of larvae in the stool of S. stercoralis-infected persons and suggest that the mechanism may involve suppression of the IgE response (AU)
Assuntos
Humanos , 21003 , Masculino , Feminino , Infecções por HTLV-I/epidemiologia , Strongyloides , Estrongiloidíase/epidemiologia , Infecções por HTLV-I/complicações , Infecções por HTLV-I/imunologia , Jamaica/epidemiologia , Prevalência , Estrongiloidíase/complicações , Estrongiloidíase/imunologiaRESUMO
Epidemiological associations of Strongyloides stercoralis and Human T-Lymphotropic Virus Type-1 (HTLV-1) were investigated at eleven (11) foci endemic for strongyloidiasis in Jamaica. Each focus was identified on the basis of residency of a parasitologically-proved case of strongyloidiasis who presented at the University Hospital. Three hundred and twelve (312) persons were contacted, and blood and stool samples were collected for HTLV-1 and S. stercoralis serology and S. stercoralis coproculture, respectively. Overall compliance was 66.6 per cent. The prevalence of S. stercoralis in the pooled foci was 8.2 per cent including and 4.0 per cent excluding the hospital presenters, and for HTLV-1 it was 11.1 per cent and 8.1 per cent. Seroprevalence of S. stercoralis infection was 30 per cent and 26.8 per cent with and without the clinical cases, respectively. The prevalence of each infection was correlated with the age of the host (Spearman Rank Correlation, p<0.001). HTLV-1 was clustered in S. stercoralis larval shedders (58.8 per cent, n=17) compared with non-shedders (8.9 per cent, n=45) (Fisher's exact test, p<0.001), but particularly so among clinical cases 7 of whom (n=9) had HTLV-1 antibodies. The association was explained on the basis of age-related total serum IgE levels in HTLV-1/S. stercoralis infection cases. Individuals uninfected by S. stercoralis displayed a tendency for decreased IgE levels with age. This especially so in HTLV-1 carriers (ANCOVA: age * HTLV-1 interaction term t = 3.176, p<0.002). In marked contrast, S. stercoralis seropositive individuals had significantly elevated IgE titres in older persons compared with seronegative controls (ANCOVA: age * S. stercoralis interaction term t = 3.733, p<0.001). In persons seropositive for both HTLV-1 and S. stercoralis, however, the elevation of IgE levels previously observed in S. stercoralis positive individuals was completely subsumed by the negative influence of HTLV-1. It is suggested that impairment of host immunity by HTLV-1, and/or S. stercoralis in the presence of HTLV-1, exacerbates strongyloidiasis resulting in increased frequency of both larval shedding and parasite disease. Effect of S. stercoralis (S) and HTLV-1 (H) infection status on the host age/serum IgE association. This figure is designed to illustrate general trends; ungrouped data were used in statistical analyses (AU)
Assuntos
Humanos , Infecções por HTLV-I/complicações , Estrongiloidíase/complicações , Jamaica , Fatores EtáriosRESUMO
A subsample (1.6 percent; n = 13,260) of a healthy Jamaican population of food-handlers, studied by Murphy et al. (1991), who were serologically positive (n = 99) or negative (n = 113) for HTLV-I was investigated for intestinal parasitic infection using coprological methods. Helminth infection included Ascaris lumbricoides (2.8 percent), Trichuris trichiura (7.1 percent) and hookworms (6.1 percent). Entamoeba coli was found in 21.8 percent of samples, while E. hartmanni, Giardia lamblia, Endolimax nana, Iodamoeba butschlii and Chilomastrix mesnili each occurred in less than 10 percent of responders. T. trichiura displayed a higher prevalence (10.6 vs 3 percent (chi 2 = 4.623;p = 0.03) in the HTLV-I negative group. G. lamblia was detected more frequently among HTLV-I carriers compared to controls (9.1 and 3.5 percent respectively), but the association was not statistically significant (chi 2 = 2.825;p = 0.09). Infection with intestinal parasites is likely to occur independent of HTLV-I status: however, possible HTLV-I-induced immunosuppression may lead to higher intensity infections of certain organisms thus facilitating easier detection using parasitological methods. The immunomodulatory potential of HTLV-I infection in the aetiology of non-malignant diseases requires further investigation. (AU)
Assuntos
Humanos , Masculino , Feminino , Portador Sadio , Anticorpos Anti-HTLV-I/sangue , Infecções por HTLV-I/complicações , Enteropatias Parasitárias/complicações , Infecções por Nematoides/complicações , Infecções por Protozoários/complicações , Análise de Variância , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Enteropatias Parasitárias/epidemiologia , Jamaica/epidemiologia , Infecções por Nematoides/epidemiologia , Prevalência , Infecções por Protozoários/epidemiologiaRESUMO
In Japan, a positive association exists between the presence of serum antibodies to HTLV-1 and S. stercoralis. Also, it has been shown in Jamaica that coincidental HTLV-I infection may influence the outcome of treatment of S. stercoralis, or even underlie development of severe strongyloidiasis in some persons. However, the relationship between HTLV-I and S. stercoralis remains unclear. This paper highlights a hitherto unreported association between the occurrence of serum antibodies to HTLV-I, to S. stercoralis, and total serum IgE and strongyloidiasis in a Jamaican community. Blood and stool samples were collected from 67 persons from 6 geographical locations in Kingston. Sera were analysed for antibodies to S. stercoralis and HTLV-I, while stool samples were subjected to charcoal coproculture. As in Japan, individuals serologically positive for S. stercoralis tended to be infected more often with HTLV-I (33 per cent) than seronegative individuals (15 per cent), but the difference was not significant (two-tailed Fisher's exact test; P = 0.15). However, parasitologically-proved strongyloidiasis and HTLV-I seroconversion were strongly associated; while occurrence of HTLV-I was 67 per cent in individuals whose stool contained S. stercoralis larvae, it was only 15 per cent in their parasitologically negative counterparts (two-tailed Fisher's exact test; P = 0.01). Analyses strongly suggest that serological status for S. stercoralis HTLV-I affect IgE titres interaction term, F = 3.54; P = 0.06). IgE titres were lower in HTLV-I seropositive than seronegative individuals in both groups with and without S. stercoralis antibodies (HTLV-I main effect, F = 11.13; P = 0.002), but more strongly so in the former group (Table). S. stercoralis infection appeared to elevate reagin levels in some individuals in the HTLV-I negative group (n=13) (one-way ANOVA, F = 2.09; P - 0.15). In contrast, however, serum IgE titres were depressed in the group (n-5) with HTLV-I and concomitant S. stercoralis infection to levels perhaps even lower than those seen in HTLV-I individuals who did not have S. stercoralis (one-way ANOVA, F = 2.39; p = 0.15). Thus, it appears that HTLV-I and S. stercoralis operate synergistically to effect a significant reduction in IgE serum antibodies in infected individuals. If expressed at the level of the intestinal mucosa, this may permit increased rates of autoinfection of the parasite and result in correspondingly greater worm loads and patient morbidity. Lower levels of IgE antibodies against S. stercoralis are known to be associated with disseminated disease (AU)
Assuntos
Humanos , Estrongiloidíase/imunologia , Infecções por HTLV-I/complicações , Infecções por HTLV-I/imunologia , Jamaica , Anticorpos Anti-HTLV-IRESUMO
It is uncertain whether HTLV-I infection and Strongyloidiasis are related other than by chance. A consecutive series of Jamaican patients and controls have been analysed retrospectively for anti-Strongyloides and HTLV-1 antibodies to determine whether either influences the outcome of anti-helminthic therapy. Twenty-seven Jamaicans (16 M, 11F) mean age 50.2 years (range 16-85), who were found to have Strongyloides stercoralis infection were studied at the University Hospital of the West Indies. At the same time, a parasite-negative group of 13 patients (6M, 7F) of mean age 37.6 years, (range 23-53), with minor or no gastrointestinal disease served as controls. Pretreatment blood samples were taken from the Strongyloides group and controls. Serum was subsequently tested for IgG antibodies to filariform Strongyloides stercoralis larval antigens by ELISA and to HTLV-1 by ELISA and Western Blot. Outcome of the treatment of Strongyloidiasis with thiabendazole (25 -mg/kg b.d. orally for 10 days was determined at 2 months. Strongyloides reciprocal antibody titre was considerably higher in patients than controls, mean 870 vs 167; median 1,024 vs 8 (p<0.001). The sensitivity of the antibody test was 93 percent, but the specificity was 69 percent at best. There was no correlation with the anti-Strongyloides antibody titre and outcome with anti-helminthic therapy. HTLV-1 antibodies were found only in the Strongyloides patients, 12 of 27 (44 percent); antibody titres were high and positive with both test used: only one patient was known beforehand to have a disease associated with HTLV-1 infection. Of those 12 with HTLV-1 antibodies, 3 (25 percent) were cured, 7 still had the infection at 2 months, a further 2 had died or defaulted from follow-up. Of the 15 patients without HTLV-1 antibodies, 9 (60 percent) were cured, 3 still had the infection and 3 had died or defaulted. By chi-square analysis, the difference is significant whether one includes all the deaths and defaulters on an intention-to-treat basis or just those who were available at 2 months post-therapy. However, since none of the deaths were related to Stongyloidiasis or HTLV-1 injection, it is probably justifiable to exclude the deaths from the computation. These results show that the association of Strongyloidiasis and HTLV-1 is more than chance clustering. Not only is the prevalence of HTLV-1 antibodies far higher in the patients with Strongyloidiasis than in the normal Jamaican population, but that concurrent asymptomatic HTLV-1 infection interferes with anti-helminthic treatment (AU)