ABSTRACT
The factors determining the development or not of visceral leishmaniasis (VL) have not been completely identified, but a Leishmania-specific cellular immune response seems to play a fundamental role in the final control of infection. Few studies are available regarding the production of cytokines in the subclinical form of VL, with only the production of IFN-g and TNF-a known. The aim of the present study was to identify immunological markers for the oligosymptomatic or subclinical form of VL. A prospective cohort study was conducted on 784 children aged 0 to 5 years from an endemic area in the State of Maranhão, Brazil, between January 1998 and December 2001. During 30 consecutive months of follow-up, 33 children developed the oligosymptomatic form of the disease and 12 the acute form. During the clinical manifestations, serum cytokine levels were determined in 27 oligosymptomatic children and in nine patients with the acute form using a quantitative sandwich enzyme immunoassay. In the subclinical form of VL, variable levels of IL-2 were detected in 52.3 percent of the children, IL-12 in 85.2 percent, IFN-g in 48.1 percent, IL-10 in 88.9 percent, and TNF-a in 100.0 percent, with the last two cytokines showing significantly lower levels than in the acute form. IL-4 was not detected in oligosymptomatic individuals. Multiple discriminant analysis used to determine the profile or combination of cytokines predominating in the subclinical form revealed both a Leishmania resistance (Th1) and susceptibility (Th2) profile. The detection of both Th1 and Th2 cytokine profiles explains the self-limited evolution accompanied by the discrete alterations observed for the subclinical form of VL.
Subject(s)
Child, Preschool , Child , Humans , Infant, Newborn , Infant , Cytokines , Leishmaniasis, Visceral , Acute Disease , Biomarkers , Cohort Studies , Cytokines , Enzyme-Linked Immunosorbent Assay , Follow-Up Studies , Immunoenzyme Techniques , Leishmaniasis, Visceral , Prospective StudiesABSTRACT
Analisou-se o comportamento da LTA em crianças e adolescentes na faixa etária de 0-15 anos, provenientes das áreas endêmicas de Buriticupu (MA) e Corte de Pedra (BA). Nestas regiões, foram cadastrados 214 pacientes no periodo de 1982 a 1993, sendo 78 (36,4%) oriundos de Corte de Pedra e 136 (63,6%) de Buriticupu. Em Corte de Pedra a faixa etária predominante foi de 0-5 anos com 29 (37,2%) casos. Destes, 62% pertenciam ao sexo masculino. Na região de Buriticupu, 88 (64,7%) casos ocorreram na faixa etária de 11-15 anos, sendo 73,8% do sexo masculino. Nas regiões estudadas, houve predomínio da cor parda com 65,4% em Corte de Pedra, e 75% em Buriticupu. Vinte e seis (33,3%) crianças provenientes de Corte de Pedra eram lavradores, sendo o sexo masculino maioria (57,7%), existindo diferença estatística significante (c2 = 11,21 p = 0,05). Vinte e um (80,8%) casos da ocupação lavrador pertenciam a faixa etária de 11-15 anos. Em Buriticupu 37,5% das crianças eram estudantes, destes 30,2% foram lavradores, todos do sexo masculino (c2 = 32,3 p = 0,05). A maioria dos lavradores, 39 (44,3%) casos eram da faixa etária de 11-15 anos. Tanto em Buriticupu como Corte de Pedra houve predomínio da lesão única, 57,7% e 53,7% dos casos, respectivamente. A duração das lesões destacou-se no período de 1 a 3 meses, com 54 (69,2%) casos em Corte de Pedra e 83 (61%) em Buriticupu (c2 = 11,82 p = 0,05). Quanto a localização das lesões, observou-se que nas duas regiões estudadas os MMII foram predominantes com 58,9% em Corte de Pedra e 77,2% em Buriticupu (c2 = 27,9 p = 0,05), havendo maior ocorrência de lesão ulcerada nas duas regiões. IDRM foi positiva em 61 (78,2%) crianças provenientes de Corte de Pedra, não havendo diferença estatística significativa entre as faixas etárias e a positividade do teste (c2 = 0,0669 p = 0,05).
A comparative study on children aged 0-15 years, with American tegumentary leishmaniasis (ATL), in the endemic regions of Buriticupu (MA) and Corte de Pedra (BA), whereby 214 cases were detected between 1982 and 1993, 78 (36.4%) of them originated from Corte de Pedra and 136 (63.6%) from Buriticupu. In Corte de Pedra, most cases were observed in patients aged between 0-5 years. Twenty nine (37.2%) cases; 62% of those were male. In the Buriticupu region, 88 (64.7%) cases occurred in patients of 11-15 years of age, where in 73.8% consisted of male. In both researched regions, brunetts were predominant, with a ratio of 65.4% in Corte de Pedra and 75% in Buriticupu. Twenty six (33.3%) children in the village of Corte de Pedra were farmers, predominantly male (57.7%), generating statistical significance (chi 2 = 11.21). Twenty one (80.8%) farmers were aged 11-15 years. Thirty seven and a half per cent of the children from Buriticupu were students, however, 41 (30.2%) were farmers, representing 39 (44.3%) cases; all of them male. Both in Buriticupu and Corte de Pedra, the unique wound was predominant, corresponding to 57.7% and 53.7%, respectively. The wounding time stood out from one to three months, with 45 (69.2%) cases in Corte de Pedra and 73 (61%) in Buriticupu (chi 2 = 11.82). As to the wound locations, it has been observed that they were most constantly present on the lower limbs, with 77.2% in Corte de Pedra and 58.9% in Buriticupu (chi 2 = 27.9). The cutaneous case mostly found in Corte de Pedra was the ulcerous one (91%). IDRM was positive in 61 (78.2%) children originated from Corte de Pedra, wherein no statistical difference was detected between age ratio and positivity of the test (chi 2 = 0.0669).