ABSTRACT
Visceral leishmaniasis (VL), also known as kala-azar, is an important public health problem. If not treated, virtually all clinically symptomatic patients die within months. The diagnosis is based on the Montenegro skin test (MST) and anti-Leishmania titers. Nevertheless, the time required for cured individuals living in a leishmaniasis-endemic area to present a positive skin test and negative anti-Leishmania serology is known. To determine the cellular and humoral immune response profile in relation to different times post-VL cure, a cross-sectional study was conducted on subjects from a kala-azar endemic area in Paço do Lumiar, MA, Brazil, on the basis of 1995-2005 notifications reported by the National Health Foundation/Regional Coordination of Maranhão. We visited cured individuals with a history of VL within the last 10 years. Seventy-four subjects (30 females) ranging in age from 1 to 44 years were included, all of them symptom free at the time of the study. A cellular immune response was observed in 73 (98.6 percent) subjects, whereas no significant antibody titers were detected by indirect immunofluorescence (IIF) in the sera of 69 (93.2 percent) cases. Ten years post-cure, 39 (52 percent) subjects had a positive MST and negative IIF reaction, while in one subject the skin and anti-Leishmania serology tests were negative. Two other subjects were positive in both tests 1 year after cure. These data suggest that a cellular immune response may still be present in subjects cured of VL regardless of post-cure time, and that the parasite persists in the host after clinical cure of the disease. This would explain the persistence of significant Leishmania sp antibody titers in some subjects after treatment.
Subject(s)
Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Male , Young Adult , Antibodies, Protozoan/blood , Immunity, Cellular/immunology , Leishmaniasis, Visceral/immunology , Antibodies, Protozoan/immunology , Cross-Sectional Studies , Fluorescent Antibody Technique, Indirect , Intradermal TestsABSTRACT
Avaliou-se a ocorrência de distúrbios na coagulação plasmática e na plaquetometria de cães infectados por Ehrlichia spp., durante 15 semanas após o contágio. Doze cães, entre machos e fêmeas, nascidos em estação experimental e com idades entre um e dois anos, foram usados no experimento. Nove cães foram infectados experimentalmente com sangue de cão naturalmente portador de Ehrlichia spp. e três foram mantidos como controle. As alterações na coagulação plasmática não diferiram entre cães infectados e não infectados. A plaquetometria oscilou durante as 15 semanas entre 61x10³/μL e 830x10³/μL, e o menor valor médio foi de 113x10³/μL na sexta semana após a infecção. Concluiu-se que a coagulação plasmática não apresentou alterações significativas nas 15 semanas após infecção e que a contagem plaquetária oscilou entre valores normais, elevados e reduzidos durante esse período.
The effect of Ehrlichia spp. in plasma coagulation and platelet count in dogs during 15 weeks after contamination was evaluated. Twelve male and female dogs one-to-two-year-old were born in the experimental station and were used for the experiment. Nine dogs were infected with blood of dogs naturally bearing Ehrlichia spp., and three were kept as controls. The variation of plasma coagulation did not significantly differ between infected and uninfected dogs. The platelet count oscillated during the period from 61x10³/μL to 830x10³/μL, and the lowest mean value was 113 x 10³/μL at the sixth week after contamination in infected dogs. In conclusion, the plasma coagulation did not significantly change and the platelet count oscillated between normal, increased, and reduced values during the first 15 weeks after Ehrlichia spp. contamination in dogs.
Subject(s)
Animals , Male , Female , Dogs , Blood Coagulation , Ehrlichia/isolation & purification , Models, Animal , Platelet Count/methodsABSTRACT
The specificity of human antileishmanial IgG and IgE antibodies to glycosylated antigens of Leishmania chagasi was evaluated. An ELISA was performed with soluble leishmanial antigen (SLA) and a panel of 95 sera including samples from patients with subclinical infection (SC) and visceral leishmaniasis (VL), subjects cured of visceral leishmaniasis (CVL), and from healthy individuals from endemic areas (HIEA). Antileishmanial IgG were verified for 18 (40 percent) of 45 SC subjects (mean absorbance of 0.49 ± 0.17). All nine sera from VL patients had such antibody (0.99 ± 0.21), while 11 (65 percent) of 17 CVL individuals were seropositive (0.46 ± 0.05). Only three (12 percent) of 24 HIEA controls reacted in IgG-ELISA. Antileishmanial IgE was detected in 26 (58 percent) of 45 SC patients (0.35 ± 0.14), and in all VL patients (0.65 ± 0.29). These antibodies were also detected in 13(76 percent) of 17 CVL subjects (0.42 ± 0.14) while all HIEA controls were seronegative. There was no correlation between antileishmanial IgG and IgE antibody absorbances. Mild periodate oxidation at acid pH of SLA carbohydrates drastically diminished its antigenicity in both IgG and IgE-ELISA, affecting mainly the antigens of 125, 102, 94, and 63 kDa as demonstrated by western immunoblotting.
Subject(s)
Humans , Animals , Antibodies, Protozoan , Antibody Specificity , Carbohydrates , Epitopes , Leishmania , Leishmaniasis, Visceral , Antigens, Protozoan , Blotting, Western , Case-Control Studies , Enzyme-Linked Immunosorbent Assay , Immunoglobulin E , Immunoglobulin GABSTRACT
Roedores silvestres, classificados como Holochilus brasiliensis nanus Thomas, 1897, foram capturados na cidade de Sao Bento, pertencente a Regiao da Baixada, do Estado do Maranhao, Brasil, naturalmente infectados com formas adultas de filaria, na cavidade peritoneal, e microfilarias sanguineas, assim como, com esquistossoma mansoni (vermes adultos e granulomas periovulares hepaticos; intestinais; pulmonares; esplenicos e pancreaticos). Animais nascidos em Bioterio, descendentes de Holochilus da Regiao da Baixada, foram infectados experimentalmente com Leishmania m. amazonensis e Schistosoma mansoni. Em observacoes semanais, foram encontradas lesoes teciduais, semelhantes as que se desenvolvem em hamsters infectados com Leishmania, e hipergamaglobulinemia. Nos esquistossomoticos, foram constatadas hipergamaglobulinemia e reacoes granulomatosas similares as encontradas nos animais infectados naturalmente. Foram observadas, tambem, lesoes hepatica graves, semelhantes as encontradas na esquistossomose humana. Estes achados sugerem a utilizacao do Holochilus b. nanus como modelo experimental destas tres doencas tropicais