ABSTRACT
The relationship between autoimmunity and malaria is not well understood. To determine whether autoimmune responses have a protective role during malaria, we studied the pattern of reactivity to plasmodial antigens of sera from 93 patients with 14 different autoimmune diseases (AID) who were not previously exposed to malaria. Sera from patients with 13 different AID reacted against Plasmodium falciparum by indirect fluorescent antibody test with frequencies varying from 33-100 percent. In addition, sera from 37 AID patients were tested for reactivity against Plasmodium yoelii 17XNL and the asexual blood stage forms of three different P. falciparum strains. In general, the frequency of reactive sera was higher against young trophozoites than schizonts (p < 0.05 for 2 strains), indicating that the antigenic determinants targeted by the tested AID sera might be more highly expressed by the former stage. The ability of monoclonal auto-antibodies (auto-Ab) to inhibit P. falciparum growth in vitro was also tested. Thirteen of the 18 monoclonal auto-Ab tested (72 percent), but none of the control monoclonal antibodies, inhibited parasite growth, in some cases by greater than 40 percent. We conclude that autoimmune responses mediated by auto-Ab may present anti-plasmodial activity.
Subject(s)
Humans , Antibodies, Protozoan/immunology , Antigens, Protozoan/immunology , Autoantibodies/immunology , Autoimmune Diseases/immunology , Immune Sera/immunology , Plasmodium falciparum/immunology , Antibodies, Monoclonal/immunology , Autoimmune Diseases/blood , Case-Control Studies , Cross Reactions , Fluorescent Antibody Technique, Indirect , Immune Sera , Plasmodium falciparum , Plasmodium falciparum/growth & developmentABSTRACT
Angiostrongilíase abdominal é uma zoonose causada pelo Angiostrongylus costaricensis, nematódeo que se localiza no interior de vasos mesentéricos. Nosso objetivo foi de abordar vários aspectos da história natural da parasitose, num estudo longitudinal clínico-sorológico. Um total de 179 indivíduos residentes em área rural no sul do Brasil, com transmissão ativa, foram seguidos por cinco anos. Neste período foram registradas prevalências de 28,2%, 4,2%, 10%, 20,2% e 2,8% e incidências de 0%, 5,9%, 8% e 1,5%. Tanto o sexo masculino quanto o feminino foram afetados com maiores frequências na faixa etária dos 30 aos 49 anos. Em 32 indivíduos, amostras de soro foram coletadas em todas as etapas e a reatividade de IgG detectada por ELISA foi variável e geralmente não persistindo mais do que um ano. Alguns padrões individuais foram sugestivos de re-infecção. Não houve associação com a ocorrência nem de dor abdominal nem com outras enteroparasitoses e não houve nenhum caso com diagnóstico confirmado (histopatológico) da infecção. Moluscos foram encontrados portando larvas infectantes de terceiro estadio, em algumas moradias, com uma prevalência geral de 16% e baixas cargas parasitárias. Em conclusão, a angiostrongilíase abdominal no sul do Brasil pode ser uma infecção frequente, porém com baixa morbidade e reatividade sorológica de gradual declínio.
Subject(s)
Adolescent , Adult , Aged , Animals , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Angiostrongylus cantonensis/immunology , Antibodies, Helminth/blood , Gastrointestinal Diseases/epidemiology , Strongylida Infections/epidemiology , Age Distribution , Brazil/epidemiology , Enzyme-Linked Immunosorbent Assay , Gastrointestinal Diseases/diagnosis , Gastrointestinal Diseases/parasitology , Incidence , Immunoglobulin G/blood , Immunoglobulin G/immunology , Longitudinal Studies , Mollusca/parasitology , Prevalence , Rural Population , Seroepidemiologic Studies , Strongylida Infections/diagnosisSubject(s)
Male , Female , Humans , Animals , Guinea Pigs , Mice , Angiostrongylus , Angiostrongylus/parasitology , Angiostrongylus/pathogenicityABSTRACT
There is a high prevalence of accidental human infection with Angiostrongylus costaricensis in some areas in southern Brazil and sometimes it presents as severe intestinal disease. Prophylaxis is important since there is no medical treatment for the disease. The ingestion of fruits and vegetables contaminated with the mucous secretion of infected molluscs (the intermediate hosts) is one of the proposed modes of transmission. Third stage larvae were incubated at 5 degrees C for 12 hours, in solutions of saturated sodium chloride, vinegar and sodium hypochlorite 1.5 per cent. The larvae had their viability tested through inoculation into albino mice. The percentage of larvae that established infection were 0 per cent in the group treated with sodium hypochloride, 1.8 per cent with NaCl and 2.4 per cent with vinegar. In conclusion, all substances tested reduced the population of viable larvae and may be useful in food decontamination, as a prophylactic measure for abdominal angiostrongylosis.