Diagnóstico de la leishmaniosis críptica en el perro. Expresión isotípica e idiotípica de los anticuerpos producidos en distintas fases de la infección
Studies about canine leishmaniosis show that clinic profile of this disease is variable, going from asymptomatic forms to sever pathology, and from spontaneously cure to fatal resolution. Seroepidemiological studies have revealed a large number of asymptomatic seropositive animals. Follow-up of these animals shows that some of them are in the prepatent infection period, others have regressive forms of the disease and others maintain low levels of antibodies without developing the disease for years. The low humoral immunoresponse characteristic of asymptomatic animals frequently places their antibody levels at the borderline of detectability where serological techniques dont discriminate between infected and noninfected animals. To determine the utility of different parasitology, immunology and molecular techniques to detect canine leishmaniosis, we applied various diagnostic methods for dogs from endemic areas and observed that antibody detection are not suitable tools to discriminate infected and noninfected animals, and parasitological methods and PCR offer more accurate results. The study of the level of specific IgG, IgG1, IgG2, and IgE in different phases of infection reveled that IgG1 and IgE are considered markers of the active disease and IgG2 expression is related to pathophysiological disorders. The idiotype expression of IgG1 and IgG2 was analyzed to detect markers related to infection, and to early phases of disease. The early Leishmania infantum infection is characterized by the recognition of polypeptide fractions of low molecular weight, mainly fractions of 14, 16 and 18 kDa by IgG1 and 14 and 16 kDa by IgG2. We have investigate the presence of anti-Leishmania antibodies in the urine of dogs with leishmaniosis and have determined that the presence of these antibodies is mainly caused by the passage into the urinary tract of blood-derived immunoglobulins and, to a lesser extent, by the local production. Dog is the main peridomestic reservoir for leishmaniosis caused by L. infantum, but some studies of molecular epidemiology show a great genetic variability. The study of feline leishmaniosis in Northwestern Mediterranean shows that specific antibodies are prevalent in cats from these ecoregions. So, it could be hypothesized that cats are a secondary reservoir host rather than simply incidental one.
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Advisor:Portús Vinyeta, Montserrat
School:Universitat de Barcelona
Source Type:Master's Thesis
Keywords:microbiologia i parasitologia sanitàries
Date of Publication:10/19/2007