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Selected Publication:
Custovic, J.
Entwicklung der Immunantwort bei Erythema migrans unter besonderer Berücksichtigung des Decorin bindenden Proteins A (DbpA)
[ Diplomarbeit/Master Thesis ] Graz Medical University ; 2009. pp.69.
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- Authors Med Uni Graz:
- Advisor:
- Aberer Elisabeth
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- Abstract:
- The Lyme borreliosis is the most common tick born infection and is being caused by Borrelia burgdorferi, a spirochetal bacterium. The disease spectrum is very wide and varies with the immunity of the affected person and the relevant Borrelia burgdorferi species. For the laboratory diagnosis of borreliosis a two-tier approach is the nowadays standard: 1. Serological search test (ELISA) 2. Confirmatory test (immunoblot). Due to the different expression of the bacterial antigens in the early and late stage of the infection, the antibody response in the infected organism varies with the duration of the infection. Our goal was to determine the time point of serological conversion of IgM and IgG antibodies in erythema migrans patients. The Decorin binding protein A (Dbp A = p 18) was investigated in detail in the current study. It is a surface antigen that binds to the extracellular matrix and is of great importance for the persistence of the Borrelia in tissue and the disease itself. It was our aim to determine the timepoint when the Dbp A antibodies would become detectable, how they were related to other antibodies and whether it was possible to draw a distinction between a latent and a new infection. To our knowledge this has not been studied yet and the role of DbpA antibodies has not yet been determined. 61 patients were tested for the development of IgM and IgG antibodies with ELISA and immunoblot before and after therapy. 20 of those sera were available for a recombinant immunoblot testing before and after therapy. Both IgM and IgG immune response showed a undulatory distribution in the increase and decrease of the serological positivity over the weeks with peaks in week 4 and 8 for IgG and week 5 and 9 for IgM antibodies. Overall there were 41% IgM and 22% IgG antibody positive sera before therapy. After therapy there was an increase in the seropositivity of IgM and a decrease in the seropositivity of IgG antibodies. The number of 20 patients investigated for p 18 antibodies was too low in order to be able to statistically determine the exact time of the serological conversion for p 18, but it seemed that the possible conversion timepoint could be after week 4 of the infection. The p 18 antibodies were often combined with VlsE, p100 and p 41 antibodies and seemed, when clearly positive, to indicate a prior infection. At this moment serological testing alone fails to provide a sufficient diagnosis of an active Borreliosis. It can only be diagnosed in combination with the clinical symptoms.