Biomedical subjects

Reinhard Burger

Publications and source records attributed to Reinhard Burger.

3 recordsLinked to original sources

PubMed2006

Failure to detect Borna disease virus antigen and RNA in human blood.

BACKGROUND: Borna disease virus (BDV) is the etiological agent of a rare progressive meningoencephalitis that affects mostly horses and sheep. There is an unresolved debate whether also humans are susceptible to infection with BDV and if so, whether this might be associated with neuropsychiatric diseases. One recent key publication employing an ELISA-based sandwich assay reported prevalences of BDV-specific circulating immune complexes in human blood as high as 30% in the normal population and up to 100% in psychiatric patients [Bode L, Reckwald P, Severus WE, Stoyloff R, Ferszt R, Dietrich DE, et al. Borna disease virus-specific circulating immune complexes, antigenemia, and free antibodies--the key marker triplet determining infection and prevailing in severe mood disorders. Mol Psychiatry 2001;6(4):481-91]. However, this report did not examine for the physical presence of BDV antigens in human blood, and therefore, these seemingly high prevalences may not reflect Borna virus-specific signals. OBJECTIVES: We attempted to correlate string plasma signals in the particular sandwich ELISA system with the presence of BDV antigens. STUDY DESIGN: Four preselected plasma samples with high reactivity in the described assay were analysed by immunoaffinity purification and highly sensitive real-time RT-PCR. RESULTS: Neither method did provide any evidence for the presence of viral proteins or nucleic acids. CONCLUSIONS: Our findings argue against the concept that the described sandwich ELISA reliably detects BDV-specific antigens in human blood, therefore do not support the hypothesis that BDV is a pathogen of humans.

Antigens, Viral↗

PubMed2003

Intravenously applied IgG stimulates complement attenuation in a complement-dependent autoimmune disease at the amplifying C3 convertase level.

Intravenously applied normal human immunoglobulin G (IgG) has anti-inflammatory effects in the treatment of autoimmune diseases. Systemic inflammation can originate from an overreacting amplification loop of the complement system. In blood, C3b2-containing complexes maintain complement amplification much better than the extremely short-lived C3b. Therefore, in patients with the complement-dependent autoimmune disease, dermatomyositis, we studied whether intravenously applied normal human IgG (IVIG) stimulated in vivo inactivation of these complexes. In the course of IVIG treatment, clinically effective in 6 of 8 patients, the concentration of C3b2-containing complexes dropped to 37% +/- 14% (n = 6) of the pretreatment level when having infused 0.5 g IgG/kg body weight, increased marginally and in parallel to factor Bb thereafter until full-dose IgG was infused. By day 14 following infusion of 2 g IgG/kg body weight the concentration of C3b2-containing complexes was 66% +/- 19%. The plasma concentration of C3 remained constant in myopathic or increased by 15% to 20% in amyopathic patients. In contrast to this, IVIG infusion was associated with consumption of up to 40% of plasma C4 at day 1 to 2 after completion of IVIG infusion. Thus, IVIG had an immediate and long-lasting attenuating effect on complement amplification in vivo, despite the fact that it induced classical complement pathway activation.

Autoimmune Diseases↗

PubMed2003

Effector functions of CD8-positive guinea pig T lymphocytes.

The response of guinea pig T lymphocytes to different stimuli was analysed with focus on the functions of CD8-positive T cells, which so far had been poorly defined in this animal model. For identification and purification of guinea pig cytotoxic T lymphocytes, three monoclonal antibodies, directed against the CD8 differentiation antigen were characterized and compared with respect to expression pattern and biochemical characteristics of the corresponding cell surface antigen. The antibodies were used for the identification of the cytotoxic T lymphocyte subpopulation within alloreactive T cell lines, and for the depletion of CD8-positive cells in in vitro assays. Purified CD4- and CD8-positive cells were tested for their ability to proliferate in response to antigen, mitogen or anti-guinea pig Thy-1 monoclonal antibodies. Both, CD4- and CD8-positive cells showed IL-2 release and subsequent proliferation after polyclonal stimulation. Cytotoxic activity in CD8-positive alloreactive T cells was expressed in vitro only after repeated stimulation.

Animals↗