Dorothea Stahl

Bio: Dorothea Stahl is an academic researcher from University of Münster. The author has contributed to research in topics: Antibody & Autoantibody. The author has an hindex of 7, co-authored 11 publications receiving 117 citations. Previous affiliations of Dorothea Stahl include Pierre-and-Marie-Curie University.

IgG2 containing IgM-IgG immune complexes predominate in normal human plasma, but not in plasma of patients with warm autoimmune haemolytic anaemia.

Abstract: The different physicochemical and sterical properties of IgG subclasses may favour a selective enrichment of defined IgG subclasses in IgM-IgG immune complexes (IC) of human plasma under physiological conditions. Such enrichment of IgG subclasses in IgM-IgG IC of plasma may differ from the normal IgG subclass distribution in plasma itself, and contribute to the physiological functions of IgM-IgG IC. Systematic studies on the IgG subclass distribution in IgM-IgG IC in humans are lacking. Using specific analytical techniques to characterise IgM-IgG IC in human plasma (i.e. fast protein liquid chromatography, enzyme-linked immunosorbent assay, affinity biosensor technology), and taking warm autoimmune haemolytic anaemia (WAIHA) of humans as a disease model, we here demonstrate that: (i) IgG2 is the predominant IgG subclass in IgM-IgG IC under physiological conditions, (ii) the predominance of IgG2 within IgM-IgG IC may get lost in polyclonal IgG-mediated autoimmune disease and (iii) the IgG subclass distribution in IgM-IgG IC influences the interaction between IC and blood cells involved in antigen presentation. The data presented here therefore extend the physiological function of IgG2, which is the protective immune response towards carbohydrate antigens in bacterial infections, and suggest IgG2-dependent regulation of immune responses to self-immunoglobulin in humans. The disturbed IgG subclass distribution in IgM-IgG IC of patients with WAIHA might influence activity of self-reactive B cells involved in the pathophysiology of the disease.

Regulation of the immune response by natural IgM: lessons from warm autoimmune hemolytic anemia.

Abstract: Natural autoantibodies are immunoglobulins of isotypes IgM, IgG and IgA that are present under physiological conditions and that are directed toward self-antigens. Repertoires of self-reactive antibodies have been analysed intensively during the last decade and have been shown to be altered in a variety of autoimmune disorders, immunodeficiency syndromes and lymphoproliferative diseases. Immunoglobulin interactions via variable regions of antibody molecules account significantly for the functional integrity of natural self-reactive antibody repertoires. Recent data indicate that natural immunoglobulins of the isotype IgM might prove particularly useful for the control of antibody-mediated autoimmune diseases under certain conditions. Warm autoimmune hemolytic anemia (WAIHA), an IgG-mediated autoimmune disorder, turns out to be a clinically relevant in vivo model to analyse the impact of autologous IgM on the development of IgG-mediated autoimmunity in humans. We here summarize current knowledge on the role of autologous IgM for regulating self-reactivity. Since natural self-reactive antibodies are critical for the regulation not only of auto- but also of alloimmune responses, as they occur for example in the setting of organ transplantation, regulation of immune homeostasis by pools of human normal IgM might be an interesting therapeutic target of broad interest for clinical medicine.

Survey of the year 2003 commercial optical biosensor literature

Abstract: In the year 2003 there was a 17% increase in the number of publications citing work performed using optical biosensor technology compared with the previous year. We collated the 962 total papers for 2003, identified the geographical regions where the work was performed, highlighted the instrument types on which it was carried out, and segregated the papers by biological system. In this overview, we spotlight 13 papers that should be on everyone's 'must read' list for 2003 and provide examples of how to identify and interpret high-quality biosensor data. Although we still find that the literature is replete with poorly performed experiments, over-interpreted results and a general lack of understanding of data analysis, we are optimistic that these shortcomings will be addressed as biosensor technology continues to mature.

Applied Multivariate Data Analysis

Abstract: Multivariate data / Mathematical and statistical background / Exploring multivariate data graphically / Exploratory factor analysis / Correspondence analysis / Multidimensional scaling / Cluster analysis / Latent class analysis / Discriminant function analysis / Multivariate dependencies / Classical multivariate inference / Longitudinal data / Problems of measurement error / Confirmatory factor analysis and structural equation models.