Michael Schneider

• Dipl. Natw ETH
• VP Regulatory Affairs at BÜHLMANN Laboratories AG

Background Calprotectin, a granulocyte-derived alarmin protein, is an established noninvasive biomarker of intestinal mucosal inflammation. Fecal calprotectin testing has become the gold standard for diagnosis of inflammatory bowel diseases. The aim of this work was to determine the stability of calprotectin in stool extracts prepared with the BÜHL...

Rationale: Basophil Activation Tests (BAT) have gained increasing importance in the field of allergy. We hypothesize a thorough assay validation study meeting CLIA requirements is possible and performed analytical and stability studies with Flow CAST BAT assay, to achieve the new EU-IVDR compliance. Methods: For all studies, four healthy blood don...

Background Pancreatic exocrine insufficiency (PEI) can be defined as an insufficient secretion of pancreatic enzymes and bicarbonate to maintain a normal digestion (1). PEI is associated to fat malabsorption, weight loss and malnutrition-related complications. Due to its important role in the digestive process, as a proteolytic enzyme and the high...

BÜHLMANN GanglioCombiTM ELISA is a multiparametric test to determine anti-ganglioside antibodies in a semi-quantitative way. It allows for a targeted investigation of immune-mediated neuropathies. There are no recognized reference materials nor reference measurement procedures for anti-ganglioside antibodies. To ensure consistency of results over t...

The BÜHLMANN anti-MAG Antibodies ELISA (MAG-ELISA) is the acknowledged gold standard in vitro diagnostic ELISA, to reliably quantify anti-MAG IgM antibodies in demyelinating neuropathies, a rare autoimmune-disease. There are no recognized reference materials or reference measurement procedures for anti-MAG antibodies. We guarantee measurement consi...

Autoimmune chronic spontaneous urticaria (aiCSU) is considered to be an important subtype of chronic spontaneous urticaria in which functional autoantibodies to IgE or its high-affinity receptor ( FcεRI) induce mast cell degranulation and subsequent urticaria development. In vitro basophil reactivity assays (basophil activation test (BAT) or basoph...

Background Therapeutic drug monitoring of inflammatory bowel disease (IBD) patients under anti-TNF therapy is based on trough level determination of the drug. Rapid assays and multiple ELISAs are available that measure anti-TNF biologics. An international standard is required to improve comparability among different assays. Recently, WHO introduced...

A proportion of chronic spontaneous urticaria (CSU) cases are of autoimmune origin. In vitro basophil reactivity assays (basophil activation test (BAT) or basophil histamine release assay (BHRA)) are considered as evidence of serum factors causing histamine release and/or basophil activation and thus, a leading evidence of probable autoreactive urt...

Background Therapeutic drug monitoring of RA patients under anti-TNF therapy is based on trough level determination of the drug. Rapid assays and multiple ELISAs are available that measure anti-TNF biologics. An international standard is required to improve comparability among different assays. Recently, WHO introduced a series of anti-TNF standard...

Background: Only some patients with peanut allergy undergoing oral immunotherapy (OIT) achieve sustained clinical response. Basophil activation could provide a functional surrogate of efficacy. Objective: We hypothesized that changes in basophil sensitivity and area under the curve (AUC) to the immunodominant allergen Ara h 2 correlate with clin...

Background The treatment of patients suffering from an inflammatory disease, like inflammatory bowel disease (IBD) may involve biologicals like infliximab. However, infliximab is a chimeric human/murine monoclonal antibody and can induce a significant immune response. Within this immune response different anti-infliximab antibodies are formed, belo...

Background Patients suffering from inflammatory bowel disease (IBD) treated with adalimumab might not respond to the biologic at all, or might suffer from a secondary loss of response (SLR). A SLR is often caused by an immune response during which neutralising anti-adalimumab antibodies (ADADs) may develop. These ADADs are by nature of different is...

The Quantum Blue® Adalimumab test enables the quantitative determination of adalimumab levels from 1 to 35 µg/mL in serum with a time to result of only 15 minutes. The developed test allows to measure adalimumab over a wide range, well beyond the therapeutic window. Hence, it represents a valuable tool for the clinician to assess adalimumab trough...

Background: Conventional data analysis of flow cytometry-based basophil activation testing requires repetitive, labor-intensive analysis that hampers efforts to standardize testing for clinical applications. Using an open-source platform, we developed and implemented a programmatic approach to the analysis of the basophil activation test (BAT) by...

Background Rheumatoid arthritis (RA) is a systemic autoimmune disease affecting approximately 1% of the population [1]. The pathogenesis of RA involves the overexpression of tumor necrosis factor alpha (TNFα) and other cytokines [2]. Adalimumab (ADA) is a human monoclonal antibody directed against TNFα and is highly effective in the treatment of RA...

Background Rheumatoid arthritis (RA) is a systemic autoimmune disease affecting approximately 1% of the population [1]. The pathogenesis of RA involves the overexpression of tumor necrosis factor alpha (TNFα) and other cytokines [2]. Adalimumab (ADA) is a human monoclonal antibody directed against TNFα and is highly effective in the treatment of RA...

Human blood basophils have recently gained interest in addition to their function as allergic effector cells. Previous work suggests the involvement of innate immune mechanisms in the development and exacerbation of allergic responses, which might be mediated by basophils. We assayed the expression levels of Toll-like receptor (TLR) 1, 2, 4 and 6 o...

BACKGROUND: Calprotectin is a multifunctional protein that plays an important role in the diagnosis and follow-up of inflammatory bowel disease (IBD). High levels of calprotectin in stool samples are associated with inflammation of the intestinal tract. We evaluated the analytical performance of a new particle enhanced turbidimetric immunoassay (PE...

Background: Specific immunotherapy with insect venom (VIT) is the treatment of choice for hymenoptera venom allergy. However, in up to 20% of VIT-treated patients no full protection can be achieved. As no reliable in vitro marker for the evaluation of VIT exists, sting challenge (SC) with the relevant living insect is still recommended before VIT i...

Hypersensitivity reactions against non-steroidal anti-inflammatory drugs (NSAIDs) like propyphenazone (PP) and diclofenac (DF) can manifest as Type I-like allergic reactions 1. In clinical practice, diagnosis of drug hypersensitivity is mainly performed by patient history, as skin testing is not reliable and oral provocation testing bears life-thre...

Patients who are clinically hypersensitive to nonsteroidal anti-inflammatory drugs (NSAIDs) sometimes present basophil activation in vitro, and in 50% of cases a parallel response to release of sulfidoleukotrienes (cellular allergen stimulation test) is observed. These phenomena occur not only in clinically hypersensitive patients, but also in some...

A decreased basophil responsiveness could be demonstrated in bee venom allergic patients after VIT compared to patients before VIT. This finding correlated with the unproblematic sting challenge in 27/29 subjects, suggesting that the higher concentration of bee venom needed to elicit a basophil activation or degranulation can serve as an in vitro s...

A multiplexed fluorescence immunoassay using a novel planar waveguide technology-based microarray system, ZeptoMARK (Zeptosens), was developed to detect simultaneously urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor-1 (PAI-1), and vascular endothelial growth factor (VEGF) in extracts of breast cancer tissues. The three a...

CcmE is a heme chaperone that binds heme transiently in the periplasm of Escherichia coli and delivers it to newly synthesized and exported c-type cytochromes. The chemical nature of the covalent bond between heme and H130 is not known. We have purified soluble histidine-tagged CcmE and present its spectroscopic characteristics in the visible range...

Protein microarrays are considered an enabling technology, which will significantly expand the scope of current protein expression and protein interaction analysis. Current technologies, such as two-dimensional gel electrophoresis (2-DE) in combination with mass spectrometry, allowing the identification of biologically relevant proteins, have a hig...

Protein microarrays are considered an enabling technology, which will significantly expand the scope of current protein expression and protein interaction analysis. Current technologies, such as two-dimensional gel electrophoresis (2-DE) in combination with mass spectrometry, allowing the identification of biologically relevant proteins, have a hig...