Hsin-Yun Hsu

Pathogen specific cytokine release reveals an effect of TLR2 Arg753Gln during Candida sepsis in humans

Toll-like receptors (TLRs) are crucial pattern-recognition receptors (PRRs) for activation of innate and adapted immunity. TLR2 heterodimerizes with TLR1 or TLR6 to recognize multiple pathogen-associated molecular patterns (PAMPs) of fungi, Gram-positive pathogens, and mycobacteria. Receptor activation culminates in monocyte, T-helper (Th)1, and Th2 cytokine release. Single nucleotide polymorphisms (SNPs) Arg753Gln and Arg677Trp affect TLR2 responsiveness and may contribute to the course of sepsis, which is associated with substantial morbidity and mortality during intensive care treatment. We genotyped 325 critically ill patients with septic shock, and performed a detailed clinical follow-up with 47 of these patients. Here, we investigated whether distinct sepsis episodes result in defined plasma cytokine patterns, and whether cytokine profiles may be linked to the TLR2 polymorphisms. Blood sampling was done daily and microbiological testing was performed on a routine basis. DNA was extracted from whole blood and TLR2 SNPs were typed by pyrosequencing. Cytokines were measured by multiplexed array technologies and the leukocyte phenotype was determined by flow cytometry. Among the 325 ICU patients, 17 individuals (5.2%) were heterozygous for Arg753Gln. The SNP Arg677Trp was not found in any patient. Episodes of Gram-negative, Gram-positive, and Candida sepsis were recorded. During Gram-positive sepsis, the cytokine pattern did not differ between Arg753Gln heterozygous patients and wild type patients. By contrast, during Candida sepsis, the Arg753Gln heterozygous patients showed biomarker patterns that differed from wild type patients with elevated TNF-alpha plasma concentrations, but reduced IFN-gamma and IL-8 levels. In conclusion, TLR2 SNP Arg753Gln results in altered cytokine release in response to Candida but not to Gram-positive sepsis.

Multiplex microsphere-based flow cytometric platforms for protein analysis and their application in clinical proteomics - from assays to results.

Advances in high‐throughput screening, together with rapid progress in genomic and proteomic sciences, have considerably stimulated the development of a variety of biomarker discovery tools and have contributed to the improvement of clinical diagnosis. Major challenges include the obtaining of high‐quality data sets based on assays that are rapid, reliable, and inexpensive, but still highly sensitive and easy to perform. The microsphere‐based flow cytometric technology is a platform that is currently entering the diagnostic market. This article reviews the development and the applications of microsphere‐based flow cytometric platforms in basic and applied proteomic research, and discusses bead‐based assays used in clinical applications.

A biomarker panel to discriminate between systemic inflammatory response syndrome and sepsis and sepsis severity

Introduction: In this study, we report on initial efforts to discover putative biomarkers for differential diagnosis of a systemic inflammatory response syndrome (SIRS) versus sepsis; and different stages of sepsis. In addition, we also investigated whether there are proteins that can discriminate between patients who survived sepsis from those who did not. Materials and Methods: Our study group consisted of 16 patients, of which 6 died and 10 survived. We daily measured 28 plasma proteins, for the whole stay of the patients in the ICU. Results: We observed that metalloproteinases and sE-selectin play a role in the distinction between SIRS and sepsis, and that IL-1α, IP-10, sTNF-R2 and sFas appear to be indicative for the progression from sepsis to septic shock. A combined measurement of MMP-3, -10, IL-1α, IP-10, sIL-2R, sFas, sTNF-R1, sRAGE, GM-CSF, IL-1β and Eotaxin allows for a good separation of patients that survived from those that died (mortality prediction with a sensitivity of 79% and specificity of 86%). Correlation analysis suggests a novel interaction between IL-1α and IP-10. Conclusion: The marker panel is ready to be verified in a validation study with or without therapeutic intervention

Miniaturized Parallelized Sandwich Immunoassays

This chapter describes the development and use of bead-based miniaturized multiplexed sandwich immunoassays for focused protein profiling. Bead-based protein arrays or suspension microarrays allow simultaneous analysis of a variety of parameters within a single experiment. In suspension microarrays capture antibodies are coupled onto color-coded microspheres. The applications of suspension microarrays are described, which allow to analyze proteins present in different types of body fluids, such as serum or plasma, cerebrospinal, pleural and synovial fluids, as well as cell culture supernatants. The chapter is divided into the generation of suspension microarrays, sample preparation, processing of suspension microarrays, validation of analytical performance, and finally pattern generation using bioinformatics tools.

Protein Microarrays: Effective Tools for the Study of Inflammatory Diseases

Inflammation is a defense reaction of an organism against harmful stimuli such as tissue injury or infectious agents. The relationship between the infecting microorganism and the immune, inflammatory, and coagulation responses of the host is intricately intertwined. Due to its complex nature, the molecular mechanisms of inflammation are not yet understood in detail and additional diagnostic tools are required to clarify further aspects. In recent years, protein microarray-based research has moved from being technology-based to application-oriented. Protein microarrays are perfect tools for studying inflammatory diseases. High-density protein arrays enable new classes of autoantibodies, which cause autoimmune diseases, to be discovered. Protein arrays consisting of miniaturized multiplexed sandwich immunoassays allow the simultaneous expression analysis of dozens of signaling molecules such as the cytokines and chemokines involved in the regulation of the immune system. The data enable statements to be made on the status of the disease and its progression as well as support for the clinicians in choosing patient-specific treatment. This chapter reviews the technology and the applications of protein microarrays in diagnosing and monitoring inflammatory diseases.

Multiplexed immunoassays for the analysis of breast cancer biopsies.

Within the last decade, protein microarray technology has been successfully used for the simultaneous quantification of target proteins from minimal amounts of samples in basic and applied proteome research. The robustness and appropriate sensitivity of these miniaturized assays have been demonstrated and thus the transfer to routine and high-throughput applications is now possible. In this study, multiplexed bead-based sandwich immunoassays were used to determine the concentrations of 54 protein analytes, including HER 2 and the estrogen receptor, from ultrasound-guided large-core needle biopsies (LCNBs) from breast cancer patients. Expression levels for HER 2, estrogen receptors and progesterone receptors were also assessed by immunohistochemical routine staining, performed in the clinic on corresponding biopsy samples. The high concordance of the data sets generated with the bead-based protein arrays and by conventional immunohistochemical assessment of HER 2 and the estrogen receptor expressed by breast cancer cells present in the biopsies was demonstrated.

Pathophysiology and Treatment of Fibromyalgia Syndrome

Fibromyalgia syndrome is not a diagnosis in itself, but merely represents a set of classification criteria. It is possible to distinguish between different subgroups. Such a distinction can be made on the basis of psychopathological, clinical and laboratory tests. One subgroup reveals elevated level of different cytokines. The treatment of primary fibromyalgia can be optimized by taking these subgroups into consideration since one group responds better to 5-HT3 receptor antagonists, whereas another benefits more from antidepressants and a third group from psychotherapy. In socalled secondary fibromyalgia, 5-HT3 receptor antagonists may be used in the attempt to manage pain that might still persist after treatment of the primary disease.