title: Heat differentiated complement factor profiling.
abstract: Complement components and their cascade of reactions are important defense mechanisms within both innate and adaptive immunity. Many complement deficient patients still remain undiagnosed because of a lack of high throughput screening tools. Aiming towards neonatal proteome screening for immunodeficiencies, we used a multiplex profiling approach with antibody bead arrays to measure 9 complement proteins in serum and dried blood spots. Several complement components have been described as heat sensitive, thus their heat-dependent detectability was investigated. Using sera from 16 patients with complement deficiencies and 23 controls, we confirmed that the proteins C1q, C2, C3, C6, C9 and factor H were positively affected by heating, thus the identification of deficient patients was improved when preheating samples. Measurements of C7, C8 and factor I were negatively affected by heating and non-heated samples should be used in analysis of these components. In addition, a proof of concept study demonstrated the feasibility of labeling eluates from dried blood spots to perform a subsequent correct classification of C2-deficiencies. Our study demonstrates the potential of using multiplexed single binder assays for screening of complement components that open possibilities to expand such analysis to other forms of deficiencies.
authors.affiliation: Clinical Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet and University Hospital, Stockholm, Sweden; Center for Inflammatory Diseases, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Carl
authors.initials: C
authors.lastname: Hamsten
authors.affiliation: Department of Laboratory Medicine, Section of Microbiology, Immunology and Glycobiology, Lund University, Lund, Sweden.
authors.forename: Lillemor
authors.initials: L
authors.lastname: Skattum
authors.affiliation: Department of Laboratory Medicine, Section of Microbiology, Immunology and Glycobiology, Lund University, Lund, Sweden.
authors.forename: Lennart
authors.initials: L
authors.lastname: Truedsson
authors.affiliation: Division of Metabolic Diseases, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Solna, Stockholm, Sweden.
authors.forename: Ulrika
authors.initials: U
authors.lastname: von Döbeln
authors.affiliation: Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Mathias
authors.initials: M
authors.lastname: Uhlén
authors.affiliation: Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Jochen M
authors.initials: JM
authors.lastname: Schwenk
authors.affiliation: Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, Sweden.
authors.forename: Lennart
authors.initials: L
authors.lastname: Hammarström
authors.affiliation: Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Nilsson
authors.affiliation: Affinity Proteomics, SciLifeLab, School of Biotechnology, KTH - Royal Institute of Technology, Stockholm, Sweden. Electronic address: Maja.neiman@scilifelab.se.
authors.forename: Maja
authors.initials: M
authors.lastname: Neiman
mesh_terms: D003167:Complement Activation; D003165:Complement System Proteins / Q000737:chemistry* / Q000172:deficiency / Q000378:metabolism; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D055550:Protein Stability
chemical_list: D003165:Complement System Proteins
keywords: Complement factors; Dried blood spots; Immunodeficiency; Multiplex immunoassay; Neonatal screening; Serum