Linnea I. Andersson , Dick J. Sjöström , Ricardo J.M.G.E. Brandwijk , Erik J.M. Toonen , Tom Eirik Mollnes , Per H. Nilsson
{"title":"Complement function and activation in human serum and plasma collected in different blood collection tubes","authors":"Linnea I. Andersson , Dick J. Sjöström , Ricardo J.M.G.E. Brandwijk , Erik J.M. Toonen , Tom Eirik Mollnes , Per H. Nilsson","doi":"10.1016/j.jim.2025.113825","DOIUrl":"10.1016/j.jim.2025.113825","url":null,"abstract":"<div><div>Complement analysis necessitates strict control of pre-analytical blood handling, including time, temperature, and additives. Here, we compared complement function and activation status across five different serum preparations and two plasma preparations. Serum was collected from ten healthy volunteers using glass tubes without additives, tubes with a silica clot activator (with or without a gel separator), and tubes containing thrombin (with or without a gel separator). Plasma was collected in the presence of EDTA or the thrombin inhibitor lepirudin. Serum and plasma aliquots were snap-frozen in liquid nitrogen and stored at −80 °C. Complement functional analysis was performed using Wieslab and Hycult Biotech pathway-specific assays. Complement activation was determined by quantifying specific activation markers: C1s/C1-INH, MASP-1/C1-INH, C3bc, C3bBbP, and sC5b-9. All serum samples exhibited increased complement activation compared to EDTA and lepirudin plasma, with serum tubes containing thrombin and gel separators showing the highest levels of complement activation. However, normal complement function was observed in all serum preparations, indicating that the complement activation and consumption that occurred did not affect complement functional analysis. While all tested serum tubes provided accurate functional activity, the type of tube and the presence of additives like thrombin and gel separators significantly influenced the degree of complement activation. We recommend preparing functionally active serum either in glass tubes or in silica clot activator tubes, and avoiding gel separators. For complement activation studies, lepirudin plasma is preferable over serum due to its complement functional capacity, low level of complement activation, and lack of excessive hemostatic activation.</div></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"538 ","pages":"Article 113825"},"PeriodicalIF":1.6,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soren Ulrik Sonder , Matthew Plassmeyer , Nikhila Schroeder , Steven Peyton , Mikell Paige , Michael Girgis , Hamed Safi , Oral Alpan
{"title":"Basophil activation test; User's manual","authors":"Soren Ulrik Sonder , Matthew Plassmeyer , Nikhila Schroeder , Steven Peyton , Mikell Paige , Michael Girgis , Hamed Safi , Oral Alpan","doi":"10.1016/j.jim.2025.113815","DOIUrl":"10.1016/j.jim.2025.113815","url":null,"abstract":"<div><div>Immediate allergic responses, orchestrated by basophils and mast cells, are pivotal in severe allergic reactions. The flow cytometry-based Basophil Activation Test (BAT) is a clinically important assay for testing allergic reactions using CD63 and CD203c as endpoints. The test measures the concentration dependent response to the allergens providing a functional readout of the patients' allergies. BAT is presently in clinical use within the Unites States as well as several other countries for the diagnosis and monitoring of allergies, most commonly against food allergens. This article details assay validation, both analytical and clinical with reference to existing regulations/recommendations through CAP, CLIA, NYS and CLSI on issues including accuracy, precision, linearity, reportable range, reference range, analytical sensitivity & specificity, pre-analytical considerations, the utility of the assay in diagnosis or monitoring and interpretation of the results; and the assay's limitations.</div><div>The BAT plays a crucial role in assessing patient suitability for food challenges and therapies such as oral immunotherapy, sublingual immunotherapy or omalizumab and can aid in predicting treatment outcomes. We further review the current research on advancing the test, focused on improvements in its clinical utility. Continuous efforts are warranted for enhanced regulatory oversight and comprehensive clinical validation, ensuring BAT's seamless integration into diverse clinical settings.</div></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"537 ","pages":"Article 113815"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143039084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Clinical utility of the lymphocyte proliferation assay, an in vitro functional readout of the adaptive immune response","authors":"Eszter Lázár-Molnár , Lisa K. Peterson","doi":"10.1016/j.jim.2025.113819","DOIUrl":"10.1016/j.jim.2025.113819","url":null,"abstract":"<div><div>Despite great advancements in the discovery of genetic variants underlying inborn errors of immunity, functional assessment of the immunological profile of patients in routine clinical practice remains challenging.</div><div>The lymphocyte proliferation assay using <sup>3</sup>H-thymidine incorporation has been the gold standard for decades for functional evaluation of T cells in the clinical laboratory, however, recently developed flow cytometric methods allowing for single cell analysis provide non-radioactive alternatives. Understanding the technical and analytical challenges of test development, validation and maintenance is essential for correct interpretation and test utilization, to assure appropriate and timely patient care. This review will discuss the technological aspects, validation and clinical utilization of <em>in vitro</em> lymphocyte proliferation assays performed in the clinical immunology laboratory, providing a diagnostic readout for T lymphocyte function, an essential hallmark of a functional cellular immune response, and allowing for the detection of impaired responses such as in patients with functional T cell defects.</div></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"537 ","pages":"Article 113819"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143039243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Overcoming cross-reactivity of antibodies against human lactate dehydrogenase","authors":"Akira Kondo, Ayumu Nakamura","doi":"10.1016/j.jim.2025.113821","DOIUrl":"10.1016/j.jim.2025.113821","url":null,"abstract":"<div><div>Lactate dehydrogenase subunit A (LD-A) plays an important role in cancer regulation and therapy. We attempted to develop an enzyme-linked immune-solvent assay (ELISA) for LD-A in human serum.</div><div>However, commercial antibodies against LD-A exhibited cross-reactivity with an unknown protein. The unknown protein was purified and characterized by protein sequencing and Western blotting. In addition, we attempted to prepare a specific antibody for the ELISA using partially synthesized peptides of LD-A as immunogens. The epitope position in LD-A was carefully selected based on bioinformatics analysis.</div><div>Peptide sequencer elucidated a ten amino acid sequence of the purified protein at the N-terminal. A BLAST search revealed that this sequence perfectly matched that at the N-terminus of the IgG heavy chain (H-chain). Furthermore, we demonstrated that twelve commercially available antibodies targeting LD-A or LD-B (subunit B) primarily cross-reacted with IgG or its H-chain, with only one specific antibody for each subunit. As the specific antibody against LD-A is no longer commercially accessible, we successfully produced two kinds of specific antibodies using partially synthesized LD-A peptides as immunogens.</div><div>In conclusion, we have successfully produced specific antibodies against LD-A. Moreover, our findings underscore the utility of bioinformatics tools for determining the optimal positions of immunizing peptides.</div></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"538 ","pages":"Article 113821"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143123061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rebecca A. Marsh , Jack J. Bleesing , Samuel Cern Cher Chiang
{"title":"Diagnostic testing for hemophagocytic lymphohistiocytosis","authors":"Rebecca A. Marsh , Jack J. Bleesing , Samuel Cern Cher Chiang","doi":"10.1016/j.jim.2025.113816","DOIUrl":"10.1016/j.jim.2025.113816","url":null,"abstract":"<div><div>Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical syndrome caused by severe systemic hyperinflammation. HLH can be rapidly fatal if unrecognized or inadequately treated. It is important that clinicians are able to utilize diagnostic testing to assess for HLH and determine the underlying causes including possible inborn errors of immunity (IEI). This article summarizes many of the tools available to aid with the diagnostic evaluation of patients with possible HLH and underlying IEI.</div></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"537 ","pages":"Article 113816"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143039295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Fas-mediated apoptosis assay: From concept to clinical application","authors":"Jack Bleesing","doi":"10.1016/j.jim.2025.113812","DOIUrl":"10.1016/j.jim.2025.113812","url":null,"abstract":"<div><div>Abnormal lymphocyte homeostasis underly several Inborn Errors of Immunity (IEoI). <em>In vitro</em> assessment of lymphocyte homeostasis is achieved by specific apoptosis assays reflective of specific homeostasis programs and pathways that are mediated through specific proteins. This review discusses those programs, pathways and proteins and describes the development and use of the <em>in vitro</em> Fas-mediated apoptosis assay, as it relates to the IEoI Autoimmune Lymphoproliferative Syndrome (ALPS) and describes other disorders of lymphocyte homeostasis in the context of other forms of <em>in vitro</em> apoptosis assessment.</div></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"537 ","pages":"Article 113812"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143059339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shannon A. Bennett, Chelsea M. Conn, Hillary E. Gill, Brenda K. Holmen, Tasha M. McDevitt, Corrisa L. Miliander, Benjamin D. Uphoff, Curtis A. Hanson
{"title":"Regulatory requirements for laboratory developed tests in the United States","authors":"Shannon A. Bennett, Chelsea M. Conn, Hillary E. Gill, Brenda K. Holmen, Tasha M. McDevitt, Corrisa L. Miliander, Benjamin D. Uphoff, Curtis A. Hanson","doi":"10.1016/j.jim.2025.113813","DOIUrl":"10.1016/j.jim.2025.113813","url":null,"abstract":"<div><div>Clinical laboratories in the United States are governed by a variety of required regulatory and optional accreditation bodies. All laboratories must comply with the federal Clinical Laboratory Improvement Amendments (CLIA) or state equivalents, while some laboratories choose additional accreditation partners. While not a regulatory body, International Standards Organization (ISO) is an internationally recognized quality system that includes best practices specific to clinical laboratories. Likewise, the Clinical Laboratory Standards Institute (CLSI) publishes guidance documents that include best practices for test validation. The Food and Drug Administration (FDA) has historically exercised enforcement discretion in regulating laboratory developed tests (LDTs), but that approach has changed with publication of the FDA's LDT final rule.</div></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"537 ","pages":"Article 113813"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Phospho-flow cytometry assays for diagnostic use – A discussion of assay utility and assay development and validation challenges","authors":"Vijaya Knight","doi":"10.1016/j.jim.2025.113818","DOIUrl":"10.1016/j.jim.2025.113818","url":null,"abstract":"<div><div>Detection of changes in phosphorylation of cell signaling molecules using flow cytometry is termed “phosphoflow” or “phospho-flow cytometry”. Phosphoflow has wide application for basic research into the mechanics of cell signaling, for evaluating aberrant signaling in cancerous cells and tissues, for studying efficacy or off-target effects during drug and vaccine development, and for functional assessment of pathogenic variants of genes that are known to play a role in development or function of the immune system. Phosphoflow has not been widely adopted in clinical laboratories owing to the challenges with developing and validating robust assays consistent with clinical laboratory regulatory standards. This review provides a brief overview of the utility of phosphoflow and points of consideration for development and validation of phosphoflow assays for diagnostic use, with a focus on inborn errors of immunity.</div></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"537 ","pages":"Article 113818"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143039301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Debra Long Priel, Karen Lau, Danielle L. Fink, Douglas B. Kuhns
{"title":"Functional assays for the diagnosis of chronic granulomatous disease","authors":"Debra Long Priel, Karen Lau, Danielle L. Fink, Douglas B. Kuhns","doi":"10.1016/j.jim.2025.113820","DOIUrl":"10.1016/j.jim.2025.113820","url":null,"abstract":"<div><div>Chronic granulomatous disease (CGD) is a rare immunodeficiency characterized by recurrent bacterial and fungal infections that are attributed to reduced production of reactive oxygen species (ROS) by a multi-component enzyme complex known as the phagocyte NADPH oxidase or NOX2. Presented in this review are descriptions of several assays that assess the production of ROS as well as assays that characterize the expression of specific proteins of NOX2.</div></div>","PeriodicalId":16000,"journal":{"name":"Journal of immunological methods","volume":"537 ","pages":"Article 113820"},"PeriodicalIF":1.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}