title: Novel tools for primary immunodeficiency diagnosis: making a case for deep profiling.
abstract: This review gives an overview of the systems-immunology single-cell proteomic and transcriptomic approaches that can be applied to study primary immunodeficiency. It also introduces recent advances in multiparameter tissue imaging, which allows extensive immune phenotyping in disease-affected tissue.
  
  
  
  Mass cytometry is a variation of flow cytometry that uses rare earth metal isotopes instead of fluorophores as tags bound to antibodies, allowing simultaneous measurement of over 40 parameters per single-cell. Mass cytomety enables comprehensive single-cell immunophenotyping and functional assessments, capturing the complexity of the immune system, and the molecularly heterogeneous consequences of primary immunodeficiency defects. Protein epitopes and transcripts can be simultaneously detected allowing immunophenotype and gene expression evaluation in mixed cell populations. Multiplexed epitope imaging has the potential to provide extensive phenotypic characterization at the subcellular level, in the context of 3D tissue microenvironment.
  
  
  
  Mass cytometry and multiplexed epitope imaging can complement genetic methods in diagnosis and study of the pathogenesis of primary immunodeficiencies. The ability to understand the effect of a specific defect across multiple immune cell types and pathways, and in affected tissues, may provide new insight into tissue-specific disease pathogenesis and evaluate effects of therapeutic interventions.
authors.affiliation: aDepartment of Immunology and Microbiology, University of Colorado Denver, School of Medicine bDepartment of Pediatrics, Division of Allergy and Immunology, University of Colorado Denver, School of Medicine and Children's Hospital Colorado, Aurora, Colorado cDepartment of Pediatrics, Division of Allergy, Immunology and Rheumatology, Stanford University, School of Medicine, Stanford, California, USA.
authors.forename: Elena W Y
authors.initials: EW
authors.lastname: Hsieh
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Hernandez
mesh_terms: D000818:Animals; D020869:Gene Expression Profiling / Q000379:methods*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007153:Immunologic Deficiency Syndromes / Q000175:diagnosis*; D016130:Immunophenotyping; D013058:Mass Spectrometry; D008670:Metals; D000071696:Proteogenomics / Q000379:methods*; D059010:Single-Cell Analysis / Q000379:methods
chemical_list: D008670:Metals