title: Absence of platelet CD40L identifies patients with X-linked hyper IgM syndrome.
abstract: CD40 ligand (CD40L), a membrane protein expressed on activated T cells, plays a pivotal role in B cell proliferation and differentiation. Mutations in the CD40L gene are associated with a rare immunodeficiency state, X-linked hyper IgM syndrome (XLHIGM). Recently, platelets have been described as capable of expressing CD40L within minutes of stimulation. We have developed a rapid technique to determine expression of CD40L on activated platelets by flow cytometry in whole blood. We have demonstrated that this technique is useful in neonatal screening, in rapid diagnosis and in determining reconstitution by donor bone marrow post-transplantation.
authors.affiliation: Portex Department of Anaesthesia, Intensive Therapy and Respiratory Medicine and Immunobiology Unit, Institute of Child Health, London, UK. D.Inwald@ich.ucl.ac.uk
authors.forename: D P
authors.initials: DP
authors.lastname: Inwald
authors.forename: M J
authors.initials: MJ
authors.lastname: Peters
authors.forename: D
authors.initials: D
authors.lastname: Walshe
authors.forename: A
authors.initials: A
authors.lastname: Jones
authors.forename: E G
authors.initials: EG
authors.lastname: Davies
authors.forename: N J
authors.initials: NJ
authors.lastname: Klein
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000276:immunology*; D016026:Bone Marrow Transplantation / Q000276:immunology; D023201:CD40 Ligand; D002469:Cell Separation; D005434:Flow Cytometry; D006801:Humans; D006942:Hypergammaglobulinemia / Q000276:immunology*; D007075:Immunoglobulin M / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D051379:Mice; D015997:Neonatal Screening; D019007:P-Selectin / Q000096:biosynthesis / Q000276:immunology
chemical_list: D007075:Immunoglobulin M; D008562:Membrane Glycoproteins; D019007:P-Selectin; D023201:CD40 Ligand