title: Falsely negative 99mTc-antigranulocyte immunoscintigraphy and positive 99mTc-HMPAO-labelled leukocyte scan in active Crohn's disease. Possible effects of immunosuppressive therapy?
abstract: A 19-year-old woman with active Crohn's disease under immunosuppressive therapy underwent scintigraphy with 99mTc-anti-NCA-95 antigranulocyte antibodies in order to determine the extent of inflammation. It turned out to be falsely negative whereas a 99mTc-HMPAO-labelled leukocyte scan revealed a marked terminal ileitis and pancolitis. It is assumed that immunosuppressive therapy was the main reason for the falsely negative antibody scan, possibly affecting the red bone marrow where most of the antibodies bind to granulocytes. Peripheral leukocytes labelled in vitro do not seem to be subject to these hypothetical effects on red bone marrow.
authors.affiliation: Department of Nuclear Medicine, Georg-August-University, Göttingen, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Ivancević
authors.forename: H
authors.initials: H
authors.lastname: Schwörer
authors.forename: D
authors.initials: D
authors.lastname: Sandrock
authors.forename: C
authors.initials: C
authors.lastname: Kaufmann
authors.forename: G
authors.initials: G
authors.lastname: Ramadori
authors.forename: D
authors.initials: D
authors.lastname: Emrich
authors.forename: D L
authors.initials: DL
authors.lastname: Munz
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal; D003424:Crohn Disease / Q000097:blood / Q000000981:diagnostic imaging*; D005188:False Negative Reactions; D005260:Female; D006098:Granulocytes / Q000276:immunology; D006801:Humans; D007249:Inflammation; D007962:Leukocytes; D007964:Leukocytosis; D015609:Organotechnetium Compounds; D010091:Oximes; D011859:Radiography; D016719:Radioimmunodetection / Q000379:methods*; D019690:Technetium Tc 99m Exametazime
chemical_list: D000911:Antibodies, Monoclonal; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime