title: Three different expression patterns of T-bet in angioimmunoblastic T-cell lymphoma.
abstract: Angioimmunoblastic T-cell lymphoma (AITL) exhibits a multifaceted clinical picture and distinct architectural patterns that correlate with disease progression and the number of neoplastic cells. In this study we investigated the expression of the transcription factor T-bet and correlated it with the architectural patterns in 29 cases of AITL. Double immunolabelings for T-bet, CD20, CD3 or PD1 revealed the following patterns: predominant T-bet expression by neoplastic T-cells (A), by aggregates of small B-cells (B) or by B-immunoblasts (C). The majority of cases of AITL pattern II showed a T-bet expression pattern B (6/8 cases), while the majority of those with pattern III exhibited the T-bet pattern A (11/21 cases). We propose that T-bet expression by B-cells represents a T-cell independent immune response trying to cope with opportunistic infections, while T-bet expression by neoplastic T-cells is linked to the introduction of a Th17 response responsible for the immunologic derangements characteristic of AITL.
authors.affiliation: Institute of Pathology, Charité University Medicine Berlin, Campus Mitte, Berlin, Germany. korinna.joehrens@charite.de
authors.forename: Korinna
authors.initials: K
authors.lastname: Jöhrens
authors.forename: Manfred
authors.initials: M
authors.lastname: Dietel
authors.forename: Ioannis
authors.initials: I
authors.lastname: Anagnostopoulos
mesh_terms: D018951:Antigens, CD20 / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D017252:CD3 Complex / Q000096:biosynthesis; D020031:Epstein-Barr Virus Infections / Q000378:metabolism / Q000821:virology; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000502:physiology; D054884:Host-Pathogen Interactions; D006801:Humans; D007119:Immunoblastic Lymphadenopathy / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D016399:Lymphoma, T-Cell / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D020825:T-Box Domain Proteins / Q000096:biosynthesis*; D000098815:T-bet Transcription Factor
chemical_list: D018951:Antigens, CD20; D017252:CD3 Complex; D012367:RNA, Viral; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor