title: Expression of activation-induced cytidine deaminase in malignant lymphomas infiltrating the bone marrow.
abstract: Somatic hypermutation of immunoglobulin genes and class switch recombination are pivotal processes in the germinal center (GC) reaction and have been implicated in the development of malignant B-cell lymphoma. Both processes require the enzyme activation-induced cytidine deaminase (AID). Expression of AID is largely restricted to GC B cells and B cells that undergo class switch recombination outside the GC. AID is also expressed in many B-cell lymphomas. This study investigates the expression of AID of malignant lymphomas infiltrating the bone marrow. Bone marrow trephines (n=130) with infiltration of Hodgkin lymphoma and non-Hodgkin lymphoma of B cell and T-cell type and trephines with reactive lymphoid follicles (n=16) were analyzed immunohistochemically for AID protein. AID is expressed in bone marrow infiltrates of malignant lymphomas. AID was generally detected in lymphomas of GC origin. Tumor cells of hairy cell leukemia are mostly AID. There is apparently no different expression of AID found in bone marrow infiltrates of malignant lymphomas compared with a control group with nodal malignant lymphoma infiltrates (n=105). These results suggest that the expression pattern of AID in lymphoma infiltrates in the bone marrow reflects that of extramedullary lymphoma infiltrates.
authors.affiliation: Senckenbergisches Institut für Pathologie, Klinikum der Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany. k.engels@em.uni-frankfurt.de
authors.forename: Knut
authors.initials: K
authors.lastname: Engels
authors.forename: Berit
authors.initials: B
authors.lastname: Jungnickel
authors.forename: Stephanie
authors.initials: S
authors.lastname: Tobollik
authors.forename: Martin-Leo
authors.initials: ML
authors.lastname: Hansmann
authors.forename: Susanne
authors.initials: S
authors.lastname: Kriener
authors.forename: Klaus
authors.initials: K
authors.lastname: Willenbrock
mesh_terms: D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology*; D002454:Cell Differentiation; D003564:Cytidine Deaminase / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017578:Immunoglobulin Class Switching; D007150:Immunohistochemistry; D017254:Leukemic Infiltration / Q000201:enzymology / Q000235:genetics*; D008223:Lymphoma / Q000175:diagnosis / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology*; D011379:Prognosis; D019310:Pseudolymphoma / Q000175:diagnosis / Q000201:enzymology / Q000235:genetics* / Q000473:pathology*; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
chemical_list: D014408:Biomarkers, Tumor; D000098830:AICDA (Activation-Induced Cytidine Deaminase); D003564:Cytidine Deaminase