title: Analytical detection of immunoglobulin heavy chain gene rearrangements in gastric lymphoid infiltrates by peak area analysis of the melting curve in the LightCycler System.
abstract: Because it is difficult to differentiate gastric mucosa-associated lymphoid tissue (MALT) lymphoma from chronic gastritis in gastric lymphoid infiltrates, molecular detection of monoclonality through immunoglobulin heavy chain (IgH) gene rearrangements is commonly performed. However, heterogeneity in the performance and results obtained from IgH gene rearrangements has been reported. To improve the accuracy in the diagnosis of gastric lymphoid infiltrates, we developed an analytical approach based on one-peak area analysis of the melting curve in the LightCycler System. Using a training-testing approach, the likelihood ratio method was selected to find a discriminative function of 4.64 in the training set (10 gastric MALT lymphomas and 10 chronic gastritis cases). This discriminative function was validated in the testing set (five gastric MALT lymphomas, six abnormal lymphocytic infiltrates with subsequently demonstrated gastric MALT lymphomas, and six cases of chronic gastritis). All but one case of gastric MALT lymphoma, as well as abnormal lymphocytic infiltrates, clustered under 4.64, and all chronic gastritis cases clustered above 4.64. These results were validated by conventional electrophoreses confirming one or two sharp bands in cases of gastric MALT lymphomas and a smear of multiple bands in cases of chronic gastritis. Analytical detection of IgH gene rearrangement in gastric lymphoid infiltrates by one-peak area analysis correctly distinguishes gastric MALT lymphomas from chronic gastritis, even in cases with diagnosis of abnormal lymphocytic infiltrates.
authors.affiliation: Departamento Laboratorio de Salud, Instituto Salud Publica de Chile, Santiago, Chile.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Retamales
authors.forename: Luis
authors.initials: L
authors.lastname: Rodriguez
authors.forename: Leda
authors.initials: L
authors.lastname: Guzman
authors.forename: Francisco
authors.initials: F
authors.lastname: Aguayo
authors.forename: Mariana
authors.initials: M
authors.lastname: Palma
authors.forename: Claudia
authors.initials: C
authors.lastname: Backhouse
authors.forename: Jorge
authors.initials: J
authors.lastname: Argandona
authors.forename: Erick
authors.initials: E
authors.lastname: Riquelme
authors.forename: Alejandro
authors.initials: A
authors.lastname: Corvalan
mesh_terms: D001706:Biopsy; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005756:Gastritis / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology / Q000473:pathology*; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D050438:Genes, Immunoglobulin Heavy Chain; D006801:Humans; D016246:Lymphocytes, Tumor-Infiltrating; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis* / Q000235:genetics / Q000276:immunology; D009691:Nucleic Acid Denaturation; D016133:Polymerase Chain Reaction / Q000295:instrumentation* / Q000379:methods; D044366:Transition Temperature