title: Recent thymic emigrants and prognosis in T- and B-cell childhood hematopoietic malignancies.
abstract: The concentration of T-cell receptor rearrangement excision DNA circles (TRECs) in peripheral blood mononuclear cells (PBMCs) is currently known to be a marker of recent thymic emigrants. We evaluated the hypothesis that TREC values would be lower in childhood T-cell hematopoietic malignancies than in childhood B-cell acute lymphoblastic leukemia (ALL) or healthy controls because the former category may reflect compromised thymic function. From the Greek national childhood leukemia/lymphoma database we obtained all 30 available T-cell leukemia/non-Hodgkin's lymphoma cases, 30 age- and sex-matched childhood B-cell origin cases of ALL and 60 healthy hospital controls. We compared TREC levels in PBMCs using a real-time PCR assay. There was highly significant reduction of TREC values in children with T-cell malignancies (median 3,100 TRECs/10(6) PBMCs), whereas children with B-cell origin ALL had slightly but nonsignificantly lower TREC values compared to healthy children (medians 19,300 and 22,500 TRECs/10(6) PBMCs, respectively). During a median follow-up period of about 19 months, only 4 children died. All of them had a T-cell hematopoietic malignancy and relatively low TREC values. The number of TRECs was higher among healthy girls than among healthy boys, and a similar pattern was evident in T-cell malignancies. It appears that there is a pattern of concordance of high TREC values with better disease prognosis in hematologic childhood malignancies. This applies to specific disease entities with better prognosis (B-cell origin ALL having higher TREC values than T-cell leukemia/lymphoma) and to gender, another important predictor of prognosis conditional on disease entity (girls having higher TREC values than boys); however, it may also be true for the survival of individual patients. These preliminary findings can be used as hypothesis-generating indications that should be confirmed in larger data sets.
authors.affiliation: Department of Hygiene and Epidemiology, Athens University Medical School, Greece. epetrid@med.uoa.gr
authors.forename: Eleni
authors.initials: E
authors.lastname: Petridou
authors.forename: Alexandra E
authors.initials: AE
authors.lastname: Klimentopoulou
authors.forename: Maria
authors.initials: M
authors.lastname: Moustaki
authors.forename: Leontios G
authors.initials: LG
authors.lastname: Kostrikis
authors.forename: Angelos
authors.initials: A
authors.lastname: Hatzakis
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Trichopoulos
mesh_terms: D017668:Age of Onset; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D002465:Cell Movement; D002648:Child; D004273:DNA, Neoplasm / Q000235:genetics; D005260:Female; D015329:Gene Rearrangement, T-Lymphocyte / Q000235:genetics; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000175:diagnosis / Q000276:immunology* / Q000473:pathology*; D011379:Prognosis; D011948:Receptors, Antigen, T-Cell / Q000235:genetics; D012727:Sex Characteristics; D015996:Survival Rate; D013601:T-Lymphocytes / Q000378:metabolism / Q000473:pathology*; D013950:Thymus Gland / Q000473:pathology*
chemical_list: D004273:DNA, Neoplasm; D011948:Receptors, Antigen, T-Cell