title: Terminal deoxynucleotidyl transferase (TdT)-containing peripheral blood mononuclear cells during remission of acute lymphoblastic leukemia: low sensitivity and specificity prevent accurate prediction of relapse.
abstract: Serial samples of peripheral blood were obtained from 75 children with acute lymphoblastic leukemia in remission. An immunofluorescence assay was used to quantitate TdT-containing (terminal deoxynucleotidyl transferase-containing) cells in the mononuclear leukocyte fraction of these specimens. Nine relapses in 8 patients were preceded by elevations (0.12-0.70%) in peripheral blood terminal deoxynucleotidyl transferase-containing cells noted 1-33 weeks prior to relapse. No such elevations were observed prior to 6 relapses in 4 patients. Peripheral blood terminal transferase deoxynucleotidyl-containing cells were elevated (0.12-0.61%) in 22 children who did not relapse over a 5-82 week period of observation. The sensitivity (67%) and specificity (68%) of this assay are inadequate to establish which patients have minimal residual leukemia.
mesh_terms: D002648:Child; D004253:DNA Nucleotidylexotransferase / Q000097:blood*; D004254:DNA Nucleotidyltransferases / Q000097:blood*; D005260:Female; D006801:Humans; D007945:Leukemia, Lymphoid / Q000097:blood / Q000201:enzymology*; D008297:Male; D008722:Methods; D009000:Monocytes / Q000201:enzymology*
chemical_list: D004254:DNA Nucleotidyltransferases; D004253:DNA Nucleotidylexotransferase