Terminal deoxynucleotidyl transferase (TdT)-positive cells in cerebrospinal fluid and development of overt CNS leukemia: a 5-year follow-up study in 113 children with a TdT-positive leukemia or non- Hodgkin's lymphoma

Abstract We investigated whether an indirect nuclear terminal deoxynucleotidyl transferase (TdT) immunofluorescence (IF) assay on single cells present in the cerebrospinal fluid (CSF) is more effective than conventional cytomorphology for early detection or exclusion of (minimal) meningeal leukemic infiltration in patients with a TdT+ malignancy. During a 5- year follow-up study, 1,661 consecutive CSF samples from 113 children with a TdT+ acute lymphoblastic leukemia (ALL) (n = 100), a TdT+ acute nonlymphoblastic leukemia (ANLL) (n = 8), or a TdT+ non-Hodgkin's lymphoma (NHL) (n = 5) were analyzed. In 1,511 (91.9%) of 1,643 evaluable CSF samples, the positive and negative findings of both cytomorphology and the TdT-IF assay were concordant. In 47 (2.9%) samples from 28 patients, the cytomorphology was suspect while the TdT- IF assay was negative; follow-up as long as 58 months revealed no CNS leukemia in any patient. In 85 (5.2%) samples, cytomorphology was negative (n = 70) or suspect (n = 15) but TdT+ cells were detected. RBC contamination seriously hampered evaluation in 31 of these 85 samples. From the remaining 54 TdT+ samples from 29 patients, 40 samples preceded overt CNS leukemia in 20 patients. Two consecutive findings of TdT+ cells in the CSF were always followed by overt CNS leukemia. At initial diagnosis, 11 children had TdT+ cells in their RBC-free CSF. In one of these children, morphology was suspect; a repeated lumbar puncture was positive on both assays. Thus, initial CNS leukemia was diagnosed. In the other ten children, morphology was negative. In six of them, CNS leukemia was diagnosed 2 to 20 months later. In 32 other children examined at initial diagnosis, neither TdT+ cells nor blasts were observed in the CSF. In none of these patients was a CNS leukemia diagnosed after a follow-up of 2.5 to 57 months (median 24 months). In 207 control CSF samples from 58 children with TdT- oncologic, hematologic, or infectious diseases, no TdT+ cells could be detected. The TdT-IF assay is easy to perform and is a more reliable diagnostic tool for detection of CNS leukemia at an early stage than is cytomorphology. At initial diagnosis, the finding of Tdt+ cells in a RBC-free CSF sample with a negative cytomorphology is highly predictive for development of overt CNS leukemia.</jats:p

High expression of the mdr3 multidrug-resistance gene in advanced-stage chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is characterized by an often indolent course with a poor therapeutic response at advanced stage. We investigated the expression of the human multidrug resistance genes mdr1 and mdr3 in 31 patients with CLL. Using specific probes for mdr1 and mdr3 mRNA, respectively, expression of both genes could be found in 29 of 31 patients. Of those, nine had high expression of mdr1 and 13 of mdr3. Although 29 of 31 patients showed coexpression of mdr1 and mdr3, the mRNA levels were not interrelated. Prior treatment did not significantly influence the level of mdr1 or mdr3 expression. In patients with advanced CLL (Rai stage 3 + 4) the mdr3 expression was significantly higher than in early-stage CLL (Rai stage 0 to 2) (mean +/- SEM, 25.4 +/- 4.2 U v 4.2 +/- 1.1 U; P less than .0001). Such a difference was not present for mdr1 expression (21.5 +/- 4.3 U v 10.7 +/- 3.1 U; P = .09). These data indicate that advanced-stage CLL is associated with an increased mdr3 expression, which may concur with a decreased sensitivity to chemotherapy.</jats:p

High expression of the mdr3 multidrug-resistance gene in advanced-stage chronic lymphocytic leukemia

Abstract Chronic lymphocytic leukemia (CLL) is characterized by an often indolent course with a poor therapeutic response at advanced stage. We investigated the expression of the human multidrug resistance genes mdr1 and mdr3 in 31 patients with CLL. Using specific probes for mdr1 and mdr3 mRNA, respectively, expression of both genes could be found in 29 of 31 patients. Of those, nine had high expression of mdr1 and 13 of mdr3. Although 29 of 31 patients showed coexpression of mdr1 and mdr3, the mRNA levels were not interrelated. Prior treatment did not significantly influence the level of mdr1 or mdr3 expression. In patients with advanced CLL (Rai stage 3 + 4) the mdr3 expression was significantly higher than in early-stage CLL (Rai stage 0 to 2) (mean +/- SEM, 25.4 +/- 4.2 U v 4.2 +/- 1.1 U; P less than .0001). Such a difference was not present for mdr1 expression (21.5 +/- 4.3 U v 10.7 +/- 3.1 U; P = .09). These data indicate that advanced-stage CLL is associated with an increased mdr3 expression, which may concur with a decreased sensitivity to chemotherapy.</jats:p

Terminal deoxynucleotidyl transferase (TdT)-positive cells in cerebrospinal fluid and development of overt CNS leukemia: a 5-year follow-up study in 113 children with a TdT-positive leukemia or non- Hodgkin's lymphoma

We investigated whether an indirect nuclear terminal deoxynucleotidyl transferase (TdT) immunofluorescence (IF) assay on single cells present in the cerebrospinal fluid (CSF) is more effective than conventional cytomorphology for early detection or exclusion of (minimal) meningeal leukemic infiltration in patients with a TdT+ malignancy. During a 5- year follow-up study, 1,661 consecutive CSF samples from 113 children with a TdT+ acute lymphoblastic leukemia (ALL) (n = 100), a TdT+ acute nonlymphoblastic leukemia (ANLL) (n = 8), or a TdT+ non-Hodgkin's lymphoma (NHL) (n = 5) were analyzed. In 1,511 (91.9%) of 1,643 evaluable CSF samples, the positive and negative findings of both cytomorphology and the TdT-IF assay were concordant. In 47 (2.9%) samples from 28 patients, the cytomorphology was suspect while the TdT- IF assay was negative; follow-up as long as 58 months revealed no CNS leukemia in any patient. In 85 (5.2%) samples, cytomorphology was negative (n = 70) or suspect (n = 15) but TdT+ cells were detected. RBC contamination seriously hampered evaluation in 31 of these 85 samples. From the remaining 54 TdT+ samples from 29 patients, 40 samples preceded overt CNS leukemia in 20 patients. Two consecutive findings of TdT+ cells in the CSF were always followed by overt CNS leukemia. At initial diagnosis, 11 children had TdT+ cells in their RBC-free CSF. In one of these children, morphology was suspect; a repeated lumbar puncture was positive on both assays. Thus, initial CNS leukemia was diagnosed. In the other ten children, morphology was negative. In six of them, CNS leukemia was diagnosed 2 to 20 months later. In 32 other children examined at initial diagnosis, neither TdT+ cells nor blasts were observed in the CSF. In none of these patients was a CNS leukemia diagnosed after a follow-up of 2.5 to 57 months (median 24 months). In 207 control CSF samples from 58 children with TdT- oncologic, hematologic, or infectious diseases, no TdT+ cells could be detected. The TdT-IF assay is easy to perform and is a more reliable diagnostic tool for detection of CNS leukemia at an early stage than is cytomorphology. At initial diagnosis, the finding of Tdt+ cells in a RBC-free CSF sample with a negative cytomorphology is highly predictive for development of overt CNS leukemia.</jats:p