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W D Ludwig

Publications and source records attributed to W D Ludwig.

At least 109 records · Page 6Linked to original sources
PubMed1995

Proposals for the immunological classification of acute leukemias. European Group for the Immunological Characterization of Leukemias (EGIL).

Criteria for the immunological classification of acute leukemias are proposed by a recently established European group designated EGIL. The main aims of EGIL are to establish guidelines for the characterization of acute leukemias based on marker expression and provide a uniform basis for the diagnosis of the various types of these hemopoietic malignancies which should be helpful for future multinational clinical and laboratory investigations. Within the two major types (B and T cell lineage) of acute lymphoblastic leukemia (ALL), several groups are delineated according to the degree of cell differentiation. Within the acute myeloid leukemias (AML), only three subtypes as defined by the FAB classification: M0-AML, M6-AML and M7-AML, can be unequivocally defined by immunological markers; prospective studies are undertaken to see whether characteristic immunological profiles are associated with particular AML subtypes defined by specific cytogenetic abnormalities. Criteria for the definition of biphenotypic acute leukemia (BAL) are devised and a scoring system is outlined aimed to distinguish BAL from those acute leukemias with expression of a marker from another lineage. In addition, an uncommon subset of acute leukemias with no evidence of lymphoid or myeloid differentiation is recognized and the useful panel of markers to investigate and establish the cell nature of the acute leukemias is outlined. EGIL will focus in the future on testing the reproducibility of the proposed guidelines, particularly those for BAL, assessing their clinical value within a framework of multicentric trials and setting up uniform methodological criteria.

Acute Disease↗
PubMed1995

Acute leukemia coexpressing myeloid, B- and T-lineage associated markers: multiparameter analysis of criteria defining lineage commitment and maturational stage in a case of undifferentiated leukemia.

Coexpression of myeloid, B-, and T-lineage associated markers was found in a patient with morphologically and cytochemically undifferentiated acute leukemia. Surface marker analysis using two-color immunofluorescence staining characterized blast cells to express CD34, CD38, CD117, and class II antigens, coexpressing TdT, CD4, CD7, CD13, CD19, and CD33. Cytoplasmic expression of myeloperoxidase, CD3, and CD22 could not be demonstrated. Monosomy for chromosome 7 was found by cytogenetic analysis. The absence of clonal rearrangements of immunoglobulin or T-cell receptor genes was shown by Southern blot analysis. Using a 3H-thymidine incorporation assay, DNA synthesis of leukemic blasts could be stimulated by IL-3, IL-6 and G-CSF in vitro. The present case did not offer specific criteria of lineage commitment. Corresponding to an equivalent counterpart in normal hematopoiesis, the involved cell population may reflect an early, most immature developmental stage within a multipotent progenitor cell compartment.

Acute Disease↗
PubMed1994

Pre-pre-B acute lymphoblastic leukemia: high frequency of alternatively spliced ALL1-AF4 transcripts and absence of minimal residual disease during complete remission.

We used the polymerase chain reaction (PCR) to detect ALL1-AF4 rearrangements, the molecular hallmark of t(4;11) in a series of 46 pre-pre-B (CD19+, CD24+, CD10/CD20/cylgM/sIgM-) acute lymphoblastic leukemias (ALL). Eighteen patients (39%) exhibited fusion transcripts including 4 of 12 children and 14 of 34 adults. This genetic defect was associated with hyperleukocytosis (median leukocyte count 176 x 10(9)/L) and expression of myeloid-associated antigens (CDw65+). In contrast, only two patients from a group of 67 common (CD19/CD10+, cylgM/sIgM-) and pre-B ALLs (CD19/cylgM+, CD10 +/-, sIgM-) showed ALL1-AF4 mRNA. All PCR-positive cases showed multiple amplification products representing alternative splicing events. Moreover, reciprocal der (4)-derived AF4-ALL1 transcripts were observed in 65% of the cases analyzed. Eight of the 18 pre-pre-B ALL patients with an ALL1-AF4 recombination are currently in complete continuous remission for up to 54 months (median, 26 months). Twelve remission samples were available from seven cases, and all of them lacked evidence of minimal residual disease. Overall this study documents a similarly high incidence of ALL1-AF4 recombinations in children (infants excluded) and adults with pre-pre-B ALL and demonstrates the decline of the leukemic cell clone below the detection level of PCR in a remarkable proportion of patients under intense treatment protocols.

Adolescent↗
PubMed1994

Chemotherapy in 998 unselected childhood acute lymphoblastic leukemia patients. Results and conclusions of the multicenter trial ALL-BFM 86.

In trial ALL-BFM 86, the largest multicenter trial of the Berlin-Frankfurt-Münster (BFM) study group for childhood acute lymphoblastic leukemia (ALL), treatment response was used as an overriding stratification factor for the first time. In the previous trial ALL-BFM 83, the in vivo response to initial prednisone treatment was evaluated prospectively. A blast cell count of > or = 1,000/microL peripheral blood after a 7-day exposure to prednisone and one intrathecal dose of methotrexate (MTX) identified 10% of the patients as having a significantly worse prognosis. In trial ALL-BFM 86 patients with > or = 1,000/microL blood blasts on day 8 were included in an experimental branch EG. Patients with < 1,000/microL blood blasts on day 8 were stratified by their leukemic cell burden into two branches, Standard Risk Group (SRG) and Risk Group (RG). SRG patients received an eight-drug induction followed by consolidation protocol M (6-mercaptopurine, high-dose [HD] MTX 4 x 5 g/m2) and maintenance. RG patients were treated with an additional eight-drug reinduction element. For EG patients protocol M was replaced by protocol E (prednisone, HD-MTX, HD-cytarabine, ifosfamide, mitoxantrone). All patients received intrathecal MTX therapy; only those of branches RG and EG received cranial irradiation. In branch RG, patients were randomized to receive or not to receive late intensification (prednisone, vindesine, teniposide, ifosfamide, HD-cytarabine) in the 13th month. During the trial reinduction therapy was introduced in branch SRG, because in the follow-up of trial ALL-BFM 83 the randomized low-risk patients receiving reinduction did significantly better. Nine hundred ninety-eight evaluable patients were enrolled, 28.6% in SRG, 61.1% in RG, 10.3% in EG. At a median follow-up of 5.0 (range 3.4 to 6.9) years, the estimated 6-year event-free survival was 72% +/- 2% for the study population, 58% +/- 5% in branch SRG for the first 110 patients without reinduction therapy, 87% +/- 3% for the next 175 patients with reinduction therapy, 75% +/- 2% in branch RG, and 48% +/- 5% in branch EG. Late intensification did not significantly affect treatment outcome of RG patients; however, only 23% of the eligible patients were randomized. Prednisone poor response remained a negative prognostic parameter despite intensified therapy. The results confirmed the benefit of intensive reinduction therapy even for low-risk patients. The strategy of induction, consolidation, and intensive reinduction may offer roughly 75% of unselected childhood ALL patients the chance for an event-free survival.

Adolescent↗
PubMed1994

Overexpression of the Raf-1 proto-oncogene in human myeloid leukemia.

The Raf-1 protein, a cytoplasmic serine/threonine kinase, plays an important role in signal transduction pathways. In order to examine the role of Raf-1 in human myeloid leukemia, we determined raf-1 mRNA expression by Northern blot analysis in blast cell samples from 27 acute myeloid leukemia (AML) cases and peripheral blood mononuclear cells from six healthy donors. A normal raf-1 transcript size was detected in all cases investigated. However, overexpression of raf-1 mRNA was found in 2 of 27 AML cases, both of which were erythroleukemias (AML, FAB M6).

Acute Disease↗
PubMed1994

Molecular characterization of illegitimate TCR delta gene rearrangements in acute myeloid leukaemia.

Recently, we and others have shown the occurrence of TCR delta gene rearrangements in acute myeloid leukaemia (AML). In this study we describe the molecular characteristics of these rearrangements by the polymerase chain reaction (PCR) and the direct sequencing of PCR products. 11 rearrangements were characterized in blast cell samples from six patients. We found a heterogenous pattern of TCR delta gene rearrangements with involvement of V delta 1-5 regions. These findings differ from observations in T-ALL and B-cell precursor ALL, where predominantly usage of V delta 1 and V delta 2 regions has been described. Furthermore, extensive diversity of junctional sites was observed, including addition of up to 37 N nucleotides, nucleotide deletions at junction sites of V delta and J delta segments and usage of up to three D delta segments. The D delta 3 fragment was the most frequently used diversity element and was found in 10 rearrangements. Nine of the 11 rearrangements were non-functional, either incomplete or out of the reading frame. Therefore a functional TCR delta cannot be expressed in these myeloid blast cells.

Adult↗
PubMed1994

Immunophenotypic features of childhood and adult acute lymphoblastic leukemia (ALL): experience of the German Multicentre Trials ALL-BFM and GMALL.

Immunophenotyping prospectively performed in about 2800 children and adults within the framework of the German multicentre ALL trials revealed marked differences in frequency distribution of immunologic subgroups with a higher incidence of immature B-cell precursor and pre-T/T phenotypic features in adults. Detailed immunophenotypic characterization by applying monoclonal antibodies to lymphoid- and myeloid-associated antigens as well as non-lineage-restricted molecules underlined the diagnostic value of pan-B and pan-T antigens that were expressed in virtually all cases of B-cell precursor (CD19, CD24) or T-cell ALL (cytoplasmic CD3, CD7) for lineage affiliation of leukemic blasts. About 10% of children and 20% of adults disclosed simultaneous expression of lymphoid markers and at least one myeloid-lineage-associated antigen. Our data confirm that immunophenotyping in ALL provides a solid basis for a biologically oriented and reliable classification of this heterogeneous disease.

Adult↗
PubMed1994

Heterogeneity of V delta 2 TCR delta gene rearrangements in acute myeloid leukemia.

In a previous study, we described the occurrence of T-cell receptor (TCR)delta gene rearrangements in 9/100 acute myeloid leukemia (AML) cases. In this study, we further characterized these rearrangements by Southern Blot hybridization using a V delta 2 specific probe and polymerase chain reaction (PCR). Southern Blot analysis revealed that rearrangements involved the V delta 2 gene segment in four patients. Interestingly the restriction fragments detected by the V delta 2 probe differed markedly in size. PCR analysis revealed a complete V delta 2(Dn)J delta 1 gene rearrangement, an incomplete V delta 2D delta 3 rearrangement and a large amplification product, which cannot be explained with normal VDJ recombinatorial processes, in one case each. Furthermore although V delta 2 and J delta were rearranged, no comigration of rearranged fragments was observed and no PCR product was obtained in one case. Obtained results in AML differ from findings in acute lymphoblastic leukemia (ALL) of B-cell lineage, where a more homogeneous pattern of rearrangements has been described. This heterogeneity might be related to the illegitimate occurrence of TCR delta gene rearrangements in AML.

Adult↗
PubMed1994

Mechanisms of p53 alteration in acute leukemias.

Disruption of normal p53 expression is the most frequent genetic change occurring in various human solid tumors; it is mostly due to sequence alterations of the p53 coding region by missense mutations or to loss of an entire, functional allele of this gene. In the present study, possible mechanisms resulting in a disruption of regulated expression of wild-type p53 were examined in acute leukemias of either lymphoid (ALL) or myeloid (AML) phenotype. p53 transcript accumulation, nucleotide sequence and gene structure were analyzed in primary leukemic cells from 50 patients. p53-specific transcripts were detected in 26/26 cases of ALL and 16/23 cases of AML using reverse transcriptase (RT)-PCR. Sequencing of transcripts did not reveal any point mutations or deletions. Heterozygosity at a polymorphic Bg/II site within intron 1 was found in 4/28 leukemic samples, and loss of one allele was noted in one of these. In addition, a novel, leukemia-associated structural abnormality located within the 5' flanking region of the p53 gene and associated with the loss of heterozygosity was observed in cells from this patient with ALL. The MDM2 gene which inactivates p53 by binding to it was neither amplified nor rearranged in 28 leukemias studied. Thus, disruption of regulated p53 expression resulting in lack of detectable p53 mRNA even by RT-PCR occurs in about 30% of cases of AML; however, p53 alterations typical for human solid tumors are an infrequent event in most types of human acute leukemias.

Acute Disease↗
PubMed1994

Detection of HRX-FEL fusion transcripts in pre-pre-B-ALL with and without cytogenetic demonstration of t(4;11).

The t(4;11)(q21;q23) characterizes a distinct clinical entity of childhood and adult acute lymphoblastic leukemia (ALL) with a pre-pre-B-phenotype, monocytoid features, coexpression of CD15 and/or CDw65 and a dismal prognosis. The molecular correlate of the t(4;11) has been identified as a fusion transcript of HRX, a gene on 11q23 with homology to drosophila trithorax gene, and FEL, a serine-proline-rich gene on 4q21 of unknown function. The aim of the current study was to establish a reverse transcription-polymerase chain reaction (RT-PCR) approach for the rapid and sensitive detection of the HRX-FEL fusion transcript associated with the t(4;11). For this purpose, two groups of patients were studied: group A comprised cases with cytogenetically proven t(4;11) including three infant and four adult pre-pre-B-ALL, as well as the two cell lines RS4;11 and MV4;11. Group B consisted of ten adult pre-pre-B-ALL with the identical phenotype, but without cytogenetic confirmation of t(4;11). Using primers complementary to HRX and FEL cDNA sequences 300 to 500 bp 5' and 3' of published breakpoints, respectively, specific amplification products were obtained in all nine cases of group A and in nine of the ten cases of group B. Three different types of fusion transcripts were identified by sequence analysis with HRX breakpoints at nucleotides 4086 and 4218 and FEL breakpoints at nucleotides 1413, 1416, and 1458. These data indicate that RT-PCR allows the detection of HRX-FEL fusion transcripts in the vast majority of cytogenetically proven and immunophenotypically suspected t(4;11) ALL. Hence, this technique may allow identification of a further subset of high risk ALL and may also be useful for the monitoring of minimal residual disease in t(4;11) ALL.

Adult↗
PubMed1994

[Immunophenotyping of acute lymphatic leukemia: diagnostic aspects and clinical relevance].

During the past two decades immunophenotyping has yielded significant new information regarding the biological heterogeneity of ALL and has provided a solid basis for a biologically oriented and reliable classification of this disease. At present, lineage commitment of acute leukaemias can be achieved in more than 98% of cases by applying a standardized panel of mAbs to pan-B-cell (CD19, cyCD22), pan-T-cell (cyCD3, CD7) and pan-myeloid antigens (CD13, CD33, MPO) that are expressed either on the surface or in the cytoplasm of the earliest progenitors of the respective cell lineage. Further subclassification of ALL based on the analysis of antigens more closely associated with different maturational stages of B- and T-cell lineage has proven useful for the identification of biologically and clinically distinct entities in both B-cell precursor and T-lineage ALL. Immunophenotyping in about 2800 patients recruited for the German multicentre trials has shown that children and adults differ markedly in frequency distribution of immunological subgroups, with a higher adult incidence of immature B-cell precursor (i.e., pre-pre-B ALL) and T-lineage ALL immunophenotypes (i.e., pre-T ALL). Detailed immunological analyses using a broad panel of mAbs have recently documented typical ALL cases inappropriately expressing myeloid antigens (My+ ALL) as well as morphologically/cytochemically defined acute myeloid leukaemia (AML) with lymphoid-associated markers (Ly+ AML). Based on our own results and a critical review of published data, leukaemic blasts in 5-20% of ALL patients disclose My+ ALL, whereas a coexpression, mostly of T-cell-associated antigens, can be identified in 10-25% of AML cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Correlation of cytogenetic findings with clinical features in 18 patients with inv(3)(q21q26) or t(3;3)(q21;q26).

An inversion in the long arm of chromosome 3--inv(3)(q21q26)--or a translocation between both homologous chromosomes 3--t(3;3)(q21;q26)--is found specifically in myeloid neoplasias characterized by disturbances of thrombopoiesis and megakaryocyte development. Cytogenetic findings were correlated with clinical and hematological data in altogether 18 patients with acute nonlymphocytic leukemia (ANLL) and with inv(3) (13 patients) or t(3;3) (five patients), six of whom were male and 12 who were female. Chromosomal changes in addition to the 3q anomalies were demonstrated in 14 out of 18 patients, predominantly numerical and structural aberrations of chromosome 7 (12 cases) and/or abnormalities of 5q (five cases). Complex karyotype abnormalities were observed in six of 13 patients with inv(3), but in only one of five patients with t(3;3). In ten out of our 18 patients a preceding myelodysplastic syndrome (MDS) and/or exposure to mutagenic/carcinogenic agents had been established. In eight patients the morphology of ANLL blasts was immature (FAB subtype M1); in three patients ANLL-M4, and in two patients each ANLL-M5, M6, and M7 was diagnosed; in one patient with antecedent MDS the leukemic blasts were not classifiable according to the FAB criteria. A disturbed megakaryocyte development, characterized by an excess of micromegakaryocytes was observed in 14 patients, seven of them showed normal or elevated platelet counts as an unusual feature in patients with ANLL. The clinical course and outcome was extremely poor: 15 of 18 patients died within 10 months after the diagnosis of ANLL. Because of their missing response to conventional chemotherapy, patients with inv(3) or t(3;3) have to be estimated as at high risk. The characterization of genes affected by inv(3) or t(3;3) could help to elucidate molecular changes leading to impaired proliferation and differentiation of hematopoietic cells, also of the megakaryocytic lineage. Based on molecular genetic findings new therapeutical approaches could be designed.

Adult↗
PubMed1994

Characterization of the monocyte-specific esterase (MSE) gene.

Carboxylic esterases are widely distributed in hematopoietic cells. Monocytes express the esterase isoenzyme (termed 'monocyte-specific esterase', MSE) that can be inhibited by NaF in the alpha-naphthyl acetate cytochemical staining. We examined the expression of MSE in normal cells and primary and cultured leukemia-lymphoma cells. The MSE protein was demonstrated by isoelectric focusing (IEF); MSE mRNA expression was investigated by Northern blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). The following samples were positive for MSE protein and Northern mRNA expression: 20/24 monocytic, 4/32 myeloid, and 1/20 erythroid-megakaryocytic leukemia cell lines, but none of the 112 lymphoid leukemia or lymphoma cell lines; of the normal purified cell populations only the monocytes were positive whereas, T, B cells, and granulocytes were negative; of primary acute (myelo) monocytic leukemia cells (CD14-positive, FAB M4/M5 morphology) 14/20 were Northern mRNA and 11/14 IEF protein positive. RT-PCR revealed MSE expression in 29/49 Northern-negative lymphoid leukemia-lymphoma cell lines. The RT-PCR signals in monocytic cell lines were on average 50-fold stronger than the mostly weak trace expression in lymphoid specimens. On treatment with various biomodulators, only all-trans retinoic acid significantly upregulated MSE message and protein levels but could not induce new MSE expression in several leukemia cell lines; lipopolysaccharide and interferon-gamma increased MSE expression in normal monocytes. Analysis of DNA methylation with sensitive restriction enzymes showed no apparent regulation of gene expression by differential methylation; the MSE gene is evolutionarily conserved among mammalian species; the half-life of the human MSE transcripts was about 5-6 h. The extent of MSE expression varied greatly among different monocytic leukemia samples. However, the MSE overexpression in a significant number of specimens was not associated with gene amplification, gross structural rearrangements or point mutations within the cDNA region. Taken together, the results suggest that MSE expression is not absolutely specific for, but strongly associated with cells of the monocytic lineage; MSE is either not expressed at all or expressed at much lower levels in cells from other lineages. The biological significance, if any, of rare MSE messages in lymphoid cells detectable only by the hypersensitive RT-PCR remains unclear. Further studies on the regulation of this gene and on the physiological function of the enzyme will no doubt be informative with respect to its striking overexpression in some malignant cells and to a possible role in the pathobiology of monocytic leukemias.

Base Sequence↗
PubMed1994

t(5;14)(q33-34;q11), a new recurring cytogenetic abnormality in childhood acute leukemia.

A novel translocation, t(5;14)(q33-34;q11), was identified in the leukemic cells of four children presenting with acute lymphoblastic leukemia (ALL). The patients were 14 months, 2 years, 10 years, and 12 years old; each presented with one or more features of bulky disease, including lymphadenopathy, organomegaly or a mediastinal mass. The leukemic blasts were B lineage in two cases and T lineage in two cases. The patients with B-lineage ALL remain in continuous remission at 22 and 19 months following diagnosis. One patient with T-lineage ALL relapsed 6 months after diagnosis. The other patient with T-lineage ALL developed acute myelocytic leukemia (AML) 17 months after diagnosis; t(5;14)(q33-34;q11) was present in both the lymphoblasts at diagnosis and the myeloblasts at relapse, consistent with a lineage switch from ALL to AML. Rearrangement of the T-cell receptor delta chain (TCRD) gene at 14q11 was demonstrated in the three cases studied, suggesting its involvement in the pathogenesis of these leukemias by alteration of the structure or expression of an unidentified gene(s) on the long arm of chromosome 5.

Child↗
PubMed1994

Ras point mutations occur in acute myeloid leukemia with illegitimate T-cell receptor delta gene rearrangement.

Mutations in the ras proto-oncogenes are the most frequently observed molecular alteration in acute myeloid leukemia (AML). Whether ras mutations occur as late or relatively early events in the multistep process of myeloid transformation, remains an open question. We previously described illegitimate T-cell receptor (TCR)-delta gene rearrangements in a subset of AML. These recombinations were detected in 9 out of 100 de novo AML cases. Southern blot analysis suggested the presence of these recombinations in the vast majority of AML cells and thus could be used as clonal markers. In order to more accurately define the role of ras proto-oncogene mutations in the multistep process of malignant transformation in myeloid leukemias, we performed single strand conformation polymorphism (SSCP) assays, slot blot and direct sequencing analysis on these nine cases with illegitimate TCR delta gene rearrangements. Ras proto-oncogene mutations were found in three of nine cases. Interestingly, SSCP, slot blot and sequencing suggested the presence of the respective mutations in most of the leukemic cells. Thus, ras mutations presumably occurred early in the process of transformation in these three cases.

Adult↗