Richter's syndrome: a report on 39 patients.

PURPOSE: The incidence, clinical features, laboratory findings, and treatment results of 39 patients with Richter's syndrome (RS) are reported. PATIENTS AND METHODS: Thirty-nine of 1,374 patients with chronic lymphocytic leukemia (CLL) developed RS. RESULTS: Features associated with RS included systemic symptoms (59%), progressive lymphadenopathy (64%), extranodal involvement (41%), elevation of lactate dehydrogenase (LDH; 82%), and a monoclonal gammopathy (44%). Analysis of the CLL karyotype showed no specific chromosomal abnormality that conferred increased risk; however, multiple abnormalities were common. Patients at all Rai stages and in complete response (CR) were at risk, including three CR patients with no residual disease at the level of detection by dual-parameter flow cytometry or restriction analysis for immunoglobulin (Ig) gene rearrangements. The incidence was not higher in patients who had received prior fludarabine or chlorodeoxyadenosine. The median survival duration was only 5 months, despite multiagent therapy. Patients who responded had prolonged survival durations (P < .001). Three of eight patients who survived more than 1 year had a de novo presentation of both CLL and large-cell lymphoma (LCL). Comparison of surface light-chain analysis from both low- and high-grade components demonstrated isotypic light-chain expression in 12 of 15 patients. Ig heavy- and light-chain gene rearrangement analysis showed identical rearrangement patterns in five of five patients. CONCLUSION: The clinical, laboratory, and survival characteristics of our RS patients were similar to those reported in earlier studies. Ig gene rearrangement and light-chain isotype analysis support a common origin for CLL and LCL. Despite progress in the treatment of CLL, the development of LCL remains a serious complication and continued surveillance in all CLL patients is warranted.

Inhibition of acute myelogenous leukemia progenitor proliferation by macrophage inflammatory protein 1-alpha.

Macrophage inflammatory protein-alpha (MIP-1 alpha), an 8-kDa peptide produced by stimulated macrophages, has been recently sequenced and cloned. In addition to its inflammatory effects, MIP-1 alpha inhibits proliferation of immature hematopoietic progenitors both in vitro and in vivo. Because the gene coding for MIP-1 alpha is expressed in peripheral blood cells obtained from patients with acute myelogenous leukemia (AML), we sought to evaluate the effect of MIP-1 alpha on AML precursors. We studied bone marrow samples from 21 AML patients using both the AML blast colony assay and the delta suspension culture assay. We found that recombinant human (rh) MIP-1 alpha significantly inhibits early and mature AML progenitors with sample-to-sample variability, by up to 79% at concentrations ranging from 40 to 1600 ng/ml. These results were obtained in the presence of fetal calf serum either alone or with granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, or interleukin-3. In contrast, rhMIP-1 alpha (400 ng/ml) did not significantly affect normal colony-forming unit granulocyte-macrophage (CFU-GM), or burst-forming unit-erythroid (BFU-E) proliferation. These data prompted us to delineate the inhibitory mechanism of MIP-1 alpha. Consequently, we used the thymidine suicide technique to measure DNA synthesis in AML progenitors and the enzyme-linked immunosorbent assay to quantify intracellular levels of interleukin-1 beta in AML blasts following incubation with MIP-1 alpha. We found that whereas MIP-1 alpha prevented AML progenitors from entering the proliferative phase of the cell cycle, it had no effect on interleukin-1 beta levels. Taken together, our data suggest that MIP-1 alpha may have clinical benefits in therapy for AML and should be considered for evaluation in a clinical setting.

Myeloid surface antigen-positive acute lymphoblastic leukemia (My+ ALL): immunophenotypic, ultrastructural, cytogenetic, and molecular characteristics.

Leukemic blasts from 40 consecutively admitted adults with untreated acute lymphoblastic leukemia (ALL) were examined for myeloid surface antigen expression. Of these, 14 (35%) were reactive with one or more myeloid monoclonal antibodies. Each example of myeloid surface antigen-positive (My+ ALL) met the standard morphologic and cytochemical criteria for ALL. In addition, none of the 13 samples studied for ultrastructural evidence of myeloperoxidase met the criteria for acute myelocytic leukemia (AML). All patient samples reacted with lymphoid monoclonal antibodies: CD10+ (8 patients), CD19+ CD10- (2 patients), T cell+ (2 patients), and T cell+ CD10+ (2 patients). Coexpression of myeloid and lymphoid determinants was established by two-color immunofluorescence studies using flow cytometry in five of five samples analyzed. Cytogenetic abnormalities that have been associated with myeloid and mixed leukemias were common, including t(9;22), 7q-, abnormalities of 11q with or without a translocation, 20q-, and -5. Blasts from seven patients were studied at the molecular level. Immunoglobulin heavy chain gene rearrangements were detected in five of five samples with B cell+ T cell- phenotypes. One sample that was T cell+ CD10+ was germline for the immunoglobulin heavy chain and the T cell receptor gamma- and beta-chain genes. The other patient with T cell+ CD10+ blasts relapsed with AML following allogeneic bone marrow transplantation. The leukemia cells at the time of diagnosis and the cells at relapse demonstrated similar cytogenetics and the same immunoglobulin gene rearrangement, suggesting a clonal relationship. As a group, the My+ ALL patients had a significantly decreased complete remission rate when compared to My- ALL patients. Further studies at the molecular level will be required to determine the significance of karyotype abnormalities in My+ ALL.

Z-138: a new mature B-cell acute lymphoblastic leukemia cell line from a patient with transformed chronic lymphocytic leukemia.

We describe a new mature B-cell acute lymphoblastic leukemia (ALL) cell line designated Z-138 that was derived from a patient with chronic lymphocytic leukemia (CLL) whose disease underwent transformation to a rare, aggressive form of mature B-cell ALL. This cell line has an L3 morphology, ultrastructural characteristics of lymphoblasts, B-lineage surface markers and an immunoglobulin heavy-chain gene rearrangement identical to the rearrangement observed in the patient's blasts from whom the cell line was derived. Z-138 cells produce granulocyte-macrophage colony-stimulating factor (GM-CSF) and high levels of granulocyte-CSF (G-CSF), but they do not exhibit a proliferative response to either cytokine. Both the patient's lymphoblasts and Z-138 cells exhibited cytogenetic abnormalities including t(8;14), t(14;18) and a chromosome 11 abnormality similar to the t(11;14) of the parental cells, resulting in marked overexpression of cyclin D1 (BCL-1 (PRAD1)) mRNA in Z-138 cells. Since these karyotypic anomalies have been associated with low grade (t(14;18)), intermediate grade (t(11;14)) and high grade (t(8;14)) lymphomas, their development may be involved in the unusual aggressive transformation of this patient's CLL.

The role of gene rearrangements for antigen receptors in the diagnosis of lymphoma obtained by fine-needle aspiration. A study of 63 cases with concomitant immunophenotyping.

To assess the efficacy of performing genotyping in addition to immunophenotyping as an adjunct to cytologic diagnosis, 63 consecutive patients with fine-needle aspirates of lymphoproliferative lesions who had concurrent immunophenotyping and genotyping performed on fine-needle aspirate cell suspensions were studied. Thirty-nine of 63 specimens (62%) that appeared to contain non-Hodgkin's lymphoma and that proved to be of B-cell lineage by genotyping were accurately phenotyped and shown to be monotypic for immunoglobulin light chains by cell suspension immunocytochemistry. Genotyping facilitated lineage assignment and/or confirmed clonality in 17 of 63 specimens (27%) that were difficult to determine based on morphologic data. These include cases of atypical lymphoid proliferations with polyclonal or inconclusive markers (n = 6), peripheral T-cell lymphoma (n = 3), extracutaneous mycosis fungoides (n = 1), lymphoblastic lymphoma (n = 4), null cell lymphoma (n = 1), and specimens with equivocal or technically unsatisfactory markers (n = 2). Based on these results, it is proposed that genotyping for lineage assignment and/or clonality be performed to include cases of atypical lymphoid proliferations, T-cell malignant neoplasms, lymphoid malignant neoplasms with equivocal markers, and differentiation of lymphoid from nonlymphoid neoplasms. Genotyping by antigen-receptor gene rearrangement appears to be redundant in cases with mature B-cell phenotypes that demonstrate monoclonality by immunophenotyping.

Strategy for breakpoint cluster region analysis in chronic myelocytic leukemia in a routine clinical laboratory.

Despite the increasing reliance on breakpoint cluster region (bcr) determinations in diagnosis of chronic myelocytic leukemia (CML), few reports have dealt with the practical aspects of specimen analysis. In the setting of a routine molecular diagnostics laboratory, samples from 68 patients with active CML were evaluated for bcr rearrangements, with the use of a variety of enzymes and two probes. The data have been used to develop an efficient strategy for bcr screening and breakpoint determination. Screening with the universal bcr (UBCR) probe on Xba I and BgI II digests yielded bcr rearrangements in 100% of the Ph1-positive patients and three of the seven Ph1-negative patients, giving bcr analysis a sensitivity of 100%. A single-enzyme screen using the UBCR probe would have resulted in a false negative rate of 10%. The false negative rate was determined during the breakpoint site analysis from additional digests hybridized to both the 3' and UBCR probes. The false negative rate for the 3' probe was 26.5%, because of deletions or 5' rearrangements. The method of breakpoint site determination was dependent on screening results. In 78% of cases, one additional hybridization with two enzyme digests was required. During breakpoint site analysis, a rare false negative result was also demonstrated with Bam HI and Eco RI. This screening strategy has made bcr analysis competitive with cytogenetic analysis at the authors' institution; although turnaround time may be slightly longer, bcr analysis can yield information (such as detecting bcr-positive/Ph1-negative patients and determining breakpoint site) that cannot be obtained by cytogenetics.

Use of peripheral blood blasts vs bone marrow blasts for diagnosis of acute leukemia.

Acute leukemia can be diagnosed when blasts constitute 30% or more of the nucleated cells in a patient's peripheral blood (PB) sample. To determine whether in such cases bone marrow (BM) aspirates are still necessary, we compared the results of diagnostic studies performed on PB samples with blast counts of 30% or more with those performed on the same patients' BM samples. We found no differences in morphologic features, cytochemistry, or immunophenotype between the blasts in PB and BM samples in any of 30 cases studied. However, in 10 (23%) of 44 cases in which cytogenetic analysis was performed, PB but not BM samples were insufficient for analysis. The converse never occurred. Five of the 10 cases had acute lymphoblastic leukemia and 5 had acute myeloid leukemia (41% of the patients with acute lymphoblastic leukemia and 17% of the patients with acute myeloid leukemia). In cases with adequate metaphases, there was strong correlation between the cytogenetic results for PB and BM samples. Some PB samples with blast counts of 30% or more are adequate for diagnosis of acute leukemia, especially when therapy can be delayed until it is known that an adequate number of analyzable metaphases are recovered from the PB samples.

Pathologic diagnosis of acute lymphocytic leukemia.

With present knowledge, the optimal management of individual patients with acute leukemia requires that every case be studied by morphology, cytochemistry, cytogenetic, immunologic and molecular techniques. An algorithm for diagnostic evaluation and classification of ALL is provided in Fig. 11. Other techniques, such as DNA or cDNA [figure: see text] microarray, are at present important research tools but have not yet had a major effect on patient care. More detailed studies of individual patients need to be conducted at specialized cancer centers, where preservation of cells, DNA, RNA, or protein is possible. Such investigations will yield important information on the clinical importance of the expression of various markers, the prevalence and relevance of bilineage and biphenotypic leukemias, and above all will reveal the mechanisms of leukemogenesis and of disease evolution. Such insights will further aid clinicians in treating ALL and in preventing refractory disease.

Advances in the diagnosis of acute leukemia.

The diagnosis and monitoring of acute leukemia requires a multiparameter approach. Although the foundation of diagnosis continues to depend on morphologic and cytochemical determinations, the importance of immunologic, cytogenetic, and molecular classifications is beginning to be emphasized and addressed worldwide. In addition to aiding in the diagnosis of acute leukemia, the information gained by these studies increases the understanding of the pathobiology of these neoplasms.

Simplified Reverse Dot Blot Analyses for Detecting of ras Oncogene Mutations.

Background: Mutations in members of the ras gene family (H-ras, K-ras, and N-ras) have been identified in various human malignancies. A variety of techniques have been used to test for ras mutations. Methods and Results: A simplified reverse dot blot (RDB) assay was used in this study. Polymerase chain reaction products were hybridized to nitrocellulose membrane-fixed synthetic probes (20 nucleotides long) specific for codons 12, 13, and 61 of H-, K-, and N-ras mutations and their wild-type sequences. No special treatment or modification of the probes was necessary to obtain adequate results in overnight film exposure when the polymerase chain reaction was carried out using (32)P-end labeled primers. It was demonstrated that this simplified RDB assay can also be used with fluorescein-11-dUTP and a chemiluminescence detection system. The RDB assay is more reliable than the single-strand conformation polymorphism (SSCP) assay. By comparison, the SSCP assay is significantly less sensitive and less specific. It was confirmed with sequencing that 11 (12%) of 93 SSCP assays were false positive and 2 (2%) were false negative, whereas no false positive or false negative RDB assay was detected. The RDB assay also provides more additional detailed information about the specific point mutation and amino acid change, which may have clinical implications in some tumors. Conclusions: The RDB assay is very sensitive and able to detect mutations when the mutant allele is in 1% of the cells and can be used to detect minimal residual disease, particularly in some cases of leukemia and myelodysplasia.

Accuracy of diagnosis of malignant lymphoma by combining fine-needle aspiration cytomorphology with immunocytochemistry and in selected cases, Southern blotting of aspirated cells: a tissue-controlled study of 86 patients.

Fine-needle aspiration (FNA) cytology of lymph nodes in malignant lymphoma is fraught with difficulty. In certain clinical situations, cytology has been documented to be useful in patients with malignant lymphoma. The intent of our investigation was to determine the accuracy of a multiparameter approach in diagnosing lymphoma. We reviewed the results of FNA cytology combined with the immunocytochemistry and, in some cases, the Southern blots of aspirated cell suspensions obtained from 86 suspected lymphoma patients who subsequently underwent surgical biopsy of the aspirated site. In four cases, in which FNA was unable to retrieve sufficient material for diagnosis, the histology showed extensive fibrosis. When the FNA diagnoses were compared with the histologic diagnoses, the diagnosis concurred in 69 cases (56 malignant lymphomas, 12 reactive, 1 atypical lymphoid proliferation). There was one false-positive, six false-negatives, and eight cases diagnosed as atypical lymphoid proliferation. Overall accuracy was 91%. There were two types of false-negative cases: those in which a diagnosis of another malignancy or unspecified malignant neoplasm was made and those that were diagnosed as reactive when the histology showed lymphoma. In seven cases, the DNA rearrangement studies of the antigen receptor genes were successfully performed on the aspirated cells and were useful in establishing lineage and clonality of both B and T lymphoid cells. Our study indicated that the use of a multiparameter approach in the diagnosis of malignant lymphoma by FNA enhanced the accuracy of diagnosis of the non-Hodgkin's lymphomas. In Hodgkin's disease, no benefit was derived from the approach.

Molecular genetics diagnostic applications in oncology.

The use of lineage and cytogenetic probes in diagnosis of oncologic disorders is reviewed. The presence of rearranged bands via Southern blot analysis may generate diagnostic support of hematopoietic malignancy in several instances. DNA probes can be used to demonstrate clonality, reveal lineage characteristics, or identify specific chromosomal aberrations. Lineage probes detect genetic events during normal lymphocyte differentiation, while cytogenetic probes detect a malignant characteristic. The number of translocations detectable using DNA probes will likely expand in the future.

Detection of minimal residual disease: relevance for diagnosis and treatment of human malignancies.

Minimal residual disease (MRD) is the tumor burden that is present after a course of treatment that has resulted in clinical remission. For hematopoietic malignancies, techniques for detection of this minimal tumor burden are being used to monitor MRD. These involve methods that are capable of identifying very low numbers of neoplastic cells in an otherwise normal marrow or lymph node. Patients with demonstrable residual neoplastic cells tend to do worse than patients without detectable cells; however, results depend on the timing of the assay and whether the detectable neoplastic cells appear to be increasing in number with subsequent assays. For bone marrow transplantation, assays incorporating chimerism analyses, cytogenetics, and morphology are used to regulate therapy.

Fine-needle aspiration evaluation of lymphoproliferative lesions in human immunodeficiency virus-positive patients. A multiparameter approach.

Forty-six fine-needle aspirates of lymphoproliferative lesions from 31 human immunodeficiency virus (HIV)-positive patients were reviewed using cytomorphologic, immunocytochemical, flow cytometric (FCM), cytogenetic, and molecular studies. There were 29 lymphomas (15 small non-cleaved cell [SNCL], 11 large cell [LCL], one small lymphocytic, and two Hodgkin's), 14 reactive hyperplasias, and three "atypical lymphoid proliferations." The reactive hyperplasias were characteristically polymorphic and polyclonal lymphoid populations; six of seven were diploid on FCM, the seventh was hypodiploid. Higher proliferative indices (mean, 11.6%) and higher RNA indices (mean, 1.2) characterized this subgroup compared with published reactive lymphoid hyperplasias from patients without HIV positivity. Aspirates of SNCL showed monotonous populations of intermediate-sized cells except in one patient where a giant cell syncytial variant occurred. Nine of 13 SNCL aspirates showed light chain restriction. JH rearrangement revealed B-cell lineage in one aspirate in which immunocytochemical study was negative for Kappa, lambda, B1, and Leu-4. Nine of 12 SNCL were diploid; the mean proliferative index was 25.6% and the mean RNA index 2.3. Chromosomal translocations involving the c-myc locus were demonstrated in five of seven SNCL aspirates karyotyped. Five of eight LCL showed light chain restriction the remaining three showed null cell phenotype. Large cell lymphomas were diploid on tetraploid with the mean proliferative index of 22.0% and mean RNA index of 2.2. One of two LCL aspirates karyotyped demonstrated c-myc translocation. Despite the multiparameter approach, a definitive diagnosis could not be reached in three aspirates.

Mixed-lineage leukemia revisited: acute lymphocytic leukemia with myeloperoxidase-positive blasts by electron microscopy.

Seven adult patients with untreated acute lymphocytic leukemia (ALL) who manifested 5% to 40% myeloperoxidase (MPO)-positive blasts by electron microscopy (EM) are reported. Six patients had an L2 morphology, and one had an L1 morphology by the French-American-British (FAB) classification. The immunophenotype was T cell in four patients. Molecular analysis showed rearrangement of the immunoglobulin JH in four patients, three of them also having rearrangement of the T-cell receptor beta or gamma. Induction chemotherapy with vincristine-doxorubicin-dexamethasone (VAD) produced a complete remission in five of six patients (83%). Our findings suggest the existence of a previously undescribed subtype of mixed-lineage leukemia, which by morphology and immunophenotype often appears as T-cell ALL but exhibits MPO-positive blasts by EM.

Interleukin 4 alters human bone marrow stroma and modulates its interaction with hematopoietic progenitors.

To investigate the functional activity of interleukin 4 (IL-4) on human marrow stroma formation, normal bone marrow (BM) samples were cultured in "Dexter-type" long-term cultures in the presence and absence of IL-4. IL-4 (0.001 to 1.0 micrograms/ml) added at the initiation of culture and once weekly when the cultures were fed effaced the culture architecture. In four-week old confluent cultures smooth muscle-like and endothelial-like cells were rare, the fibronectin network and cobblestone areas were absent, and a preponderance of monocyte-macrophages characterized the adherent layer. Exposure to IL-4 reduced the numbers of CD34+ cells, colony-forming unit granulocyte-macrophage (GFU-GM) cells and burst-forming unit-erythroid (BFU-E) cells in the adherent layer, and increased their numbers in the nonadherent layer. In five of eight IL-4-containing cultures the concentrations of macrophage colony-stimulating factor (M-CSF) were increased and in two of eight IL-4-treated cultures the concentrations of tumor necrosis factor-alpha (TNF-alpha) were significantly elevated as compared to those in control cultures, whereas there were no consistent differences in the levels of either IL-6 or transforming growth factor-beta (TGF-beta). IL-1 beta and granulocyte-macrophage CSF (GM-CSF) were not detected in any culture. These data suggest that IL-4 suppresses stroma formation and alters its structure and cellular composition.

Differential dose-related haematological effects of GM-CSF in pancytopenia: evidence supporting the advantage of low- over high-dose administration in selected patients.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a multifunctional haematopoietin which can promote production of several blood cell lineages, though the predominant target cells are neutrophils, monocytes, and their precursors. Occasional undesirable clinical effects include eosinophilia, an increase in blasts, or thrombocytopenia. Here, we describe four patients who were treated with GM-CSF, at subcutaneous doses significantly lower than are conventional, and experienced an unusual response pattern. Three patients had severe pancytopenia associated with chronic lymphocytic leukaemia (CLL) or myelodysplastic syndrome (MDS) and exhibited an unexpected switch in the responsive lineage on high- versus very low-dose therapy. The two CLL patients developed marked eosinophilia (up to 10.0 x 10(9) cells/l) without an increase in neutrophils on 125-300 micrograms/m2/d of GM-CSF. In contrast, when the dose was lowered to 10 micrograms/m2/d, the neutrophils rose to physiological levels, without significant eosinophilia. The MDS patient showed a rapid rise in peripheral blasts (baseline level = 0; post-therapy level = 5.0 x 10(9)/l), without a change in other cell types, when receiving 60 micrograms/m2/d of GM-CSF. After GM-CSF was held, blasts returned to baseline levels; reinstituting therapy at the very low dose of 6 micrograms/m2/d was followed by an increase in platelet counts from 50 to 185 x 10(9)/l with only a minor increase in blasts. The fourth patient, who suffered from severe aplastic anaemia complicated by recurrent gastrointestinal haemorrhage, was only treated with the low-dose regimen. He showed a predominant platelet effect with counts rising from 9 to 169 x 10(9)/l. Very low-dose GM-CSF therapy was devoid of constitutional side effects. The biological implications of these GM-CSF responses are discussed. Our results indicate that, in some patients, GM-CSF may stimulate different target cells depending on the dose. Therefore, in contrast to the results of administration of many classical drugs, there may not always be a direct relationship between the amount of GM-CSF given and the optimal effect.

Heterogeneity in acute undifferentiated leukemia.

From January 1985 to May 1987, we studied 256 adults with newly diagnosed acute leukemia. Acute undifferentiated leukemia (AUL) was diagnosed in 12 of the 256 (4.6%) cases when lineage could not be delineated by light microscopy and light cytochemistry. To further characterize the blasts, immunophenotyping, ultrastructural myeloperoxidase (UMPO), and ultrastructural platelet peroxidase parameters were examined in 10, 11, and 6 of the 12 cases, respectively. Five cases demonstrated UMPO and were reclassified as acute myeloblastic leukemia (AML). Of the six UMPO-negative cases, three had a myeloid and one had a mixed immunophenotype. One UMPO-negative patient with a myeloid immunophenotype was probed for the immunoglobulin heavy chain gene (JH) and the beta chain of the T-cell receptor gene (Tcr beta) with no evidence of rearrangement. Six cases were treated with standard acute lymphoblastic leukemia (ALL) chemotherapy and failed to achieve complete remission (CR). Various AML chemotherapeutic regimens produced CR in only 3 of the 12 cases. One case was treated with gamma interferon and the other 2 with high-dose Ara-C. Our findings indicate a myeloid lineage can be detected by UMPO (5/12) in some cases of AUL. A germline configuration with JH and Tcr beta in one case as well as a myeloid immunophenotype in 3 UMPO-negative cases raises the possibility that myeloid lineage commitment may occur in the absence of myeloid peroxidase (MPO) cytochemical positivity.

Phenotypic and molecular heterogeneity in Philadelphia chromosome-positive acute leukemia.

Philadelphia chromosome-positive (Ph1) acute leukemia is a heterogeneous subset of acute leukemia with a poor prognosis. We studied five patients to determine the potential for phenotypic and molecular heterogeneity. Cellular characterization studies included light myeloperoxidase (L-MPO), terminal deoxynucleotidyl transferase (TdT), ultrastructural MPO (U-MPO), and immunophenotyping by flow cytometry using T11, T3, T4, T8, Leu 1, B1, Leu 12, HLA-DR (la), CALLA (J5), OKM1, My4, My7, My8, My9, and My10. DNA was analyzed for rearrangements of the breakpoint cluster region (bcr), immunoglobulin heavy chain, joining region (JH), immunoglobulin kappa light chain constant region (C kappa), and T cell receptor (TcR beta). RNA dot blots were hybridized by using molecular probes for MPO and TdT. We found that four of five cases were acute mixed-lineage leukemia (AMLL). One patient had acute unclassifiable leukemia. Of the four patients classified as having AMLL, three showed myeloid and lymphoid features, with one patient showing myeloid, T cell, and B cell features. The last case showed T cell and B cell features only. In one patient MPO/RNA was positive in spite of insufficient L-MPO or U-MPO to diagnose acute myelogenous leukemia (AML), thereby suggesting significant MPO gene expression before the production of sufficient MPO protein to meet the French-American-British criteria for AML. Three of the five patients showed rearrangement of bcr (cases 1, 2, and 5). Studies of these five patients support the concepts of molecular and phenotypic heterogeneity in Ph1 acute leukemia, demonstrate a high incidence of AMLL in this subset of acute leukemia, and support the use of lineage-associated molecular probes to define lineage at an earlier stage than previously possible.

Quantification of the breakpoint cluster region rearrangement for clinical monitoring in Philadelphia chromosome-positive chronic myeloid leukemia.

The purpose of this report was to evaluate scintigraphy analysis of Southern blot hybridization as a method to quantify the breakpoint cluster region (BCR) rearrangement of Philadelphia chromosome (Ph)+ chronic myelogenous leukemia (CML). Cytogenetic and molecular studies performed simultaneously on 474 bone marrow and/or blood samples from 300 patients treated with alpha-interferon-based therapy were compared. Molecular results were expressed as the percentage of rearranged BCR bands versus the total scintigraphic signal. The percentage of Ph+ metaphases was calculated on 25 metaphases. The results of molecular studies obtained on both peripheral blood and bone marrow samples were identical. The rank correlation between the BCR quantification and the percentage of Ph positivity in 465 samples was excellent (r = .78). However, of 99 samples with a normal karyotype, 24% had a BCR rearrangement. Of 86 samples with no BCR rearrangement, 13% showed a Ph chromosome. Of 49 samples with partial cytogenetic remission (Ph+ metaphases, 1% to 34%), 23% had no BCR rearrangement. In samples with a minor or no cytogenetic response (Ph+ metaphases, > 34%), BCR analysis overestimated the degree of response in 73 of 326 samples (22%). Nevertheless, survival analysis by BCR quantification level showed statistically better outcome for patients in complete or partial molecular response (P < .01). Molecular quantification of BCR was useful in monitoring the course of Ph+ CML. This method, which can be used on peripheral blood, detected residual disease not shown by cytogenetic analysis and was prognostically relevant as a measure of disease suppression.