Homogeneously staining region (hsr) on chromosome 11 is highly specific for KMT2A amplification in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS)

AML and MDS are most common myeloid neoplasms that affect mainly older patients. Overexpression of certain proto-oncogenes plays an indispensable role in tumorigenesis and overexpression can be a consequence of gene rearrangement, amplification and/or mutation. Rearrangement and amplification of KMT2A located at chromosome band 11q23 is a well-characterized genetic driver in a subset of AML/MDS cases and is associated with a poor prognosis. The presence of homogeneously staining regions (hsr) also has been correlated with amplification of specific proto-oncogenes. In this study, we correlated hsr(11)(q23) with KMT2A in a large cohort of AML/MDS (n = 54) patients. We identified 37 patients with hsr(11)(q23) in the setting of AML (n = 27) and MDS (n = 10). All patients showed a complex karyotype including 12 cases with monosomy 17. KMT2A FISH analysis was available for 35 patients which showed KMT2A amplification in all patients. Among control cases with hsr involving chromosomes other than 11q [non-11q hsr, n = 17], FISH analysis for KMT2A was available in 10 cases and none of these cases showed KMT2A amplification (p = 0.0001, Fisher's exact test, two-tailed). Mutational analysis was performed in 32 patients with hsr(11)(q23). The most common mutated gene was TP53 (n = 29), followed by DNMT3A (n = 4), NF1 (n = 4), and TET2 (n = 3). Thirty (83%) patients died over a median follow-up of 7.6 months (range, 0.4-33.4). In summary, hsr(11)(q23) in AML/MDS cases is associated with a complex karyotype, monosomy 17, KMT2A amplification, and TP53 mutation.

MYC protein expression is an important prognostic factor in acute myeloid leukemia

As new drugs targeting MYC show clinical activity in acute myeloid leukemia (AML), understanding MYC expression in AML is of critical importance. We assessed MYC protein expression by immunohistochemistry in bone marrow of patients with untreated AML (n = 265). Overall, 90% of patients demonstrated MYC overexpression and MYC immunopositivity ≤6% was associated with superior complete remission (CR) duration of 23 months versus 12 months for MYC immunopositivity >6% (p = .028). Among 241 patients at higher risk for relapse, including those ≥55 years of age and patients with intermediate- and high-risk AML, MYC immunopositivity ≤6% conferred significantly superior median overall survival (OS) (24 versus 13 months; p = .042), event-free survival (EFS) (14 versus 6 months; p = .048), and relapse-free survival (RFS) (25 versus 12 months; p = .024). The prognostic impact of MYC-immunopositivity was retained on multivariate analysis of OS, EFS, and RFS. We conclude that MYC immunopositivity is an important prognostic factor in patients with untreated AML, particularly those at higher risk for relapse.

Acute lymphoblastic leukemia secondary to myeloproliferative neoplasms or after lenalidomide exposure

Philadelphia‐negative (Ph⁻) myeloproliferative neoplasms (MPN) do rarely transform to acute lymphoblastic leukemia (ALL). While causality is difficult to establish, a few cases of ALL arising after exposure to lenalidomide for registered indications (multiple myeloma, myelodysplastic syndrome with 5q deletion) have been described in the literature.

Myeloid neoplasms with concurrent BCR-ABL1 and CBFB rearrangements: A series of 10 cases of a clinically aggressive neoplasm

Chronic myeloid leukemia (CML) is defined by the presence of t(9;22)(q34;q11.2)/BCR-ABL1. Additional chromosomal abnormalities confer an adverse prognosis and are particularly common in the blast phase of CML (CML-BP). CBFB rearrangement, particularly CBFB-MYH11 fusion resulting from inv(16)(p13.1q22) or t(16;16)(p13.1;q22), is an acute myeloid leukemia (AML)-defining alteration that is associated with a favorable outcome. The co-occurrence of BCR-ABL1 and CBFB rearrangement is extremely rare, and the significance of this finding remains unclear. We identified 10 patients with myeloid neoplasms harboring BCR-ABL1 and CBFB rearrangement. The study group included six men and four women with a median age of 51 years (range, 20-71 years). The sequence of molecular alterations could be determined in nine cases: BCR-ABL1 preceded CBFB rearrangement in seven, CBFB rearrangement preceded BCR-ABL1 in one, and both alterations were discovered simultaneously in one patient. BCR-ABL1 encoded for p210 kD in all cases in which BCR-ABL1 preceded CBFB rearrangement; a p190 kD was identified in the other three cases. Two patients were treated with the FLAG-IDA regimen (fludarabine, cytarabine, idarubicin, and G-CSF) and tyrosine kinase inhibitors (TKI); seven with other cytarabine-based regimens and TKIs, and one with ponatinib alone. At last follow up (median, 16 months; range 2-85), 7 of 10 patients had died. The co-existence of BCR-ABL1 and CBFB rearrangement is associated with poor outcome and a clinical course similar to that of CML-BP, and unlike de novo AML with CBFB rearrangement, suggesting that high-intensity chemotherapy with TKI should be considered in these patients.

Double minute chromosomes in acute myeloid leukemia, myelodysplastic syndromes, and chronic myelomonocytic leukemia are associated with micronuclei, MYC or MLL amplification, and complex karyotype

Double minute chromosomes (dmin) are small, paired chromatin bodies that lack a centromere and represent a form of extrachromosomal gene amplification. Dmin are rare in myeloid neoplasms and are generally associated with a poor prognosis. Most studies of dmin in myeloid neoplasms are case reports or small series. In the current study, we present the clinicopathologic and cytogenetic features of 22 patients with myeloid neoplasms harboring dmin. These neoplasms included acute myeloid leukemia (AML) (n = 18), myelodysplastic syndrome (MDS) (n = 3), and chronic myelomonocytic leukemia (CMML) (n = 1). The AML cases consisted of AML with myelodysplasia-related changes (n = 13) and therapy-related AML (n = 5). Dmin were detected in initial pre-therapy samples in 14 patients with AML or CMML; they were acquired during the disease course in 8 patients who had AML or MDS. The presence of dmin was associated with micronuclei (18/18; 100%), complex karyotype (17/22; 77.3%), and amplification of MYC (12/16; 75%) or MLL (4/16; 25%). Immunohistochemical staining for MYC performed on bone marrow core biopsy or clot sections revealed increased MYC protein in all 19 cases tested. Except for one patient, most patients failed to respond to risk-adapted chemotherapies. At last follow up, all patients had died of disease after a median of 5 months following dmin detection. In conclusion, dmin in myeloid neoplasms commonly harbor MYC or MLL gene amplification and manifest as micronuclei within leukemic blasts. Dmin are often associated with myelodysplasia or therapy-related disease, and complex karyotypes.

B-Lymphoblastic Leukemia in Patients With Chronic Lymphocytic Leukemia: A Report of Four Cases

OBJECTIVES

B-lymphoblastic leukemia (B-LBL) arising in patients with chronic lymphocytic leukemia (CLL) is exceedingly rare and poorly characterized.

METHODS

We describe four patients with CLL and concurrent or subsequent B-LBL diagnosed by morphologic, immunophenotypic, cytogenetic, and molecular analysis and reviewed the literature.

RESULTS

In three patients, B-LBL followed CLL by 5 to 15 years, and in one patient, B-LBL was diagnosed simultaneously with CLL. In all cases, the CLL had a typical immunophenotype, and the B-LBL blasts showed an immature B-cell immunophenotype with expression of CD10, CD19, and TdT and absence of surface immunoglobulin. In two patients, B-LBL blasts harbored t(9;22)(q34;q11.2)/BCR-ABL1. We sequenced the IGHV genes in both CLL and B-LBL in two patients and showed that IGHV usage differed.

CONCLUSIONS

Our data suggest that at least some cases of B-LBL arising in patients with CLL are independent, secondary neoplasms rather than a manifestation of histologic transformation.

Acute myeloid leukemia with MYC rearrangement and JAK2 V617F mutation

Little is known about MYC dysregulation in myeloid malignancies, and the authors were unable to find published studies that evaluated MYC protein expression in primary cases of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Herein, we describe the clinical, morphologic, immunophenotypic, cytogenetic, and molecular genetic findings in two MDS/AML cases that contained both MYC rearrangement and the JAK2 V617F mutation. We also demonstrate MYC protein expression by immunohistochemistry in both patients.

MLL gene amplification in acute myeloid leukemia and myelodysplastic syndromes is associated with characteristic clinicopathological findings and TP53 gene mutation

MLL gene rearrangements are well-recognized aberrations in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). In contrast, MLL gene amplification in AML/MDS remains poorly characterized. Here, we report a series of 21 patients with myeloid neoplasms associated with MLL gene amplification from 1 institution. This series included 13 men and 8 women, with a median age of 64 years. Eleven patients presented as AML with myelodysplasia-related changes, 6 as therapy-related AML, and 4 as therapy-related MDS. All patients had a highly complex karyotype, including frequent -5/del(5q), -18, and -17/del(17p) abnormalities; 16 patients were hypodiploid. TP53 mutations were detected in all 12 patients tested, and 3 patients showed TP53 mutation before MLL amplification. Morphologically, the leukemic cells frequently showed cytoplasmic vacuoles, bilobed nuclei, and were associated with background dyspoiesis. Immunophenotypically, 15 patients had a myeloid and 4 had myelomonocytic immunophenotype. Laboratory coagulopathies were common; 7 patients developed disseminated intravascular coagulopathy, and 3 died of intracranial bleeding. All patients were refractory to therapy; the median overall survival was 1 month, after MLL gene amplification was detected. We concluded that AML/MDS with MLL gene amplification is likely a subset of therapy-related AML/MDS or AML with myelodysplasia-related changes, associated with distinct clinicopathological features, frequent disseminated intravascular coagulopathy, a highly complex karyotype, TP53 deletion/mutation, and an aggressive clinical course.

Systemic mastocytosis with associated clonal hematological non-mast cell lineage disease: clinical significance and comparison of chomosomal abnormalities in SM and AHNMD components

Some patients with systemic mastocytosis have concurrent hematological neoplasms, designated in the World Health Organization (WHO) classification as systemic mastocytosis with associated clonal hematological non-mast cell lineage disease (SM-AHNMD). In this study, we analyzed 29 patients with SM-AHNMD and compared them to 40 patients with pure SM. The AHNMDs were classified as chronic myelomonocytic leukemia (CMML) (n = 10), myelodysplastic syndrome (MDS) (n = 7), myeloproliferative neoplasms (n = 4), B-cell lymphoma/leukemia/plasma cell neoplasms (n = 7), and acute myeloid leukemia (n = 1). Patients with SM-AHNMD were older, more frequently had constitutional symptoms and hematological abnormalities, less often had skin lesions, and had an inferior overall survival compared with pure SM patients (48 months vs. not-reached, P < 0.001). Karyotypic abnormalities were detected in 9/28 (32%) patients with SM-AHNMD but not in pure SM patients (P < 0.001). Combined imaging/ fluorescence-in-situ hybridization performed in four SM-AHNMD cases revealed shared abnormal signals in mast cells and myeloid cells in two patients with SM-CMML and one patient with SM-MDS, but not in the mast cells of a case SM-associated with chronic lymphocytic leukemia with ATM-deletion. Quantitative mutation analysis showed higher levels of mutant KIT D816V in SM-CMML and SM-MDS than in pure SM (P < 0.001). Our data indicate that the SM-AHNMD category in the WHO classification is heterogeneous, including clonally related and unrelated forms of AHNMD. The presentation, treatment, and outcome of patients with SM-AHNMD is often dictated by the type of AHNMD.

The B cell antigen receptor in atypical chronic lymphocytic leukemia with t(14;19)(q32;q13) demonstrates remarkable stereotypy

The t(14;19)(q32;q13) is a recurrent chromosomal translocation reported in a variety of B-cell leukemias and lymphomas, including chronic lymphocytic leukemia (CLL). CLL cases associated with t(14;19) often have atypical morphologic and immunophenotypic features and unmutated immunoglobulin heavy chain (IGH) variable region (V) genes, associated with an aggressive clinical course. We analyzed IGHV somatic mutation status and gene use in 11 patients with t(14;19)-positive CLL. All cases were unmutated, and the IGHV genes in 10 cases showed minimal deviation from germline sequences. In 7 of 11 patients, we found homologous heavy chain rearrangements using IGHV4-39; light chain analysis revealed identical IGKV1-39 use. Corresponding V-(D)-J sequences demonstrated remarkable stereotypy of the immunoglobulin heavy and kappa light chain complementarity determining region 3 (H/K CDR3) genes. These findings raise the possibility that specific antigen drive is involved in the clonal development and/or selection of t(14;19)(q32;q13)-positive CLL cells. Our findings support the hypothesis that stimulatory signals through specific antigen receptors may promote the expansion of either CLL precursor cells or CLL clones that harbor distinct chromosomal abnormalities.

Chronic lymphocytic leukemia with t(14;19)(q32;q13) is characterized by atypical morphologic and immunophenotypic features and distinctive genetic features

The t(14;19)(q32;q13) involving the IGH@ and BCL3 loci is an infrequent cytogenetic abnormality detected in B-cell malignancies. We describe the clinicopathologic, cytogenetic, and molecular genetic characteristics of 14 cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) with t(14;19)(q32;q13). All patients (10 men and 4 women) had lymphocytosis; 10 had lymphadenopathy. Blood and bone marrow lymphocytes were predominantly small, but cytologically and immunophenotypically atypical. In all cases, t(14;19) was found in the neoplastic stem line; it was the sole abnormality in 4. Ten cases showed additional cytogenetic abnormalities, including trisomy 12 in 9 and complex karyotypes in 7. Fluorescence in situ hybridization demonstrated IGH@/BCL3 fusion gene in all cases. In all cases, the IGHV genes were unmutated, but only 7 expressed ZAP70. Seven cases preferentially used IGHV4-39. Our results indicate that t(14;19)(q32;q13) identifies a subset of CLL/SLL with distinctive clinicopathologic and genetic features. Furthermore, t(14;19) may represent an early, possibly primary, genetic event.

Chronic lymphocytic leukemia With t(2;14)(p16;q32) involves the BCL11A and IgH genes and is associated with atypical morphologic features and unmutated IgVH genes

The t(2;14)(p16;q32) has been reported previously in only 12 cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). The clinicopathologic features have been incompletely described. We describe 6 new cases of CLL/SLL with t(2;14)(p16;q32). All had marrow involvement, 4 had absolute lymphocytosis, 4 had lymphadenopathy, and 3 had hepatosplenomegaly. All showed atypical lymphocyte morphologic features with plasmacytoid differentiation and irregular nuclei; 3 had increased prolymphocytes. Flow cytometry demonstrated typical immunophenotypes in 5 and an atypical immunophenotype in 1. All expressed ZAP70; 5 assessed showed unmutated IgV(H) genes. Karyotyping identified t(2;14)(p16;q32) as the sole abnormality in 1, primary abnormality in 2, and part of a complex karyotype in 3. Fluorescence in situ hybridization analysis revealed BCL11A/IgH rearrangement in all. After chemotherapy, 3 patients died of disease and 3 were alive with disease (median follow-up, 80 months). We conclude that CLL/SLL with t(2;14) (p16;q32) and BCL11A/IgH rearrangement is characterized by atypical morphologic features and unmutated IgV(H) genes.

T-cell large granular lymphocyte leukemia associated with myelodysplastic syndrome: a clinicopathologic study of nine cases

We describe 9 patients with T-cell large granular lymphocyte leukemia (T-LGL) who also had a myelodysplastic syndrome (MDS). There were 6 men and 3 women with a median age of 60 years (range, 25-74 years). All patients had anemia at initial examination, 7 had neutropenia, and 5 had thrombocytopenia. The median absolute lymphocyte count was 1,300/microL (1.3 x 10(9)/L; range, 700-3,600/microL [0.7-3.6 x 10(9)/L]). Immunophenotypic analysis showed a CD8+ T-cell population, and molecular analysis showed monoclonal T-cell receptor gene rearrangement in every case. The MDS was classified as refractory cytopenia with multilineage dysplasia (RCMD, n = 5), refractory anemia (n = 2), RCMD with ringed sideroblasts (n = 1), and chronic myelomonocytic leukemia (n = 1). We compared the data for these patients with T-LGL/MDS with a group that had only T-LGL. The median hemoglobin level and absolute lymphocyte count were lower in patients with T-LGL/MDS (P < .05). The frequency of coexistent T-LGL and MDS at our institution suggests an etiologic relationship rather than simple coincidence.

Utility of the World Heath Organization classification criteria for the diagnosis of systemic mastocytosis in bone marrow

In the World Health Organization classification, one major and four minor criteria are specified for the diagnosis of systemic mastocytosis. We report our experience using these criteria to diagnose systemic mastocytosis involving bone marrow. A total of 59 patients with clinically suspected systemic mastocytosis underwent comprehensive bone marrow examination, including immunophenotyping by immunohistochemistry and/or flow cytometry and molecular studies for KIT exon 17 mutations. Serum tryptase levels were also assessed. Of these 59, 53 (90%) patients met the diagnostic criteria for systemic mastocytosis. In these patients, multifocal dense infiltrates of mast cells, the major criterion, was observed in 36 (68%) patients. Atypical mast cell morphology was observed in 53 (100%), an aberrant immunophenotype was identified in 50 of 52 (96%), KIT mutation was present in 33 of 44 (75%), and an elevated serum tryptase (>20 ng/ml) was detected in 44 of 52 (85%). In the six patients in which bone marrow examination could not confirm systemic mastocytosis, one had systemic mastocytosis involving spleen, one patient had chronic idiopathic myelofibrosis, and four had no specific diagnosis, but systemic mastocytosis was still considered most likely. Of these six patients, atypical mast cell morphology was identified in five, aberrant immunophenotype in five, KIT mutation in two, and elevated serum tryptase in two. None of these cases met the major criteria. We conclude that the World Health Organization criteria are useful for the diagnosis of systemic mastocytosis in bone marrow specimens. The results also show the relative values of traditional morphologic criteria (ie, major criterion) and the results of ancillary testing (ie, minor criteria). However, as illustrated by the case of splenic systemic mastocytosis as well as the patient with chronic idiopathic myelofibrosis, the current World Health Organization system is neither completely sensitive nor specific for systemic mastocytosis.

MYC translocation in chronic lymphocytic leukaemia is associated with increased prolymphocytes and a poor prognosis

Chromosomal translocations that involve MYC, characteristic of Burkitt lymphoma, are rare in chronic lymphocytic leukaemia (CLL). We report the clinical, morphological, immunophenotypic, cytogenetic and molecular genetic features of eight CLL cases with MYC rearrangement. The patients, five men and three women (median age, 71 years) had bone marrow involvement and an absolute peripheral blood lymphocytosis; five had lymphadenopathy; seven had splenomegaly. Prolymphocytes were increased (>/=10%) in all cases. Six cases were classified as CLL with increased prolymphocytes (CLL/PL; prolymphocytes 10-55%), and two were classified as CLL in prolymphocytic transformation (CLL/PT; prolymphocytes >55%). All cases co-expressed CD5, CD19, and CD23; five of eight expressed ZAP-70. Of seven cases tested, four had mutated and three had unmutated IGHV genes. Conventional cytogenetic studies demonstrated t(8;14)(q24.1;q32) in five cases, t(8;22)(q24.1;q11) in two cases, and t(2;8)(p12;q24.1) in one case. Seven cases contained additional chromosomal abnormalities. All patients received combination chemotherapy. Two developed Epstein-Barr virus (EBV)-associated diffuse large B-cell lymphomas (DLBCL) that were clonally unrelated to the CLL. At follow-up, two patients are alive, four died of underlying disease, one died of EBV-associated DLBCL, and one died of an unrelated cancer. In summary, MYC rearrangement, which occurs rarely in CLL patients, is associated with increased prolymphocytes, complex cytogenetic abnormalities, and a poor prognosis.

Immunophenotypic study of basophils by multiparameter flow cytometry

CONTEXT

The immunophenotypic profile of basophils is not yet fully established, and the immunophenotypic changes in chronic myelogenous leukemia are not fully characterized.

OBJECTIVE

To establish a comprehensive immunophenotypic spectrum of normal basophils and to assess the range of immunophenotypic aberrations of basophils in chronic myelogenous leukemia.

DESIGN

Using 4-color flow cytometry, we compared the immunophenotypic profile of basophils in peripheral blood or bone marrow samples from 20 patients with no evidence of neoplasia to basophils from 15 patients with chronic myelogenous leukemia.

RESULTS

Basophils in control cases were all positive for CD9, CD13, CD22, CD25 (dim), CD33, CD36, CD38 (bright), CD45 (dimmer than lymphocytes and brighter than myeloblasts), and CD123 (bright), and were negative for CD19, CD34, CD64, CD117, and HLA-DR. Basophils in all chronic myelogenous leukemia patients possessed 1 to 5 immunophenotypic aberrancies. The most common aberrancies were underexpression of CD38, followed by aberrant expression of CD64 and underexpression of CD123. CD34 and CD117 were present in cases with basophilic precursors. Myeloblasts showed a distinct immunophenotypic profile, as they typically expressed CD34 and CD117, showed dimmer expression (compared with basophils) of CD38, CD45, and CD123, and lacked expression of CD22.

CONCLUSIONS

Flow cytometric immunophenotyping can identify immunophenotypic aberrations of basophils in chronic myelogenous leukemia, and discriminate basophils from myeloblasts.

The t(14;19)(q32;q13)-positive small B-cell leukaemia: a clinicopathologic and cytogenetic study of seven cases

The t(14;19)(q32;q13), involving the BCL3 locus at chromosome 19q13 and the immunoglobulin heavy chain gene at 14q32, is a rare recurrent cytogenetic abnormality identified in B-cell neoplasms, most of which have been classified as chronic lymphocytic leukaemia (CLL) in the literature. We describe the clinicopathological, immunophenotypic and cytogenetic findings in seven patients with B-cell neoplasms associated with t(14;19)(q32;q13). There were five men and two women, with a median age of 48 years (range 33-68). All had absolute lymphocytosis, six had lymphadenopathy, and one had splenomegaly. Lymphocytes in blood and bone marrow aspirate smears were predominantly small and cytologically atypical. Flow cytometric immunophenotyping showed an atypical immunophenotype with low CLL scores. The growth pattern in bone marrow biopsy specimens was interstitial to diffuse; immunohistochemical stains were positive for bcl3 and negative for cyclin D1. Lymph node biopsy specimens of two patients revealed total architectural effacement by neoplasm with proliferation centres. In addition to t(14;19), cytogenetic studies demonstrated trisomy 12 in five patients. These results suggest that B-cell neoplasms with the t(14;19)(q32;q13) present frequently as leukaemia composed of small B-lymphocytes and share many features with CLL. However, these neoplasms also differ from CLL cytologically and in their immunophenotype.

Evaluation of peripheral blood involvement of mantle cell lymphoma by fluorescence in situ hybridization in comparison with immunophenotypic and morphologic findings

Mantle cell lymphoma is non-Hodgkin's B-cell lymphoma characterized by the t(11;14)(q13;q32) translocation. Peripheral blood involvement of mantle cell lymphoma is usually associated with a poor prognosis and therefore, its identification is clinically important. In this study, we performed cyclin D1/IgH-probe fusion fluorescence in situ hybridization analysis on 223 peripheral blood samples: 185 from 125 mantle cell lymphoma patients, and 38 normal controls. The cutoff values for the test were established using normal controls. Flow cytometry on peripheral blood and corresponding bone marrow samples was used to evaluate this test. In all, 26% of the 185 peripheral blood samples and 27% of the 161 corresponding bone marrow samples were flow cytometry positive for mantle cell lymphoma. The mean numbers of single and- double-fusion signals and the mean number of CD5/CD19-positive cells, absolute blood lymphocyte count, and white blood cell count were significantly higher in peripheral blood and corresponding bone marrow samples with mantle cell lymphoma-positive flow cytometry. Double-fusion signals were more specific than single-fusion ones. Fluorescence in situ hybridization was far more likely to be positive for mantle cell lymphoma when the peripheral blood and the corresponding bone marrow samples had positive flow cytometry results or morphology (P<0.01). Our study indicates that cyclin D1/IgH-fusion fluorescence in situ hybridization analysis could be used to determine the presence and character of circulating mantle cell lymphoma cells in peripheral blood, thus enhancing our ability to evaluate leukemic mantle cell lymphoma and minimum residual disease.

Expression of CD2 in acute promyelocytic leukemia correlates with short form of PML-RARalpha transcripts and poorer prognosis

We studied the immunophenotype of 100 cases of acute promyelocytic leukemia (APL) with cytogenetic evidence of t(15;17)(q22;q21), 72 hypergranular (M3) and 28 microgranular (M3v), and correlated the results with molecular and clinical features. Most neoplasms (75/100 [75%]) had a typical immunophenotype: CD13+CD33+CD34-HLA-DR-. CD64, CD2, CD34, and HLA-DR were expressed in 27% (24/88), 23% (22/94), 21% (21/100), and 9% (9/98), respectively. CD34 expression was restricted to M3v; HLA-DR and CD2 were expressed more often in M3v than in M3 (P < .001). PML-RARalpha fusion transcripts were detected by reverse transcriptase-polymerase chain reaction in all 70 patients assessed. The short form of PML-RARalpha transcripts was found more frequently in M3v (P < .002) and CD2+ APL (P < .0001) than in M3 and CD2- APL, respectively. The median follow-up was 128 weeks. CD2+ APL was associated significantly with leukocytosis (P = .004), shorter complete remission duration (P = .03), and a trend toward shorter overall survival (P = .07) than CD2- APL. Overall survival for M3v vs M3 (P = .68) and short vs long transcripts (P = .21) was not significantly different. Immunophenotyping is useful for predicting the biologic and clinical behavior of APL.

Evaluation of interphase fluorescence in situ hybridization for the t(14;18)(q32;q21) translocation in the diagnosis of follicular lymphoma on fine-needle aspirates

BACKGROUND

Diagnosing lymphoproliferative disorders on fine-needle aspiration (FNA) can be challenging due to variable cellularity and lack of architecture. Ancillary studies often are required for diagnosis. Follicular lymphoma (FL) is characterized by a monoclonal B-cell proliferation with coexpression of CD19/CD10 and a t(14;18)(q32;q21) reciprocal translocation, resulting in the immunoglobulin heavy chain/BCL-2 fusion gene. These features also can be found, with much lower frequency, in diffuse large B-cell lymphoma (DLBCL) of follicle center cell origin. The objective of the current study was to compare the accuracy in detecting FL and DLBCL of follicle center cell origin by interphase fluorescence in situ hybridization (I-FISH) versus flow cytometry immunophenotyping (FCM) on FNAs.

METHODS

Concurrent testing by FISH for t(14;18)(q32;q21) and FCM was performed on 84 FNAs, including 40 FLs and 44 non-FLs (de novo DLBCLs, mantle cell lymphomas, small lymphocytic lymphomas/chronic lymphocytic leukemias [SLLs/CLLs], small B-cell lymphomas, and reactive lymphoid hyperplasias). The final diagnosis was rendered based on the combined information from cytomorphology, FCM, FISH, immunocytochemical staining for Ki-67, monoclonality for kappa and lambda light chains, and, if available, corresponding tissue biopsy, cytogenetic analysis, and polymerase chain reaction analysis.

RESULTS

Among 40 FLs, FISH produced positive results for the t(14;18) translocation in 85.0%, negative results in 7.5%, and insufficient results in 7.5%; whereas, with FCM, 75% of cases exhibited a CD19-positive (CD19+)/CD10+ population (28 monoclonal, 2 nonclonal), 12.5% of cases exhibited a CD19+/CD10-negative population (3 monoclonal, 2 nonclonal), and 12.5% of cases were insufficient. All of nonclonal results from FCM and all of the insufficient results from FCM analysis exhibited unequivocal t(14;18) translocation by FISH. In contrast, the three negative results and the three insufficient results from FISH were monoclonal and CD19+/CD10+ on FCM. The results from FISH and FCM were concordant in 75% cases. Of 44 non-FLs, FISH produced positive results for the t(14;18) translocation in 5 DLBCLs and 2 SLLs/CLLs. The latter showed single fusion signals just above the cutoff level. All cases in the non-FL group that failed to show clonality or had insufficient results from FCM were DLBCLs. Among 17 DLBCLs, FISH detected a t(14;18) translocation in 29.4%, whereas FCM demonstrated a CD19+/CD10+ population in 23.5%.

CONCLUSIONS

I-FISH for the t(14;18)(q32;q21) translocation provided high overall accuracy in detecting FLs on FNAs. This test can be used for diagnosing or monitoring FL on FNAs when cellularity is limited or when FCM results are noncontributory. For detecting a follicle center cell origin in DLBCLs, I-FISH for the t(14;18) translocation appeared to be slightly more sensitive than FCM for the CD19+/CD10+ immunophenotype.

Molecular differences between small and large cells in patients with chronic lymphocytic leukemia

The genetic events involved in the transformation of chronic lymphocytic leukemia (CLL) to Richter's syndrome (RS) are poorly understood. Frequently large cells are seen in the bone marrows of patients with CLL and evidence of RS. Using a laser-capture microdissection we analyzed small and large leukemic bone marrow cells from 19 patients with RS for loss of heterozygosity (LOH) on chromosome 11 (D11S2179 at the ATM gene), 17 (D17S938 and D17S1852 at the TP53 site), and 20 (Plc1, D20S96, D20S110, and D20S119). Megakaryocytes were also isolated and used as a control for normal cells. Four of 15 (27.7%) informative cases showed LOH in small cells in the ATM gene while seven (46.7%) showed LOH in large cells. Six of 15 (40%) informative cases had LOH in chromosome 17 in small cells, and eight (53%) showed LOH in large cells. Eleven of 19 informative cases (61.1%) showed LOH in chromosome 20 in large cells, and eight (42.1%) showed LOH in small cells. RS cases with LOH at chromosome 20 were associated with marginally shorter survival rates (P = 0.08). Our data suggest that there are significant molecular differences between large and small cells in patients with CLL. Further analysis of the genes on these chromosomes may provide new insight into our understanding of the transformation of small CLL cells to large (Richter) cells.

Pentostatin in T-non-Hodgkin's lymphomas: efficacy and effect on CD26+ T lymphocytes

Pentostatin is an adenosine deaminase (ADA) inhibitor with antineoplastic activity. CD26 is a surface glycoprotein with a key role in T cell function as the ADA binding protein. We conducted a phase II study to evaluate pentostatin efficacy in relapsed T-non-Hodgkin's lymphoma (T-NHL) and to correlate response with tumor CD26 expression. We also examined the lymphopenic effect of pentostatin on CD26+ T lymphocytes. Eighteen patients were registered for the study. Pentostatin was administered as intravenous bolus daily over 3 days at an initial dose of 5 mg/m(2)/day, repeated every 4 weeks. CD26 surface expression on tumor cells and T lymphocytes was determined by flow cytometry. Out of 14 patients evaluable for response, there was 1 (7%) complete response (CR) and 6 (43%) partial responses (PR). Median progression-free survival for responders was 6 months (range: 2-15 months); median number of courses was 4 (range: 1-6). Responders included 1 of 2 CD26+ and 5 of 9 CD26- cases. Pentostatin also specifically depleted CD26+ rather than CD26- T lymphocytes, potentially associated with immunosuppression. We therefore conclude that while pentostatin is a safe and active agent for T-NHL regardless of CD26 expression, it may selectively deplete CD26+ T lymphocytes, with potentially significant clinical implications.

A stable aberrant immunophenotype characterizes nearly all cases of cutaneous T-cell lymphoma in blood and can be used to monitor response to therapy

BACKGROUND: Abnormal variations in the expression level of some commonly expressed T-cell antigens are a feature of many T-cell malignancies. METHODS: We sought to assess the frequency of such abnormal antigen expression by flow cytometry in peripheral blood (PB) samples from patients with mycosis fungoides (MF) and Sézary syndrome (SS). We correlated presence of morphologically identifiable tumor cells on PB smear with the frequency of abnormalities in the level of expression of CD3, CD4, CD7, CD8 and CD26. We also examined the degree of stability of these abnormal findings in tumor cells over the course of disease. The flow cytometric findings in 100 PB samples from 44 patients, including 38 who had multiple sequential PB samples (2-8 samples each), were assessed. RESULTS: Abnormalities were seen in the expression level of one or more T-cell markers in 41 cases (93%) including CD3 in 34% of patients, CD4 in 54%, CD26 in 86% and CD 45 in 40% (10 cases tested). In all but 2 cases, the abnormal T-cell immunophenotype remained similar over the course of treatment and correlated with the relative numbers of tumor cells counted on PB smear. CONCLUSIONS: Using a standard T-cell panel, stable phenotypically aberrant T-cell populations representing the tumor are detected in the vast majority of involved PB samples in MF/SS and can be used to monitor response to therapy.

More cell death in refractory anemia with excess blasts in transformation than in acute myeloid leukemia

Refractory anemia with excess blasts in transformation (RAEB-T) is a subgroup of myelodysplastic syndrome (MDS) in which the bone marrow blast count ranges from 20% to 30%. The recently proposed World Health Organization Classification of Hematologic Malignancies eliminated this category from MDS by lowering the blast count cutoff for acute myeloid leukemia (AML) from 30% to 20%. However, MDS is distinguished from AML by a significant increase in apoptosis. To investigate the difference in apoptosis between RAEB-T, AML, and other categories of MDS, we prospectively analyzed fresh bone marrow samples using the Annexin V and mitochondrial potential assays. There was a significantly higher level of apoptosis in RAEB-T than in AML according to both assays, while no significant differences between RAEB-T and other categories of MDS were noted. The data suggest that RAEB-T is more likely to be an advanced stage of MDS and biologically different from AML.

Ex vivo expansion of apheresis-derived peripheral blood hematopoietic progenitors

Because the administration of hematopoietic growth factors and the use of stem cell support often fails to alleviate the neutropenic phase induced by cytotoxic drugs, several investigators have attempted to expand ex vivo hematopoietic progenitors for clinical use. These attempts have clearly shown that the cultured cells are functional and can be safely administered to patients, but that the in vivo performance is disappointing and the concept as a whole is not yet clinically useful. The major reasons for these unsuccessful attempts are thought to be cumbersome cell fractionation techniques, contamination, prolonged incubation, and the use of less than ideal cytokine combinations. In response, we have developed a simple procedure for ex vivo expansion of myeloid progenitor cells. In this assay, unfractionated mononuclear cells from apheresis donors are incubated in nonpyrogenic plastic bags for 7 days in the presence of culture medium either containing fetal calf serum or human plasma, granulocyte colony-stimulating factor, and stem cell factor. We have demonstrated that under these conditions the number of colony-forming units (CFU) granulocyte-macrophage (CFU-GM) and of CFU-granulocyte-macrophage-erythroid-megakaryocyte (CFU-GEMM) increased 7- and 9-fold, respectively, by day 7 and the number of burst-forming units-erythroid (BFU-E) increased 2.7-fold by day 5 of culture. Significant increases in the numbers of cells expressing CD34+, CD34+/CD38+, CD34+/CD33+, CD34+/CD15+, and CD34+/CD90+ and significant declines in the numbers of cells expressing CD34+/CD38- and CD19 surface antigens were also observed. The relative numbers of cells expressing T-cell markers and CD56 surface antigen did not change. By using different concentrations of various hematopoietic growth factor combinations, we can increase the number of mature and immature cells of different hematopoietic lineages.

High CD34 cell doses do not worsen regimen-related toxicity or early mortality after autologous blood stem cell transplantation for breast cancer

BACKGROUND

Some transplant-related complications, such as the engraftment syndrome, are thought to be mediated by cytokines released during expansion of hematopoietic progenitors at the time of neutrophil recovery. Since there is an inverse correlation between CD34(+) cell dose and time to neutrophil recovery, we sought to determine if peritransplant toxicity and early mortality were adversely affected by high CD34(+) cell doses.

METHODS

The study group included 186 women with breast cancer who received high-dose cyclophosphamide, carmustine, thiotepa and an autologous PBSC transplant. The median CD34(+) cell dose was 5.9 x 10(6)/kg (1.0-154.7 x 10(6)/kg). Patients were categorized by CD34(+) cell dose (1.0-3.5, 3.6-5.9, 6.0-19.9, and 20.0-154.7 x 10(6)/kg) for assessment of outcomes.

RESULTS

Grades 2-4 mucositis occurred in 49%, cardiac toxicity in 7%, pulmonary toxicity in 5%, cystitis in 4%, diarrhea in 3%, renal toxicity in 1%, and central nervous system toxicity in 1%. A Grade 2-4 regimen-related toxicity occurred in 109 patients (59%) and Grade 3-4 in eight patients (4%). Overall survival was 100% at Day 30, 96% at Day 90, and 89% at 1 year. Treatment-related mortality was 3.8%. In multivariate analyses that included prior chemotherapy, disease status, visceral metastases, prior chest radiation and age, CD34(+) cell dose group was not an independent risk factor for Grade 2-4 mucositis, Grade 2-4 maximum toxicity, Grade > or =3 cumulative toxicity, 90 day survival or 1 year survival.

DISCUSSION

We conclude that CD34(+) cell doses >20 x 10(6)/kg do not affect transplant outcome in a negative or positive fashion.

CD56 expression predicts occurrence of CNS disease in acute lymphoblastic leukemia

We examined the pre-treatment bone marrow samples from 200 consecutive adult patients with acute lymphoblastic leukemia (ALL) treated on various protocols at the University of Texas, M.D. Anderson Cancer Center between 1986 and 1998. Standard MFC techniques were used to determine CD56 expression on the leukemia blasts cells. The expression of CD56 was correlated with clinical characteristics at diagnosis, response to therapy, survival and disease-free survival. Blast expression of CD56 (> or = 20% of leukemic blasts) was seen in 16 (8%) of patients, with a median expression of 67% (range 20-99%). CD56 expression was associated with a higher incidence of central nervous system (CNS) disease at diagnosis (19% versus 4%; P=0.016). Incidence of CNS disease at any time was higher in patients with CD56+ disease (31% versus 14%; P=0.057). Among the 109 patients uniformly treated with the hyperCVAD regimen, CD56 expression was associated with a statistically significant higher incidence of CNS disease (33% versus 9%; P=0.026). CD56 expression in ALL is uncommon but may predict a higher risk for CNS disease. If these results are confirmed, CD56 expression could be used in combination with other high-risk features (e.g. lactate dehydrogenase (LDH), S-phase fraction, mature B-cell phenotype) to design a risk-oriented approach to CNS prophylaxis.

Discrepancies in the immunophenotype of lymphoma cells in samples obtained simultaneously from different anatomic sites

Few studies have compared the immunophenotypic profiles of non-Hodgkin lymphoma (NHL) cells obtained simultaneously from different anatomic sites. In the present study, we compared flow cytometry immunophenotypic results in 64 consecutive NHL cases in which aspiration or biopsy of 2 sites was performed within 30 days to assess the potential discrepancy rate. In 14 cases (22%), discordant antigen expression was identified, including 4 (36%) of 11 cases with discordant morphologic features and 10 (19%) of 53 cases with concordant morphologic features in the 2 samples. Discrepancies involved 1 antigen in 10 patients and 2 antigens in 4 patients. Antigens most frequently discrepant included CD5 (n = 4), FMC7 (n = 3), and CD20 (n = 3). We conclude that the immunophenotype of NHL cells is generally stable, yet discrepancies can occur in a subset of patients. Differences in immunophenotype may relate to mechanisms of disease dissemination, influence of the microenvironment, or differential response to therapy.

Chronic graft-versus-host disease after allogeneic blood stem cell transplantation

The incidence, characteristics, risk factors for, and impact of chronic graft-vs-host disease (GVHD) were evaluated in a consecutive series of 116 evaluable HLA-identical blood stem cell transplant recipients. Minimum follow-up was 18 months. Limited chronic GVHD occurred in 6% (95% confidence interval [CI], 0%-13%), and clinical extensive chronic GVHD in 71% (95% CI, 61%-80%). The cumulative incidence was 57% (95% CI, 48%-66%). In univariate analyses, GVHD prophylaxis other than tacrolimus and methotrexate, prior grades 2 to 4 acute GVHD, use of corticosteroids on day 100, and total nucleated cell dose were significant risk factors for clinical extensive chronic GVHD. On multivariate analysis, GVHD prophylaxis with tacrolimus and methotrexate was associated with a reduced risk of chronic GVHD (hazard ratio [HR], 0.35; P =.001), whereas the risk was increased with prior acute GVHD (HR, 1.67; P =.046). When adjusted for disease status at the time of transplantation, high-risk chronic GVHD had an adverse impact on overall mortality (HR, 6.6; P <.001) and treatment failure (HR, 5.2; P <.001) at 18 months. It was concluded that there is a substantial rate of chronic GVHD after HLA-identical allogeneic blood stem cell transplantation, that clinical factors may alter the risk of chronic GVHD, and that high-risk chronic GVHD adversely affects outcome.

Higher levels of surface CD20 expression on circulating lymphocytes compared with bone marrow and lymph nodes in B-cell chronic lymphocytic leukemia

Differential expression of CD20 surface antigen in B-cell neoplasms at different sites is largely unknown. The number of CD20 antibodies bound per cell (CD20 ABC) in bone marrow (BM), peripheral blood (PB), and lymph node aspirate (LNA) samples from patients with B-cell chronic lymphocytic leukemia (B-CLL) or other B-cell disease was studied using quantitative flow cytometry. CD20 ABC differed significantly with the specimen type in B-CLL, being highest in PB (mean, 9,051) and lower in BM (mean, 4,067) and LNA (mean, 3,951). No difference in CD20 ABC between BM and PB samples was found in splenic lymphoma, mantle cell lymphoma, or follicular lymphoma. Also, we found a significant difference of CD20 ABC by type of disease: lowest in B-CLL; higher in splenic, follicular, and mantle cell lymphoma; and highest in hairy cell leukemia. The lower CD20 surface antigen levels in BM and LNA than in PB in B-CLL may have clinical relevance with regard to the efficacy of rituximab therapy.

CD38 expression as an important prognostic factor in B-cell chronic lymphocytic leukemia

CD38 is a transmembrane glycoprotein expressed on the surface of leukemic cells in a significant percentage of patients with B-cell chronic lymphocytic leukemia (B-CLL). A recent study suggested that CD38 expression has prognostic value in CLL. Peripheral blood samples from 218 patients with B-CLL were analyzed by flow cytometry for CD38 expression on CD5/19(+) leukemic cells. Various patient characteristics were studied including age, sex, Rai and Binet stages, splenomegaly, hepatomegaly, hemoglobin (Hgb) level, beta-2 microglobulin (beta2M) level in the serum, number of nodal sites involved with disease, and length of survival. The Kaplan-Meier method was used to construct survival curves, and the log-rank statistic was used to compare these curves. CD38 was expressed in 20% or more of leukemic cells in 43% of the patients. Patients with high CD38 expression (20% or more) had significantly shorter survival times (P =.00005). Multivariate analyses showed that CD38 expression is an important prognostic factor associated with high incidence of lymph node involvement (P =.004), lower hemoglobin level (P =.001), hepatomegaly (P =.05), and high beta2M level (P =.00005). CD38 expression identified a group of patients with aggressive disease that was considered by Rai staging to be early-stage disease (Rai stages 0-II). Patients with CD38(+) samples have significantly aggressive disease regardless of their clinical stage. Measurement of CD38 expression by flow cytometry should become a routine test in the evaluation of patients with CLL.

Absence of CD26 expression is a useful marker for diagnosis of T-cell lymphoma in peripheral blood

We report flow cytometric characterization of surface CD26 expression in 271 peripheral blood samples from 154 patients evaluated for the presence of a T-cell lymphoproliferative disorder, primarily mycosis fungoides/Sézary syndrome (MF/SS). The presence of morphologically identifiable tumor cells on peripheral blood smears was the criterion for lymphomatous involvement. In 66 of 69 samples from 28 patients, we identified an abnormal CD26-/dim T-cell population that was distinct from the variable CD26 expression seen in normal peripheral blood T cells. This population was CD26- in 23 patients and weakly CD26+ in 5 patients. CD7 was more variably expressed in MF/SS tumor cells, allowing recognition of a distinct, quantifiable abnormal T-cell population in only 34 of 69 involved samples. An increased CD4/CD8 ratio and lower surface expression of CD4 in tumor cells also helped separate the CD26-/dim atypical population for quantification. In 35 blood samples from other types of T-cell tumors, tumor cells in 10 of 11 morphologically involved cases showed absent/dim CD26. Although capable of detecting abnormalities in most cases of MF/SS, CD7 expression does not provide as clear a separation of the neoplastic population and can be replaced by CD26 staining in routine peripheral blood flow cytometric screening of MF/SS patients.

Immunophenotypes in adult acute lymphocytic leukemia. Role of flow cytometry in diagnosis and monitoring of disease

Flow cytometry has revolutionized the study of hematopoietic cells. Immunophenotyping by multiparameter flow cytometry supplements conventional morphologic diagnosis by providing information on cell lineage and differentiation in ALL and helps monitor disease by improving sensitivity in detecting minimal residual disease. The use of multiple MoAbs and multicolor study by flow cytometry has revealed heterogeneity among ALL and mixed-lineage acute leukemia, which are assigned to the same diagnostic categories by morphology. As technology has improved, clinical and research applications of flow cytometry have expanded to include evaluation of nuclear markers, oncogene proteins, apoptosis, cytokine receptors, and drug resistance. Expanded identification of MoAbs against leukemia-specific markers and the use of QFCM be a significant in managing patients with ALL in the future. In addition, flow cytometry and flow cytometric sorting will be combined more and more with other technologies, such as molecular probing or fluorescence in situ hybridization (FISH). The sorting of rare malignant cells based on immunophenotype and subsequent confirmation by PCR or FISH has already been proven feasible. Ultimately, it is hoped that further definition of subgroups of ALL by immunophenotyping using prognostically significant markers and the use of hybrid technologies of flow cytometry and molecular analysis or cytogenetics will improve treatment strategies for patients with ALL.

A comparative study of once-daily versus twice-daily filgrastim administration for the mobilization and collection of CD34+ peripheral blood progenitor cells in normal donors

Eighty-one first-time normal donors underwent leukapheresis for peripheral blood progenitor cell (PBPC) collection after mobilization with filgrastim administered either twice-daily (6 microg/kg every 12 h; n = 40) or once-daily (12 microg/kg; n = 41) subcutaneously for 3 d. The groups were similar for age, donor blood volume and target CD34+ cell dose to be collected (>/= 4 x 106 CD34+ cells/kg recipient). There was no statistically significant difference in the apheresis yield of CD34+ PBPCs (x 106) per kg recipient weight (5.6 +/- 3.3 vs. 5.6 +/- 4.3; P = 0.94) and per litre of blood processed (30 +/- 17.2 vs. 30.4 +/- 19.5; P = 0.92).

Terminal deoxynucleotidyl transferase expression in acute myelogenous leukemia and myelodysplasia as determined by flow cytometry

The significance of terminal deoxynucleotidyl transferase (TdT) expression in acute myelogenous leukemia (AML) remains controversial. Therefore, we studied TdT expression by flow cytometry in 120 previously untreated patients with AML or myelodysplastic syndrome (MDS) to determine the distribution of TdT-positive blasts and the intensity of TdT expression and to seek clinically significant associations. TdT expression measured by flow cytometry (flow TdT%) was heterogeneous, ranging from 0.1% to 87% (median, 8.5%), and 74 patients (62%) had at least 5% TdT-positive blasts. TdT positivity was associated with the M0 or M1 subtype and with expression of CD34 and CD7. No significant correlation was found between TdT expression and type of cytogenetic abnormality or rearrangement of immunoglobulin or T-cell receptor genes. Remission lasted longer in patients with a flow TdT% < 5 than in patients with a flow TdT% > 5 (median, 95 weeks vs 55 weeks, p = 0.02); however, complete remission rates did not differ when patients were classified by initial flow TdT%. Survival was slightly better for patients with flow TdT% less than 5%. Among patients with a flow TdT% > 5%, those with a higher TdT intensity survived longer than those with a lower intensity. These data suggest that quantitative TdT measurement may contribute to prognostic estimate in AML patients.

Increased CD38 expression is associated with favorable prognosis in adult acute leukemia

CD38 is expressed in acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML) blasts and its prognostic significance is unknown. We investigated CD38 expression in 304 AML and 138 ALL patients. CD38 was lower in AML-M3 compared to other FAB subtypes (5% vs. 41%; P < 0.001), but was similar among ALL subtypes (56.6%; P = 0.69). Ph + ALL and AML with t(15; 17) patients showed lower CD38 expression than the other cytogenetic groups. Overall survival favored AML and ALL patients with higher CD38 levels. Multivariate analysis revealed CD38 expression to be an independent outcome predictor in AML, but not in ALL.

De novo CD5+ Burkitt lymphoma/leukemia

CD5 is a T-cell marker aberrantly expressed in B-cell chronic lymphocytic leukemia and mantle cell lymphoma. Other B-cell neoplasms, including Burkitt lymphoma, are usually CD5-. We report 4 cases of de novo CD5+ Burkitt lymphoma/leukemia in elderly patients, all of whom were in a leukemic phase and had variable lymph node and splenic involvement. The blasts were typically medium sized, with folded nuclei, distinct but not prominent nucleoli, and moderate amounts of somewhat vacuolated basophilic cytoplasm; they were terminal deoxynucleotidyl transferase--negative and surface immunoglobulin--positive. All 4 cases demonstrated c-myc rearrangement, but none had t(14;18), t(11;14), or cyclin D1 overexpression or rearrangement. Only 1 patient achieved complete remission after hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone) therapy. One patient responded poorly to hyper-CVAD, and 2 patients died during induction chemotherapy. These rare cases of aggressive lymphoid malignancy with CD5 positivity and molecular features associated with Burkitt lymphoma/leukemia are best classified as Burkitt leukemia. However, the morphologic and immunophenotypic similarity to the blastoid variant of mantle cell lymphoma are diagnostically challenging. The diseases can be distinguished at the genetic level, since Burkitt lymphoma involves the rearrangement of c-myc, and mantle cell lymphoma usually the overexpression or rearrangement of cyclin D1.

Risk factors for acute graft-versus-host disease after allogeneic blood stem cell transplantation

We evaluated demographic characteristics and graft composition as risk factors for acute graft-versus-host disease (GVHD) in 160 adult recipients of HLA-identical allogeneic blood stem cell transplants. The patients received a median nucleated cell dose of 7.9 x 10(8)/kg and median C34(+) cell dose of 5.6 x 10(6)/kg. GVHD prophylaxis consisted of cyclosporine (CSA) and steroids, tacrolimus (FK506) and steroids, or FK506 and methotrexate. Grades 2 to 4 GVHD occurred in 31% (95% CI, 23% to 39%), and grades 3 to 4 GVHD in 14% (95% CI, 8% to 20%). In univariate analyses, GVHD prophylaxis with CSA and high CD34(+) cell doses were significant risk factors for grades 2 to 4 GVHD, but diagnosis, age, use of total body irradiation, donor sex, female donor for male recipient, donor parity, donor alloimmunization, viral serology, nucleated cell dose, CD3(+) cell dose, and CD56(+) cell dose did not alter the incidence of GVHD significantly. With a CD34(+) cell dose less than 8 x 10(6) CD34(+) cells/kg, the risk of grades 2 to 4 GVHD was significantly higher for those who received CSA (39%, 95% CI, 21% to 47%) in comparison with those on FK506 (18%, 95% CI, 10% to 26%) (P =.03), but GVHD prophylaxis regimen had less impact with a higher CD34(+) cell dose (overall grades 2 to 4 GVHD rate 52%, 95% CI, 37% to 67%). GVHD prophylaxis and CD34(+) cell dose are independent risk factors for acute GVHD after allogeneic blood stem cell transplantation.

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.

Allogeneic blood progenitor cell collection in normal donors after mobilization with filgrastim: the M.D. Anderson Cancer Center experience

BACKGROUND

Information on the safety and efficacy of allogeneic peripheral blood progenitor cell (PBPC) collection in filgrastim-mobilized normal donors is still limited.

STUDY DESIGN AND METHODS

The PBPC donor database from a 42-month period (12/94-5/98) was reviewed for apheresis and clinical data related to PBPC donation. Normal PBPC donors received filgrastim (6 microg/kg subcutaneously every 12 hours) for 3 to 4 days and subsequently underwent daily leukapheresis. The target collection was > or =4 x 10(6)CD34+ cells per kg of recipient's body weight.

RESULTS

A total of 350 donors were found to be evaluable. Their median age was 41 years (range, 4-79). Their median preapheresis white cell count was 42.8 x 10(9) per L (range, 18.3-91.6). Of these donors, 17 (5%) had inadequate peripheral venous access. Leukapheresis could not be completed because of apheresis-related adverse events in 2 donors (0.5%). Of the 324 donors evaluable for apheresis yield data, 221 (68%) reached the collection target with one leukapheresis. The median CD34+ cell dose collected (first leukapheresis) was 462 x 10(6) (range, 29-1463). The main adverse events related to filgrastim administration in donors evaluable for toxicity (n = 341) were bone pain (84%), headache (54%), fatigue (31%), and nausea (13%). These events were rated as moderate to severe (grade 2-3) by 171 (50%) of the donors. In 2 donors (0.5%), they prompted the discontinuation of filgrastim administration.

CONCLUSION

PBPC apheresis for allogeneic transplantation is safe and well tolerated. It allows the collection of an "acceptable" PBPC dose in most normal donors with one leukapheresis, with minimal need for invasive procedures.

Successful treatment of progressive multifocal leukoencephalopathy with low-dose interleukin-2

A patient with low-grade lymphoma presented 8 months after autologous marrow transplantation with dizziness, aphasia and hemiparesis. Magnetic resonance imaging (MRI) showed an abnormal T2 signal in the frontoparietal region unilaterally. Biopsy of the area demonstrated progressive multifocal leukoencephalopathy positive for JC virus and p53. Treatment with interleukin-2 at 0.5 MU/m2/day i.v. continuous infusion resulted in near complete resolution of symptoms and MRI abnormalities. The absolute number of CD3+CD4+ and CD3-CD56+ cells in the peripheral blood also increased, and the CD4/CD8 ratio normalized. She remains free of evidence of progressive multifocal leukoencephalopathy 1 year off therapy.