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Biomedical subjects

K Gajl-Peczalska

Publications and source records attributed to K Gajl-Peczalska.

At least 19 recordsLinked to original sources

Immunohistochemical identification of P-glycoprotein in previously untreated, diffuse large cell and immunoblastic lymphomas.

Expression of P-glycoprotein has been linked to multidrug resistance in cancer cell lines and human tumors. We investigated the frequency and clinical significance of P-glycoprotein immunoreactivity in 57 previously untreated diffuse large cell and immunoblastic lymphomas. Banked frozen tissue, which had been obtained prior to chemotherapy, was tested for reactivity with 2 monoclonal antibodies (MRK16 and C219) that recognize different domains of P-glycoprotein, using an immunoperoxidase technique. Thirteen of 57 lymphomas (23%) showed strong staining of greater than 50% of neoplastic cells; 15 of 57 (26%) showed labeling of a minority (11-50%) of neoplastic lymphocytes; 14 of 57 (25%) yielded equivocal results (reactivity in less than 10% of cells); and 15 of 57 (26%) were negative for P-glycoprotein. The 2 monoclonal antibodies were comparable in reactivity. Expression of MDR-1 mRNA was determined in 6 cases with sufficient available tissue, and did not correlate well with the percentages of cells reactive for P-glycoprotein by immunohistochemistry. Thirty-nine of our 57 patients completed multiagent chemotherapy. Contrary to our expectations, we found that P-glycoprotein immunoreactivity did not decrease the likelihood of response to induction chemotherapy. Median survival also was not adversely affected.

ABO Blood-Group System

Developmental hierarchy during early human B-cell ontogeny after autologous bone marrow transplantation using autografts depleted of CD19+ B-cell precursors by an anti-CD19 pan-B-cell immunotoxin containing pokeweed antiviral protein.

Sequential immunophenotypes of bone marrow (BM) and peripheral blood (PBL) lymphoid cells from 15 B-lineage acute lymphoblastic leukemia (ALL) patients who underwent autologous bone marrow transplantation (BMT) during complete remission were determined by dual-color immunofluorescence and multiparameter flow cytometry. Autografts were depleted of CD19+ B-cell precursors by an immunochemopurging protocol that combines B43-PAP, a potent anti-CD19 immunotoxin, and the cyclophosphamide congener 4-hydroperoxycyclophosphamide (4-HC). A marked interpatient variation was observed in the appearance and expansion of B-cell precursors repopulating the posttransplant marrow. The expression of CD10 and CD19 antigens during early B-cell ontogeny post-BMT preceded the expression of CD20, CD21, CD22, CD40, and sIgM. The surface antigen profiles of the emerging B-cell precursors were similar to those of fetal liver or fetal bone marrow B-cell precursors. Our comparisons of BM and PBL samples from patients in the early post-BMT period demonstrated that (1) PBL initially contains fewer B-lineage cells than does BM, and (2) circulating B-lineage lymphoid cells have a more mature immunophenotype than do BM B-lineage lymphoid cells. Comparison of the surface antigen profiles of day 30 versus day 100 or year 1 BM or PBL lymphoid cells showed an increase in the percentages of CD10+CD22- undifferentiated lymphocyte precursors, as well as CD19+sIgM- B-cell precursors (pre-pre-B), consistent with a time-dependent expansion of these B-cell precursor populations post-BMT. Importantly, the percentages of CD10+CD22+ and CD19+sIgM+ B-cell precursor (pre-B) populations also increased between 30 days and 1 year post-BMT, confirming the ability of emerging immature B-cell precursors to differentiate along the B-precursor pathway. The acquisition and expression of B-lineage differentiation antigens at different stages of the post-BMT B-cell ontogeny support the notion that the expression of these antigens is developmentally programmed. Similar to patients in previous autologous BMT studies, recipients of B-cell precursor-depleted autografts had normal or nearly normal serum immunoglobulin levels, suggesting that the maturing B-cell/plasma cell populations can produce and secrete immunoglobulins. The development of a functional CD19+ B-lineage lymphoid compartment in recipients of autografts which were depleted of CD19+ B-cell precursors corroborates the previously postulated existence of CD19- B-lineage lymphoid progenitor cells.

Antigens, CD

B-cell lymphoproliferative disorders in solid-organ transplant patients: detection of Epstein-Barr virus by in situ hybridization.

B-cell lymphoproliferative disorders (BLPDs) occur in approximately 2% of transplant recipients and are frequently fatal. Indirect serologic evidence has implicated Epstein-Barr virus (EBV) as an etiologic factor in these lesions. Direct evidence of the presence of EBV in these lesions has been obtained in relatively few cases. We used in situ hybridization (ISH) with a probe for the BamHI-W region of the EBV genome to study 52 tissue specimens from 28 solid-organ transplant patients who had BLPD. Epstein-Barr virus-infected lymphoid cells were identified in 26 of these 28 patients. The two patients without ISH evidence of EBV infection showed no distinctive clinical, morphologic, or serologic features. Previous filter-hybridization studies of these two patients had demonstrated evidence of EBV infection. Seven additional transplant patients without evidence of BLPD were studied as controls and showed no evidence of EBV in their lymphoid cells by ISH. These data provide further support for the etiologic role of EBV in the pathogenesis of posttransplantation lymphoproliferative disorders.

Adolescent

In vitro and in vivo radiation resistance associated with CD3 surface antigen expression in T-lineage acute lymphoblastic leukemia.

The radiobiologic features of primary clonogenic blasts (referred to also as T-lineage leukemic progenitor cells) from newly diagnosed and relapsed T-lineage acute lymphoblastic leukemia (ALL) patients were analyzed. Intrinsic radiation sensitivity differed substantially among primary clonogenic blasts from 34 newly diagnosed patients. The mean D0 (37% dose slope), SF2 (surviving fraction at 200 cGy), and alpha values (initial slope of the survival curve) were 141 +/- 15 cGy, 0.31 +/- 0.04, and 0.630 +/- 0.093 Gy-1, respectively. Among newly diagnosed cases, nine had SF2 values of greater than or equal to 0.50 and alpha values of less than or equal to 0.2 Gy-1, consistent with a marked intrinsic radiation resistance at the level of clonogenic blasts using the multitarget and linear quadratic models of cell survival. Of these nine radiation resistant cases, seven were CD3+. Furthermore, the mean D0 (162 +/- 20.8 cGy) and SF2 (0.377 +/- 0.057) values for the 20 CD3+ cases were significantly higher than the D0 (108.6 +/- 18.2 cGy) and SF2 (0.204 +/- 0.051) values for the 14 CD3- cases (P less than or equal to .05). Thus, clonogenic blasts from CD3+ newly diagnosed T-lineage ALL patients were more resistant to radiation than clonogenic blasts from CD3- newly diagnosed T-lineage ALL patients. Nineteen T-lineage ALL patients received autologous bone marrow transplants during complete remission. Pretransplant conditioning consisted of total body irradiation (TBI) combined with high-dose chemotherapy. Primary clonogenic blasts from patients who relapsed after bone marrow transplantation (BMT) displayed a particularly high degree of intrinsic radiation resistance with a mean D0 value of 333 cGy and an alpha value of 0.112 Gy-1. The expression of CD3 antigen appeared to predict the outcome of relapsed T-lineage ALL patients undergoing autologous BMT after TBI plus high-dose chemotherapy. The Kaplan-Meier estimates and standard errors of the probability of remaining in remission after BMT were 60% +/- 22% (mean relapse - free interval = 1.6 +/- 0.7 years) for CD3- patients and 0% +/- 0% (mean relapse - free interval = 0.2 +/- 0.0 years) for CD3+ patients (P = .002). Furthermore, the mean percentage of CD3-positive leukemic marrow blasts at presentation or relapse before BMT was significantly lower than the mean percentage of CD3-positive leukemic marrow blasts at relapse after BMT. Notably, in cultured leukemic bone marrow specimens from newly diagnosed as well as relapsed patients, colony blasts surviving in vitro radiation expressed CD3 more vividly than did colony blasts in unirradiated cultures.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent

Engagement of interleukin-7 receptor stimulates tyrosine phosphorylation, phosphoinositide turnover, and clonal proliferation of human T-lineage acute lymphoblastic leukemia cells.

The purposes of this study were to examine the biologic effects of the engagement of the interleukin-7 receptor (IL-7R) with recombinant human interleukin-7 (rhIL-7) in immunophenotypically distinct T-lineage acute lymphoblastic leukemia (ALL) blasts and to elucidate the biochemical nature of the IL-7R-linked transmembrane signal in rhIL-7-responsive T-lineage ALL blast populations. In the absence of costimulants, rhIL-7 stimulated the in vitro proliferation and colony formation of freshly isolated leukemic blasts from six to eight T-lineage ALL patients with a mean plating efficiency of 196 +/- 53 (background subtracted) colonies/10(5) blasts plated. Stimulation of T-lineage ALL blasts with rhIL-7 resulted in markedly enhanced tyrosine phosphorylation of six distinct phosphoproteins with molecular weights of 57, 72, 98, 123, 150, and 190 Kd, and induced a rapid increase in the production of inositol-1,4,5-trisphosphate (Ins-1,4,5-P3), which was inhibitable by the tyrosine-specific protein kinase inhibitor genistein, but not by the serine/threonine-specific protein kinase C inhibitor H7. Similarly, rhIL-7 stimulated Ins-1,4,5-P3 production in CEM-1.3 T-lineage ALL cells and this stimulation was inhibitable by the tyrosine-specific protein kinase inhibitors genistein and herbimycin A, but not by H-7. Thus, the transmembrane signal triggered by engagement of the IL-7R is intimately linked to a functional tyrosine-specific protein kinase pathway and stimulates the phosphoinositide (PI) turnover and proliferation of T-lineage ALL blasts. The presented data confirm and extend previous studies on the expression of functional IL-7R on T-lineage ALL blasts and support the hypothesis that IL-7 may play an important regulatory role in the biology of T-lineage ALL.

Bone Marrow

Temporal association of CD40 antigen expression with discrete stages of human B-cell ontogeny and the efficacy of anti-CD40 immunotoxins against clonogenic B-lineage acute lymphoblastic leukemia as well as B-lineage non-Hodgkin's lymphoma cells.

Detailed immunophenotypic analyses of immunologically classified leukemias and lymphomas showed that CD40 displays an exquisite B-lineage specificity within the human lymphopoietic system. Notably, 82% of B-lineage chronic lymphocytic leukemias (CLLs), 82% of B-lineage hairy cell leukemias (HCLs), 86% of B-lineage non-Hodgkin's lymphomas (NHLs), and 29% of B-lineage acute lymphoblastic leukemias (ALLs) were CD40+. Quantitative analyses of the correlated expression of CD40 and other B-lineage differentiation antigens on fetal lymphoid precursor cells by multiparameter two-color/three-color flow cytometry, combined with analyses of sequential antigen expression on fluorescence-activated cell fluorescence activated cell sorter (FACS) isolated immunologically distinct fetal B-cell precursor subpopulations during in vitro proliferation and differentiation, provided evidence that the acquisition of CD40 antigen in human B-cell ontogeny occurs subsequent to the expression of CD10 and CD19 antigens but before the surface expression of CD20, CD21, CD22, CD24, and surface immunoglobulin M (sIgM). Some leukemic pro-B cells from ALL patients as well as normal pro-B cell clones from fetal livers displaying germline Ig heavy chain genes were CD40+, indicating that the acquisition of CD40 antigen likely precedes the rearrangement of Ig heavy chain genes. CD40+ FACS-sorted malignant cells from B-lineage ALL as well as B-lineage NHL patients were capable of in vitro clonogenic growth, indicating the CD40 antigen is expressed on clonogenic leukemia and lymphoma cells. This hypothesis was confirmed by the ability of an anti-CD40 immunotoxin that we used as an antigen-specific cytotoxic probe to effectively kill clonogenic B-lineage ALL and NHL cells.

Antibodies, Monoclonal

T cell depletion with anti-CD5 immunotoxin in histocompatible bone marrow transplantation. The correlation between residual CD5 negative T cells and subsequent graft-versus-host disease.

Twenty-nine patients with advanced leukemias (median age 34 years) received histocompatible sibling marrow that had been depleted of T cells by ex vivo incubation with anti-CD5 monoclonal antibody-ricin immunotoxin (T101-R) for the purpose of graft-versus-host disease prophylaxis. Donor cell engraftment was documented in 28/29 patients by DNA restriction fragment length polymorphisms. In this pilot study the dose of T101-R incubated with donor marrow was increased in a stepwise manner from 300 ng (10 patients) to 600 ng (5 patients) to 1000 ng immunotoxin (IT)/10(7) bone marrow mononuclear cells (14 patients) in an attempt to achieve more effective GvHD prophylaxis. A statistically significant reduction in acute GvHD was achieved for patients receiving marrow pretreated with 1000 ng of immunotoxin (34%) compared to recipients of BM treated with 300 ng immunotoxin (100%, P = 0.0004). T-depleted marrow samples were evaluated for residual T cell activity using several in vitro assays including proliferation to the purified mitogen PHA (HA-17) and in mixed lymphocyte culture (MLC), T cell cytotoxicity, a limiting dilution assay for detecting precursors of proliferating T cells (LDApPTL), and phenotypic analysis of viable T cells expanded in 16-day culture with interleukin 2. The extent of T cell depletion determined by LDA assay varied widely at each immunotoxin concentration used. Thus, there was no correlation between the dose of T cells infused and subsequent GvHD. Phenotyping of lymphocytes recovered from immunotoxin-treated marrow demonstrated that residual T cells were CD5 negative in all cases tested. The only in vitro parameter that predicted subsequent acute or chronic GvHD was the demonstration of viable CD5 negative lymphocytes with T cell phenotype (CD2, CD3, and/or CD7 positive) after 16-day culture with IL-2 of the T-depleted bone marrow. We observed that such CD5 negative cells expressing other T cell markers have cytotoxic function and speculate that these cells may be capable of mediating GvHD in allogeneic transplantation.

Antigens, CD

Establishment of a leukemic cell model for studying human pre-B to B cell differentiation.

Reproducible models for examining early stages of human B cell differentiation are poorly developed. We now describe the establishment and characterization of a novel human leukemic cell line that recapitulates the pre-B to B cell stage of differentiation. This cell line, designated BLIN-1, was initially established in tissue culture medium containing low m.w. B cell growth factor, and consistently shows a dependency on this cytokine for optimal growth at low density. BLIN-1 cells have a 9p chromosomal abnormality, identical to the abnormality present in the leukemic blasts from the patient's original bone marrow aspirate. The immunologic phenotype of BLIN-1 is consistent with a cell arrested at the pre-B cell stage of development. Analysis of Ig gene rearrangement and Ig expression in a series of BLIN-1 subclones show that the cells spontaneously rearrange kappa light chain genes, leading to the differentiation of surface kappa-negative pre-B cells into surface kappa-positive B cells. The BLIN-1 cell line is, to our knowledge, the first defined human model for examining this critical developmental stage in human B cell ontogeny. As such, it offers a unique resource for examining variables influencing onset of kappa L chain gene rearrangement and expression.

B-Lymphocytes

Acute lymphoblastic leukemia of NK-cell lineage: responses to IL-2.

Acute lymphoblastic leukemias with phenotypic characteristics of natural killer cell derived lineage are extremely uncommon. We identified an ALL with a phenotype consistent with an NK-cell of origin. The blasts underwent a proliferative response to r-IL2 in culture but showed no spontaneous or r-IL2 or gamma-INF induced cytotoxicity. With r-IL2 stimulation however, the tumor cells demonstrated a dramatic acquisition of low density CD8 surface positivity and a loss of CD11b expression after short term culture. By comparison to ALL of B or T lineage, NK ALL likely represents an early stage of bone marrow derived NK-cell precursor.

Adolescent

Biphenotypic leukemic lymphocyte precursors in CD2+CD19+ acute lymphoblastic leukemia and their putative normal counterparts in human fetal hematopoietic tissues.

During detailed immunophenotypic analyses of marrow blasts from 336 acute lymphoblastic leukemia (ALL) patients, a very small percentage of cases reactive with B-cell-directed as well as T-cell-directed monoclonal antibodies (MoAbs) were identified. Five ALL cases were biphenotypic since they coexpressed CD2 (Tp50) and CD19 (Bp95) antigens at the single-cell level. The composite immunophenotype of these biphenotypic ALL cases was [TdT+HLA-ABC+CD2+CD3-CD10+CD13-CD14-CD16-CD19+CD20+ ++-CD21-CD33-CD34+Bgp95-C mu- slg-]. Low-molecular-weight B-cell growth factor (LMW-BCGF), recombinant interleukin-2 (rIL-2), and rIL-3 stimulated the proliferative activity of biphenotypic leukemic lymphocyte precursors without inducing differentiation. In the presence of the phorbol ester TPA, leukemic blasts from two cases differentiated along the B precursor pathway to the [CD2-CD10+CD19+CD20+C mu+slg-] pre-B cell stage. Biphenotypic ALL cases did not share a common configuration and gene rearrangement pattern of the immunoglobulin heavy chain genes or T-cell receptor (TCR) genes. Three cases had rearranged C mu genes but germline TCR genes, one case showed rearrangement of both C mu and TCR genes, and the remaining case had rearranged TCR genes but germline C mu genes. All five patients attained prompt remission after standard induction chemotherapy. Three to four years after initial diagnosis, four patients are now off chemotherapy and remain alive in their first remission. One patient relapsed at 3 years, 7 months, but promptly achieved complete remission after reinduction chemotherapy and remains in second remission off chemotherapy greater than 3 years after her reinduction therapy. With two-color immunofluorescence staining techniques and multiparameter flow cytometric analyses, we identified a small population of CD2+CD19+ lymphoid cells in fetal livers (FLs) and fetal bone marrows (FBMs), which may represent the putative normal counterparts of biphenotypic ALL blasts. A CD2+CD19+ normal biphenotypic lymphoid precursor cell line, designated FL 8.2 CD2+, was established from an FL of 8-weeks of gestational age by Epstein-Barr virus (EBV)-induced blastoid transformation. The composite immunophenotype of FL 8.2 CD2+ cell line was [TdT+HLA-ABC+HLA-DR+ CD2+CD5-CD7-CD10+/-CD13-CD19+CD20-CD21+ CD22+CD33-CD34+/-Bgp95-CDw40+C mu-slgD-slgM-]. FL 8.2 CD2+ cells showed germline patterns of immunoglobulin heavy-chain joining region, heavy-chain constant region, kappa light-chain constant region genes, and TCR beta-chain genes. Cross-linking of CD2 as well as CD19 antigens on FL 8.2 CD2+ cells caused an increase of intracellular ionized calcium.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Monoclonal

Detailed studies on expression and function of CD19 surface determinant by using B43 monoclonal antibody and the clinical potential of anti-CD19 immunotoxins.

Extensive immunologic surface marker analyses and binding competition assays demonstrated that B43 monoclonal antibody (MoAb) is a new member of the CD19 cluster that recognizes the same surface epitope as several other anti-CD19 MoAbs. We used B43 MoAb to test for CD19 expression on neoplastic cells from 340 leukemia and 151 malignant lymphoma patients and on nonneoplastic cells in normal lymphohematopoietic and nonlymphohematopoietic tissues. Our study more than doubles the total number of cases with classified hematologic malignancies that have been examined for CD19 antigen expression. The data presented confirm that CD19 is the most reliable B lineage surface marker and support our view that this B lineage-restricted surface determinant may be an important functional receptor. Our findings provide unique and direct evidence that (a) CD19 is expressed on leukemic B lineage lymphoid progenitor cells freshly obtained from B lineage acute lymphoblastic leukemia patients but not on normal myeloid, erythroid, megakaryocytic, or multilineage bone marrow progenitor cells; (b) ligation of CD19 with B43 MoAb induces sustained increases in [Ca2+]i when crosslinked and inhibits high-molecular weight B cell growth factor (HMW-BCGF)-induced proliferation of activated B cells without affecting their low-molecular weight B cell growth factor (LMW-BCGF) response; therefore CD19 may be a unique signal receptor; (c) HMW-BCGF and LMW-BCGF augment expression of CD19, which suggests that CD19 and BCGF receptors may be under coordinate regulatory control; (d) approximately two million B43 MoAb molecules per cell can be bound to target B lineage lymphoma cells with a Ka of 1.9 x 10(8)/mol/L; (e) CD19 can undergo B43 MoAb-induced internalization; and (f) the opportunity is thus provided for using anti-CD19 MoAb to deliver toxins to B lineage neoplastic cells for more effective treatment of high-risk leukemia/lymphoma patients.

Antibodies, Monoclonal

Marrow purging in autologous bone marrow transplantation for T-lineage acute lymphoblastic leukemia: efficacy of ex vivo treatment with immunotoxins and 4-hydroperoxycyclophosphamide against fresh leukemic marrow progenitor cells.

A lymphoblast progenitor cell assay was used to evaluate the antileukemic efficacy of marrow-purging protocols that employed intact ricin immunotoxins (IT) and 4-hydroperoxycyclophosphamide (4-HC) against clonogenic primary T-lineage marrow blasts freshly obtained from 12 T-lineage acute lymphoblastic leukemia (ALL) patients. Residual T-lineage blast colonies were observed after treatment with 1 micrograms/mL T101 (anti-CD5)-Ricin (R) + G3.7 (anti-CD7)-R in eight of 12 cases and after 100 micrograms/mL 4-HC in six of nine cases. By comparison, a combination of IT and 4-HC proved very effective against T-lineage leukemic progenitor cells, and no residual blast colonies were observed in any of the eight cases studied. We conclude that future trials should consider combined treatment protocols such as IT + 4-HC for more effective purging of autologous marrow grafts.

Antibodies, Monoclonal

B-cell growth factor receptor expression and B-cell growth factor response of leukemic B cell precursors and B lineage lymphoid progenitor cells.

The purpose of this study was to analyze the expression of B cell growth factor (BCGF) receptors and to elucidate the biologic effects of biochemically purified natural BCGF at the B cell precursor stage of human B lineage lymphoid differentiation. The specific binding of radioiodinated high-mol-wt BCGF (125I-HMW-BCGF) and low-molecular-wt BCGF (125I-LMW-BCGF) to fresh marrow blasts from B cell precursor acute lymphoblastic leukemia (ALL) patients was initially investigated. The estimated number of radioiodinated BCGF molecules bound per blast ranged from undetectable to 24.3 X 10(3) for HMW-BCGF, and from 11.5 X 10(3) to 457.8 X 10(3) for LMW-BCGF. In 3H-TdR incorporation assays, 75% of cases showed a significant response to LMW-BCGF with a median stimulation index of 9.3. By comparison, only 33% of cases showed a significant response to HMW-BCGF with a median stimulation index of 2.4. Subsequently, B cell precursor colony assays were performed to assess and compare the biologic effects of BCGF on leukemic B lineage lymphoid progenitor cells. Among 28 cases studied, 57% responded to both HMW-BCGF and LMW-BCGF, 21% responded only to LMW-BCGF, and the remaining cases showed no proliferative response to either growth factor. The response patterns of virtually pure populations of FACS-sorted leukemic B cell precursors were essentially identical to the proliferative responses of unsorted leukemic B-cell precursors. Synergistic effects between HMW-BCGF and LMW-BCGF were observed in 80% of the cases that responded to both. The numbers of cell-bound radioiodinated BCGF molecules, the stimulation indices, as well as the number of B cell precursor colonies in BCGF-stimulated cultures showed a marked interpatient variation. Patients with structural chromosomal abnormalities (SCAs) involving 12p11-13 or patients with a Philadelphia chromosome showed a greater HMW-BCGF response at the level of leukemic progenitor cells than did other patients (P = .02). The LMW-BCGF response was significantly greater for patients with SCA than for patients without SCA (P = .04). The response of leukemic progenitor cells to HMW-BCGF or LMW-BCGF did not correlate with sex, age, disease status, FAB morphology, WBC at diagnosis, or immunophenotype. To our knowledge, this study represents the first detailed analyses of BCGF receptor expression and BCGF effects in B cell precursor ALL. The data presented provide direct evidence for the expression of functional receptors for both HMW-BCGF and LMW-BCGF in B cell precursor ALL.

Acute Disease

Monoclonal antibody study of Philadelphia chromosome-positive blastic leukemias using the alkaline phosphatase anti-alkaline phosphatase (APAAP) technic.

The leukemic cells from 15 cases of Philadelphia chromosome-positive blastic leukemia were immunophenotyped by the alkaline phosphatase anti-alkaline phosphatase (APAAP) immunocytochemical technic using nine monoclonal antibodies (MoAb) reactive with various myeloid or lymphoid antigens. On the basis of morphology, cytochemistry, terminal deoxynucleotidyl transferase (TdT) reactivity, and electron microscopy, five of the cases had been classified as lymphoid; eight, myeloid; one, mixed myeloid-lymphoid; and one, undifferentiated. The blasts from all five lymphoid cases were reactive with lymphocyte differentiation antigen MoAb, and four of five reacted with MoAb to anti-common acute lymphoblastic leukemia-associated antigen (CALLA) (BA3). The blasts from all eight myeloid cases were reactive with MY7, a marker of myelomonocytic differentiation. Some of the blasts from three of the eight myeloid cases reacted with HP1-1D and AP3, markers of megakaryocytic differentiation; megakaryocyte differentiation was confirmed by electron microscopy. In the case classified as mixed myeloid-lymphoid, the blasts showed morphologic and immunophenotypic heterogeneity; ultrastructural studies demonstrated lymphoid, basophil, and erythroid differentiation. The blasts from the case classified as undifferentiated were immunophenotypically heterogeneous. In all cases in which the leukemic cells were also immunophenotyped by flow cytometry, the results correlated well with those obtained by the APAAP technic. The APAAP technic is a reliable method for immunophenotyping leukemias. Advantages of this method include its applicability to routinely prepared blood and bone marrow smears and cytocentrifuge preparations, lack of endogenous peroxidase background staining, and a permanent record.

Adult

Extramedullary presentation of the blast crisis of chronic myelogenous leukaemia.

We report the clinical histories and a multiparameter pathological study of the extramedullary lesions of seven patients with chronic myelogenous leukaemia in whom the initial clinical presentation of blast crisis (BC) was in an extramedullary site (lymph nodes in six, mandibular mass in one). Bone marrow BC was demonstrated simultaneously or within a few months in four patients. Three patients received chemotherapy only, four underwent bone marrow transplant. Six patients died within 1 year from diagnosis of extramedullary BC, one is alive without disease. The longest survivals (12+, 12, 11 months) were those of patients who never developed bone marrow BC and were recipients of bone marrow transplant. Studies of extramedullary disease included: histology; histochemistry for chloracetate esterase (CAE) and lysozyme; assays for TdT; electron microscopy; immunofluorescence for Fc-receptors, immunoglobulins and lymphoid and myeloid antigens by a panel of monoclonal antibodies; and cytogenetics. Three cases were classified as myeloid BC based on histochemistry and/or ultrastructure and immunology (OKM1+, MCS2+, IG10+); two as lymphoid BC (CAE-, lysozyme-, TdT+), one of them expressing a T-cell phenotype. Cytogenetic analysis of extramedullary lesions and simultaneous or subsequent bone marrows demonstrated identical karyotypes in three patients and significantly different karyotypes in one.

Adult

Rosette formation in malignant lymphoma.

Lymph node biopsies in a patient with follicular lymphoma showed rosette structures as seen in neuroepithelial neoplasms. These specimens were studied by histologic, immunoperoxidase (for immunoglobulins, intermediate filaments (IF), actin and neuron-specific enolase), immunofluorescence (for immunoglobulins, and with a panel of monoclonal antibodies), and electron-microscopic examination. The rosettes were formed by neoplastic lymphocytes arranged around eosinophilic fibrillary material. Ultrastructurally, this was composed of cytoplasmic processes, projecting from the lymphocytes and containing thin and intermediate filaments. Immunohistochemically, it stained for monoclonal IgM lambda, all other antigens present on the neoplastic cells, and weakly for vimentin and actin. Based on recent information about lymphocyte surface changes, it is speculated that the rosettes might represent an aggregation of neoplastic lymphocytes activated by a microenvironmental stimulus, perhaps antigen-antibody binding at the cell membrane. The practical implication of this hitherto unreported finding is that the presence of rosettes cannot be used to rule out a lymphoma.

Aged