Predominant expression of lambda light chain in adult cases with non-T-cell acute lymphocytic and chronic myelogenous leukemia in lymphoid blast crisis

The authors investigated cytoplasmic immunoglobulins of the leukemic cells from 20 adult cases with non-T-cell acute lymphocytic leukemia (ALL) and from three cases with chronic myelogenous leukemia in lymphoid blast crisis using immunoelectron microscopy. They also studied these cases using various monoclonal antibodies. Of the 23 examined cases, nine were negative for both heavy and light chains of immunoglobulins; the authors defined these as common ALL. Two cases were positive for the mu chain but were negative for light chains; the authors defined these as pre-B-cell ALL. The remaining 12 cases were positive for either kappa or lambda light chains; these were defined as B-cell ALL. Of the 12 cases positive for light chains, 11 were positive for the lambda chain. Seven cases of the 11 positive cases for the lambda chain were negative for heavy chains. Eleven cases were positive either for both My4 and My9 or for one of the two antibodies. From these results, the authors conclude the following: (1) the ratio of pre-B-cell ALL among non-T-cell ALL cases (two of 23 cases) was lower in adults than in children; (2) of the light chain-positive cases, the lambda light chain-positive cases predominated (11 of 12 cases); (3) heavy chain-negative, lambda chain-positive cases (seven cases) were observed; and (4) one half of the leukemia cases showed dual phenotypes of B-cell and myeloid cell lineages.     

Immunophenotypic spectrum of plasma cell leukemia

Four cases of plasma cell leukemia (PCL) are reported that illustrate the variable immunotype of this disorder in contrast with the immunologic profile described for normal B-cell maturation and typical multiple myeloma (MM). Mature B-lymphocytes express B1 antigen (Ag) and surface immunoglobulin (SIg) whereas maturation to the plasma cell stage is accompanied by loss of these immunologic markers and expression of T10 Ag, plasma cell Ag (PCA), and cytoplasmic immunoglobulin (CIg). Plasma cells from patients with MM have previously been found to express the immunophenotype of normal plasma cells. In contrast, none of the four cases reported here express an immunologic profile typical for specific B-cell differentiation stages. Only one of four cases was strongly positive for PCA but additionally expressed B1 Ag and SIg. Of the remaining three cases, all expressed T10 Ag and CIg; two cases also expressed SIg, weak PCA, and B1 Ag. All four cases were monoclonal for lambda light chains and negative for common ALL Ag (CALLA). The variable expression of mature B-cell markers and plasma cell markers demonstrates the immunophenotypic spectrum of PCL; the prognostic significance of this heterogeneity needs to be more closely examined.     

Cytoplasmic IgM in leukemic B cells by flow cytometry

The presence of intracellular cytoplasmic immunoglobulin M (IgM) in leukemic cells from patients with acute lymphocytic leukemia (ALL) and chronic lymphocytic leukemia (CLL) was investigated by flow cytometry. The objective of the study was to develop a reproducible flow cytometric method. A Burkitt's lymphoma-derived B-cell line, Daudi, and a pre-B ALL, Nalm-6, served as prototypes. Normal B cells and cells from patients with chronic myelogenous leukemia (CML) were used as negative controls. Cytoplasmic mu was expressed in 77.3 +/- 7.5% (n = 10) of Nalm-6 cells. CALLA+ ALL and CML cells lacked cytoplasmic mu. The surface-membrane immunoglobulin on the viable B cells was blocked with purified goat anti-human IgM. Subsequently, the B cells were fixed in cold absolute methanol and stained with a fluorescein-conjugated goat anti-human IgM to demonstrate cytoplasmic IgM. After the surface-membrane IgM was blocked, normal B cells had no cytoplasmic IgM (0.3-0.5% positive cells) detectable by flow cytometry. However, the peripheral blood lymphocytes from five patients with CLL and the Daudi cells contained cytoplasmic IgM, ranging from 7.8 to 76.7% and 45.7 to 89.3%, respectively. We conclude that cytoplasmic mu in Nalm-6, CLL, and Daudi cells can be easily and rapidly demonstrated by flow cytometry.     

Correlation of karyotype and immunophenotype in childhood acute lymphoblastic leukemia

To correlate leukemic cell karyotype with immunophenotype, we studied 364 children with acute lymphoblastic leukemia (ALL). A prognostically favorable cytogenetic feature, hyperdiploidy greater than 50 chromosomes, was found in 33% of cases classified as common ALL antigen positive (CALLA+) early pre-B (common) ALL, in contrast to 18% of pre-B cases (P = .012), 5% of T cell cases (P less than .001), and none of the B cell cases (P less than .001) or cases of CALLA negative (CALLA-) early pre-B ALL (P = .002). The frequency of translocations, an adverse cytogenetic feature, was significantly lower in CALLA+ early pre-B ALL cases (35%) than in B cell (100%; P less than .0001), pre-B (59%; P less than .001), or CALLA- early pre-B (62%; P = .016) cases. Thus, patterns of chromosomal change differ widely among the major immunophenotypic groups of ALL and may account for reported differences in responsiveness to treatment.     

Unfavorable presenting clinical and laboratory features are associated with CALLA-negative non-T, non-B lymphoblastic leukemia in children

Twenty-four (5.7%) of 424 children with newly diagnosed acute lymphoblastic leukemia (ALL) were found to have blast cells that expressed HLA-DR antigens but not the common ALL antigen (CALLA), E-rosette receptors, T-cell antigens, or cytoplasmic or surface immunoglobulins. Each of the eight cases tested expressed the B-cell associated antigen B4, but not B1 or B2 antigen. Myeloid-associated antigens were not present in any of the 10 cases tested. By comparison with common (CALLA+ B-cell precursor) ALL, patients having this immunophenotype were more likely to be children less than 2 yr of age (p less than 0.001), to have higher initial leukocyte counts (p less than 0.001), and to have blast cells with a DNA index less than 1.16 (p = 0.05), a pseudodiploid karyotype (p = 0.01) and a chromosomal translocation (p = 0.003). The presence of any chromosomal translocation in these CALLA- ALL was related to measures of increased leukemic cell burden including higher leukocyte counts, larger liver and spleen sizes and higher serum lactic dehydrogenase levels. While the patients were entered into several treatment arms of two protocols, the CALLA- cases appeared to have lower remission rate (p = 0.06) and shorter event-free survival time (p = 0.05) than did those with common ALL. The association with clinical and laboratory features of known adverse prognostic significance provides some explanation for the poor treatment outcome of CALLA- ALL.     

Biologic and cytogenetic characteristics of leukemia in infants

Clinical features, leukemic cell characterization, chromosomal findings, and treatment outcome were analyzed in a retrospective study of 30 cases with acute leukemia of infancy, 24 infants with acute lymphoblastic leukemia (ALL), and six cases with acute nonlymphoblastic leukemia (ANLL). Extensive bulky disease with organomegaly, central nervous system (CNS), and skin involvement were prominent features at diagnosis with a higher frequency in ANLL as compared to ALL. Four of six ANLL patients were classified as monocytic or myelomonocytic. In the ALL group nine of 24 (36%) were non-L1 morphology and six of 17 (33%) were common ALL antigen (CALLA) negative, the majority of them (five of six) were included in the non-L1 group. Immunophenotyping revealed four cases with early B-cell (three patients: Ia+B4+, and one patient: Ia+) and two cases with T-cell. Mixed lineage leukemia was found in five infants. Heavy chain immunoglobulin gene rearrangement was present in six cases tested, two CALLA+, two with Ia+B4+, and two were undifferentiated mixed lineage leukemia. Chromosomal aberrations were detected in ten of 18 patients, mostly in ANLL and CALLA negative ALL. Translocations were detected in six patients, involving 4q21-23 and 11q23 in three and two cases, respectively. The probability of five-year DFS were 27% for the whole group. The worst prognosis was observed in infants younger than 6 months of age, in whom the leukemia cell characteristics was compatible with stem cell: ANLL, very early pre-B, or undifferentiated mixed type. The chromosomal aberrations found in all cases included translocation with the seemingly nonrandom breakpoints at 4q21 and 11q23, and breakpoints that corresponded to known fragile sites. This finding may be suggestive of an underlying genetic predisposition associated with the poor prognosis of leukemia of infancy.     

Antigenic and enzymatic phenotypes of the pre-B subclass of acute lymphoblastic leukaemia

Leukaemias of immature B cells (pre-B cells) can be identified by the presence of cytoplasmic IgM in the absence of detectable cell surface immunoglobulin. One hundred and thirty-one cases of acute lymphoblastic leukaemia were assessed for this marker and 29 including both childhood and adult cases were positive. Twenty-eight of these had the phenotype of the major or common (c) ALL subclass, i.e. cALL antigen⁺, p28,33 antigen⁺, and were indistinguishable in presenting clinical and haematological features from IgM negative cALL. Variable proportions (10–95%) of leukaemic lymphoblasts contained detectable cytoplasmic IgM indicating differential levels of maturation arrest and a probable close developmental relationship between IgM⁺ cALL and IgM⁻ cALL.

Twenty out of 22 of these pre-B ALLs tested had elevated levels of terminal deoxynucleotidyl transferase, double antibody fluorescence tests with anti-TdT and anti-IgM revealing that individual cells contained nuclear TdT and cytoplasmic IgM. In contrast, four cases of the infrequent B-ALL subgroup had the phenotype p28,33⁺, cALL⁻ and TdT negative indicating that the latter enzyme is a correlate of immaturity in both the T and B cell lineage.

Eight out of 19 cases of pre-B ALL also had elevated levels of the I (intermediate) isoenzyme peak of hexosaminidase in common with the majority of cases of non-T, non-B or common ALL.

These observations provide further insight into the possible target cells and levels of maturation arrest in ALL.     

Cytological and immunological study of 139 patients with acute leukemia

Sixty-six children with acute lymphatic leukemia (ALL), 26 adults with ALL and 47 adults with acute myeloid leukemia (AML) were subclassified according to the classifications French-American-British (FAB) and World-Health-Organization (WHO). Nine immunological markers and 6 cytochemical stains were also used. The reproducibility of the WHO classification of the smears performed independently twice by one observer was 93%, but that between two observers only 78%. Three patients considered ALL by A were called AML by B, but all three had the common acute leukemia antigen, CALLA. In the group of 87 patients considered ALL by B, only 74 were classified ALL by A, but of the 13 non-ALL B, none had the CALLA. Ten of these thirteen patients had myeloid markers such as Philadelphia chromosomes, peroxidase or Sudan Black B positive reactions, or Fc and C3 receptors. The remaining 3 patients were non-Hodgkin lymphoma with B-cell markers. None of the 47 cases classified as AML had CALLA. Seventeen of nineteen myeloblastic leukemias (M2, FAB) had a myeloid antigen (Mag) and 13 of 15 myelomonocytic leukemias (M4, FAB) had, in addition, Fc and C3 receptors.     

Differential Prognosis Detected by Immunophenotyping in Acute Lymphoblastic Leukemia of Childhood with Poor Prognostic Factors

Immunological phenotypes of leukemlc blasts from 50 childrenwith acute lymphoblastic leukemia (ALL) have been examined witha panel of monoclonal antibodies to evaluate their prognosticsignificance. Thirty-seven of them were common-ALL positivefor CD10 "common-ALL antigen (CALLA)" (NL-1), CD19(B4) and HLA-DR.One was pre-B ALL negative for CALLA and another null-ALL whichexpressed HLA-DR alone. Six of the remaining 11 cases were traditionalT-ALL positive for CD2(9.6), and the other five tentative pre-TALL positive for CD7(Tp40) but negative for CD2. Twenty-oneout of 39 patients with non-T ALL were treated with the standardregimen. The 18 children with non-T ALL having poor prognosticfactors, five with pre-T ALL and six with T-ALL were treatedwith the more intensive regimen. The median follow-up periodwas 36 (range 4 to 74) months. Their disease-free survival probabilitieswere compared. It was found that the disease-free survival ofnon-T ALL patients with poor prognostic factors was comparableto that of the patients without such factors as a result ofthe more intensive chemotherapy. Among the patients with poorprognostic factors, those with pre-T ALL as well as those withT-ALL, which were positive for CD7 antigen, were found to havesignificantly short disease-free survival times (P < 0.03).CD7 antibody is most useful for detecting ALL patients withpoor prognoses.     

B-cell differentiation pattern of cutaneous lymphomas in infancy and childhood

This article documents four children with cutaneous lymphomas. Two of them had regional disease and the other two already had disseminated disease when they were diagnosed. Immunophenotyping of the lymphomatous infiltration disclosed a cell antigen profile with pre-pre-B (HLA-DR+, CALLA+, VIB-C5+), pre-B (HLADR+, CALLA+, VIB-C5+, cytoplasmatic immunoglobulin+), and transitional pre-B characteristics (HLA-DR+, CALLA+, VIB-C5+, surface immunoglobulin+). The morphology of the blast cells in all patients showed features of lymphoblastic lymphoma. Two patients had the convoluted cell type in common, but they were immunologically different, one displaying pre-pre-B and the other pre-B immunophenotypes. The remaining two cases were diagnosed as lymphoblastic lymphomas "type others" according to the Kiel Classification, one with pre-B and the other with transitional pre-B characteristics. The morphologic and immunohistochemical parameters as well as the clinical data from the four cases clearly indicate the heterogeneity of cutaneous non-Hodgkin's lymphomas in children.     

B-lymphocyte associated differentiation antigen expression by 'non-B, non-T' acute lymphoblastic leukemia

We investigated the neoplastic cells obtained from 37 cases of 'non-B, non-T' (SIg-E-) acute lymphoblastic leukemia (ALL) for their expression of 13 distinct monoclonal antibody defined B lymphocyte associated differentiation antigens. We correlated the expression of these B cell antigens with terminal deoxynucleotidyl transferase (TdT), HLA-DR antigen, common ALL antigen (cALLa), and cytoplasmic mu heavy chain (Cu) expression by these neoplastic cells. In this way, we were able to describe a hierarchy of B lymphocyte associated differentiation antigens as well as the marked phenotypic heterogeneity of 'non-B, non-T' ALL. TdT and HLA-DR are expressed throughout the stages of B cell differentiation represented by 'non-B, non-T' ALL. The earliest B cell antigen appears to be Leu 12 (B4) followed by BA-2 and then BL2. OKB2, BL1 and BA-1 are acquired next, followed by B1, BL3, cALLa and Cu. BL7 appears just prior to SIg. OKB1, OKB4, OKB7 and BL4 appear at or after the time of SIg expression and hence are not expressed by 'non-B, non-T' ALL cells. This developmental hierarchy is supported by the results of phorbol ester (TPA) induction studies. Thus, cases of 'non-B, non-T' ALL constitute a useful model for probing the hierarchal expression of B cell antigens and delineating the B cell developmental pathway(s).     

Monoclonal immunoglobulin light chain in urine of patients with B lymphocytic disease: its source and use as a diagnostic aid

The presence of tumour-related monoclonal light chain has been sought in urine as an immunochemical aid in the diagnosis of B lymphocytic neoplasms. The technique of isoelectric focusing in agarose followed by immunofixation has been applied to concentrated urines from 41 patients. In chronic lymphocytic leukaemia involving neoplastic B lymphocytes, monoclonal light chain was detected in 14 out of 19 patients investigated. For 2 of the positive cases (one kappa light chain type and one lambda light chain type) the urinary light chains were compared directly with culture fluids obtained after incubation of the corresponding neoplastic cells obtained from the patient's peripheral blood: identity of the light chains from urine and cells was established by isoelectric focusing demonstrating for both patients that the tumour cells were the source of the urinary light chain. In patients with non-Hodgkin's lymphoma involving neoplastic B lymphocytes, urinary monoclonal light chains were found in 7/16 of those studied. Such light chains were not detected in 11 control subjects, in 3 patients with true histiocytic tumours or in 2 patients with enlarged reactive lymph nodes. The technique is simple to perform and provides information for diagnosis and possibly monitoring of B cell neoplasms.     

Subgroup analysis of BL-cell lines with polyclonal BL-specific antibodies

A Burkitt's lymphoma (BL)-specific antibody (anti-GP70), previously described, was used to analyse 22 different BL-cell lines. The results indicated specificity of antibodies to lines that contain both surface membrane Ig (SmIg) and cytoplasmic Ig (CyIg). BL-cell lines derived from more immature B cells that do not have SmIg but rather have only CyIg were negative. A comparative study with antibody to common ALL antigen (CALLA) and to another BL-specific antigen (BLA) revealed coexpression of GP70 with those two antigens, but no identity between them.     

Purine metabolism in childhood acute lymphoblastic leukemia: biochemical markers for diagnosis and chemotherapy

Adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), 5'nucleotidase (5'NT), ecto-5'NT, hypoxanthine-guanine phosphoribosyltransferase(HGPRT), adenine phosphoribosyltransferase(APRT), adenosine kinase(AK), AMP deaminase (AMPD) and adenylate kinase(AdKin) activities were assayed in leukemic cells from bone marrow and/or peripheral blood of 43 newly diagnosed children with acute lymphoblastic leukemia(ALL). These enzyme activities have been investigated in relation to some immunological markers. ADA activity was higher in E-rosette positive leukemia(E+ ALL), while HGPRT, APRT, PNP, 5'NT, ecto-5'NT and AdKin activities were found to be lower in E+ ALL as compared to E- ALL. In common ALL (cALL) antigen positive leukemia, mean ADA activity was significantly lower as compared to cALL- leukemia, whereas PNP, 5'NT, ecto-5'NT and AdKin activities were significantly higher. cALL cells with cytoplasmic immunoglobulin M(IgM) heavy chains were found to have mean 5'NT activities twice as high as cALL cells lacking cytoplasmic IgM heavy chains. In two patients who had surface immunoglobulins on their cell membranes, low 5'NT activities were found. When measuring enzyme activities after 2-4 days of prednisone monotherapy, only mean ADA and HGPRT activities decreased in non-B, non-T ALL. These decreases were not significant in T-ALL patients. Mean enzyme activities in the leukemic cells of five patients with relapse were comparable to those in newly diagnosed patients, except for 5'NT, which was found to be within the activity range of control peripheral blood lymphocytes. It is concluded that ADA and AdKin activities are suitable as markers for E+ ALL and cALL+ leukemias respectively. 5'NT might help to distinguish between cALL cells having and lacking pre-B characteristics. Since 5'NT activity may also be decreased in B-ALL, it is not suitable as a T-ALL marker. Enzymes of purine metabolism in leukemic relapse need further investigation.     

T cell receptor gene rearrangements in B-precursor acute lymphoblastic leukemia correlate with age and the stage of B cell differentiation

Children with ALL diagnosed at less than 2 years of age have a poor prognosis when compared with older children. In an effort to identify biologic features of ALL in children less than 2 that might explain this difference, we performed extensive immunophenotypic and molecular genetic analyses on a series of patients. For comparison purposes patients were divided into four groups: CALLA- (CD10-) infants less than 2 years of age at diagnosis (n = 10), CALLA- children greater than 2 years of age at diagnosis (n = 10), CALLA+ infants (less than 2 years, n = 21) and CALLA+ children (older than 2 years, n = 21). No immunophenotyping differences in CALLA- or CALLA+ subgroups were identified when cases less than 2 were compared with cases greater than 2 years of age at diagnosis. The most interesting results were in the CALLA- group where 94% of the samples expressed the B cell antigen CD19 but 27% co-expressed CD7. Double labeling experiments confirmed leukemic blast cells co-expressed CD19 and CD7. The double-labeled cells represent either leukemic conversion of a precursor cell which has not yet committed to B or T cell lineage or aberrant expression of these antigens. Molecular genetic studies demonstrated that all samples, regardless of the patients' age or immunophenotype, had rearrangement of the Ig heavy chain gene. The most striking molecular results were in CALLA- patients; in patients less than 2 at diagnosis neither the beta- nor the gamma-chain gene of the T cell receptor (TCR) was rearranged, whereas DNA from 5 of 10 patients over the age of 2 demonstrated beta- or gamma-chain TCR gene rearrangements. The percentage of CALLA+ cases under the age of 2 years with rearrangements in TCR genes is less than that found in CALLA+ cases over the age of 2 years. The finding of no TCR rearrangements in CALLA- ALL and a decreased number of gamma-TCR rearrangements in CALLA+ cases under the age of 2 suggest that age may affect TCR gene rearrangements in lymphoblasts. The molecular differences in TCR gene rearrangements do not appear to correlate with the response to therapy.     

Clonal immunoglobulin gene rearrangements and normal T-cell receptor, bcl-2, and c-myc genes in primary cutaneous B-cell lymphomas

Fourteen cases of primary cutaneous B-cell lymphomas were investigated at the immunohistochemical and molecular level to further characterize this newly defined entity. Neoplastic cells from all cases, phenotyped with a panel of monoclonal antibodies, were positive for HLA-DR, for the B-cell markers CD19, CD22, but not CD23 (except one case), and negative for the T-cell marker CD2. Monoclonal immunoglobulin light chains were demonstrated in six cases. The reactivity with the Ki-67 monoclonal antibody indicated that the neoplastic cells are proliferating. In five biopsies the presence of dendritic cells infiltrating the neoplastic areas was revealed using the monoclonal antibody Kim4b. By Southern blot analysis, clonal rearrangement of the immunoglobulin heavy chain gene (involving one or both alleles) was shown in 12 of 14 cases and of the light chain genes in 13 cases. The bcl-2 oncogene, normally involved in nodal follicular lymphomas, was in germ-line configuration. The c-myc and the beta and gamma chain genes of the T-cell receptor were also in the germ-line configuration. None of the cases presented Epstein-Barr virus sequences. These data indicate that primary cutaneous lymphomas of B-cell origin share morphological and phenotypic similarities with the nodal B-cell lymphomas of follicular histotype, are proliferating, and express in 45% of cases clear monoclonal immunoglobulin light chain; the molecular analysis confirms the B-cell derivation and the monoclonal nature of this neoplasia; it also shows that neither bcl-2 nor c-myc oncogenes are involved and that no inappropriate rearrangements of the T-cell receptor genes are found in this lymphoma.     

Laboratory and clinical applications of monoclonal antibodies for leukemias and non-Hodgkin's lymphomas

Important insights into leukocyte differentiation and the cellular origins of leukemia and lymphoma have been gained through the use of monoclonal antibodies that define cell surface antigens and molecular probes that identify immunoglobulin and T-cell receptor genes. Results of these studies have been combined with markers such as surface membrane and cytoplasmic immunoglobulin on B lymphocytes, sheep erythrocyte receptors on T lymphocytes, and cytochemical stains. After using all of the aforementioned markers, it is now clear that acute lymphoblastic leukemia (ALL) is heterogeneous. Furthermore, monoclonal antibodies that identify B cells, such as the anti-CD20 and anti-CD19 antibodies in combination with studies of immunoglobulin gene rearrangement, have demonstrated that virtually all cases of non-T-ALL are malignancies of B-cell origin. At least six distinct subgroups of non-T-ALL can now be identified. T-ALL is subdivided by the anti-CD7, anti-CD5, and antibodies that separate T lymphocytes subsets into three primary subgroups. Monoclonal antibodies are also useful in the subclassification of non-Hodgkin's lymphoma, and certain distinct markers can be correlated with morphological classification. Although monoclonal antibodies are useful in distinguishing acute myeloid from acute lymphoid leukemias, they have less certain utility in the subclassification of acute myelogenous leukemia (AML). Attempts to subclassify AML by differentiation-associated antigens rather than by the French-American-British (FAB) classification are underway in order to document the potential prognostic utility of surface markers. Therapeutic trials using monoclonal antibodies in leukemia and lymphoma have been reported. Intravenous infusion of unlabeled antibodies is the most widely used method; transient responses have been demonstrated. Antibodies conjugated to radionuclides have been quite successful in localizing tumors of less than 1 cm in some studies. Therapy trials with antibodies conjugated to isotopes, toxins, and drugs have shown promise. Purging of autologous bone marrow with monoclonal antibodies and complement in vitro has been used in ALL and non-Hodgkin's lymphoma; preliminary data suggest that this approach may be an effective therapy and may circumvent many of the obstacles and toxicities associated with in vivo monoclonal antibody infusion.     

Establishment of novel B-cell precursor leukemia sister cell lines NALM-36 and NALM-37: shift of immunoglobulin phenotype to double light chain positive B-cell.

Two novel B-cell precursor (BCP) acute lymphoblastic leukemia (ALL) sister cell lines, designated NALM-36 and NALM-37, were established from the peripheral blood (at diagnosis) and bone marrow (at relapse) of a 37-year-old woman with ALL. Immunophenotyping showed BCP type III pre-B cell characteristics including TdT, CD10, CD19, CD22, CD79a and HLA class II. T cell and myeloid-associated antigens tested were negative except CD5 which was 100% positive for both cell lines. The surrogate light chains lambda5 and VpreB were positive for both cell lines. Cytogenetic analysis of NALM-36 revealed an abnormal karyotype with 46, XX, add(1)(q?42), -14, +mar. Southern blot analysis of the immunoglobulin (Ig) genes status of NALM-36 at 10 months after establishment showed germ line configuration of the kappa light chain gene, and rearrangement of the lambda light and mu heavy chain genes. At 16 months we detected a phenotypic shift of Ig chain protein expression from a BCP-III pre-B cell phenotype to a BCP-IV mature B cell phenotype, with kappa and lambda double Ig light chain and mu heavy chain expression, both on the cell surface and in the cytoplasm. We designated this subline as NALM-36KL. Authenticity of the NALM-36KL, NALM-36 and NALM-37 cell lines was demonstrated by DNA fingerprinting. The extensive characterization of the sister cell lines suggests that these three novel cell lines, derived from a single patient, may represent unique and relevant in vitro model systems for BCP-type leukemia cells. They may provide useful models and unprecedented opportunities for analyzing the multitude of biological aspects of normal and neoplastic B-lymphocytes and their precursors.     

Acute Lymphoblastic Leukaemia in Infancy: Clinical and Biological Features

The clinical and biological features of nineteen unselected cases of infant acute lymphoblastic leukaemia (ALL) are presented. All infants, eight male and eleven female. were 1 year of age or less at presentation of their disease and all showed the typical clinical features of ALL in infancy: hyperleucocytosis, organomegaly, frequent central nervous system (CNS) disease and one infant had cutaneous lesions. In the 17 cases which were successfully karyotyped, translocation of chromosome 11 involving band q23 were demonstrated in 16 cases (94%).

The majority fell into the B precursor, or “null” ALL, category (CD10 negative, but CD19 and HLA DR positive), two cases, however, showed concomitant expression of B cell and myeloid (CD13 and CD33) markers. Two cases were CD10, HLA DR and CD19 positive and in one of these as well as one of the CD10 negative cases, 25-30%, of the blast cells expressed cytoplasmic Ig, M, a characteristic of pre-B cells. All cases, irrespective of phenotype or karyotype, showed rearrangement of the immunoglobulin heavy chain genes (IgH), but no light chain rearrangement. Together with the expression of B cell associated markers this, provided good evidence of their B lineage. No rearrangements of the β or γ chains of the T cell receptor complex (TcR) were seen in any case, nor was any rearrangement of the insulin receptor, which maps to band 19p13, seen in the cases with the t(11;19) translocation. The prognosis was uniformly poor. The majority of cases relapsed rapidly in the bone marrow whilst on therapy and within the first six months after diagnosis. Within the group of 19 infants studied, those with the t(11;19) translocation appeared to form a subgroup with the worst prognostic features (WBC averaging 591 × 10⁹/1, profound organomegaly and proven CNS disease in 4/7). 4/7 of this subgroup received no treatment and of the three who were treated, two relapsed within the first 11 months of treatment.     

Karyotypic patterns in acute mixed lineage leukemia

We performed cytogenetic and immunologic studies of blast cells from 13 children with acute mixed lineage leukemia (AMLL) to discern patterns of chromosome alteration and antigen expression that would assist in classification of this disease entity. Six patients with 11q23 translocations--including four with the t(11;19), one with the t(9;11), and one with the t(1;11)--were characterized by a young age and hyperleukocytosis. A B cell-associated antigen (CD19) and HLA-DR antigens were expressed by blast cells from all patients; only one case was positive for the common acute lymphocytic leukemia antigen (CALLA, CD10). A myeloid-associated antigen (CD13) was expressed by blast cells from one patient at diagnosis and from another at relapse; it was also expressed by cells from the remaining four patients after brief in vitro culture without addition of differentiating agents. Four patients with t(9;22)(q34;q11) were characterized by an older age and hyperleukocytosis. Each of these cases was positive for CD13, CD19, and HLA-DR, and three were positive for CALLA. The 11q23 translocation was associated with CALLA- ALL marked by a myeloid phenotype, whereas the t(9;22) occurred in cases of acute myeloid leukemia with a CALLA+ lymphoid phenotype. One case had a 7q35-q36 translocation, which involves the region of the T cell receptor beta-chain gene. Our results suggest that karyotypic alterations can be used to refine the classification of AMLL.