Common acute lymphoplastic leukemia antigen (CALLA) and intestinal metaplasia

Intestinal metaplasia (IM) foci in 19 antral and 14 fundal gastric biopsies from patients with chronic atrophic gastritis were studied immunohistochemically for the presence of CALLA antigen. In only 2 cases were metaplastic glands completely negative, in 14 cases they were all positive, and in 17 cases variable proportions of CALLA positive and negative metaplastic glands were present. Complete IM seems to be less frequent than the incomplete type when the presence of CALLA is taken in consideration. CALLA is obviously a much better marker for complete or incomplete small IM. The possible importance of the presence of CALLA in IM foci for the future development of gastric cancer is discussed.     

Organization of the gene encoding common acute lymphoblastic leukemia antigen (neutral endopeptidase 24.11): multiple miniexons and separate 5'' untranslated regions.

The common acute lymphoblastic leukemia antigen (CALLA) is a 749-amino acid type II integral membrane protein that has been identified recently as the neutral endopeptidase 24.11 [NEP (EC 3.4.24.11)]. Herein, we characterize the organization of the human CALLA/NEP gene and show that it spans more than 80 kilobases (kb) and is composed of 24 exons. Exons 1 and 2 encode 5' untranslated sequences; exon 3 [170 base pairs (bp)] encodes the initiation codon and transmembrane and cytoplasmic domain; 20 short exons (exons 4-23), ranging in size from 36 to 162 bp, encode most of the extracellular portion of the enzyme; and exon 24 (approximately 3400 bp) encodes the COOH-terminal 32 amino acids of the protein and contains the entire 3' untranslated region (UTR). Of note, the pentapeptide sequence (His-Glu-Ile-Thr-His) associated with metalloprotease zinc binding and substrate catalysis is encoded within a single exon (exon 19). Three types of CALLA/NEP cDNAs have been identified: these clones contain 5' UTR sequences differing from one another upstream of exon 3. These human 5' sequences are homologous to those found in rat brain and rabbit kidney NEP cDNAs. The three human CALLA cDNA types result from alternative splicing of exons 1, 2a, or 2b to the common exon 3. Moreover, exons 2a and 2b share the same 5' sequence but differ from each other by the use of two distinct donor splice sites 171 bp apart in the gene. The substantial conservation of 5' untranslated sequences among species and the existence of 5' alternative splicing suggest that CALLA gene expression may be differentially controlled in a tissue-specific and/or developmentally regulated fashion.     

Expression of common acute lymphoblastic leukemia antigen (CALLA) by lymphomas of B-cell and T-cell lineage

Previous studies have demonstrated that the common acute lymphoblastic leukemia antigen (CALLA) is expressed by leukemic cells from approximately 80% of patients with non-T-cell ALL and 30%-50% of patients with chronic myelocytic leukemia in blast crisis. A small number of normal bone marrow and fetal liver cells also express CALLA, but the functional role of this molecule is unknown. In the present study, we have used a monoclonal antibody (J5) specific for CALLA to study the expression of this antigen in non-Hodgkin's lymphomas. Within the B-cell lymphomas, it was found the CALLA was expressed by almost all Burkitt's and nodular poorly differentiated lymphocytic lymphomas. Within the T-cell lymphomas, CALLA was expressed in 40% of patients with lymphoblastic lymphoma. Three of 3 Burkitt's lymphoma cell lines and three of eight T-lymphoblast cell lines were also found to express CALLA. Normal spleen, lymph node, and thymus cells were not reactive with J5 antibody. These findings indicate that expression of CALLA is not limited to relatively undifferentiated leukemic lymphoblasts but also occurs in more differentiated lymphoid malignancies. However, normal differentiated lymphoid cells in lymph node, spleen, and thymus, which have a phenotype similar to that of lymphoma cells, do not appear to express CALLA.     

Clinical features of common acute lymphoblastic leukemia antigen (CALLA)-positive myeloma: Report of four cases

Summary Four patients with common acute lymphoblastic leukemia antigen (CALLA)-positive myeloma are presented. The subclasses of monoclonal protein were IgD (1 case), IgA (1 case), and IgA (2 cases). Bence Jones proteinuria was seen in all cases. The clinical stages were determined as IIA (2 cases) and IIIA (2 cases). All patients died with a median survival time after diagnosis of 62 days due to rapid development of renal failure (3 cases), and renal insufficiency and pneumonia (1 case). According to light microscopic evaluation, these myelomas corresponded to plasmablastic (1 case), immature (2 cases), and intermediate (1 case) types. Both CALLA and a cytoplasmic immunoglobulin identical with the serum monoclonal protein were simultaneously detected in single cells from all cases using immunofluorescent double labeling. These findings suggest that CALLA-positive and plasmablastic myelomas constitute clinically a subgroup characterized by extremely poor survival but they represent cytologically different subcategories.     

Characterization of murine monoclonal antibodies against the common acute leukemia antigen (CALLA)

This study presents two murine monoclonal antibodies which react with the Common Acute Lymphoblastic Leukemia Antigen (CALLA). Both antibodies can be used for the diagnosis of common ALL (cALL). Indirect immunofluorescence studies (FACS-analysis) showed that the antibodies react with granulocytes and different human cell lines (Nalm-6, Reh, Raji, CCRF-CEM). The monoclonal antibodies BL-CALLA/1 and BL-CALLA/2 identify a single polypeptide chain of 95 kD. Both antibodies recognize the same or closely related epitope of the CALLA-molecule and are able to modulate in vitro the antigen on the CALLA-positive cell line Reh.     

CD10 (CALLA)/neutral endopeptidase 24.11 modulates inflammatory peptide-induced changes in neutrophil morphology, migration, and adhesion proteins and is itself regulated by neutrophil activation.

The common acute lymphoblastic leukemia antigen (CALLA, CD10), which is expressed on early lymphoid progenitors and neutrophils, is the zinc metalloprotease, neutral endopeptidase 24.11 (NEP, "enkephalinase"). The CD10 cell surface enzyme is known to hydrolyze a variety of biologically active peptides including met-enkephalin, formyl-met-leu-phe (f-MLP), and substance P. These three CD10/NEP substrates induce the migration and aggregation of neutrophils, suggesting that each of the peptides can function as a mediator of neutrophil inflammatory responses. Recently, inhibition of CD10/NEP was found to reduce the concentration of metenkephalin needed to activate human and invertebrate granulocytes by several orders of magnitude. Herein we show that f-MLP and substance P induce rapid changes in neutrophil morphology, migration, and adhesion molecule expression, including upregulation of Mo1 (CD11b/CD18) and shedding of LAM-1 (also known as LECAM-1, Leu8, or TQ-1, the human homologue of murine gp100MEL14). Importantly, these coordinated changes are potentiated by inhibition of cell surface CD10/NEP enzymatic activity. Neutrophil cell surface CD10/NEP enzymatic activity is also shown to be regulated by the activation state of the cell during the time period in which the enzyme has its most pronounced effects. These results suggest that in neutrophils, CD10/NEP functions to control responsiveness to multiple inflammatory peptides.     

Cultured marrow stromal cells express common acute lymphoblastic leukaemia antigen (CALLA): implications for marrow transplantation

This study demonstrates the presence of an antigenic determinant associated with the common acute lymphoblastic leukaemia antigen (CALLA), and presumably CALLA itself, on stromal cells in normal human long-term marrow cultures by using two monoclonal anti-CALLA antibodies, J-5 and 24.1. Treatment of cultured stromal cells with antibody and complement resulted in the loss of most flat angulated cells and many of the fat-containing cells. However, long-term cultures were generated with cytotoxic antibody-treated marrow buffy coat cells, and the stromal cells in these cultures were also CALLA-positive. We conclude that CALLA-bearing stromal cells arise from CALLA-negative progenitors. CALLA therefore could be either a differentiation antigen acquired on mature marrow stromal cells or may arise as a proliferation-dependent antigen. These studies suggest that the generation of long-term cultures from cytotoxic antibody-treated marrow may be an appropriate in vitro model for the functional assessment of such marrow prior to its use in autologous transplantation.     

Decreased expression of the common acute lymphoblastic leukaemia antigen (CALLA/CD10) on neutrophils from patients with thermal injury

Summary. The common acute lymphoblastic leukaemia antigen (CALLA/CD10) is a normal component of the circulating neutrophil cell surface membrane. In order to examine the potential functional significance of CALLA/CD10 we analysed the expression of this molecule on neutrophils isolated from thermal injury patients, since these patients have a well-documented constellation of neutrophil defects affecting their microbicidal functions. Expression of neutrophil CALLA/CD10 was monitored by indirect immunofluorescence and flow cytometry. We observed that CALLA/CD10 expression was quantitatively reduced on burn patient neutrophils, compared to healthy donors ( P < 0.001). In contrast, burn patient neutrophils expressed normal levels of class I HLA molecules and the C3bi receptor. Reduced expression of CALLA/CD10 was not associated with neutrophil activation or exposure to plasma 'factor(s)' in vivo . Analysis of normal bone marrow neutrophils by cell sorting indicated that expression of CALLA/CD10 occurs late in neutrophil maturation, since 25% of polymorphonucleated bone marrow neutrophils did not express cell surface CALLA/CD10. Attempts to examine the chemotactic responses of CALLA/CD10 positive and negative neutrophils from burn patients were hampered by previous exposure of these cells to chemoattractants in vivo . Collectively, our findings suggest that burn patient peripheral blood neutrophils may be deficient in CALLA/CD10 due to insufficient maturation time in the bone marrow following thermal injury.     

p16(INK4a) immunocytochemical analysis is an independent prognostic factor in childhood acute lymphoblastic leukemia

We investigated the prognostic value of p16(INK4a) immunocytochemistry (ICC) analysis in 126 cases of newly diagnosed childhood acute lymphoblastic leukemia (ALL). The incidence of negative p16(INK4a) ICC was 38.1% and was more frequent in T-lineage ALL. Overall survival (OS) and event-free survival (EFS) were significantly higher in patients with positive p16(INK4a) ICC than in patients with negative ICC (6 years OS, 90% versus 63%, P =.0014; 6 years EFS, 77.8% versus 55%, P =.0033). The p16(INK4a) ICC remained a significant prognostic factor within the subgroup of B-precursor ALL. Multivariate analysis showed that negative p16(INK4a) ICC was an independent prognostic factor for OS (relative risk [RR], 3.38; P =.02) and EFS (RR, 2.49; P =.018). Sequential study showed that p16(INK4a) expression remained stable during first relapse in most patients. These findings indicate that p16(INK4a) ICC is an independent factor of outcome in childhood ALL.     

Bortezomib with chemotherapy is highly active in advanced B-precursor acute lymphoblastic leukemia: Therapeutic Advances in Childhood Leukemia & Lymphoma (TACL) Study

Therapy of relapsed pediatric acute lymphoblastic leukemia (ALL) is hampered by low remission rates and high toxicity, especially in second and subsequent relapses. Our phase 1 study, T2005-003, showed that the combination of bortezomib with vincristine, dexamethasone, pegylated asparaginase, and doxorubicin had acceptable toxicity. We report the phase 2 expansion of this combination in patients with relapsed ALL who failed 2-3 previous regimens. Twenty-two patients with relapsed ALL were treated with bortezomib combined with this regimen; their ages ranged from 1 to 22 years, and they had either B-precursor ALL (n = 20) or T-cell ALL (n = 2). Grade 3 peripheral neuropathy developed in 2 (9%) patients. After 3 patients died from bacterial infections, treatment with vancomycin, levofloxacin, and voriconazole prophylaxis resulted in no further infectious mortality in the last 6 patients. Fourteen patients achieved complete remission (CR), and 2 achieved CR without platelet recovery, for an overall 73% response rate, meeting predefined criteria allowing for early closure. B-precursor patients faired best, with 16 of 20 (80%) CR + CR without platelet recovery, whereas the 2 patients with T-cell ALL did not respond. Thus, this combination of bortezomib with chemotherapy is active in B-precursor ALL, and prophylactic antibiotics may be useful in reducing mortality. Bortezomib merits further evaluation in combination therapy in pediatric B-precursor ALL. This study is registered at http://www.clinicaltrials.gov as NCT00440726.     

Phenotypic analysis of acute lymphoblastic leukemia (ALL) cells which are classified as non-T non-B and negative for common ALL antigen

When phenotypic marker analysis of acute lymphoblastic leukemia (ALL) cells (102 cases) was performed, a group of ALL cells (15 cases) classified as non-T non-B, and negative for common-ALL antigen (CALLA) was characterized in a focused manner. "Non-T non-B" was defined as negative for T cell properties such as E-rosetting or reactivity with anti-human T-cell monoclonal antibodies (T101, WT1), and absence of any B-cell characteristics (cell surface and/or cytoplasmic immunoglobulin and reactivity with B1 monoclonal antibody). Despite their marked heterogeneity, CALLA(-) non-T non-B ALL cells revealed three different phenotypic patterns in terms of presence of terminal deoxynucleotidyl transferase (TdT) and of reactivity with antimyeloid (MCS1) or myelomonocyte (MCS2 and OKM1) monoclonal antibodies. Four of 15 cases reacted with some myeloid-specific antibodies, but were negative for TdT. Six cases had both MCS2 antigen and TdT. The remaining five cases expressed no myeloid antigens, but were positive for TdT with some exceptions. These findings showed that acute leukemias with myeloid antigens might be involved in CALLA(-) non-T non-B ALL having no relationship to the presence of TdT, and, furthermore, that the blasts with simultaneous expression of TdT and myeloid-specific antigen (MCS2) might represent an immature stage in hematopoietic differentiation closely corresponding with the bifurcation of the lymphocyte/myeloid pathway. Alternatively, only five cases remained "unclassified leukemia." We therefore think that the detailed examination of CALLA(-) non-T non-B ALL cells using myeloid specific antibodies is helpful in clarifying the characteristics of myeloid precursors and the common bipotential stem cell of lymphoid and myeloid progenitors.     

Serum lactic dehydrogenase (LDH) levels in acute leukemia: marked elevations in lymphoblastic leukemia

Serum total lactic dehydrogenase (LDH) levels were examined in 42 patients with acute leukemia, 9 patients with chronic myeloid leukemia, 6 of them in blastic crisis, and 53 patients with lymphoma and other lymphoproliferative disorders. The mean range of serum LDH leveles in Hodgkin's and non-Hodgkin's lymphoma was 402 +/- 210 IU/liter and 313 +/- 113 IU/liter, while that of patients with nonmalignant disorders was 308 +/- 74 IU/liter. In acute nonlymphoblastic leukemia (ANLL), the range was 126-684 IU/liter (mean value 413 +/- 146 IU/liter). In 6 of the patients (11.3%) with lymphoma and in 6 cases (26.8%) with ANLL, the LDH levels were above 500 IU/liter. None of these patients had levels over 900 IU/liter. Patients with acute lymphoblastic leukemia (ALL) had a range of 402-3582 IU/liter (mean value of 1669 + 1038 IU/liter). In 15 of the 19 patients (78.9%) with ALL, serum LDH values were above 900 IU/liter. In addition, 3 patients with chronic myeloid leukemia (CLM) in blastic crisis had levels of 970-1940 IU/liter. One of these 3 patients had lymphoblastic crisis, while the second case responded clinically to vincristine and prednisone, but was not regarded as ALL. The differences in serum LDH levels between ALL and ANLL are statisticaly significant (p < 0.001). It appears that markedly elevated serum LDH levels in acute leukemia are suggestive of ALL, and that in individual patients, the LDH levels were correlated with the number of blasts during remission and relapse.     

Characterization of non-human primate antisera to acute lymphoblastic leukemia (ALL): evidence for unique antigen(s) on childhood ALL of "T" phenotype

A non-human primate antiserum was prepared to acute lymphoblastic leukemia of T-cell phenotype (T-ALL) and, after absorptions with normal blood elements, reacted by immunofluorescence and microcytotoxicity to all the T-ALL tested. In addition, the antiserum reacted with cells from about 70% of the common ALL studied and immunoprecipitated the common ALL antigen of 100,000 daltons. However, when the anti-T-ALL serum was absorbed with with lymphoblasts from common ALL, it failed to react with common ALL lymphoblasts, yet reacted significantly with cells from patients with T-ALL phenotype and defined a 100,000-dalton membrane component not found on common ALL lymphoblasts. In addition, sequential immunoprecipitation of 125I-labeled T-ALL membranes by anti- common-ALL serum followed by anti-T-ALL serum detected the T-ALL membrane component of 100,000 daltons that was not found on common ALL. Thus, our results demonstrate the presence of of a unique human T-ALL antigen present on all T-ALL distinct from the common ALL antigen.     

A comprehensive genetic classification of adult acute lymphoblastic leukemia (ALL): analysis of the GIMEMA 0496 protocol

The Gruppo Italiano Malattie Ematologiche dell'Adulto (GIMEMA) 0496 protocol, through the central handling of bone marrow samples at presentation, allowed us to combine cytogenetic and molecular information on a large series of adults with acute lymphoblastic leukemia (ALL) treated homogeneously, enabling us to define as broadly as possible their genetic profile and to determine the impact on outcome of the cytogenetic-molecular signature. Of 414 patients centrally processed, 325 were considered for the categorization into the following cytogenetic-molecular subgroups: normal, t(9;22)/BCR-ABL, t(4;11)/MLL-AF4, t(1;19)/E2A-PBX1, 9p/p15-p16 deletions, 6q deletions, miscellaneous structural abnormalities, and hyperdiploid. The inclusion into each subgroup was based on a hierarchical approach: molecular abnormalities with adverse prognosis had precedence over karyotypic changes with less-defined prognosis and the latter over ploidy. Patients without abnormalities and those with isolated 9p/p15-p16 deletions showed a relatively favorable outcome (median disease-free survival [DFS], > 3 years). The t(9;22)/BCR-ABL, t(4;11)/MLL-AF4, t(1; 19)/E2A-PBX1 defined a group with dismal prognosis (median DFS, 7 months), whereas 6q deletions, miscellaneous aberrations, and hyperdiploidy predicted an intermediate prognosis (median DFS, 19 months). This study highlights the importance of a combined cytogenetic-molecular profiling of adult ALL at presentation as a critical independent determinant of their outcome, providing further evidence of the necessity of a risk-adapted therapeutic algorithm for an optimal management of these patients.