ALBERT

Description: Pretreatment blast cells from 739 adults with acute lymphoblastic leukemia (ALL) were immunophenotyped as part of a prospective treatment protocol study. Among 192 patients (26%) with T lineage ALL, 47 (6%; 24% of T lineage ALL) had lymphoblasts without sheep erythrocyte rosette formation, but with pan-T antigen CD7 on the membrane and intracellular CD3 proteins mostly in perinuclear accumulation. The T- cell surface antigens CD5 and/or CD2 and focal acid phosphatase were additional markers of this subgroup traditionally called pre-T ALL, whereas thymocyte antigen CD1 as well as CD4 and CD8 antigens were not expressed. Hematopoietic progenitor cell markers, namely terminal deoxynucleotidyl transferase (TdT), and in part common ALL antigen (CD10), HLA-DR antigens, and/or My-10 (CD34), a unique antigen of marrow cells absent in thymus cells, further characterized this immature T-ALL form of putative prothymocytic phenotype (CD7+/intracellular CD3+/TdT+/My-10+/-/HLA-DR+/-/CD10+/-). The prethymic T cell character was supported by germ-line T-cell receptor beta genes found in 21 of 36 patients analyzed. In five cases only T gamma-chain genes were rearranged. Fifteen patients, however, had rearrangements of both T beta and T gamma genes. Immunoglobulin heavy chain genes were rearranged only in two cases. Pre-T ALL differed significantly from E-rosette+ T-ALL in some presenting clinical features, namely mediastinal mass, lymphoadenopathy, and platelet count, and independently of clinical factors in prognosis (P = .02, median remission duration: 15.7 v 33.5 months, and P = .02, median survival time: 24.6 v 50.7 months). We conclude that ALL classification based solely on T- or B-cell lineage affiliation is not sufficient but needs further subdivision according to relevant maturation stages as exemplified here within the T-cell axis. The putative prethymic T cell progenitor phenotype described might help elucidate the sequence of genetic events that commit normal hematopoietic cells to the T-cell lineage.

Description: A newly recognized family of proteins that inhibit cyclin-dependent kinases (CDKs) termed cyclin-dependent kinase inhibitors (CDKI) have an important role in regulation of cell-cycle progression. A subfamily of these CDKIs (p15INK4B/MTS2, p16INK4/MTS1, and p18) have a high degree of structural and functional homology and are candidate tumor- suppressor genes. We evaluated the mutational status of the p15, p16, and p18 genes in 103 childhood acute lymphoblastic leukemia (ALL) samples and correlated these results with both their clinical data and additional results concerning their loss of heterozygosity in the region of the p15/p16 genes. Homozygous deletions of the p16 gene occurred extremely frequently in T-ALLs (17/22; 77%), and it was also frequent in precursor-B ALLs (12/81; 15%). Homozygous deletions of the p15 gene were also very frequent in T-ALLs (9/22; 41%), and it occurred in 5 of 81 (6%) precursor-B ALL samples. No deletions of p18 was found in any of the 103 ALL samples. Also, no point mutations of the p15, p16, and p18 genes were detected. We correlated p15/p16 alterations at diagnosis with their clinical characteristics as compared with 2,927 other patients treated similarly. Those with p15/p16 alterations were older; had higher white blood cell counts, often with T-cell ALL phenotype; and more frequently had a mediastinal mass at presentation; but they had the same nonremission, relapse, and survival rates at 5 years as did those patients whose blast cells did not have a p15/p16 deletion. To better understand the extent of alterations affecting chromosome 9p21 (location of the p15/p16 genes), loss of heterozygosity (LOH) was examined at D9S171, which is about 1 megabase proximal to the p15/p16 genes. LOH was detected in 15 of 37 (41%) informative samples. Interestingly, of the 24 informative samples that had no detectable alteration of the p15/p16 genes, 7 samples (29%) had LOH at D9S171. In summary, we show in a very large study that p15 and p16, but not p18, CDKI genes are very frequently altered in ALL; those with p15/p16 alterations are more frequently older children, have higher white blood cells at presentation, and often have a T-cell ALL phenotype. The LOH analysis suggests that another tumor-suppressor gene important in ALL also is present on chromosome 9p21.

Description: A total of 68 adult patients with B-cell acute lymphoblastic leukemia (B-ALL) were treated in three consecutive adult multicenter ALL studies. The diagnosis of B-ALL was confirmed by L3 morphology and/or by surface immunoglobulin (Slg) expression with 〉 25% blast cell infiltration in the bone marrow (BM). They were characterized by male predominance (78%) and a median age of 34 years (15 to 65 y) with only 9% adolescents (15 to 20 y), but 28% elderly patients (50 to 65 y). The patients received either a conventional (N = 9) ALL treatment regimen (ALL study 01/81) or protocols adapted from childhood B-ALL with six short, intensive 5-day cycles, alternately A and B. In study B-NHL83 (N = 24) cycle A consisted of fractionated doses of cyclophosphamide 200 mg/m2 for 5 days, intermediate-dose methotrexate (IdM) 500 mg/m2 (24 hours), in addition to cytarabine (AraC), teniposide (VM26) and prednisone. Cycle B was similar except that AraC and VM26 were replaced by doxorubicin. Major changes in study B-NHL86 (N = 35) were replacement of cyclophosphamide by ifosphamide 800 mg/m2 for 5 days, an increase of IdM to high-dose, 1,500 mg/m2 (HdM) and the addition of vincristine. A cytoreductive pretreatment with cyclophosphamide 200 mg/m2, and prednisone 60 mg/m2, each for 5 days was recommended in study B-NHL83 for patients with high white blood cell (WBC) count (e 2,500/m2) or large tumor burden and was obligatory for all patients in study B-NHL86. Central nervous system (CNS) prophylaxis/treatment consisted of intrathecal methotrexate (MTX) therapy, later extended to the triple combination of MTX, AraC, and dexamethasone, and a CNS irradiation (24 Gy) after the second cycle. Compared with the ALL 01/81 study where all the patients died, results obtained with the pediatric protocols B-NHL83 and B-NHL86 were greatly improved. The complete remission (CR) rates increased from 44% to 63% and 74%, the probability of leukemia free survival (LFS) from 0% to 50% and 71% (P = .04), and the overall survival rates from 0% to 49% and 51% (P = .001). Toxicity, mostly hematotoxicity and mucositis, was severe but manageable. In both studies B-NHL83 and B-NHL86, almost all relapses occurred within 1 year. The time to relapse was different for BM, 92 days, and for isolated CNS and combined BM and CNS relapses, 190 days (P = .08). The overall CNS relapses changed from 50% to 57% and 17%, most probably attributable to the high-dose MTX and the triple intrathecal therapy. LFS in studies B-NHL83 and B-NHL86 was significantly influenced by the initial WBC count 〈 or 〉 50,000/microL, LFS 71% versus 29% (P = .003) and hemoglobin value 〉 or 〈 8 g/dL, LFS 67% versus 27% (P = .02). Initial CNS involvement had no adverse impact on the outcome. Elderly B- ALL patients (〉 50 years) also benefited from this treatment with a CR rate of 56% and a LFS of 56%. It is concluded that this short intensive therapy with six cycles is effective in adult B-ALL. HdM and fractionated higher doses of cyclophosphamide or ifosphamide seem the two major components of treatment.

Description: Expression of the interleukin-2 receptor alpha-(IL-2Ralpha-), IL-2Rbeta- , and the recently identified IL-2Rgamma-chain was examined on a wide range of cells of myeloid origin including neutrophils, monocytes, normal bone marrow-derived myeloid progenitors enriched for CD34+ cells, bone marrow blasts obtained from acute myelogenous leukemia (AML) patients, and permanent myeloid leukemia cell lines by reverse transcriptase-polymerase chain reaction and surface membrane analysis using receptor chain-specific monoclonal antibodies and flow cytometry. Expression of the p75 IL-2Rbeta- and the p64 IL-2Rgamma-chain was a common finding in most of the myeloid cell samples investigated, whereas IL-2Ralpha-chain was less frequently expressed. Although the high-affinity IL-2R form (ie, the alpha+, beta+, gamma+ IL-2R form) was detectable in a small minority of primary AML samples as well as the KG- 1 cell line and IL-2 binding to these cells was sufficient to initiate signal transduction as evidenced by an increase in overall protein tyrosine phosphorylation and more specifically in tyrosine phosphorylation of the Janus kinase (JAK) 3, in none of these cell types did exposure to IL-2 affect cell growth kinetics. These results suggest that, in myeloid cells, the IL-2R may not stimulate mitogenic responses or that its components may be expressed in a combinational association with receptors for other cytokines and that IL-2Rgamma may play a regulatory role in normal and malignant myelopoiesis possibly independent from IL-2. Because recent studies by others have indicated that the IL-2Rgamma- chain may be shared by the IL-4R, the IL-7R, and most likely the IL-9R, expression of mRNA of these receptor types was also investigated in these cell samples. Surprisingly, in a substantial part of the myeloid lineage cells examined, an IL-2Rgamma+, IL-4R-, IL7R- configuration was noted that was, however, frequently associated with expression of IL-9R. Sharing of IL-9R/IL-2R components was furthermore suggested by inhibition of 125I-IL-2 binding to primary AML cells with excess of unlabeled IL-9.

Description: Immunophenotyping using a panel of 15 antibodies was performed in 267 (87%) and cytogenetic analysis in 196 (64%) of 307 children under 17 years of age enrolled in the AML-BFM-87 study. Treatment consisted of cytosine arabinoside, daunorubicin, etoposide induction and a 6-week seven-drug consolidation chemotherapy, followed by two blocks of high-dose cytosine arabinoside with or without cranial irradiation and maintenance therapy for 1 year. Five-year event-free survival for patients with immunophenotypic data was .43 +/- .03 SE. The diagnostic value of the pan-myeloid reagents CD13, CD33, and CDw65 for the recognition of childhood acute myeloid leukemia (AML) was high with a sensitivity of 98% (positivity of at least one of these antigens), whereas, with the exception of CD41 for French American British (FAB) subtype M7, the expression of single cell-surface antigens showed no correlation with morphologic or cytogenetic subgroups. On the other hand, characteristic subgroups of AML defined by morphologic features and karyotypes could be described by low or high rates of surface antigen expression compared with those of other patients. These immunophenotypic features most probably associated with specific entities include expression of CD34 or CD13 and absence of CD14 or CD4 in M2 with Auer rods/t(8;21); absence of HLA-DR, CD34, and CD14, but expression of CD33 in M3/t(15;17); positivity of either CD34 or CD13 and either CD14 or CD2 for M4Eo/inv(16); and absence of either CD34 or CD13 and expression of either CD33 or CDw65 and either CD15 or CD4 for M5/t(9;11). In FAB M0, negativity of one or two of the three panmyeloid-associated markers (CD13/33/w65) was common; and cytogenetic results frequently showed random abnormalities. Expression of lymphoid-, progenitor- and most myeloid-associated antigens had no influence on the prognosis, whereas the outcome was significantly better for children with M2 with Auer rods, M3, or M4Eo or for those with the associated karyotypes t(8;21);t(15;17) and inv(16) than for other patients.

Description: In a clinical phase I/II study, high-dose cytosine arabinoside and mitoxantrone (HAM) were given in combination to 40 patients with refractory acute myeloid leukemia. All patients had received a 9-day combination of thioguanine, Ara-C, and daunorubicin (TAD-9) as standardized first-line treatment. Refractoriness was defined as (a) nonresponse against two TAD-9 induction cycles, (b) early relapse within the first 6 months on monthly maintenance or after TAD-9 consolidation, (c) relapse after 6 months with nonresponse against one additional TAD-9 cycle, and (d) second and subsequent relapses after successful TAD-9 therapy at the preceding relapse. Therapy consisted of HD-Ara-C 3 g/m2 every 12 hours on days 1 through 4; mitoxantrone was started at 12 mg/m2/day on days 3, 4, and 5 and was escalated to 4 and 5 doses of 10 mg/m2/day on days 2 through 5 and 2 through 6. Of the 40 patients, 21 achieved a complete remission (53%), 1 patient had a partial remission, and 5 patients were nonresponders. Thirteen patients died in aplasia due to infections (n = 11), pericardiac effusion, or acute cardiomyopathy. Nonhematologic side effects consisted predominantly of nausea and vomiting, mucositis, and diarrhea. Central nervous system (CNS) symptoms were observed during six treatment courses. Recovery of blood counts occurred at a median of 27 days from the onset of treatment; the median time to complete remission was 36 days. Two of the 21 responders underwent successful bone marrow transplantations. The median remission duration for the remaining 19 patients is 4.5 months, and the median survival time is 9 months. These data emphasize that HAM has high antileukemic activity in refractory AML and strongly suggest starting the combination at earlier stages in AML therapy.

Description: We used the polymerase chain reaction (PCR) to detect ALL1-AF4 rearrangements, the molecular hallmark of t(4;11) in a series of 46 pre- pre-B (CD19+, CD24+, CD10/CD20/cylgM/sIgM-) acute lymphoblastic leukemias (ALL). Eighteen patients (39%) exhibited fusion transcripts including 4 of 12 children and 14 of 34 adults. This genetic defect was associated with hyperleukocytosis (median leukocyte count 176 x 10(9)/L) and expression of myeloid-associated antigens (CDw65+). In contrast, only two patients from a group of 67 common (CD19/CD10+, cylgM/sIgM-) and pre-B ALLs (CD19/cylgM+, CD10 +/-, sIgM-) showed ALL1- AF4 mRNA. All PCR-positive cases showed multiple amplification products representing alternative splicing events. Moreover, reciprocal der (4)- derived AF4-ALL1 transcripts were observed in 65% of the cases analyzed. Eight of the 18 pre-pre-B ALL patients with an ALL1-AF4 recombination are currently in complete continuous remission for up to 54 months (median, 26 months). Twelve remission samples were available from seven cases, and all of them lacked evidence of minimal residual disease. Overall this study documents a similarly high incidence of ALL1-AF4 recombinations in children (infants excluded) and adults with pre-pre-B ALL and demonstrates the decline of the leukemic cell clone below the detection level of PCR in a remarkable proportion of patients under intense treatment protocols.

Description: Recently G alpha 16, a new guanosine triphosphate (GTP) binding protein alpha subunit has been described to be specifically expressed in human hematopoietic cells. Expression of G alpha 16 was observed in human cell lines of myelomonocytic and T-lymphocytic origin, but not in human B-cell lines Raji and IM9. We studied the expression of G alpha 16 in human B cells corresponding to different stages of B-cell differentiation by means of reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. The human Burkitt's lymphoma cell lines Raji, Ramos, BJAB, the lymphoblastoid cell line SKW6.4, and the plasmocytoma cell line U266 were devoid of G alpha 16. In contrast, G alpha 16 was detected in the human progenitor B cell lines Reh and Nalm-6. Using the mu+, k-cell line BLIN-1 (pre-B cell phenotype) and its derived subclone 1E8 (surface mu+, k+; B-cell phenotype) G alpha 16 expression was found to disappear on transition from pre-B to B-cell differentiation stage. The analysis of a broad panel of human neoplastic B lymphocytes ranging from progenitor B-acute lymphatic leukemia (pre-pre-B-ALL), common acute leukemias (cALL), pre-B-ALL, mature B-ALL to low grade B-cell lymphoma (chronic lymphocytic leukemia of B-cell type, leukemic centrocytic non-Hodgkins lymphoma [NHL], hairy cell leukemia) showed that G alpha 16 expression is limited to progenitor and pre-B-ALL cells. Therefore, we conclude that within B-cell differentiation, G alpha 16 is expressed solely during early B cell ontogeny and downregulated during differentiation. Thus, G alpha 16 might be an important regulator involved in signaling processes in progenitor B cells.

Description: In trial ALL-BFM 86, the largest multicenter trial of the Berlin- Frankfurt-Munster (BFM) study group for childhood acute lymphoblastic leukemia (ALL), treatment response was used as an overriding stratification factor for the first time. In the previous trial ALL-BFM 83, the in vivo response to initial prednisone treatment was evaluated prospectively. A blast cell count of 〉 or = 1,000/microL peripheral blood after a 7-day exposure to prednisone and one intrathecal dose of methotrexate (MTX) identified 10% of the patients as having a significantly worse prognosis. In trial ALL-BFM 86 patients with 〉 or = 1,000/microL blood blasts on day 8 were included in an experimental branch EG. Patients with 〈 1,000/microL blood blasts on day 8 were stratified by their leukemic cell burden into two branches, Standard Risk Group (SRG) and Risk Group (RG). SRG patients received an eight- drug induction followed by consolidation protocol M (6-mercaptopurine, high-dose [HD] MTX 4 x 5 g/m2) and maintenance. RG patients were treated with an additional eight-drug reinduction element. For EG patients protocol M was replaced by protocol E (prednisone, HD-MTX, HD- cytarabine, ifosfamide, mitoxantrone). All patients received intrathecal MTX therapy; only those of branches RG and EG received cranial irradiation. In branch RG, patients were randomized to receive or not to receive late intensification (prednisone, vindesine, teniposide, ifosfamide, HD-cytarabine) in the 13th month. During the trial reinduction therapy was introduced in branch SRG, because in the follow-up of trial ALL-BFM 83 the randomized low-risk patients receiving reinduction did significantly better. Nine hundred ninety- eight evaluable patients were enrolled, 28.6% in SRG, 61.1% in RG, 10.3% in EG. At a median follow-up of 5.0 (range 3.4 to 6.9) years, the estimated 6-year event-free survival was 72% +/- 2% for the study population, 58% +/- 5% in branch SRG for the first 110 patients without reinduction therapy, 87% +/- 3% for the next 175 patients with reinduction therapy, 75% +/- 2% in branch RG, and 48% +/- 5% in branch EG. Late intensification did not significantly affect treatment outcome of RG patients; however, only 23% of the eligible patients were randomized. Prednisone poor response remained a negative prognostic parameter despite intensified therapy. The results confirmed the benefit of intensive reinduction therapy even for low-risk patients. The strategy of induction, consolidation, and intensive reinduction may offer roughly 75% of unselected childhood ALL patients the chance for an event-free survival.

Description: T-cell receptor (TCR) delta gene rearrangements are observed in more than 80% of acute lymphoblastic leukemia (ALL) patients. Moreover, a preferential usage of specific genetic elements has been shown in different ALL subtypes: V delta 1 DJ delta 1 rearrangements predominate in T-ALL, while most B-precursor ALLs show a recombination of V delta 2 to D delta 3. Recently we have proposed a strategy for the detection of minimal residual disease (MRD) based on the isolation of clonospecific probes following the in vitro amplification of V delta 1 DJ delta 1 junctions by polymerase chain reaction (PCR) and now have adapted this method to the preparation of specific V delta 2 D delta 3 fragments. In the present study, clonospecific probes were generated from 11 T-ALL and 16 cALL patients (21 children, 6 adults). The sensitivity of these 27 probes in detecting residual leukemia cells varied between 10(-4) to 10(-6) as determined by semiquantitative evaluation of dilution experiments. PCR analysis of 55 bone marrow (BM) and peripheral blood (PB) samples obtained from the 27 patients during complete clinical remission showed the following results: (1) Evidence for MRD was obtained in the BM of all patients (eight of eight) investigated 2 to 6 months after remission induction and also in 6 of 11 cases on maintenance therapy 7 to 19 months after diagnosis. (2) In contrast, all patients but one (10 of 11) analyzed 6 to 41 months after the termination of treatment lacked apparent evidence for leukemia DNA; the exception was a girl exhibiting 10(-4) to 10(-5) residual cells in her PB 5.5 years after diagnosis. (3) Longitudinal analysis in nine patients disclosed marked individual differences in the intervals between achievement of clinical remission and complete eradication of the leukemia cell clone. (4) Differences in the duration of MRD were not associated with distinct clinical-hematologic features. (5) Detection of residual disease by PCR proceeded clinical relapse in two cases.