Traumatic lumbar puncture at diagnosis adversely affects outcome in childhood acute lymphoblastic leukemia

The effect of traumatic lumbar puncture at the time of initial diagnostic workup on treatment outcome in children with newly diagnosed acute lymphoblastic leukemia (ALL) was investigated. The findings of the first 2 lumbar punctures performed on 546 patients with newly diagnosed ALL treated on 2 consecutive front-line studies (1984-1991) at St Jude Children's Research Hospital were retrospectively reviewed. Lumbar punctures were performed at the time of diagnosis and again for the instillation of first intrathecal chemotherapy. The event-free survival (EFS) experience for patients with 1 cerebrospinal fluid (CSF) sample contaminated with blast cells was worse than that for patients with no contaminated CSF samples (P =.026); that of patients with 2 consecutive contaminated CSF samples was particularly poor (5-year EFS = 46 +/- 9%). In a Cox multiple regression analysis, the strongest prognostic indicator was 2 consecutive contaminated CSF samples, with a hazard ratio of 2.39 (95% confidence interval, 1. 36-4.20). These data indicate that contamination of CSF with circulating leukemic blast cells during diagnostic lumbar puncture can adversely affect the treatment outcome of children with ALL and is an indication to intensify intrathecal therapy.     

Vincristine-induced apoptosis in vivo in peripheral blood mononuclear cells of children with acute lymphoblastic leukaemia (ALL)

We conducted a study to demonstrate vincristine-induced apoptosis in vivo in peripheral blood mononuclear cells of children with newly diagnosed acute lymphoblastic leukaemia (ALL). In five children, apoptosis was detected by terminal deoxynucleotide transferase-mediated dUTP-digoxigenin nick-end labelling (TUNEL) assay in blood samples collected during an up-front window study of vincristine monotherapy. In one patient, we found a striking increase of apoptotic cells from 2% (SEM 0.6) before to 40.7% (SEM 2.9) 3 h after vincristine injection. In the other patients, the maximum increase ranged from 0.8% to 4.3%. Wilcoxon matched pairs analysis of all patients confirmed that vincristine induces apoptosis in vivo in peripheral blood mononuclear cells in childhood ALL (P = 0.043).     

The periodic acid-Schiff reaction and prognosis in children with acute lymphoblastic leukemia.

We evaluated the intensity of the periodic acid-Schiff (PAS) stain reaction by examining 200 lymphoblasts from the initial marrow aspirate specimen of 38 children with acute lymphoblastic leukemia (ALL). The patients were separated into low, intermediate, and high groups according to mean PAS score. The groups were then compared in terms of age, sex, initial hematologic values, T- and B-lymphocyte markers, percentage of patients in remission six months after diagnosis, and percentage surviving. Significant differences were found between the low group and the other two groups with respect to sex, height of initial white blood cell (WBC) count, outlook for continued remission at six months, and overall survival (P < 0.05). The low-score patients were predominantly males, whereas the other PAS-score groups contained approximately equal numbers of males and females. The low-score patients had a higher median initial WBC than the others, but all three groups had a similar proportion of patients with initial WBC under 20,000/cu mm. Low-score patients were less likely to be in remission six months from diagnosis, and they had shorter survival than the intermediate- and high-score patients (P < 0.05). The results suggest that children with ALL whose lymphoblasts stain weakly with PAS have a worse prognosis than those with intermediate or high PAS reactivity. PAS reactivity may vary independently of the WBC at diagnosis in children with ALL, because children with a low PAS score have a poor outlook even with initial WBC under 20,000/cu mm.     

Prognostic implications of blast cell morphology in childhood acute lymphoblastic leukemia: a report from the Childrens Cancer Study Group

The Childrens Cancer Study Group (CCSG) has evaluated French-American-British (FAB) morphology in newly diagnosed children with acute lymphoblastic leukemia (ALL) since 1975. A modification of the FAB system was used in which individual lymphoblast cells were scored and designated as either L1 or L2 on the basis of distinctive morphologic characteristics. L1 ALL was defined as less than 10% L2 cells and greater than 90% L1 cells; L2 ALL was defined as greater than or equal to 10% L2 cells and less than 90% L1 cells. FAB morphology was an independent predictor of overall survival (P = 0.02) in CCSG-141 and a highly significant predictor of successful induction of complete remission and event-free survival in the CCSG-160 series (P = 0.00001). These studies involved nearly 3900 patients. Two concordance studies have been performed. In the first (1981) study, overall concordance between the FAB reference laboratory and member institutions was 76% using a two-category system (L1, non-L1), 86% for L1 cases, and 47% for non-L1 cases. In the second (1984) concordance study, the use of more stringent, semiquantitative definitions of L1 and L2 lymphoblasts did not improve overall (75%), L1 (89%), or non-L1 (46%) concordance. The results of reference laboratory classification more powerfully predicted event-free survival than did member institutions (P = 0.016 vs P = 0.125). Quality control factors (slide preparation, cellularity, staining quality, and discipline of the reviewer) did not influence concordance. These results justify the continued assignment of patients to protocols of the CCSG-100 series on the basis of the modified FAB classification. The biological significance of the FAB morphologic variants remains to be determined.     

Lack of prognostic value of the periodic acid-Schiff reaction and blast cell size in childhood acute lymphocytic leukemia.

Conflicting evidence has been published as to the prognostic significance of the periodic acid-Schiff (PAS) reaction and cell size in acute lymphocytic leukemia (ALL). Therefore, a large collaborative study was undertaken to evaluate the prognostic significance of the PAS reaction and cell size of bone marrow lymphoblasts obtained at the time of diagnosis in children with ALL. Known prognostic factors (age and white blood cell [WBC] counts) were also evaluated. Data from 80 newly diagnosed cases of ALL were analyzed. These patients were treated with similar therapy by members of the Pediatric Division of the Southwest Oncology Group. The PAS reaction was scored. Microlymphoblasts were defined as having a diameter of less than or equal to 12 micron; macrolymphoblasts, greater than 12 micron. Patients 10 years and older at the time of diagnosis had a significantly shorter duration of first remission and survival than those younger than 10 years. Those with pretreatment peripheral WBCs of less than or equal to 25,000/microliter had significantly longer duration of first remission and survival than those with a peripheral WBC greater than 25,000/microliter. There was no significant difference in duration of first remission or survival in patients having predominantly macrolymphoblastic or microlymphoblastic marrows. PAS reaction was of no value in predicting the duration of first remission or survival.     

In vitro inhibition of cytidine triphosphate synthetase activity by cyclopentenyl cytosine in paediatric acute lymphocytic leukaemia

Cytidine triphosphate (CTP) synthetase is a key enzyme for the synthesis of cytosine (deoxy)ribonucleotides, catalysing the conversion of uridine triphosphate (UTP) into CTP, and has a high activity in several malignancies. In this preclinical study, the enzyme activity and mRNA expression of the enzyme and (deoxy)ribonucleotide concentrations were analysed in leukaemic cells of 57 children suffering from acute lymphocytic leukaemia (ALL). In addition, in vitro experiments were performed with the CTP synthetase inhibitor cyclopentenyl cytosine (CPEC). A significantly higher activity of CTP synthetase (6.5 +/- 3.9 nmol CTP/mg/h) was detected in ALL cells than in lymphocytes of healthy controls (1.8 +/- 0.9 nmol CTP/mg/h, P < 0.001) that was independent of white blood cell (WBC) count, blast percentage, age, gender or type of ALL. The enzyme activity was not correlated with the CTP synthetase mRNA expression. The activity of CTP synthetase in ALL cells compared with non-malignant CD34+ bone marrow controls (5.6 +/- 2.4 nmol CTP/mg/h) was not statistically different. In vitro treatment of ALL cells with CPEC induced a dose-dependent decrease of the CTP concentration. The lowest concentration of CPEC (0.63 microM) induced a depletion of CTP of 41 +/- 20% and a depletion of dCTP of 27 +/- 21%. The degree of CTP depletion of ALL cells after treatment with CPEC was positively correlated with the activity of CTP synthetase. The inhibition of CTP synthetase in situ was confirmed by flux studies using radiolabelled uridine. From these results, it can be expected that CPEC has a cytostatic effect on lymphoblasts of children with ALL.     

Clinical importance of minimal residual disease in childhood acute lymphoblastic leukemia

By using rapid flow cytometric techniques capable of detecting one leukemic cell in 10(4) normal cells, we prospectively studied minimal residual disease (MRD) in 195 children with newly diagnosed acute lymphoblastic leukemia (ALL) in clinical remission. Bone marrow aspirates (n = 629) were collected at the end of remission induction therapy and at 3 intervals thereafter. Detectable MRD (ie, > or = 0.01% leukemic mononuclear cells) at each time point was associated with a higher relapse rate (P < .001); patients with high levels of MRD at the end of the induction phase (> or = 1%) or at week 14 of continuation therapy (> or = 0.1%) had a particularly poor outcome. The predictive strength of MRD remained significant even after adjusting for adverse presenting features, excluding patients at very high or very low risk of relapse from the analysis, and considering levels of peripheral blood lymphoblasts at day 7 and day 10 of induction therapy. The incidence of relapse among patients with MRD at the end of the induction phase was 68% +/- 16% (SE) if they remained with MRD through week 14 of continuation therapy, compared with 7% +/- 7% if MRD became undetectable (P = .035). The persistence of MRD until week 32 was highly predictive of relapse (all 4 MRD(+) patients relapsed vs 2 of the 8 who converted to undetectable MRD status; P = .021). Sequential monitoring of MRD by the method described here provides highly significant, independent prognostic information in children with ALL. Recent improvements in this flow cytometric assay have made it applicable to more than 90% of all new patients. (Blood. 2000;96:2691-2696)     

Childhood lymphoblastic leukemia with natural killer activity: establishment of the leukemia cell lines retaining the activity

Leukemic cells from a child with acute lymphoblastic leukemia (ALL) had high natural killer (NK) activity against K562 as determined by the 51Cr release assay at a 40:1 effector:target ratio: percent lysis was 76.8% (147.4% of normal lymphocyte value) and higher than that of control leukemic cells from 12 childhood ALL (0.1% +/- 0.3%). Two leukemic cell lines (SPI-801 and SPI-802) were established from the patient, and they were essentially the same as the freshly harvested leukemic cells in their morphology, cytochemistry, immunologic markers, and functions. The cultured cell lines as well as the fresh leukemic cells had receptors for sheep red blood cells, IgG-Fc, and C3. The cultured cells were OKM1+, Ia+ and asialo-GM1+, and were OKT-3-, OKT-4- , OKT-6-, OKT-8-, Leu-7-, human monocyte-, common ALL-, T cell-, surface Ig-, and cytoplasmic IgM- as determined by the immunofluorescence method. The two cell lines shared the same chromosome abnormalities. Their chromosomes were in hypotriploid region (63--73), and 6q-, 11p+, and several marker chromosomes were demonstrated. They had spontaneous cytotoxicity against K562 (percent lysis: up to 17.8% and 33.5% of normal lymphocyte value in SPI-801 and SPI-802, respectively) and Molt-3 (38.2% and 27.8% of normal lymphocyte value), but not against Raji and mitogen-induced normal lymphoblasts. Such phenotypic and functional characteristics of the fresh leukemic cells and cultured cells are virtually identical to those of NK cells, demonstrating a new phenotype of childhood ALL of NK cell origin.     

Apoptotic effects of heparin on lymphoblasts, neutrophils, and mononuclear cells: results of a preliminary in vitro study.

In this study the apoptotic effects of heparin on lymphoblasts, neutrophils, and mononuclear cells were evaluated by flow cytometry for detection of sub-G1 peak, in vitro. Ten children with acute lymphoblastic leukemia (ALL) at diagnosis (Group I), six children with ALL at relapse (Group II), and 10 healthy children (controls) were included in this study. Lymphoblasts in ALL patients, and neutrophils and mononuclear cells in controls, were incubated in increasing heparin concentrations (0, 5, 10, 20 U/ml). Flow cytometric analyses were performed at 0, 1, and 2 hours of incubation in heparin for determination of the apoptotic effects of heparin. In Group I apoptosis was detected in all different levels of heparin concentration except 0 U/ml at 0, 1, and 2 hours. The apoptotic effects of heparin on blast cells peaked at the first hour in 5-, 10-, and 20-U/ml heparin concentrations (p < 0.0001). In Group II similar findings were observed only at zero hour and apoptosis was higher than those in Group I except in 5-U/ml heparin concentration (p < 0.001). Apoptosis was found to increase with heparin levels in both groups (p < 0.02). In the control group, apoptosis was detected only at the 20-U/ml heparin concentration and only at the first and second hours. Lymphoblasts are more sensitive to apoptotic effects of heparin than either neutrophils and mononuclear cells (p < 0.004). It can be suggested that low-dose heparin may cause significant apoptosis of lymphoblasts while inducing no apoptosis on neutrophils and mononuclear cells. The findings of this preliminary study indicate that further and more comprehensive research on the apoptotic effect of heparin on lymphoblasts should be done.     

Clinical relevance of BCL-2 overexpression in childhood acute lymphoblastic leukemia

Enforced BCL-2 gene expression in leukemic cell lines suppresses apoptosis and confers resistance to anticancer drugs, but the clinical significance of increased BCL-2 protein levels in acute lymphoblastic leukemia (ALL) is unknown. Among 52 children with newly diagnosed ALL, BCL-2 expression in leukemic lymphoblasts ranged widely, from 4,464 to 59,753 molecules of equivalent soluble fluorochrome per cell (MESF), as determined by flow cytometry. The mean (+/- SD) level of MESF in 43 cases of B-lineage ALL (19,410 +/- 11,834) was higher than that detected in CD10+ B-lymphoid progenitors from normal bone marrow (450 +/- 314; P < .001), and CD19+ peripheral blood B lymphocytes (7,617 +/- 1,731; P = .02). Levels of BCL-2 in T-ALL cases (17,909 +/- 18,691) were also generally higher than those found in normal CD1a+ thymocytes (1,762 +/- 670), or in peripheral blood T lymphocytes (9,687 +/- 3,019). Although higher levels of BCL-2 corresponded to higher leukemic cell recoveries after culture in serum-free medium, they did not correlate with higher cell recoveries after culture on stromal layers, or with in vitro resistance to vincristine, dexamethasone, 6- thioguanine, cytarabine, teniposide, daunorubicin or methotrexate. BCL- 2 protein levels did not correlate with presenting clinical features. Unexpectedly, however, lower-than-median MESF values were significantly associated with the presence of chromosomal translocations (P = .010). Notably, all six cases with the Philadelphia chromosome, a known high- risk feature, had low levels of BCL-2 expression (P = .022). Higher levels of BCL-2 were not associated with poorer responses to therapy among 33 uniformly treated patients, and were not observed in three patients studied at relapse. In conclusion, increased BCL-2 expression in childhood ALL appears to enhance the ability of lymphoblasts to survive without essential trophic factors, and is inversely related to the presence of chromosomal translocations. However, it does not reflect increased disease aggressiveness or resistance to chemotherapy.     

Use of peripheral blood instead of bone marrow to monitor residual disease in children with acute lymphoblastic leukemia

In children with acute lymphoblastic leukemia (ALL), response to treatment is assessed by bone marrow aspiration. We investigated whether minimal residual disease (MRD) can be effectively monitored in peripheral blood. We used flow cytometric techniques capable of detecting 1 leukemic cell among 10 000 or more normal cells to compare MRD measurements in 718 pairs of bone marrow and peripheral blood samples collected from 226 children during treatment for newly diagnosed ALL. MRD was detected in marrow and blood in 72 pairs and in marrow but not in blood in 67 pairs; it was undetectable in the remaining 579 pairs. Remarkably, findings in marrow and blood were completely concordant in the 150 paired samples from patients with T-lineage ALL: for each of the 35 positive marrow samples, the corresponding blood sample was positive. In B-lineage ALL, however, only 37 of 104 positive marrow samples had a corresponding positive blood sample. Notably, peripheral blood MRD in these patients was associated with a very high risk for disease recurrence. The 4-year cumulative incidence of relapse in patients with B-lineage ALL was 80.0% +/- 24.9% for those who had peripheral blood MRD at the end of remission induction therapy but only 13.3% +/- 9.1% for those with MRD confined to the marrow (P =.007). These results indicate that peripheral blood may be used to monitor MRD in patients with T-lineage ALL and that peripheral blood MRD may provide strong prognostic information in patients with B-lineage ALL.     

Acute lymphoblastic leukemia with TEL-AML1 fusion has lower expression of genes involved in purine metabolism and lower de novo purine synthesis

Because de novo purine synthesis (DNPS) is a target of widely used antileukemic agents (eg, methotrexate, mercaptopurine), we determined the rate of DNPS and the expression of genes involved in purine metabolism in different subtypes of acute lymphoblastic leukemia (ALL). Among 113 children with newly diagnosed ALL, lymphoblasts with the TEL-AML1 translocation had significantly lower DNPS than all other genetic subtypes of B-lineage ALL or T-lineage ALL (352 +/- 57 versus 1001 +/- 31 or versus 1315 +/- 76 fmol/nmol/h, P <.0001). By assessing the expression of 82 genes involved in purine metabolism (KEGG pathway database) in ALL blasts from 38 patients with B-lineage ALL (14 with TEL-AML1, 24 without), we identified 16 genes that were differentially expressed in TEL-AML1-positive and TEL-AML1-negative ALL (P <.001, false discovery rate [FDR] = 5%). The pattern of expression of these 16 genes discriminated TEL-AML1-positive ALL with a true accuracy of 84% in an independent test set (n = 17, confidence interval 70% to 94%, P <.001). Western blots of selected genes documented corresponding levels of the proteins encoded. Differentially expressed genes included HPRT, IMPDH, PAICS, and GART, all of which were expressed at a significantly lower level in TEL-AML1 ALL. These findings have established that TEL-AML1 ALL has significantly lower de novo purine synthesis and differential expression of genes involved in purine metabolism.     

High glucocorticoid receptor content of leukemic blasts is a favorable prognostic factor in childhood acute lymphoblastic leukemia

We have previously shown that the number of glucocorticoid receptors (GR) per cell in malignant lymphoblasts from children with newly diagnosed pre-B- and early pre-B-cell acute lymphoblastic leukemia (ALL) has a positive correlation with the probability of successful remission induction (Quddus et al, Cancer Res, 45:6482, 1985). We report now on the long-term outcome for these patients treated on a single protocol with 3 different treatment arms, all of which included glucocorticoid pulses during maintenance therapy. GR were quantitated in leukemic cells from 546 children with ALL at the time of diagnosis. Immunophenotyping studies were performed on all specimens. Prior studies showed that in pre-B- and early pre-B-cell ALL, successful remission induction was associated with a median GR number of 9,900 sites/cell, whereas induction failure was associated with a median receptor number of 4,800 sites/cell. Long-term follow-up of these patients shows an association between higher GR number and improved prognosis. The 5-year event-free survival of 61.0% (SE 2.8%) for patients whose leukemic cells had greater than 8,000 receptors/cell and 47.3% (SE 3.3%) for those with less than 8,000 receptors/cell is significantly different (P < .001). This difference remains significant when adjusted multivariately for blast immunophenotype and clinical risk factors (P < .001) or for treatment type (P < .001). We conclude that GR number greater than 8,000 sites/leukemic cell is a favorable prognostic marker for children with acute lymphocytic leukemia. This finding offers deeper insights into molecular mechanisms of anti- leukemia therapy and suggests that manipulation of steroid receptor number might augment the antitumor response, thus opening new avenues for basic and clinical research.     

Cytogenetic features and serum lactic dehydrogenase level predict a poor treatment outcome for children with pre-B-cell leukemia

Leukemic cells from 89 (24%) of 369 children with newly diagnosed acute lymphoblastic leukemia (ALL) were found to have a pre-B immunophenotype. By comparison with blasts having the common ALL phenotype, the pre-B cells were more likely to have a DNA index less than 1.16 (P = 0.02), a pseudodiploid karyotype (P less than 0.001), and a chromosomal translocation (P = 0.001). Increased serum lactic dehydrogenase levels (P = 0.001) were also characteristic of pre-B ALL; otherwise, the clinical and laboratory features of the two groups were similar. A nonrandom chromosomal translocation, t(1;19)(q23;p13.3), was identified in blast cells from 16 (23%) of the 70 patients with pre-B ALL and adequate chromosome banding studies; different translocations were found in 11 of the remaining patients. The presence of any chromosomal translocation in the pre-B group was significantly related to a higher leukocyte count, an increased level of serum lactic dehydrogenase, an increased percentage of S-phase cells, black race, and a blast cell DNA index less than 1.16. Four presenting features were found to confer an increased risk of treatment failure among pre-B patients: pseudodiploidy, chromosomal translocation, black race, and higher serum lactic dehydrogenase level. In a multivariate analysis, pseudodiploidy emerged as the strongest factor for predicting relapse in pre-B ALL. The frequent association of chromosomal abnormalities of known adverse prognostic significance and high serum lactic dehydrogenase levels with pre-B-cell ALL explains, at least in part, the poor treatment outcome reported for children with this subtype of leukemia.     

Malignancy: The Number of Nucleoli and Main Nucleolar Types in Lymphoblasts of Children Suffering from Acute Lymphoid Leukemia

Nucleoli were studied in lymphoblasts of children (untreated with cytostatic therapy) suffering from acute lymphoblastic leukemias (ALL) by means of a simple cytochemical procedure for the demonstration of RNA to provide information on the incidence of the main nucleolar types and the number of nucleoli in these cells. The values of the nucleolar coefficient reflecting the number of nucleoli per lymphoblast ranged between 1.66 and 2.03. The slightly larger values of the nucleolar coefficient in T-ALL were not statistically significant in comparison with those in nonT-ALL. Lymphoblasts in the bone marrow as well as the peripheral blood of both nonT and T-ALL patients mostly contained, "active" (RNA transcribing) large nucleoli with a relatively uniform distribution of RNA. "Inactive" micronucleoli or particularly "resting" ring shaped nucleoli were noted less frequently in these cells. On the other hand, the larger percentage of lymphoblasts determined in specimens stained with the panoptic staining (May-Grünwald-Giemsa) in comparison with that of lymphoblasts with "active nucleoli" in specimens stained for RNA apparently indicates the absence of such nucleoli in some of these cells. These cells might represent ageing, not proliferating, cells the existence of which has been already suggested by previous studies based on a different methodical approach.     

New markers for minimal residual disease detection in acute lymphoblastic leukemia

To identify new markers for minimal residual disease (MRD) detection in acute lymphoblastic leukemia (ALL), we compared genome-wide gene expression of lymphoblasts from 270 patients with newly diagnosed childhood ALL to that of normal CD19?CD10? B-cell progenitors (n = 4). Expression of 30 genes differentially expressed by ≥ 3-fold in at least 25% of cases of ALL (or 40% of ALL subtypes) was tested by flow cytometry in 200 B-lineage ALL and 61 nonleukemic BM samples, including samples containing hematogones. Of the 30 markers, 22 (CD44, BCL2, HSPB1, CD73, CD24, CD123, CD72, CD86, CD200, CD79b, CD164, CD304, CD97, CD102, CD99, CD300a, CD130, PBX1, CTNNA1, ITGB7, CD69, CD49f) were differentially expressed in up to 81.4% of ALL cases; expression of some markers was associated with the presence of genetic abnormalities. Results of MRD detection by flow cytometry with these markers correlated well with those of molecular testing (52 follow-up samples from 18 patients); sequential studies during treatment and diagnosis-relapse comparisons documented their stability. When incorporated in 6-marker combinations, the new markers afforded the detection of 1 leukemic cell among 10(5) BM cells. These new markers should allow MRD studies in all B-lineage ALL patients, and substantially improve their sensitivity.     

Analysis of cell proteins in lymphoblasts of acute lymphocytic leukemia by two-dimensional gel electrophoresis

The two-dimensional gel electrophoresis (2-DE) method developed by O'Farrell was used to analyze the differences of major proteins between lymphoblasts from children with acute lymphocytic leukemia (ALL) at diagnosis (lymphoblasts, n = 6), normal lymphocytes (n = 6) and lymphocytes from children with ALL in complete remission (lymphocytes in CR, n = 12). Among all the spots, those which were deeply stained and large were termed 'major spots'. Their number was 118. Two spots (No. B1 and B2) were characteristic of lymphoblasts, three spots (No. N1-N3) were characteristic of normal lymphocytes. In lymphocytes in CR, the latter spots were not always detected, and furthermore, the former spots were detected in several gels. These findings may relate to the insufficient recovery of functions of lymphocytes in CR. Several spots (No. 6, 55 and 57) in lymphoblasts were remarkably larger than those in normal lymphocytes. Spot No. 67, an actin spot, in lymphoblasts was smaller than that in normal lymphocytes. Spots No. 6, 55 and 57 in lymphocytes in CR were relatively small in size.     

Receptors for peanut agglutinin (Arachus hypogea) in childhood acute lymphoblastic leukemia: possible clinical significance

The presence of lymphocyte receptors for peanut agglutinin in significant numbers (greater than 15%) was identified on leukemic cells from T-cell acute lymphoblastic leukemia (T-ALL) (3/4), B-cell ALL (B- ALL) (2/4), null cell ALL (8/17), and on normal fetal thymic lymphocytes but not on normal human peripheral blood lymphocytes. Peanut agglutinin (PNA) binding was blocked specifically on leukemia lymphoblasts and thymic lymphocytes by the addition of galactose to the medium. When all immunologic subgroups of ALL are combined, preliminary data suggest that of the 13 ALL patients having greater than 15% PNA- positive lymphoblasts, 8 had relapsed, whereas none of the 12 ALL patients with less than 15% PNA-positive cells have recurrent disease at this time. It is likely that analysis of PNA receptors on ALL lymphoblasts may be a useful adjunct to the existing clinical and immunologic prognostic indicators.     

The Number of Nucleoli and Main Nucleolar Types in Lymphoblasts of Children Suffering from Acute Lymphoid Leukemia

Nucleoli were studied in lymphoblasts of children (untreated with cytostatic therapy) suffering from acute lymphoblastic leukemias (ALL) by means of a simple cytochemical procedure for the demonstration of RNA to provide information on the incidence of the main nucleolar types and the number of nucleoli in these cells. The values of the nucleolar coefficient reflecting the number of nucleoli per lymphoblast ranged between 1.66 and 2.03. The slightly larger values of the nucleolar coefficient in T-ALL were not statistically significant in comparison with those in nonT-ALL. Lymphoblasts in the bone marrow as well as the peripheral blood of both nonT and T-ALL patients mostly contained, “active” (RNA transcribing) large nucleoli with a relatively uniform distribution of RNA. “Inactive” micronucleoli or particularly “resting” ring shaped nucleoli were noted less frequently in these cells. On the other hand, the larger percentage of lymphoblasts determined in specimens stained with the panoptic staining (May-Grünwald-Giemsa) in comparison with that of lymphoblasts with “active nucleoli” in specimens stained for RNA apparently indicates the absence of such nucleoli in some of these cells. These cells might represent ageing, not proliferating, cells the existence of which has been already suggested by previous studies based on a different methodical approach.