Radiobiological features of fresh leukemic bone marrow progenitor cells in acute lymphoblastic leukemia

The radiobiological features of leukemic progenitor cells (LPC) freshly obtained from 14 T-lineage acute lymphoblastic leukemia (ALL) and 11 B-lineage ALL patients were evaluated using LPC colony assays. No significant radiobiological differences were observed between T-lineage versus B-lineage ALL LPC. Notably, the D0 values displayed a significant interpatient variation in both groups, indicating a pronounced heterogeneity in the radiation sensitivity of LPC. LPC from some patients were very radioresistant, and in additional experiments using cryopreserved bone marrow blasts, up to 32% of LPC could survive 1600 cGy delivered at 100 cGy/min. In six of 11 T-lineage ALL cases and five of ten B-lineage ALL cases, a distinct initial shoulder was present on the single dose radiation survival curves, providing circumstantial evidence that LPC are able to repair sublethal radiation damage. A greater proportion of LPC survived 400 cGy when the dose was delivered in two fractions instead of a single dose, providing direct evidence that LPC in ALL possess a substantial capacity to repair sublethal radiation damage. The interpatient differences in Dq and recovery factor values indicated a marked heterogeneity in the ability of LPC to repair sublethal radiation damage. Analysis of the dose rate effects on the radiation survival of LPC in four ALL cases suggested that the radiation sensitivity of LPC is dose rate dependent. Normal bone marrow progenitor cells (colony-forming unit, granulocyte-macrophage, and burst-forming unit, erythroid) were more radiosensitive and unable to repair sublethal radiation damage. To our knowledge, this report represents (a) the first detailed comparative analysis of the radiobiological features of freshly obtained LPC in T-lineage and B-lineage ALL patients, and (b) the first elucidation of radiobiological differences between leukemic ALL versus normal bone marrow progenitor cells.     

Residual bone marrow leukemic progenitor cell burden after induction chemotherapy in pediatric patients with acute lymphoblastic leukemia.

We used highly sensitive multiparameter flow cytometry and blast colony assays to quantify the leukemic progenitor cell (LPC) burden of postinduction chemotherapy bone marrows from newly diagnosed and relapsed pediatric patients with acute lymphoblastic leukemia (ALL). Of 890 newly diagnosed patients, 243 (27%) had detectable LPC in the postinduction bone marrow samples with an average (mean +/- SE) LPC content of 22+/-9 LPC/10(6) mononuclear cell (MNC; range, 0-7199/10(6) MNC; median, 0/10(6) MNC). By comparison, 24 of 50 (48%) patients with relapsed ALL had detectable LPC in their postinduction bone marrow specimens (P = 0.003), and their average LPC content was 202+/-139 LPC/10(6) MNC. Fewer patients with B-lineage ALL (170 of 786; 22%) than patients with T-lineage ALL (73 of 104; 70%) harbored residual LPC in their postinduction bone marrow specimens (P < 0.0001). This correlation with immunophenotype was independent of the National Cancer Institute risk classification. Similarly, 19 of 44 (43%) patients with relapsed B-lineage ALL versus 5 of 6 (83%) patients with relapsed T-lineage ALL harbored residual LPC in their postinduction bone marrow specimens (P = 0.09). Among newly diagnosed patients, those with high-risk ALL seemed to have larger numbers of residual LPC in their bone marrow after induction chemotherapy than those with standard risk ALL (53+/-26, n = 286 versus 7+/-1, n = 604, P = 0.04). LPC of patients with standard risk ALL who had a slow early marrow response at day 7 seemed to be more resistant to the three-drug induction chemotherapy than patients who had a rapid early marrow response. Overall, the order of chemosensitivity of LPC was: newly diagnosed standard risk B-lineage > newly diagnosed higher risk B-lineage > newly diagnosed standard risk T-lineage > newly diagnosed higher risk T-lineage > relapsed B-lineage > relapsed T-lineage. Notably, LPC- patients whose end-of-induction remission bone marrow specimens had zero LPC had an excellent early event-free survival outcome. Within the standard and high-risk subsets, LPC- patients had a 2.6-fold lower and 2.4-fold lower incidence of events, respectively, than LPC+ patients. At 6 months, 12 months, as well as 24 months, the ranking order for better event-free survival was: standard risk, LPC- > high risk, LPC- > standard risk, LPC+ > high risk, and LPC+.     

Bone marrow leukemic progenitor cell content in pediatric T-lineage acute lymphoblastic leukemia patients with an isolated extramedullary first relapse.

Isolated extramedullary relapse in childhood acute lymphoblastic leukemia (ALL) is associated frequently with the T-lineage immunophenotype and may be accompanied by occult bone marrow disease. We employed highly sensitive multiparameter flow cytometry and blast colony assays to quantify the leukemic progenitor cell (LPC) burden in the pretreatment bone marrows of 15 pediatric T-lineage ALL patients with an isolated extramedullary first relapse. Sites of extramedullary relapse were CNS (11 patients), testes (3 patients), and both CNS and testes (1 patient). Bone marrow LPC were detectable in 8 patients (53%) and undetectable in 7 patients (47%) at day 0 of post-relapse induction therapy, with LPC counts ranging from 0/10(6) mononuclear cells (MNC) to 518/10(6) MNC (mean +/- SEM, 50+/-34/10(6) MNC). Five of 9 patients with an early relapse (< 18 months after achieving a first complete remission [CR1]) and 3 of 6 patients with a late relapse (> or = 18 months from CR1) had detectable bone marrow LPC at day 0. Five of 8 patients with NCI-defined poor risk ALL and 3 of 7 patients with NCI-defined standard risk ALL had detectable LPC at day 0. Following post-relapse induction chemotherapy. LPC counts were detectable in bone marrows of 4 of 6 evaluated patients. Thus, approximately half of the extramedullary relapse T-lineage ALL patients studied had substantial occult involvement of the bone marrow. These findings may partly explain the previously observed poor prognosis of T-lineage patients following a CNS relapse.     

Radiobiological features of human pluripotent bone marrow progenitor cells (CFU-GEMM)

The purpose of this study was to evaluate the radiobiologic features of human pluripotent bone marrow progenitor cells (CFU-GEMM; colony forming unit-granulocyte-erythroid-macrophage/monocyte-megakaryocyte). Experiments were performed using fresh bone marrow cells as well as bone marrow cells stimulated with recombinant granulocyte-macrophage-colony stimulating factor (rGM-CSF) to increase the CFU-GEMM pool. The D0 values for CFU-GEMM in normal bone marrow samples (n = 9) ranged from 30.9 cGy to 85.7 cGy (mean +/- SE = 54.4 cGy +/- 6.2 cGy) and the D0 value of the composite radiation survival curve was 56.9 cGy, indicating that CFU-GEMM were acutely sensitive to the lethal effects of ionizing radiation. There was no distinct shoulder on the single dose radiation survival curves with Dq values ranging from -29.6 cGy to 4.4 cGy, and no increase in CFU-GEMM survival was observed when the radiation was fractionated. Hence, CFU-GEMM were unable to repair sublethal radiation damage. These findings confirm and extend previous studies on the radiobiologic features of human hematopoietic progenitor cell populations.     

Autologous bone marrow transplantation for acute lymphoblastic leukemia

Forty-four children with acute lymphoblastic leukemia (ALL) who had relapsed (N = 43) or had refractory disease (N = 1) were intensively treated with combination chemotherapy, had remission bone marrow (BM) harvested and purged in vitro with monoclonal antibodies specific for leukemia-associated antigens, underwent postharvest ablative chemotherapy and radiotherapy and subsequently were infused with their autologous marrow. Of the 44 patients treated between November 1980 and January 1988, 19 relapsed, 10 died of complications, and 15 remained in complete remission for a median of 28.5 months (range, 10+ to 94+). Event-free survival (EFS) (+/- SE) at 5 years after autologous transplantation was 29 +/- 8%. For the 26 patients whose initial remission was greater than 2 years, event-free survival was 51 +/- 10%. These results compare favorably with allogeneic transplantation and chemotherapy trials for patients with relapsed ALL, and provide an alternative transplantation option for children without histocompatible donors.     

CD99 expression in T-lineage ALL: implications for flow cytometric detection of minimal residual disease.

Expression of CD99 is higher on immature than on mature T cells. We postulated that this marker could be used to assess minimal residual disease (MRD) in T-lineage acute lymphoblastic leukemia (T-ALL). In diagnostic bone marrow (BM) samples from 27 children with T-ALL, expression of CD99 on leukemic lymphoblasts by flow cytometry was in median 7.7 times higher than on normal T lymphocytes from within the same sample. In 85% of cases, leukemic MFI values were higher than the mean MFI+2 s.d. of normal populations. We applied CD99 to study MRD in 39 follow-up samples from 15 consecutive T-ALL patients, and compared the results with those obtained with the well-established MRD-marker terminal deoxynucleotidyl transferase (TdT). Either antibody was combined in four-color flow cytometry with CD7, surfaceCD3, and cytoplasmicCD3. We found that CD99 was a valid complement to TdT in quantifying T-ALL MRD. Given a considerable interpatient variability, CD99 could be favorably used in nine patients, and TdT in other five patients. Both approaches showed a similar very low nonspecific background throughout 12 weeks from diagnosis (in median 0.002% of nucleated BM cells in patients with non-T ALL). We conclude that CD99 is a highly informative tool for MRD detection in T-ALL, bearing the advantage of surface expression in contrast to TdT.     

Autologous bone marrow transplantation with monoclonal antibody purged marrow for high risk acute lymphoblastic leukemia

Fifty-four patients with acute lymphoblastic leukemia (ALL: 1 relapse, 21 high risk first complete remission (CR 1), 29 second CR (CR 2), and 3 third CR (CR 3) were treated by autologous bone marrow transplantation at three centers. Before storage, the marrows were purged ex vivo with appropriate MAbs RFAL3 (CD10), SB4 (CD19), and RFT2 (CD7), with rabbit serum as the source of complement. All patients received total body irradiation either 750 cGy (middose 15 cGy/min) as a single fraction or 6 x 200 cGy over 3 days (midline dose 16 cGy/min) with lung shielding from 1,100 cGy. The patients who received 750 cGy also received cyclophosphamide or the same drug combined with ara-C or prednisone, teniposide, vincristine, ara-C, and dauno-rubicin. Patients receiving 200 cGy x 6 also received either cyclophosphamide, melphalan, or ara-C and cyclophosphamide. Three patients died of post transplantation complications (interstitial pneumonia, hepatitis B liver necrosis, or encephalitis). This gives a procedure related mortality of 5%. Nonfatal complications were 10 cases of septicemia, 4 interstitial pneumonia, 2 interstitial nephritis, 1 veno-occlusive disease (VOD), and 1 case of hemolytic uremic syndrome. The patient autografted in relapse died of relapse within 2 months. In CR 1 6 or 21 patients have had a relapse, and the actuarial leukemia free survival from CR is 65% (median follow-up 16 months). In CR 2-3 18 of 32 patients have relapsed, and the actuarial leukemia free survival is 31% (median follow-up 18.5 months) from CR. Twelve patients have achieved an inversion, (i.e., present CR longer than previous CR), with a further seven with the potential to achieve inversion. We conclude that ABMT in high risk ALL has a low procedure related mortality (5%), and there are few other complications. The in vitro purging with MAbs had no adverse effect on bone marrow reconstitution, but this study was not designed to demonstrate its antileukemic efficacy. The actuarial leukemia free survival time in the present study for patients with high risk CR 1 and the inversions in CF 2-3 are promising and indicate a potential beneficial effect of ABMT.     

Expression pattern of hybrid phenotype in adult acute lymphoblastic leukemia.

We examined the expression of hybrid phenotype in 236 adults with acute lymphoblastic leukemia (ALL; 188 B-lineage ALL and 48 T-lineage ALL). In B-lineage ALL, myeloid antigen (mAg) CD15 was concentrated in CD10-CD20- cases (49%); CD13 (42%); and CD33 (43%) in CD10+CD20- cases. This trend had no correlation with the presence of Ph1 or t(4;11) chromosomal abnormality. T-cell antigen CD2, CD4, and CD7 was seen in four, four, and two cases, respectively, and CD4+ and CD7+ cases commonly expressed CD13 and/or CD33 (CD13/CD33). In T-lineage ALL, expression of mAg, CD11b (47%), CD13 (38%), CD15 (28%), and CD33 (51%) was restricted to CD3- cases. B-cell antigen CD19 was found in two cases with CD7 solely as T-cell antigen, and these cases possessed CD13/CD33. CD21 was detected in three cases with CD3. In whole ALL, CD13/CD33 was associated closely with the presence of stem-cell antigen CD34, and in T-lineage ALL, CD13/CD33 had a significant correlation with additional stem-cell features, such as HLA-DR, multidrug resistance 1 (MDR1) and c-kit gene expression. Our results suggest that immature ALL cells frequently express B+M+, T+M+, and occasionally B+T+M+ phenotype; that B+T+M- phenotype is extremely rare; and that mAg expression in B-lineage ALL is complicated as compared to T-lineage ALL.     

Prognostic significance of T-lineage leukemic cell growth in SCID mice: a Children's Cancer Group study

Contemporary intensive therapies are effective for the majority of pediatric T-lineage acute lymphoblastic leukemia (ALL) patients, thus current challenge is to identify patients who may benefit from alternative treatment modalities. Previously, we demonstrated that human leukemic cell growth in the severe combined immunodeficiency (SCID) mouse was a significant prognostic factor for very high risk B-lineage ALL patients. In the current report we show that primary leukemic cells from 24 of 88 (27%) T-lineage ALL patients (SCID+) caused histopathologically detectable leukemia in SCID mice. These SCID+ patients were similar to SCID- (n = 64) patients with respect to virtually all presenting features, including age, sex, race, and leukocyte count. Growth of primary leukemic cells in SCID mice was not a significant predictor of outcome for the aggregate population of T-lineage ALL patients. Two-year event-free survival (EFS) outcomes for SCID+ patient and SCID- patients were 76.2% (SD = 5.6%) and a 64.0% (SD = 10.4%; p = 0.20). Overall survival also was similar between the two groups (p = 0.36). Among the subset of patients with M1 or M2 marrow status by day 7 of induction chemotherapy (rapid early responders), those who were SCID+ had poorer outcomes than those who were SCID-, with a 2-year EFS of 68.4% (SD = 11.9%) vs. 85.7% (SD = 6.0%) and relative hazard rate of 3.06 (p = 0.06). These data suggest that leukemic cell growth in SCID mice may identify a subset of T-lineage ALL patients who are at higher risk for relapse despite achieving a rapid early response to induction chemotherapy.     

Expression and Long-Term Prognostic Value of CD34 in Childhood and Adult Acute Lymphoblastic Leukemia

Clinical and laboratory characteristics at diagnosis, and long-term (up to 7 years) evolution, were analysed in 156 patients (66 adults and 90 children) with acute lymphoblastic leukemia (ALL), according to the expression of CD34. Eighty-three patients had CD34+ and 73 patients CD34- blasts at diagnosis. In adults, CD34+ ALL was more often of B-lineage (p = .003). White blood cell counts were higher both in children with CD34- B-lineage ALL (p = .02) and adults with CD34- T-lineage ALL (p = .05). Adult patients with CD34- T-lineage ALL were older (p = .04) and had more frequent splenic or liver enlargement (p = .02). Children with CD34+ ALL had a significantly (p = .04) longer event-free follow-up than CD34- children. Survival curves showed that after induction of remission, relapses were less frequent during the first 2 years for patients with CD34+ B-lineage ALL. After 2 years, however, event-free survival curves of CD34+ and CD34- patients merged. Thus it seems that CD34+ has no significant benefit for ALL patients.     

Minimal residual disease in acute lymphoblastic leukemia detected by immune selection and gene rearrangement analysis

We have developed an assay for the detection of malignant residual cells in the bone marrow from patients with B- or T-lineage acute lymphoblastic leukemia (ALL) in clinical remission. This assay involves an immune selection step followed by immunoglobulin or T-cell receptor gene rearrangement analysis and allows the detection of one contaminating tumor cell out of 1,000 normal bone marrow cells. We have examined the bone marrow of 11 patients with adult ALL in remission over a 24-month period. Five patients relapsed in the bone marrow and one in the CNS. The assay allowed the detection of minimal residual disease in four of five patients that subsequently relapsed in the bone marrow, 1.5 to 9 months before the relapse became morphologically and clinically manifest. Residual disease was not found in the bone marrow from patients in continuous remission and from the single patient who relapsed in the CNS. We conclude that the ability of the assay described here to detect minimal residual disease with high specificity can provide information for further understanding of the biology of ALL and hopefully for the clinical management of patients with this disease.     

Low-dose oral etoposide-based induction regimen for children with acute lymphoblastic leukemia in first bone marrow relapse.

We evaluated the clinical response to low-dose etoposide in relapsed acute lymphoblastic leukemia (ALL). Of the 45 patients with ALL in first bone marrow relapse enrolled on the ALL R15 protocol, 44 had received epipodophyllotoxins during frontline therapy. In the first week of remission induction therapy, patients received etoposide (50 mg/m(2) per day) administered orally as a single agent once or twice daily. On Day 8, patients started to receive dexamethasone, vincristine, and L-asparaginase. Etoposide was administered until Day 22. Two courses of consolidation therapy were followed by continuation therapy or hematopoietic stem cell transplantation. After 7 days of single-agent etoposide treatment, peripheral blast cell counts (P=0.013) and percentages of bone marrow blasts (P=0.016) were significantly reduced. In all, 38 (84.4%) attained second remission. Only time to relapse was significantly associated with outcome (P=0.025): the 5-year event-free survival estimates (+/-se) were 52.0+/-9.6% for those with late relapse and 20.0+/-8.0% for those with early relapse. We conclude that low-dose etoposide administered orally has a cytoreductive effect in relapsed ALL.     

Feasibility of ESHAP + G-CSF as peripheral blood hematopoietic progenitor cell mobilisation regimen in resistant and relapsed lymphoma: a single-center study of 22 patients.

The purpose was study the feasibility of ESHAP + G-CSF for peripheral blood hematopoietic progenitor cell (PBPC) mobilisation in resistant/relapsed Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). Twenty-two consecutive patients with HD (8) and N-HL (14) received ESHAP chemotherapy and G-CSF (5 microg/Kg/d). When a minimum number of 10,000 peripheral blood CD34+ cells/mL was observed patients underwent leukapheresis until a CD34+ cell dose > or = 2.5x10(6)/Kg was collected or the PBPC peak was lost. Blood cells kinetics and toxicity were analysed. Data concerning the day of first apheresis, number of procedures per patient, and cellular yield of the aphereses were recorded. Correlation between the CD34+ cell content in the apheresis product and the two diagnosis groups was attempted. Twelve patients (54%) developed short-lived severe neutropenia (<0.5x10(9)/L). Thrombocytopenia (<25x10(9)/L) had a median duration of 1 day. Fever appeared in 4 patients and CN Staph bacteriemia in 2 cases. Bleeding events did not supervene and no deaths occurred. Aphereses started at day +15 (median) and the median number of apheresis/patient was 2. Seventeen patients underwent 1 or 2 leukaphereses. Thirteen patients (59%) achieved the CD34+ cell target in the first apheresis. NHL patients obtained statistically significant better CD34+ cell collections than HD. Only 2 HD patients failed to mobilise, 1 previously treated with high-dose therapy and autologous bone marrow transplantation. ESHAP + G-CSF has been shown to be feasible for PBPC mobilisation in resistant/relapsed lymphoma. Toxicity was low and CD34+ cell yield high, especially in N-HL. This mobilisation regimen should be further explored in a larger patient population.     

抗原处理相关转运因子在小儿急性白血病患者中的表达及其临床意义

背景与目的:抗原处理相关转运因子(transporterassociatedwithantigenprocessing,TAP)参与免疫监视,因而可能与肿瘤发生有关。本文旨在探讨急性白血病TAP分子表达及其临床意义,探讨急性白血病的治疗策略。方法:采用RT-PCR检测34例初治急性淋巴细胞白血病(acutelymphoblasticleukemia,ALL)(初治组)、15例复发ALL(复发组)及20例急性髓系白血病(acutemyeloidleukemia,AML)患者骨髓中TAP亚单位TAP1和TAP2的表达。20例无全身性疾病外科住院患儿作为对照组。使用数码成像分析仪测定并计算扩增条带的相对于阳性内对照GAPDH的吸光度(A)值。结果:ALL初治组和ALL复发组的TAP1A值(分别为0.448±0.167和0.169±0.021)及TAP2的A值(分别为0.196±0.180和0.112±0.020)均低于对照组,P均<0.01;AML组TAP2的A值低于对照组(P<0.01);ALL复发组TAP1的A值低于ALL初治组,P<0.05;ALL初治组复发者(6/34)TAP1的A值(0.215±0.159)较持续完全缓解(constantcompleteremission,CCR)者低(24/34,0.462±0.189,P<0.05)。结论:小儿ALL和AML均存在TAP分子低表达,这可能促使白血病细胞逃避免疫监视;TAP1亚单位低表达可能与ALL的复发有关。     

Detection of minimal residual disease (MRD) after bone marrow transplantation (BMT) by multi-parameter flow cytometry (MPFC)

Multi-parameter flow cytometry (MPFC) was used to detect minimal residual disease (MRD) following bone marrow transplantation (BMT) in 21 patients. Bone marrow (BM)was analyzed pre-transplant and 3-4 months post-BMT while the patients were in clinical and morphological remission. MRD was detected by identifying cells with aberrant antigen expression and/or leukemia-associated phenotype (LAP) using MPFC. Prior to BMT, 8 out of 21 patients exhibited normal antigen expression based on normal BM samples while 13 BM aspirates had abnormal MPFC. Pre-BMT MPFC was abnormal in all 10 patients who were not in complete remission (CR) (>5% blasts in BM) as well as 3 patients acute lymphoblastic leukemia (ALL) who were in CR. In BM from ALL patients, an abnormal uniform B cell population was observed however antigen expression patterns varied greatly between patients. BM from acute myeloblastic leukemia (AML) patients showed an abnormal distribution of CD34+ cells. In addition, a correlation was observed between pre-BMT cytogenetics and MPFC. Only 2 out of 8 (25%) patients with normal MPFC pre-autologous bone marrow transplantation (ABMT) relapsed (AML), while 6 out of 13 (46%) patients with abnormal pre-BMT MPFC relapsed including 2 out of 3 patients who were transplanted in clinical CR. Pre-BMT MPFC may thus be an effective tool for detection of MRD by detection of a pre-transplant MPFC abnormality.     

Outcome of allogeneic hematopoietic stem-cell transplantation in adult patients with acute lymphoblastic leukemia: no difference in related compared with unrelated transplant in first complete remission.

PURPOSE: The role of unrelated allogeneic stem-cell transplantation in acute lymphoblastic leukemia (ALL) patients is still not clear, and only limited data are available from the literature. We analyzed factors affecting clinical outcome of ALL patients receiving a related or unrelated stem-cell graft from matched donors. PATIENTS AND METHODS: The total study population was 264 adult patients receiving a myeloablative allogeneic stem-cell transplant for ALL at nine bone marrow transplantation centers between 1990 and 2002. Of these, 221 patients receiving a matched related or unrelated graft were analyzed. One hundred forty-eight patients received transplantation in complete remission; 62 patients were in relapse; and 11 patients were refractory to chemotherapy before transplant. Fifty percent of patients received bone marrow, and 50% received peripheral blood stem cell from a human leukocyte antigen-identical related (n = 103), or matched unrelated (n = 118) donor. RESULTS: Disease-free survival (DFS) at 5 years was 28%, with 76 patients (34%) still alive (2.2 to 103 months post-transplantation), and 145 deceased (65 relapses, transplant-related mortality, 45%). We observed an advantage regarding DFS in favor of patients receiving transplantation during their first complete remission (CR) in comparison with patients receiving transplantation in or after second CR (P =.014) or who relapsed (P <.001). We observed a clear trend toward improved survival in favor of B-lineage ALL patients compared with T-lineage ALL patients (P =.052), and Philadelphia chromosome-positive patients had no poorer outcome than Philadelphia chromosome-negative patients. Total-body irradiation-based conditioning improved DFS in comparison with busulfan (P =.041). CONCLUSION: Myeloablative matched related or matched unrelated allogeneic hematopoietic stem-cell transplantation in ALL patients should be performed in first CR.     

Prognostic impact of CD45 antigen expression in high-risk, childhood B-cell precursor acute lymphoblastic leukemia.

To evaluate the clinical implications of CD45 expression in acute childhood lymphoblastic leukemia (ALL), we measured the CD45 expression of blast cells from 133 untreated patients with childhood B-precursor ALL (n = 118) or T-ALL (n = 15). CD45 expression (> or = 20%) was detected in all 15 cases (100%) of T-ALL, and 101 cases (86%) of B-precursor ALL. In 122 cases, the fluorescence intensity of the CD45 expression was measured as a relative value; the ratio of average linear values (RALV) of CD45 on the blasts to that on CD3-positive T-lymphocytes from the same specimen. The expression was more intense in the T-ALL cases than in the B-precursor ALL cases (RALV, mean +/- SE: T-ALL 0.230 +/- 0.04 vs. pro-B ALL 0.150 +/- 0.012/pre-B ALL 0.153 +/- 0.019, p < 0.05). However, the intensity of the CD10, CD19, CD20 and CD34 antigen immunoreactivity did not correlate with the CD45 expression. Patients with hyperdiploidy (chromosome number > 50) showed significantly lower levels of CD45 expression than patients with t(1;19) or normal karyotypes (RALV, mean +/- SE: 0.081 +/- 0.022 vs. 0.133 +/- 0.03/0.143 +/- 0.019, p < 0.05). Other clinical features such as age, gender and WBC count did not correlate with CD45 expression. The prognostic implications of CD45 expression were studied in non-high-risk (low-risk + intermediate-risk) (n = 60) and high-risk patients (n = 52) with B-precursor ALL who had been treated with the risk-directed protocol of ALL-941 trial. Although CD45 expression did not correlate with the event-free survival (EFS) of the non-high-risk patients, there was a significant correlation between the expression levels and the EFS of the high-risk patients: the 3-year EFS rate of the CD45low group (n = 26, RALV = 0.017-0.132) was 88 +/- 7% versus the CD45high group (n = 26, RALV = 0.133-0.450) at 34 +/- 24% (p < 0.05). These results show that the levels of expression of the CD45 antigen on leukemic lymphoblasts are significantly correlated with the clinical features and prognosis of childhood ALL.     

Late onset of renal dysfunction in survivors of bone marrow transplantation

Between 1980 and 1986, 44 children with acute lymphoblastic leukemia (ALL) or Stage IV neuroblastoma (NB) underwent allogeneic or autologous bone marrow transplantation (BMT). Twenty-nine of these patients were alive and in remission 3 months post BMT and were evaluable for this analysis of whom eleven have developed renal dysfunction. Six of 17 (35%) evaluable ALL patients developed renal dysfunction (3.5 to 6 months post BMT). This group was transplanted for CALLA positive ALL and received an autologous transplant. Preparation included tenopiside (VM 26) cytosine arabinoside, and cyclophosphamide followed by total body irradiation (TBI). One patient received 850 cGy in a single fraction, while all other patients received fractionated TBI (1200-1400 cGy in 6-8 fractions over 3-4 days). Five of 7 (71%) evaluable patients who received a BMT for NB have developed late renal problems (4-7 months after BMT). The preparation for NB patients included VM 26, cis-platinum, melphalan, cyclophosphamide, and fractionated TBI (1200-1296 cGy). All seven NB patients had received cis-platinum as induction treatment prior to transplantation. All patients presented with anemia, hematuria, and elevations of BUN and creatinine. Two patients underwent renal biopsies which were consistent with radiation nephropathy or hemolytic uremic syndrome. In conclusion, a high incidence of renal dysfunction has occurred 3 to 7 months after BMT for children with NB and ALL. The clinical and laboratory features are consistent with either acute radiation nephropathy or hemolytic-uremic syndrome. These patients were prepared for BMT with multiple chemotherapeutic agents as well as TBI. The relatively young age of these patients and conditioning with intensive multi-agent chemotherapy may decrease the tolerance of the kidney to radiation injury.     

Total lymphoid irradiation, high-dose chemotherapy and autologous bone marrow transplantation for chemotherapy-resistant Hodgkin's disease

Seventeen patients with advanced stage Hodgkin's disease who relapsed or failed to respond to multiple regimens of combination chemotherapy (mostly Mechlorethamine, Vincristine, Procarbarzine, Prednisone and Adriamycin, Bleomycin, Vinblastine, Dacarbazine) were treated with accelerated hyperfractionated total lymphoid irradiation (TLI) and high-dose chemotherapy followed by autologous bone marrow transplantation (AuBMT). Candidates for the protocol did not have prior radiation therapy and had no evidence of bone marrow involvement. Their bone marrow was initially harvested and cryopreserved. The treatment protocol consisted of reinduction with conventional doses of combination chemotherapy followed by boost local field irradiation to areas of residual disease (1500 cGy within 5 days) and total lymphoid irradiation (2004 cGy given in 12 fractions of 167 cGy each t.i.d. delivered within 4 days). The patients were treated with Etoposide (250 mg/m2/day I.V. X 3 days) and high-dose Cyclophosphamide (60 mg/kg/day I.V. X 2 days). Cryopreserved (unpurged) autologous bone marrow was infused 48 hr after completion of chemotherapy. Of the 17 patients treated, four were in relapse and 13 refractory to multiple regimens of combination chemotherapy. Four patients died during the immediate peritransplant period (2--septicemia, 2--pulmonary complications). Of the 13 surviving patients, 12 entered a complete remission and one had a partial remission and died of disease 6 months later. One patient relapsed 5 months after treatment and is currently alive with disease. Eleven patients (65%) are alive with no evidence of disease 4-35 months (median 20 months) following completion of therapy. Treatment with this protocol results in a high rate of complete remission and a potential for long-term disease-free survival in previously unirradiated patients with advanced stage refractory or relapsed Hodgkin's disease who have exhausted conventional modes of chemotherapy.