Biomedical subjects

C Horton

Publications and source records attributed to C Horton.

At least 55 records · Page 3Linked to original sources

PubMed1997

Autologous transplantation with CD52 monoclonal antibody-purged marrow for acute lymphoblastic leukemia: long-term follow-up.

During 1984-86, 23 patients (5-37 years, median 16) with acute lymphoblastic leukemia (ALL) in first remission (n = 11) or beyond (n = 12) underwent autologous transplantation (ABMT) using marrow purged with the rat anti-CD52 monoclonal antibody Campath-1M after melphalan and total-body irradiation (TBI). Median time to 0.5 x 10(9)/L neutrophils and 50 x 10(9)/L platelets was 38 and 51 days respectively. Myeloid engraftment was significantly slower compared with ALL patients receiving unpurged marrow (P = .01). Eight patients died due to transplant-related causes 53-205 days after the procedure. Six of eight patients receiving 1150 cGy TBI died of toxicity compared with two of 15 receiving less than 1150 cGy (P = .006, Fisher's exact test). Nine patients relapsed at 45-195 days (median 97); eight died and one is alive at nine years in a chemotherapy-induced remission. Six patients are alive and well in continuous remission 9-10 years (median 10) after transplant. The 10-year probabilities of disease-free survival and relapse are 26% (95% CI: 11-45%) and 51% (95% CI: 37-59%) respectively. We conclude that it is feasible to purge marrow for autografting using Campath-1M without killing normal stem cells. Myeloid engraftment is slow but consistent, and long-term survival is seen in a proportion of patients. The role of CD52 monoclonal antibodies for purging in ALL still requires further study.

Adolescent↗

PubMed1996

Retinoic acid is required for the initiation of outgrowth in the chick limb bud.

BACKGROUND: Retinoic acid (RA) is present in the chick limb bud, and excess RA induces limb duplications. Here, we have investigated the role of endogenous RA during chick limb development by preventing the synthesis of RA and testing the effect on various genes expressed during limb initiation and outgrowth. RESULTS: We demonstrate that the stage 20/21 limb bud synthesizes didehydroretinoic acid (ddRA), and that the posterior half of the limb bud synthesizes ddRA at a higher rate than the anterior half. Disulphiram inhibits this synthesis at micromolar concentrations. Administering disulphiram to embryos prior to limb bud outgrowth (stages 12-18) abolishes outgrowth, and no limb develops in the majority of cases. Disulphiram treatment also prevents the expression of Sonic hedgehog (Shh), but the expression of the fibroblast growth factor-8 gene (Fgf-8) appears as normal in the ectoderm over the prospective limb bud. The application of a bead soaked in RA can rescue Shh expression. Disulphiram treatment of later limb buds (stages 20-23) similarly down-regulates Shh, and also Fgf-4, expression, whereas the expression of Fgf-8, as at earlier stages, is initially unaffected. Again, RA can rescue the expression of Shh in these limb buds. CONCLUSIONS: RA, in conjunction with Fgf-8, may be needed for the induction of the chick limb bud and the induction of Shh and Fgf-4 expression. The expression of Shh and Fgf-4 remains dependent upon the continued synthesis of RA within the limb bud. Didehydroretinoic acid is the major active retinoid in the stage 20 chick limb bud.

Animals↗

PubMed1996

Specific loss of protein kinase activities in senescent erythrocytes.

Rabbit erythrocytes of progressively increasing age were isolated using an avidin-biotin affinity technique and the activity of protein kinases and other enzymes was analyzed in cytosols and membranes from the isolated cells. The activities of cytosolic protein kinase C (PKC), cAMP-dependent kinase (PKA), and casein kinase type I and II (CKI and II) were all found to undergo an age-dependent decrease of twofold to fourfold over the 8-week lifespan of the cells. Membrane-associated tyrosine kinase showed little or no decrease, but membrane-associated CKI showed a dramatic eightfold decrease over the 8-week period. By contrast, various cytosolic enzymes, including lactate dehydrogenase, phosphoglycerate kinase, pyruvate kinase, and acid phosphatase, showed no change in activity over the same time period. Density-separated human erythrocytes showed qualitatively similar decreases in cytosolic protein kinase activities in the densest fractions, which contain the oldest cells. Our results show that aging erythrocytes undergo progressive loss of protein kinases that may adversely affect various cellular processes. The age-dependent loss of kinase activity reported here is one of the most striking manifestations of erythrocyte senescence yet to be reported.

Acid Phosphatase↗

PubMed1996

Endogenous retinoids in the zebrafish embryo and adult.

Retinoic acid and its isoforms are considered to be endogenous compounds which regulate embryonic development. In the work reported here we have determined which retinoids are present in zebrafish embryos and how their levels change throughout development and into adulthood. All-trans-RA is present and its level does not change significantly during embryogenesis. We failed to detect other retinoic acid isomers such as 9-cis-RA and 4-oxo-RA, but we did observe a rapid rise in the level of didehydroretinol after gastrulation. The most striking result is that the zebrafish embryo, like Xenopus and tunicates, contains a vast excess of t-retinal whereas the embryos of higher vertebrates have an excess of t-retinol. However, as the zebrafish grows, the levels of t-retinol rise so that by adulthood t-retinol and t-retinal concentrations are more equivalent, indicating a changing pattern of retinoid metabolism with growth. To examine the significance of the use of t-retinal as a precursor of t-RA we treated embryos with disulphiram, an inhibitor of retinaldehyde dehydrogenase. This resulted in embryos with an undulating notochord and correspondingly abnormal somites and ventral floor plate. In contrast to this effect, 4-methylpyrazole, which inhibits alcohol dehydrogenases, had no effect on development. This effect of disulphiram suggests that t-RA may be involved in the establishment of the anteroposterior axis of the embryo.

Alcohol Dehydrogenase↗

PubMed1996

Comparison of interferon tolerance after autologous bone marrow or peripheral blood stem cell transplants for myeloma patients who have responded to induction therapy.

Interferon (INF) has been incorporated as part of maintenance therapy after high dose treatment in order to make remissions more durable. In this study we have compared peripheral blood stem cell transplant (PBSCT) versus autologous bone marrow transplant (ABMT) with respect to INF tolerance. Thirty nine PBSCT patients have been compared to 37 ABMT patients for INF tolerance. This is followed by a comparison of 15 PBSCT patients versus 21 ABMT patients for engraftment details, response and survival. INF was started at a median of 61 days in the PBSCT and 58 days in the ABMT patients (P = NS). It was well tolerated in both groups without a significant difference in toxicity in the two arms. Engraftment was more rapid in the PBSCT patients with platelet recovery being significantly faster. Response and survival showed a favourable trend for ABMT patients though statistical significance was not reached and the cost of PBSCT was 12% cheaper. We were thus able to conclude that PBSCT grafts were as durable and could tolerate INF just as well as ABMT. Engraftment was more rapid and the procedure of PBSCT was also cheaper. Further studies with a larger group of patients will be required before comments on the efficacy of treatment can be made.

Adult↗

PubMed1996

Outcome of autologous rescue after failed engraftment of allogeneic marrow.

Ten patients experiencing primary graft failure after allogeneic bone marrow transplantation received autologous marrow or blood cells as hematopoietic rescue 21-40 (median 22.5) days after the original transplant after which immunosuppression with cyclosporine was tapered off rapidly. The leukocyte count at the time of rescue was 0.1-0.3 x 10(9)/l with < 0.1 x 10(9)/l neutrophils. The clinical course was uneventful after rescue with hematologic recovery to 0.5 x 10(9)/l neutrophils occurring 9-61 days (median 20) later in nine patients, and to 50 x 10(9)/l platelets 17-595 days (median 40) later in eight patients. No patient had a life-threatening infection at the time of or after rescue. No patient experienced acute graft-versus-host disease. Four patients with acute leukemia had recurrent disease 46-117 days after autologous rescue, and died of relapse. Five patients with acute leukemia are alive in continuous remission at 270-3382 days, and one patient with chronic myeloid leukemia is alive in hematologic remission at 228 days. We conclude that infusion of back-up autologous cells can prevent the immediate infectious consequences of primary allogeneic graft failure through consistent myeloid recovery, and may result in long-term survival of patients with good-risk disease.

Acute Disease↗

PubMed1996

Bone marrow transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia.

Between 1986 and 1995, 19 patients with Philadelphia chromosome-positive (Ph + ) acute lymphoblastic leukemia underwent 20 autologous (n = 9) or allogeneic (n = 11) blood or marrow transplant procedures in first (n = 12) or second (n = 3) remission, or in relapse (n = 5). Four patients died due to transplant-related causes, 11 relapsed at 3-39 months, one survives with disease which did not remit after transplant, and three are alive in continuous remission at 1, 26 and 65 months. Two of the relapsing patients are alive; one autografted patient after an allograft in second remission and one allografted patient after a donor leukocyte infusion. The projected overall survival is 37.5% at 3 years and 12.5% at 5 years. The 3-year probabilities of relapse and disease-free survival for autografted patients are 65.9% and 25.6% respectively, and for allografted patients, 63.4% and 21.8% respectively. The stage of the disease at the time of transplant or the type of transplant did not affect the outcome significantly, and late relapses beyond 3 years were seen after allogeneic as well as autologous transplantation. In our experience, the outcome of patients with Ph + acute lymphoblastic leukemia continues to be poor despite high-dose therapy due to high relapse rates, and the development of additional measures to enhance the antileukemic efficacy of bone marrow transplantation is necessary.

Acute Disease↗

PubMed1996

Central nervous system relapse after bone marrow transplantation for acute leukemia in first remission.

Four hundred and eighty-seven patients undergoing allogeneic or autologous BMT for acute leukemia in first remission received no prophylactic intrathecal chemotherapy after BMT. The conditioning regimen included total body irradiation in 433 (89%). Patients with acute lymphoblastic leukemia received cranial irradiation if they had no central nervous system (CNS) disease and all patients with CNS disease received craniospinal irradiation. Eleven of 311 patients examined had CNS disease at presentation, but none had active CNS disease at the time of BMT. Lumbar punctures were performed in 93 patients 1-2229 days (median 98) after BMT because of suspected CNS infection, hemorrhage or relapse (n = 65), or after systemic relapse (n = 28). CNS disease was seen in seven patients at 217-1209 days (median 340), none of whom had CNS disease pre-transplant. Systemic relapse had preceded CNS relapse by 4-207 (median 128) days in all seven and no isolated CNS relapse was seen. The actuarial risk of CNS and systemic relapse at 5 years was 2.9 and 35.9%, respectively. We conclude that CNS relapse is uncommon after BMT for acute leukemia in first remission, and that isolated CNS relapse is likely to be extremely uncommon. Therefore, routine prophylactic intrathecal chemotherapy is not warranted after BMT for acute leukemia in first remission.

Actuarial Analysis↗

PubMed1996

Melphalan-total body irradiation and autologous bone marrow transplantation for adult acute leukemia beyond first remission.

Forty-four adults with AML (n = 18) or ALL (n = 26) beyond first remission underwent unpurged (n = 39) or purged (n = 5) autografting after 110-140 mg/m2 melphalan and 1050 cGy TBI. ALL patients were eligible to receive maintenance chemotherapy with 6-mercaptopurine and methotrexate for 2 years after hematologic recovery. The duration of first remission was 1-167 months (median 11). The median time to 50 x 10(9)/I platelets was 76 days, and that to 0.5 x 10(9)/I neutrophils 31 days. Eight patients died of transplant-related toxicity; seven within 1 year. Twenty-two patients relapsed at 1-20 months (median 2.5 months). The 3-year probabilities (95% CI) of relapse and disease-free survival are 58% (43-75%) and 31% (17-45%), respectively. The duration of the first remission (< 1 year vs > or = 1 year) and the stage of transplant (second remission vs other) had no effect on relapse or disease-free survival. There was a trend towards higher relapse rates (76 vs 34%) and poorer disease-free survival (19 vs 49%) among ALL patients compared with AML which did not reach significant levels due to small patient numbers. We conclude that melphalan-TBI is a suitable conditioning regimen for autografting in advanced leukemia. The outcome of AML patients is comparable to standard regimens, but the outcome of ALL patients is poor and measures to enhance the anti-leukemic efficacy are necessary.

Acute Disease↗

PubMed1996

Transfusion requirements after bone marrow transplantation from HLA-identical siblings: effects of donor-recipient ABO incompatibility.

Transfusion requirements of 477 patients with hematologic malignancies undergoing BMT from HLA-identical siblings were studied. The median (range) number of red cells transfused in the first, second and third months were 4 (0-32), 1 (0-39), and 0 (0-22) respectively, and the number of random donor platelet concentrates 32.5 (0-196), 0 (0-220) and 0 (0-135). On multivariate analysis, diagnosis other than acute leukemia, conditioning regimen other than cyclophosphamide-TBI, cyclosporine-methotrexate GVHD prophylaxis, and occurrence of acute GVHD increased platelet requirements significantly in the first month. Diagnosis other than acute leukemia, donor-recipient ABO incompatibility, conditioning regimen other than cyclophosphamide-TBI, and age over 18 years increased red cell requirements significantly in the first month. Platelet requirements in the second month and red cell requirements in the second and third months were increased significantly by the occurrence of acute GVHD, a diagnosis other than acute leukemia, and a conditioning regimen other than cyclophosphamide-TBI. Platelet requirements in the third month were influenced only by acute GVHD. We conclude that ABO incompatibility does not influence platelet requirements after allogeneic BMT. It affects red cell requirements in the first month along with the diagnosis, conditioning regimen, and age. However, other factors outweigh the influence of ABO-incompatibility on red cell requirements beyond the first month.

ABO Blood-Group System↗

PubMed1996

Factors affecting engraftment and hematopoietic recovery after unpurged autografting in acute leukemia.

Factors affecting hematologic recovery to 0.5 x 10(9)/l neutrophils and 50 x 10(9)/l platelets after unpurged autografting (210 marrow, 30 blood) were analyzed in 240 patients with acute myeloid (AML, n = 128) or lymphoblastic (ALL, n = 112) leukemia. Cytokines were not administered routinely after transplant. Age, sex and cryopreservation did not influence hematologic recovery in multivariate analysis. Blood cell grafts (P < 0.0001), ALL (P = 0.003), and a nucleated cell dose of > or = 2 x 10(8)/kg (P = 0.035) were associated with faster neutrophil recovery. First remission (P = 0.001), a higher cell dose (P = 0.011), ALL (P = 0.023), and a short remission-transplant interval (P = 0.023) were associated with faster platelet recovery. There was a strong correlation between blood cell grafts and higher cell doses, and marrow and lower cell doses. Amongst marrow recipients, neutrophil recovery was faster in ALL (P = 0.001) and with higher cell doses (P = 0.032). Platelet recovery was faster in first remission patients (P = 0.005) and ALL (P = 0.043), and with higher cell doses (P = 0.031). We conclude that hematologic recovery after autografting is faster in ALL and first remission patients, probably due to the nature and the amount of prior chemotherapy. Using blood stem cells hastens engraftment, but even if marrow is used due to concern over relapse with blood, higher cell doses are associated with faster recovery.

Adolescent↗

PubMed1996

Long-term follow-up of patients undergoing allogeneic bone marrow transplantation for acute myeloid leukemia in first complete remission after cyclophosphamide-total body irradiation and cyclosporine.

Eighty-five patients (median age 28 years) with acute myeloid leukemia (AML) in first remission underwent allogeneic bone marrow transplantation (BMT) from HLA-identical siblings between 1978 and 1987 after cyclophosphamide and single-fraction total body irradiation with cyclosporine for graft-versus-host disease (GVHD) prophylaxis. The actuarial probabilities of development of acute and chronic GVHD were 57% and 47%, respectively. Twenty-six patients died of transplant-related complications at a median of 3.5 months, and two of unrelated causes. Seventeen patients relapsed at a median of 6.5 months. Forty patients were alive and well at 74-197 months (median 157) after BMT; seven (18%) with limited chronic GVHD requiring therapy. The actuarial 10-year probabilities of transplant-related death, relapse, and disease-free survival were 33%, 25% and 48% respectively. In multivariate analysis, infusion of a lower cell dose, development of GVHD, and age > 35 years were associated with increased transplant-related mortality, donor-recipient ABO incompatibility with a lower relapse rate, and age > 35 years and a lower cell dose with poorer disease-free survival. We conclude that with long-term follow-up, allografting in AML after cyclophosphamide-TBI and cyclosporine has resulted in disease-free survival that is comparable to most currently reported series. Patients who are alive and well 3-4 years after BMT have excellent prospects of long-term survival.

Adolescent↗

PubMed1996

Idarubicin, high-dose cytarabine, and etoposide for induction of remission in acute leukemia.

Between 1990 and 1944, 52 newly diagnosed patients with primary (n = 47) or therapy-related (n = 5) acute myeloid leukemia (AML) under the age of 55 years received an induction chemotherapy protocol (designated BF12) consisting of idarubicin ([IDA] 5 mg/m2), high-dose cytarabine ([HD-Ara-C] 2 mg/m2 per 12 hours, 3-hour infusion), and etoposide ([VP-16] 100 mg/m2, 1-hour infusion) on each of 5 consecutive days. Thirty-seven of 51 assessable patients (72.5%), including all five patients with therapy-related AML, attained remission with one cycle. The overall remission rate was 78.4%. Total therapy of AML, with BF12 followed by two courses of consolidation therapy and allogeneic or unpurged autologous bone marrow transplantation (BMT) in first remission, has resulted in actuarial 3-year survival of 49.9% of consecutive unselected patients with newly diagnosed primary AML (minimum follow-up period, 1 year). Twenty-five patients have received BF12 for relapsed acute leukemia, including 13 relapsing after BMT. Five patients died of toxicity and were not assessable for response. Of the remaining 20 patients, five were refractory, two attained partial remissions, and 13 (65%) achieved complete remission (CR). Four of the 13 patients relapsing after BMT died of toxicity, four were refractory, and five of nine assessable patients (56%) attained CR. We conclude that the combination IDA/HD-Ara-C/VP-16 is highly effective in the treatment of newly diagnosed AML and relapsed acute leukemia.

Acute Disease↗

PubMed1996

Melphalan alone prior to allogeneic bone marrow transplantation from HLA-identical sibling donors for hematologic malignancies: alloengraftment with potential preservation of fertility in women.

Melphalan has rarely been used as a single agent for conditioning prior to allogeneic marrow transplantation. Twenty-eight patients (median age 19.5 years) undergoing allogeneic BMT for acute leukemia (n = 26) or lymphoblastic lymphoma (n = 2) in first remission (n = 10) or beyond (n = 18) from HLA-identical siblings received 240 mg/m2 melphalan. Death due to primary graft failure was seen in two patients. Sustained hematopoietic recovery was seen in all the others (n = 22) not dying early due to toxicity (n = 2) or persistent active disease (n = 2). The 3-year probabilities of transplant-related mortality and relapse were 35% and 62%, respectively. Seven patients are alive and well at 103-163 months (median 136) with Karnofsky scores of 100% (10-year disease-free survival, 25%). Of the 16 patients with donors of the opposite sex, seven underwent cytogenetic studies after BMT and showed complete chimerism with donor cells. Amongst the four women who were 15-30 years at the time of the transplant, there were seven pregnancies over 297 months of follow-up beyond 2 years from transplant. In contrast, no pregnancies were seen in 53 women with hematologic malignancies who were conditioned with other regimens over 3524 months of follow-up beyond 2 years from transplant. The pregnancy rate was significantly higher (P < 0.001) for women conditioned with melphalan alone (three of four) than for those conditioned with other regimens (0 of 53). We conclude that pre-transplant conditioning with melphalan alone permits alloengraftment of marrow from HLA-identical siblings, and may preserve fertility better than other regimens in some women.

Adolescent↗

PubMed1995

Endogenous distribution of retinoids during normal development and teratogenesis in the mouse embryo.

We have analysed the endogenous retinoids present in whole mouse embryos from day 9 to day 14 of development and in individual components of the embryo at two stages, day 10.5 and day 13, by HPLC. We can only detect two retinoids, all-trans-RA (tRA) and all-trans-retinol (t-retinol), and t-retinol is 5-10-fold in excess over tRA. We cannot detect 9-cis-RA or any didehydroretinoids; thus mammalian embryos seem to differ in their retinoid content from other embryos such as chick, Xenopus, and fish. The levels of tRA do not change significantly over the 6 days of development analysed, whereas t-retinol rises sharply as the liver develops. Within the embryo, tRA is present at high levels in the developing spinal cord and at very low levels in the forebrain; indeed there is a gradient of endogenous tRA from the forebrain to the spinal cord. Other parts of the embryo had intermediate levels of tRA. When a teratogenic dose of RA was administered to day 10.5 embryos, the levels of tRA present in individual tissues of the embryo rose dramatically--from 175-fold to 1,400-fold--and the levels rose in all tissues not in any exclusive areas. We then determined which areas of the embryo were malformed by such a teratogenic dose. The lower jaw, palate, vertebrae, tail, and limbs were consistently abnormal, and since these areas received a dose of tRA no higher than any other it was concluded that cell-specific factors must determine the teratogenic response of these tissues. We then considered whether cellular retinoic acid-binding protein I or II (CRABP I or II) played any role in this response by determining their relative levels in each of the tissues analysed. There was no correlation between the presence of CRABP I and II and the distribution of administered RA. Neither was there a clear correlation in detail between the presence of CRABP I and II and the sites of teratogenesis. We therefore conclude that other factors, for example, nuclear factors, must be responsible for the teratogenic response to RA.

Animals↗

PubMed1995

Anteriorization of CRABP-I expression by retinoic acid in the developing mouse central nervous system and its relationship to teratogenesis.

We have investigated the role that cellular retinoic acid binding protein I (CRABP-I) may play in the development of the murine hindbrain. Since the central nervous system (CNS) represents a major site of the teratogenic action of retinoic acid (RA), we have also determined the effects of exposure of high levels of RA on CRABP-I expression within the CNS. Expression of CRABP-I can first be detected within the presumptive hindbrain of presomitic mouse embryos and later also appears in neural crest cells and neural crest derivatives; it is thus tissue specific at these early stages. Exposure of 7.75-day mouse embryos to RA induces two phenotypes: one is externally normal and the other is exencephalic. In the exencephalic embryos we show that there is abnormal crest migration, a fusion of the trigeminal and facial-acoustic ganglia, a rostral and lateral shift of the otic vesicle, and a loss of hindbrain rhombomeres. Furthermore, and in contrast to in vitro studies, we demonstrate that CRABP-I appears to be up-regulated in both phenotypes of mouse embryos treated with RA and that this up-regulation is accompanied by an anteriorization of its expression within the nervous system. This new CRABP-I expression domain thus retains its tissue specificity. The role that CRABP-I may play in normal development of the hindbrain and in teratogenesis and the similarity of these results to those obtained with various Hox genes are discussed.

Animals↗

PubMed1995

Relationship between donor-recipient blood group incompatibility and serum bilirubin after allogeneic bone marrow transplantation from HLA-identical siblings.

Data on 477 patients with hematologic malignancies undergoing allogeneic bone marrow transplantation from HLA-identical siblings were analyzed for correlation between donor-recipient ABO blood group incompatibility and the development of elevated bilirubin levels (over 17 mmol/l) after transplantation. The median bilirubin on day 15 after transplant and the maximum bilirubin in the first 100 days were significantly higher in 155 patients with ABO-mismatched donors compared with 322 patients with ABO-matched donors. In univariate analysis, age > 16 years (P = 0.000006), ABO incompatibility (P = 0.0004), a conditioning regimen other than cyclophosphamide-total body irradiation (P = 0.0005) and a diagnosis other than acute leukemia (P = 0.01) were associated with a higher probability of developing elevated bilirubin. Incidence of clinically diagnosed graft-versus-host disease (GVHD), and transplant-related mortality, relapse rates and overall survival were not influenced by ABO incompatibility. The hyperbilirubinemia was therefore unlikely to be the result of an increased incidence of hepatic complications such as GVHD or veno-occlusive disease. We suggest that studies on serious transplant-related complications such as GVHD and veno-occlusive disease which rely on bilirubin values for diagnosis should take donor-recipient ABO incompatibility into account.

Adolescent↗

PubMed1995

Autologous bone marrow or peripheral blood stem cell transplantation followed by maintenance chemotherapy for adult acute lymphoblastic leukemia in first remission: 50 cases from a single center.

The aim of this study was to evaluate the use of maintenance chemotherapy after autotransplantation in adult acute lymphoblastic leukemia (ALL), and to compare the relative durability of marrow and peripheral blood stem cell grafts to chemotherapy. Fifty consecutive ALL patients received 200 mg/m2 melphalan alone or 110 mg/m2 melphalan with total-body irradiation in first remission, followed by autologous marrow (ABMT, n = 38) or peripheral blood stem cells (PBSCT, n = 12). After hematologic recovery, 6-mercaptopurine and methotrexate were administered for 2 years. 6-mercaptopurine could be given to 78.9% of ABMT recipients at a median daily dose of 33.5 mg/m2, and to 91.7% of PBSCT recipients at a median daily dose of 44.1 mg/m2. ABMT recipients started 6-mercaptopurine at a median of 58.5 days post-transplant, and PBSCT recipients at 32 days (P = 0.002). 52.6% of ABMT recipients and 75% of PBSCT recipients received weekly methotrexate. No graft failure was seen as a result of chemotherapy. The actuarial 5-year probabilities of overall survival, survival in first remission and relapse were 56.2, 53.2, and 30.6%, respectively. We conclude that administration of maintenance chemotherapy after autografting in adult ALL may reduce relapse. A randomized study is required to evaluate the relative efficacy of PBSCT vs ABMT, and the role of post-transplant maintenance chemotherapy.

Adolescent↗