Platelet glycoprotein complex Ia/IIa antibodies cause neonatal alloimmune thrombocytopenia but do not inhibit megakaryopoiesis and platelet recovery after allogeneic cord blood stem cell transplantation

A sibling cord blood (CB) transplantation was performed in a boy with Wiskott-Aldrich syndrome. The CB (31 x 10(6) CD34(+) cells) derived from a newborn sister with neonatal alloimmune thrombocytopenia (NAIT) with 40,000 platelets/microl, caused by a maternal anti-HPA-5b and HLA-A2 antibody. Maternal serum did not inhibit clonogenicity after in vitro testing of megakaryopoiesis. Accordingly, this CB was accepted for sibling transplantation. The transplantation showed a good course with fast and sustained hematopoietic reconstitution (granulocytes >500/microl on day +16, platelets >50,000/microl on day +30). This case demonstrates a successful CB transplantation from a donor suffering from NAIT.

Association of complementation group and mutation type with clinical outcome in fanconi anemia. European Fanconi Anemia Research Group

Fanconi anemia (FA) is a clinically and genetically heterogeneous disorder. Clinical care is complicated by variable age at onset and severity of hematologic symptoms. Recent advances in the molecular biology of FA have allowed us to investigate the relationship between FA genotype and the nature and severity of the clinical phenotype. Two hundred forty-five patients from all 7 known complementation groups (FA-A to FA-G) were studied. Mutations were detected in one of the cloned FANC genes in 169 patients; in the remainder the complementation group was assigned by cell fusion or Western blotting. A range of qualitative and quantitative clinical parameters was compared for each complementation group and for different classes of mutation. Significant phenotypic differences were found. FA-G patients had more severe cytopenia and a higher incidence of leukemia. Somatic abnormalities were less prevalent in FA-C, but more common in the rare groups FA-D, FA-E, and FA-F. In FA-A, patients homozygous for null mutations had an earlier onset of anemia and a higher incidence of leukemia than those with mutations producing an altered protein. In FA-C, there was a later age of onset of aplastic anemia and fewer somatic abnormalities in patients with the 322delG mutation, but there were more somatic abnormalities in patients with IVS4 + 4A --> T. This study indicates that FA patients with mutations in the FANCG gene and patients homozygous for null mutations in FANCA are high-risk groups with a poor hematologic outcome and should be considered as candidates both for frequent monitoring and early therapeutic intervention. (Blood. 2000;96:4064-4070)

Spectrum of mutations in the Fanconi anaemia group G gene, FANCG/XRCC9

FANCG was the third Faconi anaemia gene identified and proved to be identical to the previously cloned XRCC9 gene. We present the pathogenic mutations and sequence variants we have so far identified in a panel of FA-G patients. Mutation screening was performed by PCR, single strand conformational polymorphism analysis and protein truncation tests. Altogether 18 mutations have been determined in 20 families - 97% of all expected mutant alleles. All mutation types have been found, with the exception of large deletions, the large majority is predicted to lead to shortened proteins. One stop codon mutation, E105X, has been found in several German patients and this founder mutation accounts for 44% of the mutant FANCG alleles in German FA-G patients. Comparison of clinical phenotypes shows that patients homozygous for this mutation have an earlier onset of the haematological disorder than most other FA-G patients. The mouse Fancg sequence was established in order to evaluate missense mutations. A putative missense mutation, L71P, in a possible leucine zipper motif may affect FANCG binding of FANCA and seems to be associated with a milder clinical phenotype.

Transplant activities in Germany in 1998--a survey facilitated by the National Registry for Hemopoietic Stem Cell Transplantation

To improve the infrastructure of hemopoietic stem-cell transplantations in our country, the German Registry for Hemopoietic Stem-Cell Transplantations (DRST) was established in 1998. The present paper summarizes the current status of the DRST and gives a survey of transplant activities in Germany in 1998 in terms of transplant units, transplant types, transplant frequencies and underlying diseases.

Immunomagnetic selection of CD34+ cells: factors influencing component purity and yield

BACKGROUND

In immunomagnetic selection of CD34+ cells from HPC transplants, not all factors that affect yield and purity of CD34+ cells are known.

METHODS

Forty-three consecutive procedures of immunomagnetic selection of CD34+ cells from peripheral blood HPCs and bone marrow harvests (autologous harvests, n = 27; allogeneic harvests; n=16) were performed by use of a cell selection system (Isolex 300i, Baxter Immunotherapy). The composition of the starting component and the subsets of CD34+ cells were analyzed for correlation with the yield and purity of the final component.

RESULTS

The mean purity of the final components was 84.3 percent (range, 27-99%), and the mean yield was 51.4 percent (range, 9.4-80. 4%). Partial regression analysis showed that, among the factors correlating with purity and/or yield, the RBC volume in the starting fraction had the highest predictive impact on the purity and yield of CD34+ cells, even after the exclusion of procedures using bone marrow harvests as an HPC source (beta coefficient, -0.704; p = 0. 001).

CONCLUSION

The use of the Isolex 300i system allows efficient recovery of CD34+ cells in routine selection procedures. The volume of RBCs in the starting component should be minimized to ensure a high yield and purity of the final component.

Improved treatment results in childhood B-cell neoplasms with tailored intensification of therapy: A report of the Berlin-Frankfurt-Münster Group Trial NHL-BFM 90

In study NHL-BFM 90, we investigated whether the serum lactate dehydrogenase (LDH) concentration and early response are useful markers for stratification of therapy for childhood B-cell neoplasms in addition to stage, if the outcome of patients with abdominal stage III and LDH >/=500 U/L can be improved by high-dose (HD) methotrexate (MTX) at 5 g/m(2) instead of intermediate-dose (ID) MTX at 500 mg/m(2) in the preceding study 86; whether 2 therapy courses are enough for patients with complete resection; and whether combined systemic and intraventricular chemotherapy is efficacious for central nervous system-positive (CNS(+)) patients. After a cytoreductive prephase, treatment was stratified into 3 risk groups: patients in R1 (completely resected) received 2 5-day courses (ID-MTX, dexamethasone, oxazaphorins, etoposide, cytarabine, doxorubicin, and intrathecal therapy), patients in R2 (extra-abdominal primary only or abdominal tumor and LDH <500 U/L) received 4 courses containing HD-MTX, and patients in R3 (abdominal primary and LDH >/=500 U/L or bone marrow/CNS/multilocal bone disease) received 6 courses. Incomplete responders after 2 courses received an intensification containing HD-cytarabine/etoposide. Patients with no or necrotic tumor thereafter received 3 more courses; 6 patients with viable tumor received autologous bone marrow transplantation. From April 1990 through March 1995, 413 evaluable patients were enrolled (R1, 17%; R2, 40%; and R3, 43%). The 6-year event-free survival (pEFS) was 89% +/- 2% for all and 100%, 96% +/-2%, and 78% +/- 3% in R1, R2, and R3, respectively. The pEFS of patients with abdominal stage III and LDH >/=500 U/L was 81% +/- 4% as compared with 43% +/- 10% in study 86. Of 26 CNS(+) patients, 5 died early, but only 3 relapsed.

Heterogeneous spectrum of mutations in the Fanconi anaemia group A gene

Fanconi anaemia (FA) is a genetically heterogeneous autosomal recessive disorder associated with chromosomal fragility, bone-marrow failure, congenital abnormalities and cancer. The gene for complementation group A (FAA), which accounts for 60-65% of all cases, has been cloned, and is composed of an open reading frame of 4.3 kb, which is distributed among 43 exons. We have investigated the molecular pathology of FA by screening the FAA gene for mutations in a panel of 90 patients identified by the European FA research group, EUFAR. A highly heterogeneous spectrum of mutations was identified, with 31 different mutations being detected in 34 patients. The mutations were scattered throughout the gene, and most are likely to result in the absence of the FAA protein. A surprisingly high frequency of intragenic deletions was detected, which removed between 1 and 30 exons from the gene. Most microdeletions and insertions occurred at homopolymeric tracts or direct repeats within the coding sequence. These features have not been observed in the other FA gene which has been cloned to date (FAC) and may be indicative of a higher mutation rate in FAA. This would explain why FA group A is much more common than the other complementation groups. The heterogeneity of the mutation spectrum and the frequency of intragenic deletions present a considerable challenge for the molecular diagnosis of FA. A scan of the entire coding sequence of the FAA gene may be required to detect the causative mutations, and scanning protocols will have to include methods which will detect the deletions in compound heterozygotes.

Different binding mechanisms of myeloid leukemic cells to adhesion molecules on bone marrow stromal fibroblasts induced by TNF-alpha and IL-4

To study the mechanisms of adhesion of myeloid leukemic cells to bone marrow stroma, we analyzed the interaction of bone marrow stromal fibroblasts with myeloid leukemic cell lines and the modulation of adhesion molecule expression on stromal fibroblasts by TNF-alpha and IL-4. Like others, we found up-regulation of VCAM-1 and ICAM-1 on fibroblasts with TNF-alpha treatment, whereby IL-4 acted synergistically with TNF-alpha. VCAM-1 expression on the cell surface was maximal after 10 h, while ICAM-1 expression increased up to 48 h. All myeloid leukemic cell lines tested (HL-60, K562, TMM, U937, ML-2, PLB-985, THP-1, KG1a) revealed weak adhesion to untreated bone marrow fibroblasts (< or =10% bound cells). TNF-alpha and IL-4 significantly enhanced adhesiveness of fibroblasts to the cell lines PLB-985, THP-1, and ML-2, with a peak between 6 and 10 h of treatment. Adhesiveness to the cell line TMM was increased up to eightfold in a time-dependent manner for up to 48 h. The enhanced binding of ML-2-, THP-1-, and PLB-985 cells to stimulated fibroblasts was due at least partially to the interaction of VLA-4 with VCAM-1. Increased adhesion of TMM cells was impaired neither by antibodies to VLA-4, LFA-1, or Mac-1 nor by antibodies to their counter-receptors VCAM-1 or ICAM-1, suggesting that adhesion molecules distinct from VCAM-1 or ICAM-1 are involved in enhanced adhesiveness of the fibroblasts to myeloid leukemic cells.

Relapse and clonal disease in children with aplastic anemia (AA) after immunosuppressive therapy (IST): the SAA 94 experience. German/Austrian Pediatric Aplastic Anemia Working Group

Since the introduction of combined immunosuppressive therapy (IST) into management of aplastic anemia (AA) in childhood response and probability of survival improved. In contrast to bone marrow transplantation (BMT), however, patients after IST are not considered cured as high rates of relapse and development of clonal disease demonstrate. From 11/93 to 9/97 114 children (65 m, 49 f; median age 9.5 y.) from 37 centers in Germany and Austria were registered in the SAA 94 study. 86 patients lacking a matched sibling donor received IST. Most of the patients suffered from very severe (VSAA: PMN < 200/microliter) or severe AA (SAA: PMN < 500/microliter). All patients were treated with combined IST consisting of ALG and Cyclosporin A (CSA). VSAA and SAA patients were additionally treated with G-CSF. Therapy response was evaluated at day 112, after 6, 12 and 18 months. 8/86 patients died, the probability of survival being 87% after 4 years. At d 112 61% of evaluable patients became independent of transfusions (IST response: CR + PR), 13% with normal blood counts (CR). After 6 months 33% showed CR. At 12 and 18 months response improved to 74% resp. 80%, 39% resp. 55% CR. The best response was achieved in the subgroup of VSAA with 90% (PR + CR) and 65% CR after 18 months. 4 patients developed AML 3-19 months after the beginning of IST. In 2/4 pts. an aberrant clone (-7; 5q-) could be detected retrospectively in BM at diagnosis of AA. 3 nonresponders developed chromosomal aberrations (+19; -7, +12; +8) after 4, 12 and 16 months without morphological signs of AML or MDS. Overall 11 relapses occurred at a median time of 12 months (range 5-27 months) after the beginning of IST. 2 of them relapsed under CSA therapy, 2 under tapering of CSA and 7 after cessation of CSA. 7 patients responded again to CSA monotherapy. Overall response rate is 77% with a probability of event free survival (EFS) of 54% after 4 years regarding all complications mentioned as events.

Allogeneic bone marrow transplantation for a subset of children with acute lymphoblastic leukemia in third remission: a conceivable alternative?

In the BFM Relapse Study registry we retrospectively identified 136 patients with a first marrow relapse who had undergone BMT in second complete remission (CR2) (group A) and 33 patients who received transplants only after a 2nd bone marrow (BM) relapse had occurred (group B). Event-free survival (EFS) rates at 6 years after BMT were 0.49 +/- 0.05 and 0.48 +/- 0.09 for patients transplanted in CR2 and CR3, respectively. In context with the BFM chemotherapy trials for relapsed childhood ALL there is a clear benefit from BMT in 2nd CR for children with unfavorable prognostic features (isolated early BM relapse, very early BM relapse or BM relapse of T cell ALL). Similar control of leukemia can be achieved with either chemotherapy or BMT in late BM relapse of ALL. Assuming a 60% failure rate with chemotherapy for patients in second relapse, a third remission can be achieved in about 60% of patients who have received chemotherapy, rendering them eligible for BMT in 3rd CR. With this strategy 58% of these patients would survive and late sequelae of BMT be restricted to a minority. To withhold BMT in CR2 and not perform BMT before a 2nd BM relapse has occurred, may be a conceivable alternative for children with late ALL BM relapse, at least if no related donor is available.

Evidence for at least eight Fanconi anemia genes

Fanconi anemia (FA) is an autosomal recessive chromosomal breakage disorder with diverse clinical symptoms including progressive bone marrow failure and increased cancer risk. FA cells are hypersensitive to crosslinking agents, which has been exploited to assess genetic heterogeneity through complementation analysis. Five complementation groups (FA-A through FA-E) have so far been distinguished among the first 20 FA patients analyzed. Complementation groups in FA are likely to represent distinct disease genes, two of which (FAC and FAA) have been cloned. Following the identification of the first FA-E patient, additional patients were identified whose cell lines complemented groups A-D. To assess their possible assignment to the E group, we introduced selection markers into the original FA-E cell line and analyzed fusion hybrids with three cell lines classified as non-ABCD. All hybrids were complemented for cross-linker sensitivity, indicating nonidentity with group E. We then marked the three non-ABCDE cell lines and examined all possible hybrid combinations for complementation, which indicated that each individual cell line represented a separate complementation group. These results thus define three new groups, FA-F, FA-G, and FA-H, providing evidence for a minimum of eight distinct FA genes.

[Transplantation of hematopoietic stem cells. II: Indications for transplantation of hematopoietic stem cells after myeloablative therapy]

The destruction of hematopoiesis and lymphopoiesis by total body irradiation or high dose chemotherapy for the treatment of malignancy can be reversed by the transplantation of allogeneic or autologous hematopoietic stem cells. In primary disorders of bone marrow or immune system, allogeneic stem cells replace deficient cells. Acute leukemias can be cured, with in 50 to 80% disease free survival after 5 to 8 years. The allogeneic graft versus leukemia effect by immunoreactive cells reduces the relapse rate in myeloid and lymphoid malignancies. 40 to 70% of patients with chronic myeloid leukemia remain disease free after more than 5 years. Patients with malignant lymphoma have a 40 to 70% chance of cure with autologous transplantation, which is not increased by allogeneic cells, because of a higher incidence of severe complications. An increasing number of patients without option for cure is treated with the aim of prolonging remission or retarding disease progression, such as in chronic myeloid leukemia, multiple myeloma and certain solid tumors. New studies suggest in breast cancer with axillary lymph node metastases, that adjuvant high dose chemotherapy with autologous stem cell support will significantly improve disease free survival from 30 to over 60% after 3 to 5 years. In congenital metabolic and storage diseases deficient enzymes are substituted by the allogeneic cells. Clinical trials explore the use of stem cell transplantation after myeloablative therapy in autoimmune disorders as well as in gene therapy with transfected hematopoietic stem cells.

German consensus on immunogenetic donor search for transplantation of allogeneic bone marrow and peripheral blood stem cells

In Germany allotransplantation of bone marrow or peripheral blood stem cells is presently performed by 34 different teams operating more or less independently. Thus, strategies of immunogenetic donor search, use of the various tissue typing techniques and policy on acceptable HLA mismatches in related and unrelated settings may vary considerably from one transplant centre to another. This paper summarises the results of the first German consensus meeting on immunogenetic donor search for bone marrow/peripheral blood stem cell grafting. The main goal of the participating transplant physicians and immunogeneticists was to define national standards for the above issues.

Allogeneic bone marrow transplantation for chronic myelomonocytic leukemia in childhood: a report from the European Working Group on Myelodysplastic Syndrome in Childhood

PURPOSE

To evaluate the role of allogeneic bone marrow transplantation (BMT) in children with chronic myelomonocytic leukemia (CMML).

PATIENTS AND METHODS

Forty-three children with CMML given BMT and reported to the European Working Group on Myelodysplastic Syndrome in Childhood (EWOG-MDS) data base were evaluated. In 25 cases, the donor was a human leukocyte antigen (HLA)-identical or a one-antigen-disparate relative, in four cases a mismatched family donor, and in 14 a matched unrelated donor (MUD). Conditioning regimens consisted of total-body irradiation (TBI) and chemotherapy in 22 patients, whereas busulfan (Bu) with other cytotoxic drugs was used in the remaining patients.

RESULTS

Six of 43 patients (14%), five of whom received transplants from alternative donors, failed to engraft. There was a significant difference in the incidences of chronic graft-versus-host disease (GVHD) between children transplanted from compatible/one-antigen-mismatched relatives and from alternative donors (23% and 87%, respectively; P < .005). Probabilities of transplant-related mortality for children given BMT from HLA-identical/one-antigen-disparate relatives or from MUD/ mismatched relatives were 9% and 46%, respectively. The probability of relapse for the entire group was 58%, whereas the 5-year event-free survival (EFS) rate was 31%. The EFS rate for children given BMT from an HLA-identical sibling or one-antigen-disparate relative was 38%. In this latter group, patients who received Bu had a better EFS compared with those given TBI (62% v 11%, P < .01).

CONCLUSION

Children with CMML and an HLA-compatible relative should be transplanted as early as possible. Improvement of donor selection, GVHD prophylaxis, and supportive care are needed to ameliorate results of BMT from alternative donors.

[Transplantation of hematopoietic stem cells. I: Definitions, principle indications, complications]

The transplantation of hematopoietic and lymphopoetic stem and progenitor cells has become a standard procedure for the treatment of many malignant diseases. Autologous stem cells are derived from the patient himself, allogeneic cells from an HLA-identical or HLA-compatible family or unrelated donor. Hematopoietic stem cells can be obtained from bone marrow, blood and fetal cord blood. After 3 to 5 days treatment, the granulocyte-colony stimulating factor (G-CSF) mobilizes stem- and progenitor cells from the marrow into the blood. This method is now standard in autologous transplantation and is increasingly preferred in allogeneic transplantation. The time to hematopoietic recovery is shorter with blood stem cells than with bone marrow cells. With myeloablative high dose therapy followed by stem cell transplantation, long term disease free survival is possible in many cases and great proportions of patients can be cured (see part II). Improvements of supportive care have reduced toxicity of treatment substantially, however severe complications still occur at oropharynx, gastrointestinal tract, liver, lung, skin, kidney, urinary tract and nervous system. After allogeneic transplantation immunocompetent donor cells can react with the recipients tissue. In HLA-identical donor and recipients differences in the minor histocompatibility antigens account for this graft-versus-host-reaction (GvH), which is mainly mediated by transplanted T-cells. The GvH-reaction can affect skin, liver, gut and other organs and cause clinically relevant GvH-disease (GvHD). The GvHD is more severe in HLA-mismatched or unrelated transplantations. Immunodeficiency and organ dysfunction due to GvHD may predispose infections and impair the outcome of transplantation. Unrelated cord blood stem cells may have a minor risk of inducing acute GvHD, as stem and T-cells are immature. After allogeneic stem cell transplantation, the relapse rate of leukemia or lymphoma is significantly reduced by immunoreactive cells:graft-versus-tumor (GvT) or graft-versus-leukemia effect (GvL).

Which children do benefit from bone marrow transplant? The EBMT Paediatric Diseases Working Party

The development of chemotherapy in childhood ALL has been the leader of the success story of paediatric oncology. At least 2/3 of the children can be cured nowadays at the first attempt of treatment. From the remaining again 1/3 can be treated successfully for the relapse of their disease with conventional therapeutic strategies. This means, however, that there is no chance for cure with chemotherapy alone for 20 to 25% of the children. BMT has been shown for a long time to be an alternative therapy especially in those cases in which conventional chemotherapy fails. In spite of the fact that many children with ALL have been transplanted during recent years there is still no general agreement on the question which children need BMT. However a few statements can be made: The value of ABMT in ALL is probably not better than that of chemotherapy alone. In 1st CR a group of children can be defined, which might benefit from BMT. In 2nd CR the value of chemotherapy depends very much from the duration of 1st remission. Allogeneic BMT is the only chance for cure in very early relapses, superior to chemotherapy in early and late relapses and possibly equal to chemotherapy in very late relapses. The paper tries to summarise our current knowledge about the situation.

[10 years transplantation of bone marrow and hematopoietic stem cells in adults at the Hannover Medical School]

PATIENTS AND METHODS

From January 1986 until August 1995 230 adult patients received an allogeneic or autologous transplantation of bone marrow or hematopoietic blood stem cells. The conditioning and myeloablative treatment regimens were chosen according to the underlying disease and type of transplant.

RESULTS

The observation period comprises 1 to 115 months after transplantation. After allogeneic transplantation from HLA-identical family donors, the probabilities of disease-free survival were for acute myeloid leukemia in first complete remission (CR) (n = 35) 77%, for acute lymphoid leukemia in 1st CR (n = 7) 72% and in 2nd CR (n = 10) 40%, in first chronic phase of chronic myeloid leukemia (n = 34) 50% and in severe aplastic anemia (n = 7) 100%. Following myeloablative therapy and autologous transplantation the probabilities of disease-free survival were 47% in relapsed Hodgkin's disease (n = 22) and 42% for relapsed high-grade non-Hodgkin's lymphoma (n = 12). Eight of 10 patients with acute myeloid and 7 of 8 with acute lymphoid leukemia suffered a leukemic relapse after autologous bone marrow transplantation. Three of 8 patients with relapsed testicular cancer survived relapse-free. Treatment failures were due to more advanced acute graft versus host disease after allogeneic transplantation and caused by relapse after autologous transplantation. Current protocols evaluate the allogeneic transplantation of enriched CD34+ blood stem cells. In chronic myeloid leukemia the autologous transplantation of blood stem cells after myeloablative therapy is being studied.

Effects of bone marrow fibroblasts on the proliferation and differentiation of myeloid leukemic cell lines

The effects of normal bone marrow fibroblasts (BM FB) on proliferation and differentiation of 10 myeloid leukemic cell lines were investigated in a serum-free co-culture system. The proliferation of three of the cell lines was supported by BM FB. Three of the myeloid cell lines were inhibited 40-70%. The co-culture supernatants were tested for the secretion of hematopoietic cytokines by bioassays. Except for IL-6, which was already produced constitutively by BM FB, only little amounts of interleukin-1 (IL-1), granulocyte colony-stimulating factor (G-CSF), or granulocyte-macrophage colony-stimulating factor (GM-CSF) could be detected in several co-culture supernatants. It could be shown that, according to cytologic and functional criteria, the myeloid leukemic cell lines ML-2 and PLB-985 differentiate along the monocyte-macrophage pathway after co-culture with BM FB. They revealed a histiocytic phenotype and could be induced to produce reactive oxygen intermediates (ROI) after stimulation with zymosan or phorbol-myristate-acetate (PMA). Additional proof for differentiation was obtained from flow cytometric analysis of surface differentiation antigens and adhesion molecules. The neutralization of IL-6 activity in the co-cultures by antibodies resulted in prevention of differentiation of PLB-985 cells, while differentiation of ML-2 cells in the co-cultures was not affected by addition of anti-IL-6 antibodies. Furthermore, in co-culture experiments with fibroblasts from skin and foreskin, we found a differentiation of PLB-985 cells comparable to that in co-cultures with BM FB, but poor differentiation of ML-2 cells. These data suggest that different mechanisms are involved in the differentiation of ML-2 and PLB-985 cells.

Autologous bone-marrow transplants compared with chemotherapy for children with acute lymphoblastic leukaemia in a second remission: a matched-pair analysis. The Berlin-Frankfurt-Münster Study Group

It is unclear how best to treat children with acute lymphoblastic leukaemia (ALL) who are in a second remission. Treatment with bone-marrow transplants from HLA-identical siblings results in a statistically greater likelihood of leukaemia-free survival than does chemotherapy. Less than 25% of relapsed patients are able to benefit from this therapy due to a lack of matching donors; chemoradiotherapy or autologous BMT are considered for the rest. We compared treatment results for children who underwent autologous BMT with those who had chemotherapy. All patients were registered between 1983-94 in the multicentre trials. We selected groups of patients by matching variables associated with treatment outcome and duration of second remission. 52 matched-pairs were studied. The probability of event-free survival at 9 years was 0.32 (SD 0.07) for patients receiving chemotherapy versus 0.26 (SD 0.07) for patients who underwent autologous BMT. For two groups--children with prognostic factors indicating high risk of relapse and those with factors indicating lower risk--the outcome from transplantation did not differ significantly from that of chemotherapy: no advantage of autologous BMT over chemotherapy as post-induction treatment for children with ALL in a second remission could be detected with regard to event-free survival. Because autologous BMT has been used as the final step of treatment it is possible that its relative ineffectiveness has been due to the lack of continuation therapy after transplant. Attempts should be made to complement autologous BMT by subsequent immunotherapy, molecular biotherapy, chemotherapy, or a combination of these.

Isolated extramedullary relapse in children with acute lymphoblastic leukemia: a comparison between treatment results of chemotherapy and bone marrow transplantation. BFM Relapse Study Group

The purpose of this study was to determine the therapeutic efficacy of different treatment strategies, namely chemotherapy, allogeneic and autologous bone marrow transplantation (BMT), for extramedullary relapse of acute lymphoblastic leukemia (ALL) in children in second or subsequent remission. Between 1983 and 1993, 165 patients up to 19 years of age with extramedullary relapse of ALL were registered in the multicenter ALL-REZ BFM trials. One hundred and thirty four children received chemotherapy only; 17 children were grafted from HLA-identical sibling donors 152 days (46-392 days) after diagnosis of relapse, and 14 children underwent autologous BMT after a median time of 137 (range 23-300) days. Event-free survival (EFS) at 5 years was 0.47 +/- 0.05 for patients receiving chemotherapy: 0.76 +/- 0.07 for late, 0.33 +/- 0.08 for early and 0.33 +/- 0.07 for very early relapsed patients. Sixty five patients are in complete remission (CR), 61 patients relapsed, 5 died from therapy related complications, 2 patients in CR were lost to follow-up and one patient developed a second malignancy. For patients who had undergone BMT, EFS at 5 years was 0.36 +/- 0.10 without significant difference between autologous BMT (8 of 14 in CR, 6 relapsed) and allogeneic BMT (6 of 17 in CR, 4 died of acute toxicity, and 7 relapsed).(ABSTRACT TRUNCATED AT 250 WORDS)

Extramedullary erythropoiesis in human liver grafts

Extramedullary erythropoiesis in the adult is very rare and is generally confined to situations of severe bone marrow irritation or replacement. In this study, we describe the occurrence of intrahepatic erythropoiesis in patients who have received a liver allograft and who have no evidence of bone marrow dysfunction. By routinely performed transplant aspiration cytology (TAC), marked intrahepatic erythropoiesis could be detected in 39 of 312 patients (12.5%) with liver allograft. In 19 patients, including 5 of 8 (63%) after combined liver and kidney transplantation, intrahepatic erythropoiesis occurred within the first 3 weeks after surgery. Twenty patients showed intrahepatic erythropoiesis between 3 weeks and 4 months after transplantation. Erythropoiesis was usually transient, lasting between 1 and 3 weeks. Cytologically, mature as well as immature erythroblasts of GlyA+ CD36+ CD45- phenotype could be detected in the grafts, whereas they were absent in blood; histologically, the cells could be localized to the sinusoids of the liver. There was no clear correlation of preoperative or postoperative hemoglobin levels, graft function, kidney function, and immunosuppressive medication with the presence or absence of erythropoiesis. Moreover, serum levels of erythropoietin (EPO) and stem cell factor (SCF) in patients with and without intrahepatic erythropoiesis in the early postoperative phase did not show significant differences. These findings show that intrahepatic erythropoiesis can occur transiently in human liver allografts and suggest that systemic stimuli as well as local factors may contribute to it.

Can busulfan replace fractionated total body irradiation as conditioning regimen for allogeneic bone marrow transplantation in children with acute lymphoblastic leukemia

The results of allogenic bone marrow transplantation (allo-BMT) in 26 children with ALL treated with the same initial- and relapse-BFM-protocols, but transplanted in different centers (Poznań, Wroclaw, Hannover) after conditioning with two different regimens have been compared. Ten children (6 in Poznań, 4 in Wroclaw) were conditioned for BMT with busulfan and cyclophosphamide when fractionated TBI (FTBI) was not available there. Sixteen children obtained FTBI and etoposide (11 in Hannover, where in children with ALL exclusively chemoradioconditioning regimen has been employed, and 5 in Poznań). It has been found, that the chemoconditioning procedure was probably less effective (5-year EFS 18%) than the regimen with FTBI (7-year EFS 60%). Therefore, TBI seems to be at this point still mandatory in pediatric ALL patients, unless combinations of chemotherapeutic drugs might be able to substitute the radiation in the future.