Management of acquired aplastic anemia in children.

The diagnosis of aplastic anemia in children requires exclusion of a variety of inherited or acquired BM failure syndromes with similar phenotypes. An efficient diagnostic plan is important because time from diagnosis to 'final' treatment is directly related to outcome regardless of the therapeutic option chosen. The gold standard of therapy remains hematopoietic SCT with a graft of BM cells for those children with matched sibling donors. Conversely for children without a sibling donor the high response and markedly improved overall survival rates of combined immunosuppressive therapy have proven robust, especially when horse derived anti-thymocyte globuline plus ciclosporine A are used. Incomplete response, relapse and progression to myelodysplasia/leukemia however have emerged as significant long-term issues. Improvements in outcome of alternative donor transplantation and the use of established and novel immunosuppressive agents provide multiple alternatives for treating refractory or relapsed patients. Regardless of the type of therapeutic approach, patients require centralized treatment in a center of excellence, ongoing monitoring for recurrence of disease and/or therapy-related immediate side effects and long-term effects.

Long-term follow-up of HCV-infected hematopoietic SCT patients and effects of antiviral therapy.

This prospective study was initiated in 1993 with the aim to study late effects and responses to antiviral therapy in a cohort of hepatitis C virus (HCV)-infected patients. A total of 195 patients were included from 12 centers. In all, 134 patients had undergone allogeneic and 61 autologous hematopoietic SCT (HSCT). The median follow-up from HSCT is currently 16.8 years and the maximum 27.2 years. Overall 33 of 195 patients have died of which 6 died from liver complications. The survival probability was 81.6% and the cumulative incidence for death in liver complications was 6.1% at 20 years after HSCT. The cumulative incidence of severe liver complications (death from liver failure, cirrhosis and liver transplantation) was 11.7% at 20 years after HSCT. In all, 85 patients have been treated with IFN; 42 in combination with ribavirin. The sustained response rate was 40%. The rates of severe side effects were comparable to other patient populations and no patient developed significant exacerbations of GVHD. Patients receiving antiviral therapy had a trend toward a decreased risk of severe liver complications (odds ratio=0.33; P=0.058). HCV infection is associated with morbidity and mortality in long-term survivors after HSCT. Antiviral therapy can be given safely and might reduce the risk for severe complications.

Use of intrathecal chemoprophylaxis in children after SCT and the risk of central nervous system relapse.

Conflicting conclusions can be drawn from the available data concerning antileukemic efficacy and risks of intrathecal (i.t.) chemoprophylaxis to children after hematopoietic SCT (HSCT). To address this, we enrolled six transplantation centers with similar treatment and patient material. Of the 397 children included, 136 patients had received post-HSCT i.t. treatment (i.t. group) and 261 had not (non-i.t. group). The two groups were, apart from the i.t. therapy given or not given, at equal risk of post-HSCT central nervous system (CNS) relapse, which was the primary endpoint studied. Isolated CNS relapses were observed in 2 (1.5%) patients from the i.t. group and 2 (1%) from the non-i.t. group. Combined relapses, including CNS, involved 4 (3%) patients from the i.t. group and 6 (2%) from the non-i.t. group. Overall survival and the occurrence of neurological side effects did not differ significantly between the groups. There was no statistically significant difference in the incidence of isolated or mixed CNS relapses between the two groups, suggesting little or no benefit from i.t. therapy post-HSCT in children.

Endocrinological late complications after hematopoietic SCT in children.

The main challenge for a pediatric hemato-oncologist today is to obtain a cure for the sick child with the minimum of treatment-related complications. Children on their way to achieving adulthood face many risks after hematopoietic SCT (HSCT). Continuous follow-up includes assessment of organ function, focus on vaccinations and screening for secondary malignancies. Updated treatment protocols are already adjusted according to the knowledge obtained on late effects, and the potential risks for complications are well balanced with expected benefits hopefully resulting in decreased potential risk for organ damage but still maintaining an unchanged or improved survival rate. Recent developments on pre-HSCT regimens, such as the introduction of new anticancer regimens and immunosuppressive agents will hopefully contribute to minimize the frequency and the severity of late complications. Knowledge about increased risk for long-term complications due to cancer therapy and pre-HSCT preparative regimens should encourage each caring physician to stick to follow-up protocols and treatment guidelines not only to improve the survival rate of transplanted children but also to improve their quality of life. To achieve adulthood by maintaining cognitive ability and psychosocial skills is the highest goal for an individual to become a competent member of a society. This review of late endocrine complications after HSCT focuses on growth, pubertal development, thyroid disorders and glucose metabolism in long-term survivors.

Non-endocrine late complications in children after allogeneic haematopoietic SCT.

Non-endocrine events represent a heterogeneous group of complications occurring in children who survive long term after haematopoietic SCT. This review highlights the late sequel in a growing child. The preparative regimen itself with high-dose chemotherapy and/or radiotherapy (TBI) or the treatment given before the transplant procedure may cause organ damage with permanent sequel. Immune reconstitution and chronic GvHD have crucial role in occurrence of clinical abnormalities and late severe infections. Autoimmune syndromes may occur after use of novel transplant modalities (cord blood transplantation, reduced intensity conditioning regimen and haploidentical T-cell-depleted SCTs). Exposure to chemo- and/or radiotherapy increases the risk of second malignant neoplasms. Surveillance strategy focusing on each potential complication risk at continuous follow-up will allow vigilant post transplant care. Each paediatrician must be well versed in appropriate monitoring of these complications. Guidelines and recommendations are provided for serious problems occurring at follow-up, which must rapidly be identified so that appropriate intervention can be initiated. To achieve cure at a lowest possible price in terms of suffering and cost expenditures for health care is an extended frontier of paediatric haematopoietic SCT and biggest challenge for a paediatrician.

Recent improvement in outcome of unrelated donor transplantation for aplastic anemia.

The aim was to determine whether outcome of unrelated donor transplantation for severe aplastic anemia has improved in recent years and whether this is due to patient selection or better transplant technology. We analyzed 498 patients transplanted during 1990-2005. By running univariate regression models dichotomizing year of transplantation we defined 1998 as the year of the most significant change in survival. Five-year survival increased from 32+/-8% before 1998 to 57+/-8% after 1998 (P<0.0001). When comparing the cohort before (n=149) and after 1998 (n=349), there were no differences except for older age, and more frequent use of PBSCs, after 1998. High-resolution HLA typing data were unavailable. After 1998, there was less graft failure (11 vs 26%, P<0.0001), less acute GvHD (cumulative incidence 28 vs 37%, P=0.02) and less chronic GvHD (22 vs 38%, P=0.004). In multivariate analyses adjusting for differences in age, HLA-mismatch, performance score and time to transplantation, there was no change in the year of transplant effect (relative risk of death in transplants after 1998: 0.44 (95% confidence interval 0.33-0.59)). There is no evidence for patient selection to explain significantly improved survival in patients transplanted after 1998. We speculate that this is due to better donor matching.

Imatinib mesylate is effective in children with chronic myelogenous leukemia in late chronic and advanced phase and in relapse after stem cell transplantation.

A multicentric phase 2 study was conducted to determine the efficiency and the tolerance of imatinib mesylate in children with chronic myelogenous leukemia (CML) in advanced phase of the disease, in relapse after stem cell transplantation, or in case of failure to an interferon alpha-based regimen. In all, 30 children from eight European countries were enrolled. In 18 children assessable for hematologic response, imatinib mesylate induced complete hematologic response in eight (80%) of the 10 patients included in chronic phase and in six (75%) of eight enrolled in advanced phase of the disease with acceptable toxicity. In 27 patients assessable for cytogenetic response, imatinib mesylate induced disappearance of Philadelphia chromosome-positive bone marrow cells in 12 (60%) of 20 children included in chronic phase and in two (29%) of seven included in advanced phase. A reduction of the bcr-abl/abl ratio to less than 10(-4) was achieved in 11 (50%) of the children included in chronic phase. Estimated 12-month overall survival rate was 95% (95% CI, 87-100%) for the patients included in chronic phase and 75% (95%CI, 45-100%) for those enrolled in advanced phase. Imatinib mesylate is well tolerated and molecular remission can be achieved in children with CML.

A novel and cytogenetically cryptic t(7;21)(p22;q22) in acute myeloid leukemia results in fusion of RUNX1 with the ubiquitin-specific protease gene USP42.

Although many of the chromosomal abnormalities in hematologic malignancies are identifiable cytogenetically, some are only detectable using molecular methods. We describe a novel cryptic t(7;21)(p22;q22) in acute myeloid leukemia (AML). FISH, 3'RACE, and RT-PCR revealed a fusion involving RUNX1 and the ubiquitin-specific protease (USP) gene USP42. The genomic breakpoint was in intron 7 of RUNX1 and intron 1 of USP42. The reciprocal chimera was not detected - neither on the transcriptional nor on the genomic level - and FISH showed that the 5' part of USP42 was deleted. USP42 maps to a 7p22 region characterized by segmental duplications. Notably, 17 kb duplicons are present 1 Mb proximal to USP42 and 3 Mb proximal to RUNX1; these may be important in the genesis of t(7;21). This is the second cryptic RUNX1 translocation in hematologic malignancies and the first in AML. The USPs have not previously been reported to be rearranged in leukemias. The cellular context in which USP42 is active is unknown, but we here show that it is expressed in normal bone marrow, in primary AMLs, and in cancer cell lines. Its involvement in the t(7;21) suggests that deregulation of ubiquitin-associated pathways may be pathogenetically important in AML.

Identification of various exon combinations of the ews/fli1 translocation: an optimized RT-PCR method for paraffin embedded tissue -- a report by the CWS-study group.

BACKGROUND: Chromosomal translocations t(11;22) (q24;q12) are characteristic of about 80-90 % of Ewing's sarcoma family of tumors [bone and soft tissue Ewing's sarcoma and peripheral neuroectodermal tumors (PNET)]. They generate ews/fli1 rearrangements showing great diversity in breakpoint exon combination. In about 5 % of Ewing's tumors, ews is fused to the erg gene at 21q22. The various chimeric proteins encoded may function as aberrant oncogenic transcription factors. These specific translocations can be used for exact molecular diagnosis in these poorly differentiated small round-cell tumors. Moreover, the prognostic relevance of different translocational variants has been previously suggested. Furthermore, the sensitive molecular detection of minimal metastatic and residual disease and its clinical significance can be evaluated. To address these questions more definitively in the large number of patients registered in multicenter studies, it is often necessary to access archival paraffin-embedded tumor tissue if no fresh or frozen tumor material is available for analysis by RT (reverse transcription)-PCR. Specific problems arise from formalin-fixed and paraffin-embedded tissue due to the degradation of RNA and insufficient extraction efficiency. Therefore, primer distance and product size are limited for successful PCR amplification. This conflicts with the requirement for identification of various possible exon combinations by PCR simultaneously using one single primer pair with larger distance. PATIENTS: We examined paraffin embedded soft part tumor tissue samples from 47 Ewing's tumor patients. Patients were treated according to either CWS (Cooperative Weichteilsarkomstudie, CWS-91 or CWS-96) or Euro-E.W.I.N.G. 99 therapy protocols. METHOD: We established a novel RT-PCR method, using 3 different exon specific sets of PCR primer pairs, selected according to the coding ews and fli1 nucleotide sequences (NCBI database), suitable for RT-PCR identification of variant ews/fli1 fusion transcripts in RNA isolated from formalin-fixed, paraffin-embedded tissue. For use in combination with ews -primer, an erg specific primer was selected to alternatively test for ews/erg fusion transcripts. As positive control for the integrity of isolated mRNA, we used the ubiquitously expressed gapdh transcript for RT-PCR amplification in each sample. RESULTS: In 31 cases (= 66 %) of 47 paraffin samples of Ewing's tumors analysed, gapdh control indicated adequate quality of RNA. In 16 cases no gapdh control fragment was amplifiable, nevertheless in 2 of these 16 samples distinct ews fusion products could be detected. In 23 cases we identified ews fusion transcripts. Thereof in 65 % ews exon 7 being fused to fli1 exon 6 (fusion type I), in 22 % to fli1 exon 5 (fusion type II). In 4 % each ews exon 10 being juxtaposed to fli1 either exon 6 or exon 5, respectively. An ews/erg fusion was detected in 4 % ( ews exon 7 fused to erg exon 6). In 10 samples, a gapdh fragment was amplified, but no ews/fli1 or - erg fusion transcript could be identified. The reference pathological review (I. L., Kiel, Germany) disproved the primary histopathology in 5 cases. CONCLUSIONS: Using our different sets of exon specific primer pairs, it was possible to detect 4 different breakpoints of ews/fli1 fusion transcripts and the ews/erg fusion by RT-PCR in RNA isolates from formalin-fixed, paraffin-embedded Ewing's tumor tissue. This method can be a very useful alternative in clinical situations (to ensure diagnosis and perform minimal metastatic and residual disease investigations) and in order to assess prognostic significance of translocation subtypes when no fresh tumor tissue is available.

Acute myeloid leukemia with inv(16)(p13q22): involvement of cervical lymph nodes and tonsils is common and may be a negative prognostic sign.

Acute myeloid leukemia (AML) with inv(16)(p13q22) or the variant t(16;16)(p13;q22), is strongly associated with the FAB subtype M4Eo. A high incidence of CNS involvement was reported in the 1980s, but otherwise little is known about the pattern of extamedullary leukemia (EML) manifestations in this AML type. We have compiled clinical and cytogenetic data on 27 consecutive AML cases with inv(16)/t(16;16) from southern Sweden. In general, these AMLs displayed the clinical features that have previously been described as characteristic for this disease entity: low median age, hyperleukocytosis, M4Eo morphology, and a favorable prognosis. However, CNS leukemia was only seen in relapse in one patient diagnosed in 1980, whereas the most common EML manifestation in our series was lymphadenopathy (5/27, 19%), most often cervical with or without gross tonsillar enlargement. A review of previously published, clinically informative cases corroborates that lymphadenopathy, with preference for the cervical region, is the most common EML at diagnosis in inv(16)-positive AML (58/175, 33%). CNS leukemia, on the other hand, has been reported in only 17% of the cases, mostly in the relapse setting, with a diminishing frequency over time, possibly due to protective effects of high-dose cytarabine. Other reported EML sites include the scalp, ovaries, and the intestine. Cervicotonsillar EML was in our series associated with a shorter duration of first remission, (P < 0.05), and may hence prove to be an important clinical parameter when deciding treatment strategies in AML with inv(16)/t(16;16).

Population pharmacokinetic analysis resulting in a tool for dose individualization of busulphan in bone marrow transplantation recipients.

The aims of the present study were (1) to investigate and quantify the pharmacokinetics, including inter-occasion variability and covariate relationships, of busulphan in BMT patients and (2) to develop a user-friendly initial dosing and therapeutic drug monitoring (TDM) strategy for the treatment of those patients with busulphan. The pharmacokinetics of busulphan was studied in 64 adults and 12 children who received busulphan (1 mg/kg) four times daily for 4 days. A one-compartment model with first order absorption and a lag time was sufficient in describing the concentration-time profile. Oral clearance (CL/F) was found to be correlated to weight (+1.2%/kg), ALT (-13%/microcat/l) and concomitant phenytoin treatment (+21%). CL/F and the volume of distribution (V/F) were estimated to 9.23 l/h and 39.3 l, respectively, in a typical individual. Inter-occasion variability (9.4%) in CL/F was estimated to be less than inter-individual variability (28%), a prerequisite for the value of TDM. Bayesian CL/F estimates based on three samples were in good accordance with those based on all samples. The final population model was implemented into the program Excel. The resulting flexible and easy to use dosing program might be used for both initial and, requiring only three plasma samples, maintenance dose individualization of busulphan therapy.

No disadvantage in outcome of using matched unrelated donors as compared with matched sibling donors for bone marrow transplantation in children with acute lymphoblastic leukemia in second remission.

PURPOSE: We evaluated the outcome of children with acute lymphoblastic leukemia (ALL) in second remission (2CR), comparing bone marrow transplantation (BMT) using either matched sibling donors or unrelated donors (URDs). PATIENTS AND METHODS: A total of 65 patients, aged 2 months to 20 years at BMT, with ALL in 2CR underwent allogeneic BMT at seven Nordic centers during 1990 to 1997. Of the first relapses, 85% were in bone marrow; 46% occurred on therapy, and 54%, off therapy. The preparative regimens were cyclophosphamide plus total-body irradiation +/- antithymocyte/antilymphocyte globulin, busulfan plus cyclophosphamide +/- antithymocyte/antilymphocyte globulin, or cytarabine plus total-body irradiation. Of the allografts, 37 were from HLA-matched siblings and 28 were from URDs. RESULTS: In the sibling versus URD graft recipient groups, the posttransplantation 5-year event-free survival was 39% versus 54% (P =.4), the estimated posttransplantation relapse rate was 76% versus 40% (P = not significant [NS]), and the toxic death rate was 19% versus 11% (P = NS). The incidence of significant (grade 2 to 4) acute graft-versus-host disease (GVHD) was 38% versus 64% (P <.05) and was 14% versus 32% (P <.10) for severe (grade 3 to 4) acute GVHD; the incidence of chronic GVHD was 26% versus 57% (P <.05) and was 13% versus 22% (P = NS) for extensive chronic GVHD in the sibling and URD groups. CONCLUSION: BMT with matched URD allografts offers at least equal survival for children with ALL in 2CR, as compared with allografts from matched sibling donors. URD allografts were not associated with a higher toxic mortality rate, although both acute and chronic GVHD were more frequent with URD. Indications for using matched URD allografts in ALL 2CR can be considered the same as for using matched sibling donors.

Cytogenetic and FISH studies of a single center consecutive series of 152 childhood acute lymphoblastic leukemias.

Between 1977 and 1996, cytogenetic investigations were performed on 182 childhood (< or = 16 yr) acute lymphoblastic leukemias (ALL), constituting 94% (182 of 194) of all ALL patients diagnosed and treated at the Departments of Pediatrics, Lund and Malmo University Hospitals, Sweden, during these two decades. The cytogenetic analyses were successful in 152 cases (84%). The failure rate was higher for the ALL investigated before 1987 (30% vs. 4%, p < 0.0001), and also the incidence of cytogenetically normal cases was higher during 1977-86 (43% vs. 25%, p < 0.05). Clonal chromosomal abnormalities were found in 103 (68%) ALL. Structural rearrangements were detected, by chromosome banding alone, in 76 cases (50%). Fluorescence in situ hybridization (FISH) was used to identify cases with t(12;21), 11q23 rearrangements, and 9p deletions, using probes for ETV6/CBFA2, MLL, and CDKN2A/B, in 72 cases from which cells in fixative and/or unstained metaphase preparations were available. In total, the most common structural rearrangements were del(9p) (17%), t(12;21) (15%), del(6q) (8%), and MLL rearrangements (4%). Six (32%) of nineteen cytogenetically normal ALL analyzed by FISH harbored cryptic abnormalities; three displayed t(12;21) and four had del(9p), one of which also carried a t(12;21). Five (45%) of the t(12;21)-positive ALL showed +der(21)t(12;21) or ider(21)(q10)t(12;21), resulting in the formation of double fusion genes. Among the more rare aberrations, eight structural rearrangements were identified as novel recurrent ALL-associated abnormalities, and nine cases harbored rearrangements previously not reported. Sixteen cases displayed karyotypically unrelated clones at different investigations. Seven ALL (5%) showed simple chromosomal changes, unrelated to the aberrations detected at diagnosis, during morphologic and clinical remission, and in all but one instance the patients remained in remission, with the abnormal clone disappearing in subsequent investigations. This indicates that the emergence of novel clonal chromosomal aberrations during remission in childhood ALL is rather common and does not by necessity predict a forthcoming relapse.

The effect of busulphan on the pharmacokinetics of cyclophosphamide and its 4-hydroxy metabolite: time interval influence on therapeutic efficacy and therapy-related toxicity.

Busulphan and cyclophosphamide (Bu/CP) are widely used in preparative regimens for bone marrow transplantation. Many studies have shown a wide variation in busulphan pharmacokinetics. Moreover, higher rates of liver toxicity were reported in Bu/CP protocols than in a total body irradiation (TBI)-containing regimen. In the present paper we investigated the effect of the time interval between the last dose of busulphan and the first dose of cyclophosphamide on the pharmacokinetics of CP and its cytotoxic metabolite 4-hydroperoxycyclophosphamide (4-OHCP). Thirty-six patients undergoing bone marrow transplantation (BMT) were included in the study. We also investigated the occurrence of veno-occlusive disease, mucositis and graft-versus-host disease. Ten patients conditioned with CP followed by TBI served as a control group (TBI). Twenty-six patients were conditioned with Bu/CP. The patients received Bu (1 mg/kg x 4 for 4 days), followed by CP (60 mg/kg for 2 days) administered as a 1-h infusion. Patients received their CP therapy either 7-15 h (group A, n = 12) or 24-50 h (group B, n = 14) after the last dose of Bu. None of the patients were given phenytoin or any other drug known to enhance CP metabolism. The administration of CP less than 24 h after the last dose of Bu resulted in: (1) a significantly (P = 0.003) lower clearance for cyclophosphamide was observed in group A (0.036 l/h/kg) compared to 0.055 and 0.055 l/h/kg, in the B and TBI groups, respectively; (2) significantly (P = 0.002) longer elimination half-life in group A (10.93 h) than in groups B and TBI (6.87 and 7.52 h, respectively); (3) significantly (P < 0.001) lower exposure to the cytotoxic metabolite (4-OHCP), expressed as the ratio AUC4-OHCP/AUCCP, in group A (0.0053) than that obtained in group B (0.013) and group TBI (0.012); (4) the patients in group A had a significantly (P < 0.05) higher incidence of VOD (seven of 12) than the other groups, B and TBI (2/14 and 1/10, respectively); and (5) mucositis was significantly higher in group A patients (8/12), being seen in only one patient in group B and none in the TBI group. The present study has shown that the interval between busulphan and cyclophosphamide administration can negatively affect the pharmacokinetics of cyclophosphamide and its cytotoxic metabolite. We conclude that the timing of CP administration must be considered in order to improve drug efficacy and reduce conditioning-related toxicity.

Abnormalities on brain MR images during the course of familial haemophagocytic lymphohistocytosis in a child. A case report.

PURPOSE: To describe and report the neuroradiological findings and clinical features in a patient with familial haemophagocytic lymphohistocytosis (FHL), a rare hereditary immune dysregulation in early childhood characterised by multisystem involvement, including in approximately 30% of cases also the central nervous system (CNS). MATERIAL AND METHODS: Serial brain MR examinations were carried out in a 4.5-year-old boy with FHL, finally complicated with Epstein-Barr virus (EBV)-driven posttransplantation lymphoma. RESULTS: Multiple brain MR examinations before and after contrast enhancement showed discrete perivascular non-enhancing areas of high signal intensity on T2 images, and later also an enhancing lesion in the right caudate nucleus. CONCLUSION: FHL should be included in the differential diagnosis of patchy white matter abnormalities in young patients. EBV-driven post-transplantation lymphoma, which may present as meningial and/or parenchymal CNS infiltration, is a differential diagnostic problem.

Outcome of 69 allogeneic stem cell transplantations for Fanconi anemia using HLA-matched unrelated donors: a study on behalf of the European Group for Blood and Marrow Transplantation.

Allogeneic stem cell transplantation is the only treatment that can restore a normal hematopoiesis in Fanconi anemia (FA). In this retrospective multicenter study, we analyzed the results of this approach using HLA-matched unrelated bone marrow donors, and tried to identify covariates predicting the outcome of the transplant. From January 1985 to June 1998, 69 FA patients were transplanted with unrelated HLA-matched donors. Patients' characteristics before and after transplant were provided by the European group blood and marrow transplant registry and were analyzed in collaboration with the European Fanconi Anemia Registry. The 3-year probability of survival was 33%. Extensive malformations, a positive recipient cytomegalovirus serology, the use of androgens before transplant, and female donors were associated with a worse outcome. Primary graft failures were observed more frequently when female donors were used, mainly because the grafts contained lower nucleated cell doses per kilogram of recipient body weight compared with grafts coming from male donors. The probability of grade III-IV acute graft-versus-host disease (GVHD) was 34%. Elevated serum alanine/aspartate transaminases before transplantation; limb, urogenital tract, or nephrologic malformations; and non-T-cell-depleted grafts were predictors of severe acute GVHD. This study shows the dramatic impact of preexisting congenital malformations on the outcome of FA patients transplanted with HLA-matched unrelated donors. If the use of T-cell depletion has led to a dramatic reduction of acute GVHD incidence, no significant outcome improvement was observed with this approach, mainly because of an increased risk of graft failure. (Blood. 2000;95:422-429)

Granulocytic sarcomas in body cavities in childhood acute myeloid leukemias with 11q23/MLL rearrangements.

Three childhood acute monoblastic leukemias (AML M5) with granulocytic sarcomas (GSs) are described. All displayed 11q23/MLL abnormalities, t(9;11)(p22;q23) in two cases and t(11;17)(q23;q21) in one case, constituting around 20% of all 11q23-positive AML cytogenetically investigated in our department. Two of the patients had GS in multiple locations, and all three had abdominal GS. In two of them, t(9;11)-positive GS was diagnosed prior to the diagnosis of AML. Fourteen (1.9%) of 752 published AML cases with 11q23 aberrations have had GS, either as a presenting feature or during disease progression. The incidence of GS has varied significantly (P < 0.05) between children (3.8%) and adults (0.8%). The most common AML subtype has been AML M5 ( approximately 75%) and the most frequent GS sites have been the skin, abdomen, orbit, and thorax. Considering the possibility of underreporting of GS in published cases and the relatively high frequency in our own series, we believe that 11q23/MLL rearrangements may predispose to GS development. Although extramedullary infiltrates in the skin are known to be frequent in cases of AML M5, which is often associated with 11q23 aberrations, the present findings indicate that GS in the abdomen, orbit, and thorax may also be common, especially in pediatric AML. Thus, the possibility of 11q23/MLL-positive GS should be suspected when tumors of uncertain derivation occur in these sites. Finally, the identification of 11q23/MLL abnormalities in GSs in two patients without overt AML underscores the importance of using cytogenetic and molecular genetic investigations as a diagnostic approach in the evaluation of tumorous lesions of unknown origin. Genes Chromosomes Cancer 27:136-142, 2000.

[Umbilical cord blood from unrelated donor. An alternative to bone marrow transplantation]. / Navelsträngsblod från icke besläktad givare. Alternativ till benmärgstransplantation.

Unrelated umbilical cord blood (UCB) as a source of haematopoietic stem/progenitor cells has been used for the first time in Sweden for allografting two boys (6 and 11 1/2 years old) with acute leukaemia in complete remission. Double class-II HLA-mismatch UCB units, from the Milan and New York cord blood banks, respectively, were used. Pre-transplant preparation consisted in fractionated total body irradiation in both cases, followed by cytoreductive high-dose cyclophosphamide for the 6-year-old with acute lymphocytic leukaemia (ALL) and fludarabine-melphalan for the 11 1/2-year-old with acute non-lymphocytic leukaemia (ANLL). Despite delayed haematopoietic recovery (probably due to HLA disparity) or reactivated cytomegalovirus infection in one boy, the immediate post-graft course was uneventful and extramedullary toxicity mild in both cases. Only transient acute graft-versus-host disease occurred, and complete donor chimerism was confirmed. Unfortunately, the out-come was unfavourable in both cases, the ANLL patient succumbing on day 96 due to pneumonia followed by multiorgan failure, and the ALL patient on day 140 due to combined medullar and central nervous system relapse. Although UCB transplantation needs further evaluation, it may contribute substantially to successful salvage procedures. Thus the introduction of cord blood banking in Sweden merits consideration.

Fludarabine-based preparative protocol for unrelated donor cord blood transplantation in children: successful engraftment with minimal toxicity.

Unrelated umbilical cord blood (UCB) is a new source of hematopoietic stem cell (HSC) for allogeneic transplantation. The optimal conditioning for UCB transplant has not been defined. Intensive immunosuppression is frequently employed because of the higher risk of graft failure. Fludarabine monophosphate is shown to be an effective agent for facilitating allogeneic HSC engraftment. We have recently encountered three children who were not ideal candidates for 'conventional' conditioning protocols. TBI followed by fludarabine and melphalan were used for transplant preparation. The UCB units were one HLA-antigen (n = 1) and two HLA-antigen mismatched with the recipients. All three patients engrafted successfully. There was mild extramedullary toxicity. Two patients are alive with complete chimerism 8 and 20 months after transplant. A fludarabine-based protocol may be considered for selected cases of UCB transplants.