Hepatic sinusoidal obstruction syndrome and short-term application of 6-thioguanine in pediatric acute lymphoblastic leukemia

Long-term treatment with 6-thioguanine (6-TG) for pediatric acute lymphoblastic leukemia (ALL) is associated with high rates of hepatic sinusoidal obstruction syndrome (SOS). Nevertheless, current treatment continues to use short-term applications of 6-TG with only sparse information on toxicity. 6-TG is metabolized by thiopurine methyltransferase (TPMT) which underlies clinically relevant genetic polymorphism. We analyzed the association between hepatic SOS reported as a serious adverse event (SAE) and short-term 6-TG application in 3983 pediatric ALL patients treated on trial AIEOP-BFM ALL 2000 (derivation cohort) and defined the role of TPMT genotype in this relationship. We identified 17 patients (0.43%) with hepatic SOS, 13 of which with short-term exposure to 6-TG (P < 0.0001). Eight of the 13 patients were heterozygous for low-activity TPMT variants, resulting in a 22.4-fold (95% confidence interval 7.1-70.7; P ≤ 0.0001) increased risk of hepatic SOS for heterozygotes in comparison to TPMT wild-type patients. Results were supported by independent replication analysis. All patients with hepatic SOS after short-term 6-TG recovered and did not demonstrate residual symptoms. Thus, hepatic SOS is associated with short-term exposure to 6-TG during treatment of pediatric ALL and SOS risk is increased for patients with low-activity TPMT genotypes.

Nimotuzumab and radiotherapy for treatment of newly diagnosed diffuse intrinsic pontine glioma (DIPG): a phase III clinical study

BACKGROUND

Diffuse intrinsic pontine glioma (DIPG) is a devastating cancer of childhood and adolescence.

METHODS

The study included patients between 3 and 20 years with clinically and radiologically confirmed DIPG. Primary endpoint was 6-month progression-free survival (PFS) following administration of nimotuzumab in combination with external beam radiotherapy (RT). Nimotuzumab was administered intravenously at 150 mg/m² weekly for 12 weeks. Radiotherapy at total dose of 54 Gy was delivered between week 3 and week 9. Response was evaluated based on clinical features and MRI findings according to RECIST criteria at week 12. Thereafter, patients continued to receive nimotuzumab every alternate week until disease progression/unmanageable toxicity. Adverse events (AE) were evaluated according to Common Terminology Criteria for Adverse Events (CTC-AE) Version 3.0 (CTC-AE3).

RESULTS

All 42 patients received at least one dose of nimotuzumab in outpatient settings. Two patients had partial response (4.8%), 27 had stable disease (64.3%), 10 had progressive disease (23.8%) and 3 patients (7.1%) could not be evaluated. The objective response rate (ORR) was 4.8%. Median PFS was 5.8 months and median overall survival (OS) was 9.4 months. Most common drug-related AEs were alopecia (14.3%), vomiting, headache and radiation skin injury (7.1% each). Therapy-related serious adverse events (SAEs) were intra-tumoral bleeding and acute respiratory failure, which were difficult to distinguish from effects of tumor progression.

CONCLUSIONS

Concomitant treatment with RT and nimotuzumab was feasible in an outpatient setting. The PFS and OS were comparable to results achieved with RT and intensive chemotherapy in hospitalized setting.

Consensus of German transplant centers on hematopoietic stem cell transplantation in Fanconi anemia

Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative therapy for the severe hematopoietic complications associated with Fanconi anemia (FA). In Germany, it is estimated that 10-15 transplants are performed annually for FA. However, because FA is a DNA repair disorder, standard conditioning regimens confer a high risk of excessive regimen-related toxicities and mortality, and reduced intensity regimens are linked with graft failure in some FA patients. Moreover, development of graft-versus-host disease is a major contributing factor for secondary solid tumors. The relative rarity of the disorder limits HSCT experience at any single center. Consensus meetings were convened to develop a national approach for HSCT in FA. This manuscript outlines current experience and knowledge about HSCT in FA and, based on this analysis, general recommendations reached at these meetings.

TGFβ and IL10 have an impact on risk group and prognosis in childhood ALL

BACKGROUND

Cytokines and their genes have been described to have an influence on incidence and prognosis in malignant, infectious and autoimmune disease. We previously described the impact of cytokine production on prognosis in paediatric standard-risk acute lymphoblastic leukaemia (ALL).

PROCEDURE

In this study, we investigated the influence of cytokine gene polymorphisms (TNFα, TGFβ, IL10 and IFNγ) on frequency, risk group and prognosis in 95 paediatric ALL-patients. We further report on intracellular production of these cytokines in T-cells.

RESULTS

IL10 high-producer-haplotypes were reduced in ALL-patients compared with healthy controls and resulted in a reduced relapse rate compared with low-producer haplotypes. TGFβ high-producer-haplotypes were correlated with a high initial blast-count (codon 25: G/G) and were elevated in high-risk ALL-patients (codon 10: T/T). IL10 was positively and IFNγ-production was negatively correlated with initial blast-count. At diagnosis the expression of TNFα and IFNγ was reduced in patients compared with healthy controls. This was more pronounced in high-risk and in T-ALL-patients.

CONCLUSION

We conclude that gene-polymorphisms of the regulatory/anti-inflammatory cytokines, TGFβ and IL10, but not of the pro-inflammatory cytokines, IFNγ and TNFα, have an impact on prognosis and risk-group of ALL. However, the reduced capacity to produce pro-inflammatory cytokines at diagnosis may serve as another important, functional risk factor. These data may help in further risk stratification and adaptation of therapy-intensity in paediatric patients with ALL.

Children with relapsed or refractory nephroblastoma: favorable long-term survival after high-dose chemotherapy and autologous stem cell transplantation

BACKGROUND

High-dose chemotherapy (HDC) with autologous stem-cell rescue (ASCR) is a treatment option for pediatric patients with relapsed nephroblastoma. We present long term results of 9 patients treated between 1993 and 2013 at our center.

PROCEDURE

Reinduction therapy was carried out according to GPOH and SIOP recommendations. The conditioning regimen consisted of carboplatin (1 200 mg/m²), etoposide (800 mg/m² or 40 mg/kg) and melphalan (180 mg/m²). Purging of the grafts with immunomagnetic CD34 positive selection was performed in 5 patients.

RESULTS

8 of 9 Patients (90%) are alive without evidence of disease after a median follow-up of 8.5 years. Leukocyte engraftment occurred after a median of 10 days (range 8-12). Median numbers of 667/µl CD3+, 329/µl CD4+, 369/µl CD8+T cells and 949/µl B cells were reached after 180 days. No negative impact of CD34 selection was observed. No transplantation-related death occurred. Acute toxicity comprised mucositis III°-IV° in all and veno-occlusive disease in one patient. Long term effects probably related to treatment occurred in 3/7 evaluable patients and comprised hearing impairment, reduced renal phosphate reabsorption, mild creatinine elevation and hypothyroidism (n=1, each).

CONCLUSION

Thus, in our experience HDC with ASCR is an effective treatment of recurrent or refractory nephroblastoma with acceptable side effects. However, a randomized trial proving its efficiency with a high level of evidence is needed.

Successful treatment of an infant with CDA type II by intrauterine transfusions and postnatal stem cell transplantation

Congenital dyserythropoietic anemias are rare hematological disorders leading to ineffective erythropoiesis with chronic anemia, complicated by iron overload. Here we present a remarkable clinical course of an infant with CDA type II who first presented as a severe fetal hydrops, requiring serial intrauterine red cell transfusions. While postnatal transfusion dependency persisted, the patient was successfully transplanted with a myeloablative conditioning regimen and peripheral blood stem cells of a matched donor. We believe that allogeneic HSCT is a reasonable therapeutic approach for patients with very severe CDA, even if only a matched unrelated donor is available.

High-dose chemotherapy (HDCT) with auto-SCT in children with atypical teratoid/rhabdoid tumors (AT/RT): a report from the European Rhabdoid Registry (EU-RHAB)

A retrospective analysis of data from the European Rhabdoid Registry (EU-RHAB) was performed to describe the outcome of children with atypical teratoid/rhabdoid tumors (AT/RT) who underwent high-dose chemotherapy (HDCT) with auto-SCT. Nineteen patients (male, n=15; median age at diagnosis 21 months) were identified. Nine patients presented with metastatic disease at diagnosis. A partial or subtotal resection was achieved in 11, a total resection in five and a biopsy in three patients. Patients received a median of six chemotherapy cycles prior to HDCT. Additional radiotherapy was performed in 14 patients (first-line, n=9; following progression, n=5). Six patients underwent tandem auto-SCT. Disease status before HDCT was CR in six, PR in eight, stable disease in two and progressive disease (PD) in two patients (data missing, n=1). With a median follow-up of 16 months, 14 patients progressed. Estimated progression-free and OS at 2 years were 29% (±11%) and 50% (±12%), respectively. At last follow-up, eight patients were alive (first CR, n=4; second CR, n=2; PR, n=1; PD, n=1). Eleven patients died of PD. Median time-to-progression was 14 months. Selected patients with AT/RT might benefit from HDCT with radiotherapy. The definitive impact of this treatment modality has to be evaluated prospectively in a randomized trial.

Testicular sex cord stromal tumors: analysis of patients from the MAKEI study

BACKGROUND

In children and adolescents, testicular sex cord stromal tumors (TSCSTs) are rare. There is only limited information available regarding their clinical presentation, biology, and prognosis.

METHODS

Between 1993 and 2009, 42 patients were prospectively reported to the cooperative MAHO and MAKEI studies on childhood germ cell tumors. Based on standardized documentation, data on epidemiology, clinical presentation, diagnostic features, histopathological differentiation, therapy, and follow-up were evaluated.

RESULTS

During the study period, a gradual increase of the documentation of these rare tumors was observed. Palpable, indolent testicular swelling was the most common clinical finding. In three patients, retention of the testis was observed. Two patients showed sexual precocity, and one patient showed a 45X/46XY mosaic. Juvenile granulosa cell tumors (n = 16) and Sertoli cell tumor (n = 15) were the leading histopathological subtypes. The first were commonly diagnosed during the first weeks of life (median age: 6(0-162) days, the latter during infancy (median 7(0-14) months, P < 0.05). Other histological diagnoses included Leydig cell and Large Cell Calcifying Sertoli cell tumors (both n = 3) and not-otherwise-specified TSCSTs (n = 5), which were diagnosed during childhood and adolescence. All tumors were limited to the testis; there were no metastases. Treatment was surgical, only. After a median follow-up of 3.8 years, no relapse was observed.

CONCLUSIONS

Diagnosis and therapy of testicular tumors should be planned in accordance with the recommendations of the respective childhood germ cell tumor protocols. High inguinal orchiectomy is safe and constitutes definitive therapy. Diagnostic work-up and follow-up should also consider potentially associated tumor predisposition syndromes.

Human leukocyte antigen distribution in German Caucasians with advanced Ewing's sarcoma

BACKGROUND

Risk stratification criteria for patients with Ewing's sarcoma family of tumors (ESFT) are still limited. We hypothesized divergent human leukocyte antigen (HLA) patterns in ESFT patients and compared HLA-A, -B and -DR phenotype frequencies of patients with advanced ESFT with those of healthy controls.

PATIENTS

HLA types of all German Caucasian patients with advanced ESFT and available HLA-A, -B and -DR data registered in the European Group for Blood and Marrow Transplantation, Paediatric Registry for Stem Cell Transplantation and the MetaEICESS data bases (study group, n=30) were retrospectively compared with HLA types of healthy German stem cell donors (control group, n=8 862 for single HLA frequencies and n=8 839 for allele combinations). Study group patients had been immuno-typed due to eligibility for allogeneic stem cell transplantation for high risk of treatment failure, and thus constituted a selected subgroup of ESFT patients.

RESULTS

After Bonferroni correction for multiple testing (PC), phenotype frequencies of HLA-A24 remained significantly higher in the study group compared to controls (PC<0.05). Furthermore, several HLA combinations were significantly more frequent in the study group compared to controls (all PC<0.05).

CONCLUSION

We report an increased incidence of circumscribed HLA patterns in German Caucasians with advanced ESFT. The possible clinical significance of this observation has to be re-assessed in prospective trials comprising larger ESFT patient numbers of all risk groups.

A prospective comparison of immune reconstitution in pediatric recipients of positively selected CD34+ peripheral blood stem cells from unrelated donors vs recipients of unmanipulated bone marrow from related donors

Positively selected CD34(+) hematopoietic stem cells from unrelated donors (UD-HSCT) have been successfully transplanted, but little is known about immune reconstitution in this setting. Here we report a prospective comparison of immune reconstitution in recipients of UD-HSCT and of unmanipulated bone marrow from matched sibling donors (MSD-BMT). T-cell reconstitution occurred more than 100 days later in the UD-HSCT than in the MSD-BMT group. The first T cells after UD-HSCT were almost exclusively CD45RO(+) HLA-DR(+), whereas early-emerging T cells after MSD-BMT more frequently expressed CD62L, CD28, and CD25. In both groups, numbers of CD45RA(+) naive T cells increased after 180 days. After UD-HSCT, the T-cell-receptor (TCR)-repertoire was severely skewed and showed significantly reduced diversity during the first year, but only minor abnormalities were seen after MSD-BMT. TCR-diversity increased simultaneously with the number of naive T cells. In both groups, we observed transient expansions of gammadelta T cells. B cells were reconstituted more rapidly in UD-HSCT than in MSD-BMT recipients, whereas the rapidity of NK-cell reconstitution was similar in the two groups. In summary, T-cell reconstitution was slower after UD-HSCT than after MSD-BMT because of the delayed recovery of early memory-type T cells with reduced TCR-diversity, whereas naive T-, NK-, and B cells were reconstituted similarly in the two groups.

A prospective analysis of the pattern of immune reconstitution in a paediatric cohort following transplantation of positively selected human leucocyte antigen-disparate haematopoietic stem cells from parental donors

Transplantation of haematopoietic stem cells from human leucocyte antigen (HLA)-disparate parental donors presents a promising new approach for the treatment of patients lacking a HLA-matched donor. Success against major obstacles such as graft-versus-host disease (GvHD) and graft rejection has recently been demonstrated, so that immune reconstitution is one of the prime factors that determines the long-term prognosis following transplantation. Twenty children transplanted with megadoses of highly purified CD34(+) haematopoietic stem cells after rigorous T-cell depletion were prospectively monitored for their immune reconstitution during the first post-transplant year. Natural killer (NK) cells showed a marked increase on d +30. T and B cells began to reconstitute on d +72 and +68 respectively. During extended follow-up, their numbers and proliferative capacity upon mitogen stimulation continually increased. Early reconstituting T cells were predominantly of a primed, activated phenotype with severely skewed T-cell receptor (TCR)-repertoire complexity. Naive T cells emerged 6 months post transplantation, paralleled by an increase in TCR-repertoire diversity. All patients self-maintained sufficient immunoglobulin levels after d +200. This study demonstrates that paediatric recipients of highly purified, haploidentical stem cells are able to reconstitute functioning T-, B- and NK-cell compartments within the first post-transplant year. This, together with the absence of significant GvHD, provides a strong indication for this approach to be considered in children who lack a HLA-matched donor.

Megadose transplantation of purified peripheral blood CD34(+) progenitor cells from HLA-mismatched parental donors in children

We performed HLA-mismatched stem cell transplantation with megadoses of purified positively selected mobilized peripheral blood CD34(+) progenitor cells (PBPC) from related adult donors in 39 children lacking an otherwise suitable donor. The patients received a mean number of 20.7 +/- 9.8 x 10(6)/kg purified CD34(+) and a mean number of 15.5 +/- 20.4 x 10(3)/kg CD3(+) T lymphocytes. The first seven patients received short term (<4 weeks) GVHD prophylaxis with cyclosporin A, whereas in all the following 32 patients no GVHD prophylaxis was used. In 38 evaluable patients, five patients experienced primary acute GVHD grade I and one patient grade II. In 32 patients, no signs of primary GVHD were seen and GVHD only occurred after T cell add backs. T cell reconstitution was more rapid if the number of transplanted CD34(+) cells exceeded 20 x 10(6)/kg. Of the 39 patients, 15 are alive and well, 13 died due to relapse and 10 transplant-related deaths occurred. We conclude that the HLA barrier can be overcome by transplantation of megadoses of highly purified mismatched CD34(+) stem cells. GVHD can be prevented without pharmacological immunosuppression by the efficient T cell depletion associated with the CD34(+) positive selection procedure. This approach offers a promising therapeutic option for every child without an otherwise suitable donor.

OKT-3-based reconditioning regimen for early graft failure in HLA-non-identical stem cell transplants

Primary non-engraftment or early rejection after transplantation of haematopoietic stem cells represent life-threatening complications of allogeneic stem cell transplantation. Management of early graft failure has been problematic, as the risk of fatal infectious complications increases with the time of pancytopenia and as a second transplant preceded by a conventional myeloablative conditioning regimen has been associated with high rates of cumulative organ toxicity. For paediatric patients with early graft failure following the transplantation of highly purified major histocompatibility complex (MHC)-disparate haematopoietic stem cells, we have evaluated an immunosuppressive OKT-3/methylprednisolone-based reconditioning regimen with low toxicity in preparation for a secondary transplant of purified haematopoietic stem cells from the same donor. This report presents the results from a 4-year pilot study including six patients with early graft failure. The results demonstrate that this antibody-based regimen can be used effectively to prepare patients for secondary transplantation. Successful engraftment after a second transplant procedure was achieved in five of these six high-risk patients. The median interval between first and second transplant was 27 d (range 22-51 d), and the median time for engraftment was 10 d (range 9-13 d). Chimaerism analysis of microsatellite regions by polymerase chain reaction (PCR) demonstrated complete donor chimaerism in four of these patients within the first month after secondary transplant and revealed mixed chimaerism in one patient who converted to complete chimaerism after T-cell add-back.

Characterization of lineage-specific chimaerism in patients with acute leukaemia and myelodysplastic syndrome after allogeneic stem cell transplantation before and after relapse

Recently, we have shown that patients with acute leukaemias and myelodysplastic syndromes (MDS), who showed increasing mixed chimaerism (MC) upon serial PCR analysis after transplant, have a significantly increased risk of relapse. To determine whether the increasing MC in these patients is caused by the reappearance of normal recipient haematopoiesis or by the reoccurrence of malignant cells, we purified different leucocyte subpopulations and analysed these subfractions with regard to their donor-recipient ratio by a PCR-based method for the analysis of minisatellite DNA regions. In 14 patients [eight acute lymphoblastic leukaemia (ALL), three acute myelogenous leukaemia (AML) and three MDS] subfractions were analysed when increasing MC was first noted upon serial analysis of the peripheral blood. In seven of these 14 patients (four ALL, two AML and one MDS), subfractions were characterized at the time of frank haematological relapse. In all 14 patients investigated with increasing MC, recipient cells were detected in different mononuclear cell subpopulations. In patients characterized during frank relapse, two distinct distribution patterns were found. Patients who relapsed before day +300 (one ALL, two AML and one MDS) showed recipient-derived (normal) cells in addition to blast populations in different mononuclear subsets as well as granulocytes. In patients with acute leukaemias who relapsed after day +300 (two ALL and one AML), only leukaemic cells were found that were of recipient origin, whereas all other haematopoietic cell lines were donor derived. These data show that persistent MC in the early post-transplant period is caused predominantly by normal recipient haematopoietic cells. This finding further supports the hypothesis that a state of mixed haematopoietic chimaerism may reduce the clinical graft-versus-leukaemia (GVL) effect of alloreactive donor-derived effector cells in patients with acute leukaemias and MDS, and thus facilitate the proliferation of residual malignant cells that may have survived the preparative regimen.

PG27, an extract of Tripterygium wilfordii hook f, induces antigen-specific tolerance in bone marrow transplantation in mice

PG27, an active fraction purified from an extract of a Chinese herb, Tripterygium wilfordii hook f, was used to prevent graft-versus-host disease (GVHD) in a murine model. Lethally irradiated BALB/c (H-2(d)) recipients of B10.D2 (H-2(d)) donor grafts were given daily intraperitoneal injections of PG27 (40 mg/kg per day) for the first 35 days after transplantation. Control mice were given daily injections of solvent vehicle (Ethanol and Cremophor EL). All the control recipients (15/15) died of GVHD within 90 days, but all the recipients given prophylactic treatment with PG27 (15/15) survived beyond 100 days without any signs of GVHD. Furthermore, the GVHD-free recipients were used as donors, and their bone marrow and spleen cells were transplanted into lethally irradiated normal BALB/c (same party) or lethally irradiated normal C3H (H-2(k), third party) mice. Although 10 of 10 same-party recipients survived more than 100 days without any signs of GVHD, 10 of 10 third-party C3H recipients died of GVHD within 40 days. Further studies of PG27 in the murine BCL1 leukemia/lymphoma model demonstrated that animals treated with PG27 partially retained the graft-versus-leukemia (GVL) effect of the graft without GVHD. These results suggest that treatment with PG27 induces host-specific tolerance and retains the GVL effect of allogeneic marrow grafts. (Blood. 2000;95:705-710)

GVHD: overview on pathophysiology, incidence, clinical and biological features

Acute and chronic graft-versus-host disease (GVHD) develop in a significant proportion of transplant recipients and still represent one of the major causes of morbidity and mortality after allogeneic BMT. Prevention of GVHD does not only attempt to reduce acute toxicity and morbidity of transplantation but also to ameliorate long term outcome. GVHD is a T-cell mediated disease affecting multiple target organ systems. Recent research has tremendously improved our understanding of the pathophysiology of the disease. These new data are reviewed with main emphasis on their impact for children. The most important task for the future will be to make these new strategies fruitful for clinical application.

Serial and quantitative analysis of mixed hematopoietic chimerism by PCR in patients with acute leukemias allows the prediction of relapse after allogeneic BMT

Within a prospective study we analyzed hematopoietic chimerism in serial peripheral blood samples taken from 55 patients with acute leukemias (ALL 21, AML 20, MDS 14) with a median age of 13.5 years at very short time intervals following allogeneic bone marrow transplantation (allo-BMT). The investigation was performed to determine the implications of mixed hematopoietic chimerism (MC) with regard to the clinical outcome in patients with acute leukemias after allo-BMT. Analysis of chimerism was performed by PCR of variable number of tandem repeat (VNTR) sequences with a maximum sensitivity of 0.8%. Thirteen male patients transplanted with the marrow of a female donor were also studied by amplification of a Y-chromosome-specific alphoid repeat (0.1-0.01% sensitivity). VNTR analysis in 55 patients revealed complete chimerism (CC) in 36 cases, MC in 18 follow-ups and autologous recovery in one patient. Quantitative analysis of MC identified 10/18 patients with increasing autologous patterns in whom 9/10 subsequently relapsed. The patient with autologous recovery relapsed as well. Eight of 18 patients with MC showed decreasing amounts of autologous DNA and became CC upon further follow-up. In contrast, only 7/36 patients with CC in the prior analysis of chimerism status relapsed. However, in 4/7 patients the interval between last CC confirmation and relapse was more than 4 months. In 2/7 patients autologous DNA was not detectable in peripheral blood but in bone marrow aspirates. One of these seven patients developed a fulminant relapse within 3 weeks. The probability of relapse-free survival for patients with CC is 0.67 (n = 36), for patients with decreasing MC 1.0 (n = 8) and for patients with increasing MC 0.1 (n = 10). In summary, the results demonstrate that serial and quantitative chimerism analysis at short time intervals by PCR provides a reliable and rapid screening method for the early detection of recurrence of underlying disease and is therefore a prognostic tool to identify patients at highest risk of relapse.

Hepatic veno-occlusive disease in pediatric stem cell recipients: successful treatment with continuous infusion of prostaglandin E1 and low-dose heparin

Limited data exist on therapeutic options for established hepatic veno-occlusive disease (VOD) in pediatric patients after stem cell transplantation (SCT). In this report, we present data on the successful treatment of VOD in three children following allogeneic SCT and report the duplex ultrasound criteria for the confirmation of the diagnosis and for the evaluation of the treatment progress. All patients were <2 years at the time of transplantation and had received preparative regimens containing busulfan and cyclophosphamide. There were no known pretransplant risk factors for VOD. Allogeneic stem cell transplantation was performed from a sibling donor for CMML and from unrelated donors for Wiskott-Aldrich syndrome and familial hemophagocytic lymphohistiocytosis (FHL). The onset of first clinical symptoms of VOD (as defined by the Seattle and Baltimore criteria) was relatively late in all three patients (days +19, +20, and +25, respectively). Time from onset of first symptoms until confirmation of diagnosis by serial duplex ultrasound examination was 4-11 days. Duplex ultrasound criteria are as follows: complete change of direction of blood flow in the portal vein, decrease of flow in the hepatic veins, and development of collateral circulation. Treatment was initiated upon confirmation of VOD by continuous infusion of prostaglandin E1 (initial dose 0.075 microg/kg/h) in addition to low-dose heparin (100 units/kg/d). Treatment was continued at the maximum tolerated dose of 0.3-0.5 microg/kg/h of PGE1. After 9, 14, and 25 days of treatment respectively, normal portal vein flow was restored and treatment could be discontinued. All three patients are alive and well without apparent sequelae.

Additional immunotherapy on the basis of increasing mixed hematopoietic chimerism after allogeneic BMT in children with acute leukemia: is there an option to prevent relapse?

The success of allogeneic BMT (allo-BMT) in children with acute leukemias is mainly affected by relapse. There is evidence that these patients have only a little or no benefit from additional immunotherapy if the treatment is started in frank hematological relapse. Recently we were able to demonstrate that pediatric patients with acute leukemias and increasing mixed chimerism (MC) post-transplant have a significantly enhanced risk of developing relapse. We asked whether there is a possibility of preventing relapse, eg by withdrawal of post-transplant immunosuppression or by administration of donor lymphocytes in an early phase of the development of relapse. We present the case reports of two children (MDS and AML) with rapidly increasing MC in whom withdrawal of post-transplant immunosuppression or donor lymphocyte infusion (DLI) did prevent relapse.

Studies on the mechanism and specificity of the effect of the synthetic random copolymer GLAT on graft-versus-host disease

Graft-versus-host disease (GVHD), which occurs when donor T-cells recognize multiple minor host histocompatibility antigens as non-self, presents the major limitation to successful allogeneic bone-marrow transplantation. The synthetic random copolymer of the amino acids, L-Glu, L-Lys, L-Ala and L-Tyr, termed GLAT, with promiscuous binding to multiple MHC class II alleles, reduces the incidence, onset and severity of disease in the BIO.D2 --> BALB/c model of lethal GVHD. GLAT inhibited the proliferative response towards host of both spleen cells from mice with GVHD and also of the effector T cell line established from these mice. Administration of GLAT for a limited period after transplantation completely abolished the cytotoxic activity toward host cells exerted by spleen cells from mice with GVHD. Whereas spleen and bone marrow cells from control mice with GVHD secreted IL-2 and INF-gamma when cocultured with host cells, these inflammatory cytokines could not be detected in supernatants of cells from GLAT treated mice. Moreover spleens and bone marrow cells from GLAT treated mice secreted small but significant amounts of IL-4 and IL-6 when cocultured with GLAT, suggesting that GLAT not only inhibits pro-GVHD cytokines but also causes a beneficial effect by inducing secretion of Th2 type cytokines. GLAT binds strongly to MHC molecules of host as well as donor haplotype. D-GLAT, identical to GLAT but composed of D-amino acids is also effective in preventing GVHD. D-GLAT does not cross-react with L-GLAT, but still binds strongly to MHC-class II molecules. These findings indicate that MHC blocking is involved in the therapeutic effect of GLAT on GVHD. The cumulative data demonstrate that GLAT modulates the effector mechanisms involved in GVHD, and can be potentially used for the prevention of GVHD across minor histocompatibility barriers.

Mixed hematopoietic chimerism after allogeneic bone marrow transplantation: the impact of quantitative PCR analysis for prediction of relapse and graft rejection in children

It still remains unclear whether patients with mixed hematopoietic chimerism (MC) after allogeneic bone marrow transplantation (allo-BMT) have an increased risk of developing relapse or graft failure. To address this question, we monitored the individual dynamics of chimerism after allo-BMT in pediatric patients within a prospective case control study. The individual ratio of donor to recipient peripheral white cells was determined by quantification of genomic variable number of tandem repeats (VNTRs) with a polymerase chain reaction (PCR) approach. Within the study period from 1 January 1994 until 1 July 1996 we investigated 50 sequences of 46 pediatric patients after allo-BMT (32 with malignant, 18 with nonmalignant diseases). We found complete chimerism (CC) in 34/50 cases, MC in 12/50 follow-ups and 4/50 patients revealed autologous recovery (AC). Eight of 12 patients with MC showed increasing autologous patterns and subsequently relapsed or rejected their graft, 3/12 decreasing amounts of recipient DNA and turned to CC upon further follow-up. One patient of 12 who had severe combined immunodeficiency (SCID), attained engraftment with a stable MC pattern. Three patients of 34 with CC relapsed lacking a transitional MC interval. However, the time span between last CC confirmation and relapse in each of these three patients was 6 months or longer. We suggest that these patients also developed a stage of transitional MC but that the critical timepoint of molecular confirmation by PCR was missed as time intervals in the individual follow-up of these three patients were too long (> or = 6 months). In summary, the results demonstrate that the individual risk of developing relapse or graft failure is significantly enhanced in the MC situation (P < 0.0005). Therefore the quantitative analysis of MC at short time intervals might be of great value to identify high risk patients which will have a significantly/enhanced risk for relapse or graft rejection.

Chemotherapeutic induction of long-term remission in metastatic medulloblastoma

The treatment of extraneural metastatic medulloblastoma is mainly a domain of chemotherapy. Although previous results were promising, the overall poor prognosis high relapse rates and the still unknown ideal combination of chemotherapeutic agents leave many questions open. In this study, the effectiveness of previously used chemotherapeutic agents for the treatment of metastatic medulloblastoma is reviewed, and the effectiveness and complexity of emerging new treatment strategies including high-dose chemotherapy with bone marrow and peripheral blood stem-cell transplantation are discussed. Furthermore, we describe a case of bone-metastasized recurrent medulloblastoma with the longest remission ever reported (120 months) after regimens containing doxorubicine, vincristine, cyclophosphamide (ACO-protocol) [1, 2] and methotrexate. When relapse with bone and bone marrow infiltration occurred, a second chemotherapeutically induced complete remission was achieved. High-dose-chemotherapy with autologous peripheral blood stem-cell transplantation was used as a consolidating regimen. Complete remission has persisted for over 15 months now.

Administration of a CD31-derived peptide delays the onset and significantly increases survival from lethal graft-versus-host disease

The CD31 monoclonal antibody, LYP21, binds to the CD31 domain 6 and inhibits the human mixed-lymphocyte reaction (MLR) in a specific and dose-dependent fashion. A synthetic CD31 peptide based on human CD31 epitope (amino acids 551 to 574) recognized by LYP21 is equally effective in inhibiting the MLR. In this study, we used the murine homolog of CD31 peptide 551 to 574 and a control peptide to study the role of CD31 molecule on T-cell activation. In vitro, CD31 peptide inhibited the MLR across several major and minor histocompatibility differences in a specific and dose-dependent fashion, similar to the results observed in the human system. Maximal inhibition was achieved at a dose of 200 microg/mL. In the cytotoxic T-lymphocyte (CTL) assay, CD31 peptide inhibited CTL responses by 97%. To study the in vivo effect of this peptide, graft-versus-host disease (GVHD) across minor histocompatibility barriers was induced in the B10.D2 (H-2d) --> BALB/c (H-2d) model. BALB/c recipients received CD31 peptide (100 microg/d), or phosphate-buffered saline (PBS), or control peptide (100 microg/d) intraperitoneally (IP) for the first 5 weeks. CD31 peptide delayed onset of graft-versus-host disease and significantly increased long-term survival. Twelve of 14 mice receiving CD31 peptide survived more than 100 days after transplantation, as compared with none of 10 mice receiving PBS and none of five mice receiving control peptide (P = .0001). Long-term engraftment of allogeneic bone marrow was documented in all transplanted mice by polymerase chain reaction (PCR) analysis of microsatellite region in the interleukin (IL)-1beta gene. Our data suggest that the CD31 molecule has an important functional role in T-cell activation in vitro and in vivo.

The role of adhesion and costimulation molecules in graft-versus-host disease

A cascade of signaling events directs and regulates the trafficking, homing and activation of T lymphocytes after allogeneic transplantation. These adhesion receptors include selectins, integrins and adhesion molecules of the immunoglobulin superfamily. Tissue-specific homing receptors direct the tissue-specific trafficking of T lymphocytes. When T cells encounter their antigen(s) presented by MHC molecules on APC, the antigen-specific signal mediated through the T-cell receptor (TCR) needs to be accompanied by additional costimulatory signals for complete T-cell activation to occur. The costimulatory signal determines the outcome of the first signal generated through the TCR, leading to either complete activation, partial activation or to a long-lasting state of antigen-specific unresponsiveness, termed anergy. Complete activation of T cells results in IL-2R (CD25) receptor expression, IL-2 production and T-cell proliferation.

Influence of age on the outcome of 500 autologous bone marrow transplant procedures for hematologic malignancies

PURPOSE

To determine the effect of age on the outcome of autologous bone marrow transplantation (ABMT) and/or peripheral-blood progenitor-cell (PBPC) transplantation.

PATIENTS AND METHODS

A retrospective analysis was performed on 500 consecutive patients who ranged in age from 1 to 65 years (median, 40) with non-Hodgkin's lymphoma (NHL), Hodgkin's disease (HD), multiple myeloma (MM), or acute nonlymphoblastic leukemia (AML) who underwent autologous hematopoietic-cell transplant procedures at Stanford University Medical Center.

RESULTS

The actuarial 5-year event-free survival (EFS) rate was 44%, the relapse rate 47%, and the regimen-related mortality (RRM) rate 8.6%. Disease status at time of transplantation, categorized as either minimal or advanced disease, was the strongest predictive factor for EFS (relative risk (RR) for advanced-disease group, 1.8; P < .0003) and relapse rate (RR for advanced-disease group, 1.9; P < .0004). Patients with minimal or advanced disease had an EFS rate of 48% and 30% and relapse rates of 43% and 72%, respectively. The EFS rate of patients less than 50 years verus > or = 50 years of age was 46% versus 34% (P = .03). Cox regression analysis showed that age was predictive for EFS (RR for patients 50 to 65 years, 1.4; P = .03). The actuarial RRM rate for these age groups was 7.4% versus 12.7% (P = .07), respectively. Multivariate analysis demonstrated that age (odds ratio [OR] for patients 50 to 65 years, 1.9; P < .05) and period of transplantation (OR for most recent years [1991 to 1995], 0.6; P = .06) were the most predictive factors for RRM.

CONCLUSION

Although age greater than 50 years is associated with an inferior outcome following autologous hematopoietic-cell transplantation, it does not appear to be warranted to limit this potentially curative procedure based solely on age. The upper age limit of high-dose therapy with autologous progenitor-cell and/ or bone marrow support remains to be defined.

Immunomodulatory peptides with high binding affinity for class II MHC molecules for the prevention of graft-versus-host disease

Graft-versus-host disease (GVHD) represents the major barrier to successful allogeneic bone marrow transplantation. Positive and negative selection studies have unequivocally demonstrated that donor T cells are responsible for the induction phase of GVHD. Inhibition of the early steps of T cell antigen recognition leading to graft-versus-host disease has become an area of intense investigation. Peptides with high binding affinity for class II MHC molecules have been shown to compete for the single class II binding site and to inhibit T cell proliferative responses in vitro. Recent work has extended this approach to the prevention of murine GVHD in vivo.

A synthetic random basic copolymer with promiscuous binding to class II major histocompatibility complex molecules inhibits T-cell proliferative responses to major and minor histocompatibility antigens in vitro and confers the capacity to prevent murine graft-versus-host disease in vivo

Graft-versus-host disease (GVHD) is a T-cell-mediated disease of transplanted donor T cells recognizing host alloantigens. Data presented in this report show, to our knowledge, for the first time that a synthetic copolymer of the amino acids L-Glu, L-Lys, L-Ala, and L-Tyr (molecular ratio, 1.9:6.0:4.7:1.0; Mr, 6000-8500) [corrected], termed GLAT, with promiscuous binding to multiple major histocompatibility complex class II alleles is capable of preventing lethal GVHD in the B10.D2 --> BALB/c model (both H-2d) across minor histocompatibility barriers. Administration of GLAT over a limited time after transplant significantly reduced the incidence, onset, and severity of disease. GLAT also improved long-term survival from lethal GVHD: 14/25 (56%) of experimental mice survived > 140 days after transplant compared to 2/26 of saline-treated or to 1/10 of hen egg lysozyme-treated control mice (P < 0.01). Long-term survivors were documented to be fully chimeric by PCR analysis of a polymorphic microsatellite region in the interleukin 1beta gene. In vitro, GLAT inhibited the mixed lymphocyte culture in a dose-dependent fashion across a variety of major barriers tested. Furthermore, GLAT inhibited the response of nylon wool-enriched T cells to syngeneic antigen-presenting cells presenting minor histocompatibility antigens. Prepulsing of the antigen-presenting cells with GLAT reduced the proliferative response, suggesting that GLAT inhibits antigen presentation.

Prevention and treatment of graft-versus-host disease

Graft-versus-host disease remains a formidable barrier in allogeneic bone marrow transplantation. Studies have shown that effective prophylaxis results in improved overall survival for patients following allogeneic bone marrow transplantation. Various methods to prevent GVHD have been devised over the years including drug therapy, monoclonal antibodies, and T-cell depletion. Many of these prophylaxis regimens have been successful in improving the outcome in patients, with some regimens resulting in only a 9% incidence of acute GVHD in selected patients. Yet, GVHD remains an important problem for those patients in whom prophylaxis fails. Therapy for GVHD has relied on drugs and monoclonal antibodies, and the results of therapy for severe GVHD have been unsatisfactory. As immunologic understanding of the afferent and efferent phases of GVHD continues to be elucidated, more targeted therapy will be introduced and hopefully will result in better outcomes.

Inhibition of T cell costimulation by VCAM-1 prevents murine graft-versus-host disease across minor histocompatibility barriers

Activation of T cells leading to graft-vs-host disease (GVHD) requires two signaling events: the Ag-specific signal generated through the engagement of the TCR/CD3 complex with antigenic peptide fragments presented by MHC molecules on APCs and the second signal provided through additional costimulatory ligands. T cells have preferential costimulatory requirements depending on their state of activation-induced maturation. In the present study, we investigated the role of the receptor-ligand pair VLA-4 (alpha 4 beta 1) and VCAM-1 in allogeneic T cell responses in vitro and in vivo. Anti-VCAM-1 mAb effectively inhibited mixed lymphocyte culture (MLC) across several major MHC barriers and secondary MLC across minor histocompatibility Ags (95.5% and 90.0% inhibition, respectively). In contrast, anti-VLA-4 mAb inhibited a CD8(+)-mediated primed CTL response in vitro by 100%, yet had little effect on proliferative responses. In the B10.D2/nSnJ-->BALB/c (both H-2d) system of GVHD, BALB/c received anti-VCAM-1, or anti-VLA-4 or controls NS-1 or Y13-259 for the first 5 wk after transplant. Anti-VLA-4 mAb delayed the onset of GVHD, but failed to reduce incidence, severity or GVHD-related mortality. In contrast, anti-VCAM-1 reduced the incidence of GVHD from 100% (18/18) in control animals to 53.3% (8/15) (p < 0.01) on day 70 post-transplant and significantly decreased GVHD-related mortality. Sixty percent (9/15) of anti-VCAM-1 recipients survived more than 180 days after transplant. Long-term engraftment of allogeneic bone marrow was documented in all transplanted mice by PCR analysis of a microsatellite region in the IL-1 beta gene.

Inhibition of T cell costimulation by VCAM-1 prevents murine graft-versus-host disease across minor histocompatibility barriers

Activation of T cells leading to graft-vs-host disease (GVHD) requires two signaling events: the Ag-specific signal generated through the engagement of the TCR/CD3 complex with antigenic peptide fragments presented by MHC molecules on APCs and the second signal provided through additional costimulatory ligands. T cells have preferential costimulatory requirements depending on their state of activation-induced maturation. In the present study, we investigated the role of the receptor-ligand pair VLA-4 (alpha 4 beta 1) and VCAM-1 in allogeneic T cell responses in vitro and in vivo. Anti-VCAM-1 mAb effectively inhibited mixed lymphocyte culture (MLC) across several major MHC barriers and secondary MLC across minor histocompatibility Ags (95.5% and 90.0% inhibition, respectively). In contrast, anti-VLA-4 mAb inhibited a CD8(+)-mediated primed CTL response in vitro by 100%, yet had little effect on proliferative responses. In the B10.D2/nSnJ--&gt;BALB/c (both H-2d) system of GVHD, BALB/c received anti-VCAM-1, or anti-VLA-4 or controls NS-1 or Y13-259 for the first 5 wk after transplant. Anti-VLA-4 mAb delayed the onset of GVHD, but failed to reduce incidence, severity or GVHD-related mortality. In contrast, anti-VCAM-1 reduced the incidence of GVHD from 100% (18/18) in control animals to 53.3% (8/15) (p &lt; 0.01) on day 70 post-transplant and significantly decreased GVHD-related mortality. Sixty percent (9/15) of anti-VCAM-1 recipients survived more than 180 days after transplant. Long-term engraftment of allogeneic bone marrow was documented in all transplanted mice by PCR analysis of a microsatellite region in the IL-1 beta gene.

Does thalidomide affect IL-2 response and production?

The exact mechanism of immunosuppression by thalidomide is poorly understood. A common denominator in the pathogenesis of graft-vs.-host disease, graft rejection, reactional lepromatous leprosy, and autoimmune disorders modulated by thalidomide is the activation of T lymphocytes culminating in the synthesis of interleukin-2 (IL-2), the expression of high-affinity IL-2 receptors, and the induction of proliferation. We investigated the effect of thalidomide on the production of IL-2 by the human leukemia cell line Jurkat through induction of IL-2 gene enhancer activity and through the presence of IL-2 in supernatants. beta-galactosidase activity, encoded by a reporter lac z construct and controlled by a transcription factor in thalidomide-treated PMA- and ionomycin-stimulated Jurkat cells, was similar (97 +/- 1.33%; p > 0.1) to non-thalidomide-treated controls at all drug concentrations tested. IL-2 enhancer-driven beta-galactose activity of thalidomide-treated and stimulated cells was also similar to that of untreated controls (p > 0.2). The IL-2 production of activated nontransfected Jurkat cells was gauged by using the IL-2-dependent cell line HT-2 as a readout and by ELISA. Jurkat cells were subcloned by limiting dilution. Bulk cultures and three subclones (J.5.2.5., J.5.2.9., and J.5.3.8.) were assayed at 6, 12, and 24 hours after PHA/PMA-induced stimulation. No inhibitory effect on the IL-2 production by thalidomide could be detected at any of the drug concentrations tested (5-30 micrograms/mL), whereas 10 to 100 ng/mL of cyclosporine inhibited the IL-2 production by 95 to 100%. In addition, we observed neither inhibition of IL-2-dependent proliferation of HT-2 nor inhibition of PHA-induced proliferation of peripheral mononuclear cells by thalidomide at all drug concentrations used (5-30 micrograms/mL). These results do not support the possibility of a modulatory effect on the immune response by thalidomide via IL-2 production and IL-2 response.

Prevention of graft-versus-host disease by peptides binding to class II major histocompatibility complex molecules

Graft-versus-host disease across minor histocompatibility barriers was induced in two different models by transplanting allogeneic bone marrow and spleen cells into irradiated H-2-compatible recipient mice. In this report, we show that administration of peptides with high binding affinity for the respective class II major histocompatibility complex molecules after transplantation is capable of preventing the development of graft-versus-host disease in two different murine models. The peptides used were myelin basic protein residues 1 through 11 with alanine at position 4 (Ac 1-11[4A]) for I-Au (A alpha uA beta u), and the antigenic core sequence 323 through 339 of ovalbumin with lysine and methionine extension (KM core) for I-As (A alpha sA beta s). In both systems, the mechanism of prevention was found to be major histocompatibility complex-associated, because nonbinding control peptides did not have any effect. Engraftment of allogeneic bone marrow cells was shown by polymerase chain reaction analysis of DNA polymorphisms in a microsatellite region within the murine interleukin-5 gene.

[Ophthalmoplegia interna after varicella]

We present the case of a 5 1/2 year old girl. 14 days after the onset of the typical rash, the right pupil was dilated and fixed to light. Her manifest refraction was O.D. +1.0 dpt. No signs of iridocyclitis could be found, the fundus was normal. One year later, the pupil of the right eye was still dilated, whereas accommodation had slightly improved (+0.5 dpt). Internal ophthalmoplegia complicating chickenpox is rare, 13 cases have been reported so far.