Confirmation of paternal disomy in a twin molar pregnancy. A case report

BACKGROUND

Paternal dispermy can be the pathogenesis of complete molar pregnancy.

CASE

A 23-year-old, white woman, gravida 4, para 1, was pregnant with a twin gestation by ovulation induction with metrodin. Ultrasound evaluation confirmed an intrauterine pregnancy in conjunction with what appeared to be a hydatidiform mole. The karyotype in the molar pregnancy, obtained from chorionic villus sampling, showed a pair of paternally derived inverted chromosomes 9, confirming the diagnosis of a complete mole. Uncontrollable hemorrhage with a rapid rise in the beta-human chorionic gonadotropin titer necessitated evacuation of the uterus. The patient was followed with beta-human chorionic gonadotropin titers for a year, with no evidence of recurrence.

CONCLUSION

This case illustrates paternal disomy in a complete molar pregnancy documented by a paternal chromosome 9 inversion.

Identification of three distinct regions of deletion on the long arm of chromosome 11 in childhood acute lymphoblastic leukemia

Cytogenetic analysis of childhood acute lymphoblastic leukemia (ALL) identified deletions of chromosome arm 11q. These observations led us to analyse the loss of heterozygosity (LOH) of chromosome arm 11q in 113 primary childhood ALL samples using 14 microsatellite markers. LOH was found in 18 (16%) patients. Detailed examination identified three distinct regions of deletion. The first region is flanked by D11S901 and D11S1391 at 11q22-23 containing the ATM gene. Mutational analysis suggested that the altered gene in this region is not the ATM gene. The second region is flanked by D11S614 and D11S924 at 11q23 containing the MLL gene. The third region is flanked by D11S1356 and D11S614 at 11q23 containing the MLL gene. All the cases with LOH at MLL locus lacked detectable MLL gene rearrangements. In addition, 20 children have been studied both at initial diagnosis and relapse; none of the individuals who relapsed acquired LOH of 11q, suggesting that 11q deletions were infrequently involved in the progression of childhood ALL. Children with 11q LOH had a good response to induction chemotherapy (P=0.015). These data suggest that alterations of putative tumor suppressor genes on 11q are important events in development of childhood ALL. Our map provides important information toward cloning putative tumor suppressor genes associated with childhood ALL.

High cure rates and reduced long-term toxicity in pediatric Hodgkin's disease: the German-Austrian multicenter trial DAL-HD-90. The German-Austrian Pediatric Hodgkin's Disease Study Group

PURPOSE

To further reduce therapy-related late effects in patients with pediatric Hodgkin's disease (HD) while maintaining the high cure rates achieved with vincristine, prednisone, procarbazine, and doxorubicin (OPPA) or OPPA/cyclophosphamide, vincristine, prednisone, and procarbazine (COPP) chemotherapy and involved-field radiotherapy. The risk of testicular dysfunction was addressed by substituting etoposide for procarbazine (OEPA) in the induction therapy for boys. Radiation doses and fields were further reduced.

PATIENTS AND METHODS

Three hundred nineteen boys and 259 girls younger than 18 years with previously untreated HD, enrolled onto the study between 1990 and 1995, were allocated to treatment group (TG)1 (early stages), TG2 (intermediate stages), or TG3 (advanced stages). All groups underwent two cycles of OEPA (boys) or OPPA (girls) for induction chemotherapy. TG2 and TG3 continued on additional two or four cycles, respectively, of COPP. Low-dose radiotherapy was given to the initially involved sites, ie, reduced involved fields.

RESULTS

Initial response to OPPA or OEPA induction was virtually identical. Eight of 578 patients experienced early progression of HD. Thirty-seven relapses, three secondary tumors, and no secondary leukemias have been recorded, with a median follow-up duration of 5.1 years (maximum, 8.1 years). Thirteen of 578 patients died. The probability of 5-year event-free survival/overall survival is 91%/98% in the total group, 94%/97% with OPPA, and 89%/98% with OEPA induction therapy. Risk factor analysis showed two significant prognostic factors: histologic subtype NS2 and "B" symptoms. OEPA induction therapy, large mediastinal tumor, and age were not significant. Preliminary studies of testicular function indicate a lower risk of germ cell damage than previously documented with OPPA.

CONCLUSION

OEPA is a satisfactory alternative to OPPA. Radiotherapy can be confined to involved sites when combined with appropriate chemotherapy. The DAL-HD-90 regimen represents a comprehensive treatment program for all stages of pediatric HD and offers a favorable benefit/risk ratio, combining excellent disease control, moderate acute toxicity, and reduced long-term toxicity.

Therapy for non-Hodgkin lymphoma in children with primary immunodeficiency: analysis of 19 patients from the BFM trials

BACKGROUND

Non-Hodgkin lymphomas (NHL) represent an important complication of primary immunodeficiency (ID), posing new therapeutic challenges in this patient population. This study analyzes clinical data and therapy results of pediatric patients with primary ID and NHL in three consecutive NHL-BFM trials.

PROCEDURE

Retrospective analysis of children with primary ID and NHL, treated according to protocol NHL-BFM, was performed regarding clinical presentation, diagnostic features, therapy, and outcome.

RESULTS

From October, 1986, to April, 1997, 19 of 1,413 newly diagnosed patients with NHL were registered as suffering from primary ID. Age at diagnosis of NHL was lower in patients with ID. Six patients suffered from humoral ID, 13 patients from combined ID (ataxia teleangiectasia n = 3; Nijmegen breakage syndrome n = 4; PNP deficiency n = 1; IL2 receptor defect n = 1, other combined ID n = 4). Thirteen lymphomas were of B-cell and six of T-cell-lineage. Four of thirteen patients with combined ID were diagnosed with T-NHL, nine with B-NHL. Two of six patients with humoral ID presented with T-NHL and four with B-NHL. NHL entities differed significantly between ID and non-ID patients (P < or = 0.01): centroblastic and immunoblastic lymphomas (31.6% vs. 8.1%), anaplastic large cell lymphoma (26.3% vs. 10.7%), Burkitt lymphoma and B-ALL (21% vs. 47. 8%). Seventeen patients received polychemotherapy. Therapy-related toxicity was increased in ID- compared to non-ID-patients. Three patients died of sepsis; three died of tumor progression; one patient relapsed; one died of BMT-related toxicity; one died of second malignancy. Ten patients are in first continuous remission after a median follow-up of 4 years.

CONCLUSIONS

Curative treatment of NHL in the presence of primary ID is possible and should be attempted.

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.

Accurate and rapid analysis of residual disease in patients with CML using specific fluorescent hybridization probes for real time quantitative RT-PCR

We sought to establish a rapid and reliable RT-PCR approach for detection and quantification of BCR-ABL fusion transcripts using the LightCycler technology. This device combines rapid thermocycling with online detection of PCR product formation and is based on the fluorescence resonance energy transfer (FRET) between two adjacent hybridization probes carrying donor and acceptor fluorophores. A pair of probes was designed that was complementary to ABL exon 3, thus enabling detection of all known BCR-ABL variants and also normal ABL as an internal control. Conditions were established to amplify less than 10 target molecules/reaction and to detect one CML cell in 105 cells from healthy donors. To determine the utility of the assay, we quantified BCR-ABL and ABL transcripts in 254 samples (222 peripheral blood, 32 bone marrow) from 120 patients with CML after therapy with IFN-alpha (n = 219), allogeneic BMT (n = 17), chemotherapy (n = 11), or at diagnosis (n = 7). The level of residual disease in the 245 BCR-ABL positive specimens was expressed as the ratio of BCR-ABL/ABL. This ratio was compared to results obtained by three established methods from contemporaneous specimens. A highly significant correlation was seen between the BCR-ABL/ABL ratios determined by the LightCycler and (1) the BCR-ABL/ABL ratios obtained by nested competitive RT-PCR (n = 201, r = 0.90, P < 0. 0001); (2) the proportion of Philadelphia chromosome positive metaphases determined by cytogenetics (n = 81, P < 0.0001); and (3) the BCR ratio determined by Southern blot analysis (n = 122, P < 0. 0001). We conclude that real-time PCR with hybridization probes is a reliable and sensitive method to monitor CML patients after therapy. The major advantages of the methodology are (1) amplification and product analysis are performed in the same reaction vessel, avoiding the risk of contamination; (2) the results are standardized by the quantification of housekeeping genes; and (3) the complete PCR analysis takes less than 60 min.

Prednisone response is the strongest predictor of treatment outcome in infant acute lymphoblastic leukemia

To define prognostic factors in infant acute lymphoblastic leukemia (ALL), the outcome of 106 infants (age </=12 months) during 3 consecutive multicenter trials of the Berlin-Frankfurt-Münster group (ALL-BFM 83, 86, and 90) was retrospectively analyzed according to presenting features and early in vivo response to prednisone. The prednisone response was defined as the cytoreduction (number of blood blasts per microliter at day 8) to a 7-day prednisone prephase and 1 intrathecal dose of methotrexate on day 1. Prednisone good responder (PGR; <1,000 blasts/microL) received conventional therapy and prednisone poor responder (PPR; >/=1,000 blasts/microL) received intensified therapy. Infant ALL was characterized by a high incidence of a white blood cell count greater than 100 x 10(3)/microL (57%), central nervous system leukemia (24%), lack of CD10 expression (59%), 11q23 rearrangement (49%) including the translocation t(4;11) (29%), and a comparatively high proportion of PPR (26%), which were all significantly associated with inferior outcome by univariate analysis. The estimated probability for an event-free survival at 6 years (pEFS) was by far better for PGR compared with PPR, who had a dismal prognosis despite intensified treatment (pEFS, 53% +/- 6% v 15% +/- 7%, P =.0001). Infant PGR, who were less than 6 months of age (n = 40), lacked CD10 expression (n = 43), and/or had an 11q23 rearrangement (n = 17) fared significantly better compared with corresponding PPR, as indicated by a pEFS of 44% +/- 8%, 49% +/- 8%, and 41% +/- 12%, respectively. In multivariate analysis, PPR was the strongest adverse prognostic factor (relative risk, 3.3; 95% confidence interval, 1.9 to 5.8; P <.0001). Infants with PGR, comprising a major subgroup (74%) among infants, might successfully be treated with conventional therapy, whereas PPR require new therapeutic strategies, including early treatment intensification or bone marrow transplantation in first remission.

[Fatal accidental mixed poisoning of 3 men at the same time]

The case history presented reports on three 30- to 40-years-old men, who were found dead in a party like situation in the living room. The toxicological investigation proved alcohol and THC as well as therapeutic Flunitrazepam- and Pentobarbital levels and toxic 7- Amino-Flunitrazepam concentrations. The background of this surprising scene led up to the conclusion of an accidental death caused by a mixed intoxication.

Transplantation of megadoses of purified haploidentical stem cells

Peripheral mobilized parental CD34+ progenitors were isolated and used for the hematopoietic reconstitution after a myeloablative therapy in 23 pediatric patients with various diseases. Fourteen donors were human leukocyte antigen (HLA) three-loci mismatches, 6 donors were two-loci and 3 donors were one-locus mismatches. For depletion of T-lymphocytes, a positive selection of the mobilized peripheral CD34+ progenitors using the method of magnetic-activated cell sorting (MACS) was used. The purity of the CD34+ cells after MACS-sorting was 98-99%, the average number of transplanted CD34+ cells was 14.2 x 10(6)/kg (range 5.4-3.9 x 10(6)/kg) and the average number of infused T-lymphocytes was 1.4 x 10(4)/kg. Due to this low T cell number, only a short-term or no prophylaxis of graft-versus-host disease (GVHD) was necessary and no GVHD was seen. A significant GVHD was only seen in patients after add-back of donor T-lymphocytes, which was performed in some patients for prevention of relapse or in patients who showed a transient mixed chimerism. Since the B lymphocyte contamination of the isolated CD34+ cells was low in the range of 0.2%, no Epstein-Barr virus (EBV)-associated lymphoproliferative syndrome was observed. A primary engraftment was seen in 18 patients. Nonengraftment and rejection occurred in three and two patients, respectively. In four of these 5 patients, a second transplant using purified CD34+ cells from the same donor after an immunological reconditioning regimen resulted in a complete and sustained hematopoietic reconstitution. The speed of the immunological recovery was dependent on the number of transplanted CD34+ cells and was more rapid if this number was > 20 x 10(6)/kg. Eleven of the 23 patients are alive and disease free with a median follow-up of 12 months (range 2-30). The main cause of death was relapse (7 patients), and only one fatal infection was seen. Our data suggest that the transplantation of megadoses of haploidentical CD34+ cells is a realistic therapeutic option for patients who otherwise have no suitable donor, and an alternative to the use of unrelated cord blood.

Synthesis of Pseudomonas aeruginosa lipopolysaccharide core antigens containing 7-O-carbamoyl-L-glycero-alpha-D-manno-heptopyranosyl residues

The monosaccharide allyl 7-O-carbamoyl-L-glycero-alpha-D-manno- heptopyranoside, the reducing disaccharide 7-O-carbamoyl-L-glycero-alpha-D- manno-heptopyranosyl-(1-->3)-L-glycero-D-manno-heptopyranose and the disaccharides allyl 7-O-carbamoyl-L-glycero-alpha-D-manno-heptopyranosyl-(1-->3)-L-glycero- beta- and alpha-D-manno-heptopyranoside were prepared in good yields. The 7-O-carbamoyl substituent was regioselectively introduced via NH3-NH4HCO3 treatment of a 6,7-O-carbonate group. Glycosylation steps were carried out using Me3SiOTf or BF3.Et2O promoted coupling of allyl alcohol with trichloroacetimidate or fluoride glycosyl donors, respectively. The deprotected allyl glycosides were reacted with cysteamine to afford spacer glycosides which were subsequently linked to bovine serum albumin. The artificial antigens which are related to the dephosphorylated heptose region of the lipopolysaccharide core region from Pseudomonas aeruginosa classified into RNA group I may be used for the characterization of monoclonal antibodies directed against inner core epitopes of human-pathogenic Pseudomonas species.

Fusion of ETV6 to the caudal-related homeobox gene CDX2 in acute myeloid leukemia with the t(12;13)(p13;q12)

The t(12;13)(p13;q12) is a rare, recurrent translocation reported in a range of hematological malignancies. We have analyzed the molecular basis of this lesion in three patients with acute myeloid leukemia (AML), two of whom were known to have chromosome 12 breakpoints within the ETV6 gene. Fluorescence in situ hybridization (FISH) with ETV6 cosmids indicated that this gene was also disrupted in the third patient, while the normal ETV6 allele was retained. 3' rapid amplification of cDNA ends (RACE) polymerase chain reaction (PCR) from bone marrow mRNA of this individual identified a novel sequence fused to ETV6 that was homologous to a region just upstream of the mouse CDX2 homeobox gene, the human homologue of which has previously been mapped to chromosome 13q12. PCR primers designed to amplify an ETV6-CDX2 fusion identified two major transcripts from this patient. First, a direct in-frame fusion between exon 2 of ETV6 and exon 2 of CDX2, and second, a transcript that had an additional sequence of unknown origin spliced between these same exons. Surprisingly, apparently normal CDX2 transcripts, usually expressed only in intestinal epithelium, were also detectable in cDNA from this patient. Neither normal nor fusion CDX2 mRNA was detectable in the two other patients with a t(12;13), indicating that this translocation is heterogeneous at the molecular level. Reverse transcription-PCR analysis showed that CDX2 mRNA, but not ETV6-CDX2 mRNA, was strongly expressed in 1 of 10 patients with chronic myeloid leukemia in transformation, suggesting that deregulation of this gene may be more widespread in leukemia. CDX2 is known to regulate class I homeobox genes and its expression in hematopoietic cells may critically alter the balance between differentiation and proliferation.

The genomic structure of ZNF198 and location of breakpoints in the t(8;13) myeloproliferative syndrome

The t(8;13)(p11;q12) is the most common translocation associated with the 8p11 myeloproliferative syndrome and results in an identical mRNA fusion between ZNF198 at 13q12 and FGFR1 at 8p11 in all cases thus far reported. ZNF198 is a widely expressed gene that is predicted to encode a 1377-amino-acid protein with five Zn finger-related motifs known as MYM domains. To determine the genomic DNA structure of ZNF198, we employed bubble PCR from PAC clones with a panel of gene-specific primers. Sequencing of these products revealed that ZNF198 consists of 26 exons with the initiation codon located in exon 4. The t(8;13) results in a consistent mRNA fusion of ZNF198 exon 17 to FGFR1 exon 9. Notable features of the structure of ZNF198 include three noncanonical GC donor splice sites and the presence of an alternatively spliced intron within exon 4. Amplification of genomic DNA from six t(8;13) patients with primers to ZNF198 exon 17 and FGFR1 exon 9 yielded patient-specific products ranging in size from 500 bp to 2.5 kb, indicating that the positions of the breakpoints in the t(8;13) are tightly clustered. The positions of the six t(8;13) breakpoints were determined and found to be distributed across ZNF198 intron 17 and FGFR1 intron 8 with no apparent subclustering. No consistent sequence motifs, repeats, or topoisomerase II cleavage sites were found at or near the breakpoints. It remains unclear why the t(8;13) translocation breakpoints occur within such small genomic regions, and it is possible that strict ZNF198-FGFR1 coding requirements restrict the positions of the breakpoints.

Philadelphia chromosome-positive (Ph+) childhood acute lymphoblastic leukemia: good initial steroid response allows early prediction of a favorable treatment outcome

Among 4,760 acute lymphoblastic leukemia (ALL) patients enrolled from 1986 to 1995 in two subsequent trials of the BFM and AIEOP study group, 61 patients were found to have Philadelphia chromosome-positive (Ph+) ALL. These patients were analyzed for presenting features and treatment outcome to identify specific prognostic factors. Treatment stratification was based on initial cell mass and early response as determined by blast count in peripheral blood after a 7-day induction prephase with prednisone and one dose of intrathecal methotrexate on day 1. All patients were treated by similar intensive Berlin-Frankfurt-Münster (BFM) protocols. The median age of Ph+ patients was 7.5 years, the median white blood cell count (WBC) was 75 x 10(9)/L, 77% of patients had common ALL, and 29% coexpressed myeloid markers. After a median observation time of 4.2 years, 29 of 61 patients are alive (survival probability [pSUR] at 4 years, 0.49; standard error [SE], 0.06), and 24 of 61 are in first complete remission (CR1; probability of event-free survival [pEFS] at 4 years, 0.38; SE, 0.06). Twenty (35%) of 57 evaluable patients had >/=1,000 leukemic blasts per microliter of blood on day 8 of induction (defined as prednisone-poor-response [PPR]). These patients were older (10.0 v 6.88 years; P = .02) and had a higher WBC (144 v 29 x 10(9)/L; P = .0016) as compared with patients with prednisone good response (PGR; <1,000 blasts/microL at day 8). Only 2 of 20 patients (10%) with PPR remained in CR1 and alive: 6 patients with PPR did not survive after allogeneic bone marrow transplantation (BMT) due to recurring disease (n = 3) and toxicity (n = 3), and 12 nontransplanted patients died due to progression (n = 5) or relapse (n = 7). In contrast, 26 (70%) of the 37 patients with PGR are alive. Of 18 patients transplanted by allo-BMT, 1 relapsed (now in CR2) and 4 died after BMT. Among the 19 patients with PGR treated by chemotherapy alone, 8 remained in CR1 and 11 relapsed, of which 4 are in CR2 or CR3. The prednisone response emerged as the only independent prognostic factor for survival in Cox regression analysis. Thus, two thirds of Ph+ childhood ALL cases can be identified early by PGR, which, when treated with intensive BFM chemotherapy, with or without BMT, have a significantly lower risk of treatment failure. With a median continuous complete remission (CCR) time of 4.1 years, pEFS for PGR is 0.55 (SE, 0.08) compared with 0.10 (SE, 0.07) in patients with PPR (P = .0001). PGR is also an indicator for treatment responsiveness and durable second remission after relapse, which in turn may provide a second chance for BMT.

Intermediate dose methotrexate is as effective as high dose methotrexate in preventing isolated testicular relapse in childhood acute lymphoblastic leukemia

PURPOSE

We evaluated the influence of three different dosages of methotrexate (MTX) during consolidation on the incidence of testicular relapse in children with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

One thousand one hundred forty-four boys with newly diagnosed ALL, enrolled in three consecutive trials of the Berlin-Frankfurt-Münster group (ALL-BFM 81, 83, 86), were retrospectively evaluated for the influence of MTX on testicular relapse-free interval. The basic treatment design was similar in all trials. No intravenous MTX was used in trial ALL-BFM 81 in the group who received cranial irradiation (CRT) except for a part of standard risk patients. Four courses of intermediate dose MTX (IDM) (0.5 g/m2) were introduced for all patients in trial ALL-BFM 83 (IDM group), which were replaced by high dose MTX (HDM) (5 g/m2) in trial ALL-BFM 86 (HDM group). The media observation time was > 9 years.

RESULTS

The cumulative incidence of isolated testicular relapses was significantly higher in the CRT group as compared to the IDM and HDM groups (6.7% versus 2.5% and 2.3%, p = 0.02 and 0.01). HDM decreased neither the incidence nor the rate of isolated testicular relapses any further. Event-free survival (EFS) for boys was similar between trial ALL-BFM 81 and 86 (64% versus 69%, p = 0.35), but differed significantly between trials ALL-BFM 83 and 86 (61% versus 69%, p = 0.0078).

CONCLUSION

The introduction of IDM reduced the incidence of isolated testicular relapses significantly by a factor two, but had no significant influence on overall survival. HDM did not result in a more effective prevention of testicular relapses, but resulted in better systemic control and hence better survival than IDM.

BCR-ABL-positive progenitors in chronic myeloid leukaemia patients in complete cytogenetic remission after treatment with interferon-alpha

To determine the source of residual disease detected in patients with chronic myeloid leukaemia (CML) in complete cytogenetic remission (n=8) after treatment with interferon-alpha (IFN-alpha), we have tested CFU-GM colonies grown from bone marrow mononuclear cells or from plastic-adherent (Pdelta) cells for BCR-ABL mRNA using a nested multiplex RT-PCR. We compared our results with those obtained by analysis of colonies from newly diagnosed patients (n=4) and patients achieving no cytogenetic response (n=1) or incomplete cytogenetic response to treatment with IFN-alpha (n=5). A total of 1239 informative colonies were analysed. A small proportion of BCR-ABL-positive colonies was detected in all eight patients in complete cytogenetic remission, suggesting the persistence of leukaemia that could potentially lead to relapse. The overall proportion of BCR-ABL-positive colonies in patients achieving a cytogenetic response to IFN-alpha correlated with the levels of BCR-ABL transcripts detected in the peripheral blood by competitive RT-PCR (P=0.004). We conclude that residual disease detected in the peripheral blood of complete cytogenetic responders to IFN-alpha is at least partly derived from clonogenic myeloid cells. It is probable that the leukaemia clone in CML is only very rarely or never entirely eradicated by treatment with IFN-alpha.

Consistent fusion of ZNF198 to the fibroblast growth factor receptor-1 in the t(8;13)(p11;q12) myeloproliferative syndrome

The 8p11 myeloproliferative syndrome is a rare, aggressive condition associated with reciprocal translocations of chromosome band 8p11, most commonly the t(8;13)(p11;q12). To identify the genes involved in this translocation, we used fluorescence in situ hybridization (FISH) analysis to show that the chromosome 8 breakpoints fell within YAC 899e2 and that the chromosome 13 breakpoints are clustered in a region flanked by YACs 929f11 and 911h8. FISH using chromosome 13 PAC clones indicated that the t(8;13) is not simply a reciprocal translocation but also involves an inversion of 13q11-12. Exon trapping of a PAC that spanned the chromosome 13 translocation breakpoints led to the identification of a gene, ZNF198, that detected rearranged bands when used as a probe against Southern blots of patient DNA. Conceptual translation of the full-length ZNF198 cDNA sequence predicts a protein of 1377 amino acids that shows significant homology to the DXS6673E/KIAA0385 and KIAA0425 proteins. Alignment of these three proteins revealed a novel, conserved Zn-finger-related motif (MYM domain) of the general form CX2C19-22CX3CX13-19CX2CX19-25FCX3CX3F/Y that is repeated five times in each protein. To identify the translocation partner gene on chromosome 8, 5' and 3' RACE polymerase chain reactions (PCRs) were performed on patient RNA with several combinations of ZNF198 primers. Clones were identified in which the ZNF198 was fused to exon 9 of the fibroblast growth factor receptor-1 (FGFR1), a gene known to map to 8p11. An identical ZNF198-FGFR1 fusion was detected in the three patients with a t(8;13) for whom RNA was available; reciprocal FGFR1-ZNF198 transcripts were not detected. Rearrangements of both ZNF198 and FGFR1 were found in two further patients by Southern blotting. ZNF198-FGFR1 includes the five MYM domains of ZNF198 and the intracellular tyrosine kinase domain of FGFR1. We hypothesize that this fusion leads to constitutive activation of the FGFR1 tyrosine kinase in a manner analogous to the activation of ABL by BCR in chronic myeloid leukemia.

Expression and regulation of c-kit receptor and response to stem cell factor in childhood malignant T-lymphoblastic cells

The cytokine stem cell factor (SCF) synergizes with IL-7 to enhance the proliferation of thymocytes. We therefore investigated the role of the SCF receptor, the protooncogene c-kit, in the pathogenesis of pediatric T-lineage malignancies. Expression and regulation of c-kit in cells from children with non-Hodgkin's lymphoma (T-NHL) or acute lymphoblastic leukemia (T-ALL) and the proliferative effect of SCF on these cells were examined in seven cell lines and 21 biopsy tumor cell preparations. Inducibility of c-kit receptors by SCF, IL-1beta, IL-2, IL-7, TGF-beta, TNF-alpha, PMA or calcium ionophore A23187 was studied by flow cytometry (FCM). C-kit receptors were detected in three out of seven T-lymphoblastic cell lines and in nine out of 21 biopsy tumor cell preparations. Upregulation of c-kit could be induced by cultivation, and to a higher extent by cultivation and addition of IL-1beta, TNF-alpha, TGF-beta or A23187. Downregulation of c-kit occurred in the presence of SCF or PMA. SCF caused a downregulation of c-kit receptors in eight of nine, and a proliferative response in three of 11 c-kit-positive T-lymphoblastic cell preparations. We conclude that c-kit is able to transduce a growth stimulatory signal in some T-lymphoblastic cells and that its expression may not be detectable in a resting metabolic or proliferative state.

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.

Prevention of CNS recurrence in childhood ALL: results with reduced radiotherapy combined with CNS-directed chemotherapy in four consecutive ALL-BFM trials

BACKGROUND

The introduction of cranial radiotherapy (CRT) has provided efficient control of overt or subclinical meningeosis in acute lymphoblastic leukemia (ALL). Especially due to the long-term toxicity of CRT, reduction or elimination of radiotherapy appeared mandatory after cure rates of more than 70% had been achieved in ALL. The Berlin-Frankfurt-Münster (BFM) Study Group initiated several attempts in certain ALL subgroups to omit or reduce CRT while using more CNS-directed chemotherapy but without extended intrathecal treatment during maintenance therapy. This analysis summarizes the essential results that are in particular relevant because irradiation of the central nervous system (CNS) has been further reduced in the most recent trial ALL-BFM 95.

PATIENTS AND METHODS

More than 4000 patients enrolled between 1981 and 1995 in one of the last four ALL-BFM trials have been analyzed to demonstrate the efficiency of intensive systemic and intrathecal chemotherapy with or without reduced CRT in the prevention of CNS relapses.

RESULTS

In trial ALL-BFM81, it was shown that only in low-risk (LR) patients preventive radiotherapy can be replaced safely by intermediate dose (0.5 g/m2) methotrexate (MHD-MTX). In intermediate risk (IR) patients this attempt failed: IR pts had 8 times more CNS relapses if treated by MHD-MTX without CRT. In the subsequent trial ALL-BFM 83, all pts received MHD-MTX. IR pts were randomly treated with 12 or 18 Gy of preventive CRT which did not result in a significantly different outcome. The results from the subsequent trial ALL-BFM 86, using a more intensive consolidation with high-dose methotrexate (HD-MTX), demonstrated that the elimination of CRT in low-risk ALL, the reduced CRT of 12 Gy for IR, 18 Gy for medium (MR), and the reduced CRT with 18 Gy for high risk (HR) ALL, respectively, was justified: the incidence of relapses with CNS involvement was reduced to less than 5% (Reiter et al. 1994, Blood 84: 3122). When even less intensive preventive CRT (12 Gy for all medium and high risk patients) was used in trial ALL-BFM 90, the rate of CNS-related relapses was again below 5%. HR patients now treated with more CNS-directed chemotherapy had the lowest rate of CNS-related relapses observed so far in the BFM trials, even though CRT was also reduced to 12 Gy. Patients with T-cell ALL were shown to be protected from CNS recurrence by the combination of CRT (12 Gy) and HD-MTX more effectively than by HD-MTX in consolidation and TIT therapy during maintenance, especially if they presented with high WBC as shown in a joint AIEOP/BFM analysis (Conter et al. 1997, JCO 15: 2786). Patients with overt meningeosis which are characterized by a high leukemic cell load at diagnosis had a rate of recurrences that was comparable to that of patients with high WBC but no CNS disease.

CONCLUSION

Low-risk ALL patients can be efficiently prevented from CNS relapse by intensive systemic and intrathecal chemotherapy without CRT. Patients with intermediate or medium risk ALL, including T-cell ALL, did not suffer from more CNS or systemic relapses when CRT was reduced to only 12 Gy. Patients with inadequate response to therapy are at particularly high risk for relapse with CNS involvement. Therefore, more CNS-directed systemic and intrathecal chemotherapy was applied in trial ALL-BFM 90, combined with only 12 Gy cranial irradiation, and improved the control of CNS recurrence. It seems likely that larger subsets of B-precursor ALL can be protected from CNS-related relapse by intensive chemotherapy without extended IT treatment and without CRT. This is being investigated in the ongoing trial ALL-BFM 95.

Impaired renal function and tumor lysis syndrome in pediatric patients with non-Hodgkin's lymphoma and B-ALL. Observations from the BFM-trials

OBJECTIVE

Tumor lysis syndrome and renal failure remain important complications early in the course of therapy for pediatric Non-Hodgkin's lymphoma (NHL), frequently leading to therapeutic alterations. In the presented series, children with NHL and tumor lysis syndrome are retrospectively analysed regarding clinical features of acute renal failure and its implications on therapy.

PATIENTS AND METHODS

From 4/1990 to 10/1997, 1192 patients diagnosed of any form of NHL have been registered in the NHL-BFM trials. 63 of these patients were reported to have suffered from impaired renal function and/or tumor lysis syndrome before or during initial treatment. Clinical data of these patients were analysed regarding diagnosis, stage, tumor mass, therapy and complications.

RESULTS

62 of 63 patients with impaired renal function and/or tumor lysis syndrome were diagnosed of Burkitt's lymphoma or B-ALL; 58 (92%) of these patients had advanced stages of disease and high LDH-levels (> 500 U/l). 43 of 63 patients had already signs of impaired renal function at admission. Hyperuricemia was the commonest cause of impaired renal function. Renal infiltration or enlargement was observed in 27 of 63 patients. 6 patients were diagnosed of urinary tract obstruction. 25 patients required hemodialysis. Despite improved renal function before administration of MTX, 21 of 63 patients suffered from protracted MTX-elimination during the first course of therapy. 7 of 63 patients (11%) with tumor lysis syndrome died of sepsis after the first course of therapy, another two patients died within 48 hours of therapy due to electrolyte imbalances.

CONCLUSIONS

In pediatric NHL-patients, Burkitt's lymphoma and B-ALL appear to be the commonest cause of metabolic complications early in chemotherapy. Patients with advanced stages and large tumor mass are at high risk for renal failure. Impaired renal function predisposes patients to further complications and toxic death. Prophylactic use of urate-oxidase in all patients with advanced stage NHL might limit the incidence of tumor lysis syndrome. Prospective studies on renal function prior to and during therapy are required in order to develop a clinical profile reliably detecting patients at risk for developing renal failure and subsequent complications.

Frequent loss of heterozygosity on the long arm of chromosome 6: identification of two distinct regions of deletion in childhood acute lymphoblastic leukemia

Cytogenetic analysis of childhood acute lymphoblastic leukemia (ALL) identified nonrandom chromosomal abnormalities of the long arm of chromosome 6. Most of the alterations are deletions that are thought to be indicative of the presence of a tumor suppressor gene that is mutated on the remaining allele. These observations led us to consider whether 6q loss may contribute to the pathogenesis of childhood ALL. To define further a region containing this gene, we analyzed the loss of heterozygosity (LOH) of chromosome 6 in 113 primary ALL samples with matched normal DNA using 34 highly informative microsatellite markers. LOH was found in 17 (15%) samples at one or more of the loci, and partial or interstitial deletions of 6q were detected in 11 of these tumors. On the basis of these results, we performed a detailed deletional map and identified two distinct regions of deletion. The first region is flanked by D6S283 and D6S302 loci at 6q21-22. The second region is flanked by D6S275 and D6S283 loci at 6q21. Clinical analysis determined that LOH of 6q was demonstrated both in precursor-B cell ALLs (15 of 93; 16%) and in T cell ALLs (2 of 19; 11%). In addition, 19 patients have been studied at diagnosis and relapse; 18 showed the same 6q21-22 structural abnormality at relapse (normal, 16 patients; LOH, 2 patients) as their initial presentation, suggesting, albeit with a small patient sample size, that 6q21-22 deletions may be an initial event in leukemogenesis and may occur less frequently during the progression of childhood ALL. These data suggest the presence of putative tumor suppressor genes on chromosome arm 6q that are important in the development of both T and precursor-B childhood ALLs. Our map provides important information toward cloning putative ALL tumor suppressor genes.