Spectral karyotyping and fluorescence in situ hybridization detect novel chromosomal aberrations, a recurring involvement of chromosome 21 and amplification of the MYC oncogene in acute myeloid leukaemia M2.

Recurring chromosomal aberrations are of aetiological, diagnostic, prognostic and therapeutic importance in acute myeloid leukaemia (AML). However, aberrations are detected in only two thirds of AML cases at diagnosis and recurrent balanced translocations in only 50%. Spectral karyotyping (SKY) enables simultaneous visualization of all human chromosomes in different colours, facilitating the comprehensive evaluation of chromosomal abnormalities. Therefore, SKY was used to characterize 37 cases of newly diagnosed AML-M2, previously analysed using G-banding. In 15/23 patients it was possible to obtain metaphases from viably frozen cells; in 22 additional cases, fixed-cell suspensions were used. Of the 70 chromosomal aberrations identified by SKY, 30 aberrations were detected for the first time, 18 aberrations were redefined and 22 were confirmed. SKY detected two reciprocal translocations, t(X;3) and t(11;19). In five cases, eight structural aberrations resulted in partial gains of chromosome 21, six of which were undetected by G-banding. In 4/5 cases, these resulted in copy number increases for AML1. Amplification of MYC was detected in three cases. Using SKY and FISH, clonal aberrations were identified in 5/18 cases with a presumed normal karyotype; 3/5 aberrations were of known unfavourable prognostic significance. Karyotypes were entered into a custom-designed SKY database, which will be integrated with other cytogenetic and genomic databases.

Jumping translocations are common in solid tumor cell lines and result in recurrent fusions of whole chromosome arms.

Jumping translocations (JTs) and segmental jumping translocations (SJTs) are unbalanced translocations involving a donor chromosome arm or chromosome segment that has fused to multiple recipient chromosomes. In leukemia, where JTs have been predominantly observed, the donor segment (usually 1q) preferentially fuses to the telomere regions of recipient chromosomes. In this study, spectral karyotyping (SKY) and FISH analysis revealed 188 JTs and SJTs in 10 cell lines derived from carcinomas of the bladder, prostate, breast, cervix, and pancreas. Multiple JTs and SJTs were detected in each cell line and contributed to recurrent unbalanced whole-arm translocations involving chromosome arms 5p, 14q, 15q, 20q, and 21q. Sixty percent (113/188) of JT breakpoints occurred within centromere or pericentromeric regions of the recipient chromosomes, whereas only 12% of the breakpoints were located in the telomere regions. JT breakpoints of both donor and recipient chromosomes coincided with numerous fragile sites as well as viral integration sites for human DNA viruses. The JTs within each tumor cell line promoted clonal progression, leading to the acquisition of extra copies of the donated chromosome segments that often contained oncogenes (MYC, ABL, HER2/NEU, etc.), consequently resulting in tumor-specific genomic imbalances. Published 2001 Wiley-Liss, Inc.

Simultaneous immunomagnetic CD34+ cell selection and B-cell depletion in peripheral blood progenitor cell samples of patients suffering from B-cell non-Hodgkin's lymphoma.

The reduction of residual tumor cells is one of the main targets of leukapheresis product (LP) processing. Immunomagnetic enrichment/selection of CD34+ progenitor cells (Baxter Isolex 300i) can achieve a reduction of contaminating B-cells of approximately 2-3 logs in B-cell non-Hodgkin's lymphoma patients. Specific release of the enriched CD34+ cells (stem cell releasing agent PR34+; Baxter) and the use of antibody-coated immunobeads targeted against B-cell markers (CD10, CD19, CD20, CD22, CD23, and CD37) during this procedure allows the GMP-like simultaneous capture of residual B cells within a closed system. This combination of two purging techniques enhances the B-cell depletion capacity up to 4.5 logs. By performing 10 clinical-scale purging procedures, we could show that the simultaneous immunomagnetic purging method is easy to perform and highly efficient. We evaluated B-cell log depletion by flow cytometry for cases with marker-positive cells detectable before and after the purging procedure. The mean reduction of B-cells in these cases was 3.5 logs; the mean CD34+ cell yield and purity were 47 and 92%. Using three LPs, we tested the procedure on a modified Baxter Isolex 300i device with software adaptations for this procedure (software version 2.0) in direct comparison with CD34+ cell selection only, using the former version (version 1.12). The CD34+ cell yield was 49% (40-54%) for the CD34+ cell selection and 51% (19-72%) for simultaneous double selection. The mean purity was 96% for CD34+ cell selection and 98% for simultaneous double selection. B-cell depletion was 1.9 logs for CD34+ cell selection, and after simultaneous double selection, the B-cell content was decreased by 3.7 log steps (P = 0.0495). Clinical application of double-purged cells has not prolonged the hematopoietic recovery times after high-dose therapy as compared with nonpurged peripheral blood progenitor cell autotransplants. In conclusion, we could show that the simultaneous double selection protocol developed leads to a highly increased B-cell purging efficacy when compared with CD34+ cell selection without any negative effects regarding CD34+ cell yield and engraftment times after high-dose therapy.

Spectral Karyotyping (SKY) of Hematologic Malignancies.

The discovery of the Philadelphia chromosome in chronic myeloid leukemia (CML) by Novell and Hungerford in 1960 (1), the subsequent clarification of this chromosomal abnormality as areciprocal translocation t(9;22)(q34;q1 1) by Rowley in 1973 (2), the identification of the genes involved at the translocation breakpoints (3,4), and ultimately the demonstration of the leukemogenic activity of the resulting fusion product (5), represent hallmarks for our understanding of malignant diseases as genetic disorders. The elucidation of the Philadelphia translocation emphasizes the importance of cytogenetic analysis of hematologic malignancies. Clarification of this chromosomal aberration as a reciprocal translocation became only possible after the development of cytogenetic banding techniques by Caspersson et al. in 1970 (6). Chromosome banding analysis revealed numerous nonrandom chromosomal aberrations, particularly balanced translocations in leukemias and lymphomas, e.g., the translocation t(8;21)(q22;q22) in acute myeloid leukemia (AML) first described by Rowley et al. in 1973 (7). These balanced translocations were shown to be of etiologic as well as diagnostic, prognostic, and therapeutic importance. They result in an altered gene function by two main mechanisms: (1) sequences of, in most instances, a transcription factor or receptor tyrosine kinase gene are fused to a normally unrelated gene, creating specific fusion proteins with oncogenic properties, and (2) protooncogenes are repositioned to the vicinity of promoter/enhancer elements of the immunoglobulin- or T-cell receptor genes, thereby initiating their activation (8).

Acute myelogenous leukemia after treatment for malignant germ cell tumors in children.

PURPOSE: To identify the long-term sequelae of therapy for malignant germ cell tumors (GCTs). PATIENTS AND METHODS: Between 1980 and 1998, 1,132 patients were prospectively enrolled onto the German nontesticular GCT studies. A total of 442 patients received chemotherapy using combinations of the drugs cisplatin, ifosfamide, etoposide, vinblastine, and bleomycin, and 174 patients were treated with a combination of chemotherapy and radiotherapy. Median follow-up duration was 38 months (range, 6 to 199 months). RESULTS: Six patients developed therapy-related acute myelogenous leukemia (t-AML). There was no t-AML among patients treated with surgery (n = 392) or radiotherapy only (n = 124). The Kaplan-Meier estimates of the cumulative incidence (at 10 years) of t-AML were 1.0% for patients treated with chemotherapy (three of 442) and 4.2% for patients treated with combined chemotherapy and radiotherapy (three of 174). Notably, four of these six patients had been treated according to a standard protocol with modest cumulative chemotherapy doses. Five patients had received less than 2 g/m(2) epipodophyllotoxins, and four patients had received less than 20 g/m(2) ifosfamide. Four patients presented with AML, two with myelodysplasia in transformation to AML. In five patients, cytogenetic aberrations were found, four of which were considered characteristic for t-AML. Four patients died despite antileukemic therapy. One patient is alive but suffered a relapse of his GCT, and one patient is alive and well. No secondary solid neoplasm was observed. CONCLUSION: In patients with AML after treatment for GCT, several pathogenetic mechanisms must be considered. AML might evolve from a malignant transformation of GCT components without any influence of the chemotherapy. On the other hand, the use of alkylators and topoisomerase II inhibitors is associated with an increased risk of t-AML. Future studies will show if the reduction of treatment intensity in the current protocol reduces the risk of secondary leukemia in these patients.

Analysis of B-cell neoplasias by spectral karyotyping (SKY).

B-cell neoplasias represent a heterogeneous group of diseases, including acute lymphocytic leukemia (ALL) and the broad spectrum of non-Hodgkin's lymphomas (NHL). Conventional cytogenetic analysis has revealed specific chromosomal aberrations in ALL as well as in NHL. Spectral karyotyping (SKY) is a novel molecular cytogenetic technique which allows the visualization of all human chromosomes in different colors, therefore greatly facilitating the recognition of chromosomal aberrations. The potential of SKY is exemplified by the fact that in our experience, 70% of the cases analyzed resulted in karyotypes where the majority of aberrations were either refined or new aberrations were detected when compared to their G-banding karyotypes. This also applies to the analysis of B-cell neoplasias. In hematologic malignancies, especially acute leukemias, specific chromosomal aberrations are of etiologic as well as diagnostic and prognostic importance. The identification of new recurrent chromosomal aberrations could therefore lead to a better characterization of disease entities or subgroups in ALL and NHL and further improve diagnosis, treatment stratification and ultimately prognosis. Interestingly, the comparison of the pattern of chromosomal aberrations in hematological neoplasias and carcinomas revealed striking differences. While about 50% of the aberrations in hematological malignancies are balanced translocations, such aberrations are exceedingly rare in epithelial cancers in which unbalanced structural and numerical aberrations prevail.

Efficacy and safety of simultaneous immunomagnetic CD34+ cell selection and breast cancer cell purging in peripheral blood progenitor cell samples used for hematopoietic rescue after high-dose therapy.

We have established a new simultaneous positive/negative selection procedure using the Baxter Isolex 300i system. We tested its tumor cell (TC) purging efficacy by tumor contamination tests ex vivo and its safety in a group of 17 breast cancer (BC) patients by measuring hematopoietic recovery after high-dose (HD) therapy and autologous stem cell rescue with the selected cells. Tumor contamination tests resulted in a TC depletion of 4.1-6.0 log steps. The CD34+ cell yield in this experimental setting was 38.9-91.5%, and the CD34+ cell purity was 86.0-96.0%. In a group of 17 BC patients (5 high-risk adjuvant, > or = 10 lymph nodes positive, and 12 metastatic), we processed leukapheresis products (LPs) by simultaneous positive/negative selection. In these clinical samples, the mean CD34+ cell yield was 56.2% (range, 14.0-80.1%), and the CD34+ cell purity was 94.5% (range, 69.0-99.8%). Additionally, we screened samples of the patients' LPs before and after the purging procedure for contaminating TC by immunocytochemistry. In 15 of 17 tested cases, TCs were detectable prior to the purging procedure. After the procedure, we could not detect residual TCs in 16 of 17 cases. In one case, we found a highly reduced number of TCs. Furthermore, we evaluated the times for hematopoietic reconstitution in a group of five BC patients in the high-risk adjuvant situation who underwent HD chemotherapy and hematopoietic rescue with positive/negative selected stem cells and compared it with our own data from 10 BC patients who, after identical HD therapy, received only positively selected CD34+ cells and 14 patients who, after identical HD therapy, received autografts purged by incubation with toxic ether lipids (ET-18-OCH3). In all groups, a leukocyte count of >2000 cells/microl was reached at day +10. A platelet count of > 50,000 cells/microl was reached at day +12 in the ET-18-OCH3 group and at day +14 in the other two groups. Furthermore, 12 patients with metastatic disease rescued with positive/negative selected stem cells after HD therapy also showed fast and comparable hematopoietic recovery. The new simultaneous immunomagnetic positive/negative selection using a closed system is effective and safe. Processing LPs leads to a similar CD34+ cell yield, a higher TC depletion compared to standard CD34+ cell selection, and no delay in hematopoietic recovery.

Is there a place for 2-CDA in the treatment of B-CLL?

There is no doubt about 2-CDA being a very potent lymphotoxic agent that displays high efficacy in the treatment of CLL. It interferes with the intranuclear machinery of DNA regulation, and causes death to proliferative active, as well as resting lymphocytes. Interruption of crucial pathways that are evident for cell survival translates into high clinical response rates in CLL. CR and PR rates comparable to those reported on fludarabine are achieved in relapsed or refractory CLL. Even though trials on previously untreated CLL are still ongoing, a consistent trend towards durable, high CR rates becomes apparent. The toxicity is comparable to that of fludarabine and consists of infections, as well as thrombocytopenia. Clinical as well as in vitro studies suggest a crossresistance between the two purine analogues, indicating that sequential treatment is not useful. Given these data, although preliminary in case of de novo CLL, 2-CDA has to be recognized as one of the most effective cytostatic drugs currently available for CLL treatment. Large prospective trials (in comparison with fludarabine) will assess the role of 2-CDA as standard treatment. Such trials should also have the aim to substantiate the potential of 2-CDA as induction treatment followed by high-dose consolidation.

Ex vivo expansion of human umbilical cord blood does not lead to co-expansion of contaminating maternal mononuclear cells.

One of the main limiting factors for increased use of human umbilical cord blood (UCB) in adult allogeneic transplantation is the small number of progenitor cells that can be collected and infused. Ex vivo expansion of UCB might help to overcome this limitation. Whether an expansion of UCB cells will also lead to co-expansion of contaminating maternal cells, and thus may alter graft characteristics and lead to an increased incidence of GVHD, has not been looked at so far. We initiated cultures with UCB mononuclear cells (MNC) in a standard medium containing stem cell factor (SCF), flt-3L, II-3, IL-6, EPO and G-CSF. To address the question of contaminating maternal cells we performed interphase FISH analysis of the X and Y chromosome simultaneously. Male (XY) cord blood samples were investigated for maternal (XX) cells at day 0 and at several time points during culture. We could not detect maternal cells in any of the nine samples studied when cultures were started at day 0. Culturing did not expand previously undetected maternal cells into a range that could be seen with FISH technology, as all samples remained negative for maternal cells throughout culture periods of 14 days. We then artificially contaminated male UCB with maternal mononuclear cells at concentrations of 5 and 15% at day 0. After 14 days, maternal MNC were still detectable, but the percentage was reduced to 1.7% and 6%, respectively. During culturing of CD34+-selected UCB the content of maternal cells also declined from a mean of 1.6% after contamination to 0.4% on day 7. Taken together we could show that maternal cells co-cultured with UCB do not co-expand and thus do not interfere with ex vivo expansion of UCB for adult allogeneic transplantation.

[Experiences with modified BFM protocols in the treatment of children with acute lymphoblastic leukemia (ALL) in East Germany 1981-1991]. / Erfahrungen mit modifizierten BFM-Protokollen bei der Behandlung von Kindern mit akuten lymphoblastischen Leukämien (ALL) in den ostdeutschen Ländern von 1981 bis 1991.

Between September and August 1991 818 previously untreated children and adolescents up to 18 years of age with acute lymphoblastic leukemia were entered into two modified BFM-protocols. Patients with B-ALL were excluded. From 1981 to 1987 524 patients were entered into the randomized multicenter study ALL VII/81 (modified ALL-BFM 81 protocol). Patients were divided into three risk groups standard (SR), medium (MR), high risk (HR) using the BFM risk factor. In a connecting study from 1988 to 1991 294 patients were registered on the stratified and randomized multicentric trial ALL VIII/87 (modified ALL-BFM 86 study). The main modification in study ALL VII/81 concerned the duration of treatment. Patients were randomized into two groups. The first group received as a late reinduction protocol III and then therapy was stopped. The second group received 6-MP and MTX for another six months. The other whole treatment strategy of ALL-BFM 81 was adopted. In protocol ALL VIII/87 the only modification was the reduction of the MTX dosage from 5 g/m2 to 1 g/m2 with an infusion time of 24 hours (leucovorin rescue 15 mg/m2 after 48 and 54 hours). The probability of the event-free-survival (EFS) for study ALL VII/81 was 59%. CNS events were significantly more frequent in standard risk patients with intermediate dose MTX (4 x 0.5 g/m2) compared with the irradiation group (18 Gy). The EFS for SR patients amounts to 61%, for MR patients to 59% and for HR patients to 36%. There was no significant difference of EFS for the two groups with different duration of therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

[Diagnostic evaluation of skeletal scintigraphy in comparison to roentgen studies in histiocytosis X in childhood. Case report]. / Diagnostische Wertigkeit der Skelettszintigraphie im Vergleich zur Röntgenuntersuchung bei der Histiozytose X im Kindesalter. Erfahrungsbericht.

We have compared whole body skeletal scintigraphy with X-ray examination in 15 children suffering from histiocytosis X, 14 of whom also showed involvement of the skeleton. In 9 of 20 cases, relapses, included, involvement of the skeleton was found both in scintigraphy and X-ray examination. In 7 cases only X-ray examinations have revealed lessons, which could not be proved by scintigraphy. Vice versa, in 4 cases scintigraphy was positive alone. These results confirm the necessity to use both methods for an exact documentation of the extent of the disease before undertaking any therapy. Dispensing with one of the two methods may cause incorrect therapeutic decisions and increase the risk of relapses and late complications.

Improved treatment results in childhood acute nonlymphoblastic leukemia with the BFM-AML protocol 78 in a multicenter study in the GDR.

Eighty-seven children with acute nonlymphoblastic leukemia were treated with the AML protocol BFM 78 between June 1979 and February 1986 in a multicenter study in the GDR. Seventeen children (20%) died from early complications, eight did not respond to therapy. Fifty-eight patients (70%) achieved a complete remission. Twenty-three patients relapsed. The life table analysis revealed after 5 years a probability for event-free survival of 36% (SD = 6%) and an event-free interval of 51% (SD = 8%). Six patients were transplanted in first remission. Two of them died; one (M 1) on day + 19 from encephalopathy and one (M 4) on day + 60 from acute GVHD. The overall results are in good correlation with the original BFM study, but there are differences in the subtypes. Results are superior to other AML protocols in our group.