In vivo clonal evolution of pre-B to B-cell acute lymphoblastic leukemia in childhood.

Two cases are described that provide further evidence for clonal evolution in pre-B-cell acute lymphoblastic leukemia. Two infants, whose lymphoblasts at diagnosis were morphologically subtyped as L1 and immunophenotyped as HLA DR+, CD19+, CD10+/- and C mu-, were induced and maintained in remission. One child relapsed 6 months after initiation of therapy. This time his lymphoblasts had L3 morphology and immunophenotyping demonstrated the appearance of surface immunoglobulins. The second child relapsed 18 months after initiation of therapy with a lymphomatous picture. He also had peripheral and bone marrow blasts with L3 morphology and surface immunoglobulins. A lymph node biopsy showed diffuse small non-cleaved lymphoma with a 'starry sky' appearance compatible with Burkitt's lymphoma. Only one case with a similar clonal evolution has been reported in the literature, but no surface immunoglobulins were demonstrated. The significance of clonal evolution in these cases and its potential practical implications are discussed.

Detection and clinical relevance of genetic abnormalities in pediatric acute lymphoblastic leukemia: a comparison between cytogenetic and polymerase chain reaction analyses.

The E2A/PBX1 and the BCR/ABL fusion genes result from the t(1;19)(q23;p13) and the t(9;22)(q34;q11), respectively, and encode oncoproteins which are thought to play an important role in the development of acute lymphoblastic leukemia (ALL) subtypes associated with adverse prognosis. The use of the polymerase chain reaction (PCR) for the detection of these genetic rearrangements may offer advantages over cytogenetic techniques which are often unsatisfactory in patients with ALL and, furthermore, provide a useful tool for monitoring of residual disease. However, it has not yet been evaluated whether the employment of PCR at the time of diagnosis improves the detection rate of these clinically relevant genetic anomalies. We have developed a multiprimer-PCR protocol which facilitates the detection of each of the four chimeric E2A/PBX1 and BCR/ABL mRNAs in a single reaction. This protocol was used for the evaluation of bone-marrow or blood samples from 251 children with ALL in whom cytogenetic analyses had been performed. Of the 251 patients, 221 had a B-cell precursor immunophenotype. In this group, 21 patients (9.5%) carrying the E2A/PBX1 rearrangement and three patients (1.4%) with BCR/ABL transcripts were detected by PCR. Twelve of these cases had escaped the detection by conventional cytogenetic analysis. In two of 12 patients with a typical t(1;19)(q23;p13), no E2A/PBX1 transcripts were identified by PCR, thus suggesting the presence of different molecular rearrangements. Residual leukemic cells were detected by PCR in five of eight patients who were followed during complete clinical remission. The frontline use of PCR has an important impact on the timely diagnosis, therapeutic decisions, and monitoring of high-risk patients with B-cell precursor leukemia who carry the E2A/PBX1 or BCR/ABL fusion genes.

A search for bcl1, bcl2, and c-myc oncogene rearrangements in chronic lymphocytic leukemia.

Three cellular or putative oncogenes: c-myc, bcl1, and bcl2 were previously found to be rearranged in some B cell malignancies due to chromosomal translocations. Data concerning the role of such genetic rearrangements in B-CLL are very scanty and limited to few cases in which bcl1 rearrangements were found. We studied DNA samples from 38 cases of B-CLL by Southern blot technique in order to find out the existence and frequency of such events. No bcl1 or bcl2 rearrangements were found in any of the studied cases; thus, involvement of these genes in CLL must be rare. In one patient who had an aggressive and resistant disease, c-myc rearrangement was found.

More than two immunoglobulin heavy chain J region genes in the majority of infant leukemia.

Congenital and infant leukemia are rare conditions associated with a very poor prognosis due to the high frequency of adverse clinical and laboratory parameters. As the occurrence of multiple immunoglobulin heavy chain hybridization band in childhood leukemia has been associated with poor prognosis, we studied whether it was present in this type of leukemia as well. Seven cases were examined, 4 of them less than 7 months of age. The immunophenotype was lymphoid in 5 and hybrid in 2. Most had abnormal karyotypes. In 5 of the 7, including all with congenital leukemia, an immunoglobulin heavy chain J region multiband pattern was found by Southern blot. The multiband pattern, whether primary or due to clonal evolution, seems to be associated with poor prognosis.

Chimerism testing and detection of minimal residual disease after allogeneic hematopoietic transplantation using the bioView (Duet) combined morphological and cytogenetical analysis.

Recurrent disease remains a major obstacle to cure after allogeneic transplantation. Various methods have been developed to detect minimal residual disease (MRD) after transplantation to identify patients at risk for relapse. Chimerism tests differentiate recipient and donor cells and are used to identify MRD when there are no other disease-specific markers. The detection of MRD does not always correlate with relapse risk. Chimerism testing may also identify normal hematopoietic cells or other cells not contributing to relapse. In this study we report our initial experience with a novel system that provides combined morphological and cytogenetical analysis on the same cells. This system allows rapid automatic scanning of a large number of cells, thus increasing the sensitivity of detection of small recipient population. The clinical significance of MRD detection is improved by identifying the morphology of recipient cells. Identification of recipient characteristics within blasts predicts overt relapse in leukemia patients and precedes it by a few weeks to months. Identification within mature hematopoietic cells may not be closely associated with relapse. The system also allows chimerism testing after sex-mismatched transplants, within cellular subsets, with no need for sorting of cells. The system merits further study in larger scale trials.

Mutation analysis of the FAS and TNFR apoptotic cascade genes in hematological malignancies.

OBJECTIVE: The existence of properly functioning apoptotic pathways is of utmost importance in the maintenance of a normal cell count. Several groups have searched for mutations in the FAS receptor, a well-characterized apoptotic protein carrying a death domain, and reported the existence of rare mutations in multiple myeloma, T-acute lymphoblastic leukemia (T-ALL), and adult T-cell leukemia. Our aim was to expand these searches by looking for mutations in the death domains of FAS, FADD, TNFR, TRADD, and RIP, in the promoter region of FAS, and in the protease domain of caspase 10, in a larger variety of hematological malignancies, some of which express an apoptosis-resistant phenotype. METHODS: We extracted RNA and DNA samples from 92 hematological malignancies: chronic lymphocytic leukemia (CLL; 31 cases), chronic myelogenous leukemia (CML; 28 cases), essential thrombocythemia (ET; 8 cases), acute lymphocytic leukemia (ALL; 6 cases), acute myeloblastic leukemia (AML; 6 cases), hairy-cell leukemia (HCL; 3 cases), Burkitt's lymphoma (3 cases), polycythemia vera (PV; 3 cases), myelofibrosis (2 cases), and chronic myelomonocytic leukemia (CMML; 2 cases) and performed PCR-SSCP and sequence analysis on these samples. RESULTS: Five polymorphic patterns were found: three in the death domain of the FAS gene in CML patients, one in the promoter of this gene in a CLL patient, and the fifth in the death domain of the TRADD gene in a CML patient. No mutations, altering amino acids, were found in these genes in any of the aforementioned malignancies. CONCLUSIONS: These observations imply that mutations in the death domains of FAS, FADD, TNFR, TRADD, and RIP and in the protease domain of caspase 10 are not a major cause for failure of apoptosis in hematological malignancies, mainly CML and CLL. Regulatory and epigenetic abnormalities in these apoptotic cascade members and aberrations in other components of all death machinery should be looked for.

Amplification of immunological functions by subcutaneous injection of intermediate-high dose interleukin-2 for 2 years after autologous stem cell transplantation in children with stage IV neuroblastoma.

BACKGROUND: Immunotherapy given post-autologous stem cell transplantation may eliminate residual tumor cells escaping the conditioning protocol. METHODS: Five children suffering from stage IV neuroblastoma were treated by recombinant interleukin-2 (IL-2) post-autologous peripheral blood stem cell transplantation. The patients' peripheral mononuclear cells were monitored for CD3+ and CD56+ levels, their proliferative response and killing of various cell lines targets. RESULTS: An increase in the level of total lymphocytes, mainly due to expansion of T cells, and enhanced proliferative response to phytohemaglutinin were observed. Elevated cytotoxicity against K562 and neuroblastoma target cells was detected in four patients and against K562 targets in one patient. Toxicity included mild thrombocytopenia, and fever in four patients and mild to moderate encephalopathy which necessitated withdrawing one patient from the protocol. Three of five patients studied are alive today, one of them whose IL-2 was stopped, is in relapse. Two patients have died. CONCLUSIONS: Immunotherapy with s.c. intermediate-high dose IL-2 is feasible and results in expansion of T cells and in stimulation of killing activity against several targets including in some cases, neuroblastoma tumor cells.

Acute lymphoblastic leukemia subtypes in Israel: the Sheba medical center experience.

During the period from 1978 to 1981, 52 patients with ALL were diagnosed and treated at the Chaim Sheba Medical Center. Using standard cell markers to subtype the blasts, 49 of the patients could be classified: 16 were found to be T-cell ALL, 10 common ALL, five null ALL, four pre-B and 14 were partially characterized as non-B, non-T. Analysis of the series revealed two distinctive features: high prevalence (30%) of T-cell ALL among both Jews and Arabs and a high proportion, two-thirds, of high risk patients due to high initial WBC counts, unfavourable age or T-cell characteristics. The minimal incidence of ALL among the Gaza Strip Arab children during the study period is 4:100,000, which is close to the incidence in the Western world. During previous years the leukemia incidence in the Gaza Strip was very low while the most common lymphatic malignancies were Burkitt tumor and other non-Hodgkin lymphomas.

Engraftment-associated hypophosphatemia--the role of cytokine release and steep leukocyte rise post stem cell transplantation.

Hypophosphatemia associated with bone marrow transplantation has been infrequently reported. The suggested mechanism is phosphate uptake by the replicating cells. Various cytokines are associated with the development of hypophosphatemia. The present study evaluated the interrelationship between cytokine release, the rise in WBC and the development of hypophosphatemia during the engraftment period. Blood samples were obtained from 60 patients undergoing peripheral blood stem cell transplant, on the day of admission and then daily from the day of transplant until discharge. Hypophosphatemia developed in 62% of the patients. The median day of minimal phosphorus level was +8 and it antedated engraftment by 2 days. There was a significant correlation between the day of minimal phosphorus level and the day of maximal WBC and a significant correlation between the fall in phosphorus level and WBC rise. IL-6 and IL-8 showed similar kinetics. Higher IL-6 and IL-8 levels were directly associated with lower phosphorus levels. In conclusion, hypophosphatemia commonly occurs in the post-transplant period. We assume that both a direct effect of cytokine release and an increased consumption by the dividing WBCs contribute to its appearance. As its occurrence usually antedates engraftment it can be used as a forerunner for WBC recovery.

Successful human umbilical cord blood stem cell transplantation without conditioning in severe combined immune deficiency.

A 2-month-old girl with severe combined immunodeficiency (SCID), presented with mild staphylococcal skin infection, lymphopenia, low T cell number, absence of B cells, high number of NK cells, and a negligible response to mitogens. Since her older brother died as a result of SCID 2 years earlier, cord blood was harvested from a sister born 2 1/2 years earlier, who was normal and fully matched both by serology and molecular typing. In view of her clinical condition and in spite of a high number of NK cells with normal activity, HUCBT without preparative conditioning was performed. No G-CSF was administered. Engraftment with mixed chimerism was evident 3 weeks post transplantation. There were no peritransplantation complications. Eighteen months post transplantation, the girl is in excellent condition, blood counts are normal, T cell engraftment is complete, B cell engraftment is proceeding gradually, and the mitogen stimulation tests are normal. Due to the unique nature of HUCB hematopoietic cells, engraftment without conditioning may be possible in patients with SCID with fully matched donors. This is the first HUCBT performed without conditioning.

Subgroup of patients with Philadelphia-positive chronic myelogenous leukemia characterized by a deletion of 9q proximal to ABL gene: expression profiling, resistance to interferon therapy, and poor prognosis.

A major deletion of the region proximal to the rearranged ABL gene on 9q was found in 14/94 (15%) of chronic myelogenous leukemia Philadelphia-positive patients by interphase fluorescent in situ hybridization with the BCR/ABL extra signal dual-color probe. Preliminary results indicated that the prognosis of the deletion 9q patients is probably worse than that of the non-deletion 9q patients. Twelve of the 14 deletion 9q patients were treated with alpha-interferon and none had a major cytogenetic response. The median duration of the chronic phase in patients not undergoing BMT was significantly shorter for the deletion 9q patients as compared to the non-deletion 9q patients (p =.0144). DNA microarray technology was performed in order to compare the gene expression patterns between the two groups of patients. A number of genes exhibiting differential expression, especially involving cell adhesion and migration, were identified. This finding may identify a sub-group of CML patients with different cell properties and a relatively poor prognosis.

In vitro proliferative advantage of bone marrow cells with tetrasomy 8 in Ewing sarcoma.

We describe a case of a 14.5-year-old boy with a clinically aggressive pelvic Ewing sarcoma. The tumor cells showed the presence of a typical t(11;22)(q24;q12) aberration and gains of chromosomes 8, 10, 14, and 21. To determine the size of the trisomy and tetrasomy 8 clones an interphase analysis by fluorescence in situ hybridization with a centromere-specific chromosome 8 probe was performed. Significant quantitative differences between metaphase and interphase data were obtained. It was shown that culturing of bone marrow cells leads to enrichment of tetrasomy 8 population that may be explained by the proliferative advantage of the tetrasomy 8 cells.

Analysis of microsatellite repeats in pediatric brain tumors.

Tumorigenesis has been shown to proceed through a series of genetic alterations involving protooncogenes and tumor suppressor genes. However, investigation of genomic instability of microsatellites has disclosed a new mechanism for human carcinogenesis, which is involved not only in hereditary nonpolyposis colon cancer (HNPCC) but also in a number of other malignancies. To determine whether microsatellite instability is involved in pediatric brain tumors, we screened 15 such tumors using seven microsatellite marker loci on six chromosomes 4, 5, 9p, 9q, 11, 14, and 17. Using the polymerase chain reaction method, DNA samples from the tumors and from normal peripheral blood leukocytes from each patient were compared for the allelic pattern produced at each locus. Our preliminary results indicate loss of heterozygosity at the fatty acid binding protein (FABP) locus, located on chromosomal arm 4q28-q31, the only trinucleotide repeat in the panel of markers used, for 3 of 15 cases, suggesting the presence of previously unidentified sequences relevant to brain tumorigenesis at or in the vicinity of this locus. We did not observe any microsatellite instability in these samples, indicating that the mechanisms operating in HNPCC are not active in this subset of pediatric brain tumors.

Hexasomy of chromosome 8 and trisomy of chromosome 11 characterize two karyotypically independent clones in a case of acute non-lymphocytic leukemia. Conventional cytogenetic and FISH investigation.

A case of ANLL following a myelodysplastic syndrome, probably resulting from occupational exposure to ionizing irradiation, with two cytogenetically unrelated clones, hexasomy 8 and trisomy 11, was investigated by conventional cytogenetics and FISH. Significant quantitative differences between data obtained by metaphase and interphase analysis of the hexasomy 8 clone were observed. A difference in the sensitivity to chemotherapy of the two clones was found: while the hexasomy 8 clone markedly decreased in response to treatment, the trisomy 11 clone remained unchanged.

Standardization criteria for the detection of BCR/ABL fusion in interphase nuclei of chronic myelogenous leukemia patients by fluorescence in situ hybridization.

Fluorescence in situ hybridization (FISH), as a new clinical test, is not presently standardized. For practical reasons, each laboratory must build its own criteria. In this work, we present our standardization criteria for clinical practice, which include not only the methods for cell fixation, specimen preparation, and hybridization conditions, but mainly the definition of false-positive range and the scoring criteria of microscopic analysis. These include signal assessment, difference between individual microscopists, evaluation of specimen homogeneity, and the minimum number of scored nuclei required for a clinically reliable result. For this purpose, we analyzed by FISH 24 healthy volunteer donors, 31 patients affected by non-chronic myelogenous leukemia (CML) hematological malignancies, 47 CML patients at diagnosis, and 82 CML patients during treatment for the BCR/ABL fusion. In this article, we present several quality control and assurance methods that can be useful in providing standardization of the FISH technique.

Coexistence of several unbalanced translocations in a case of neuroblastoma: the contribution of multicolor spectral karyotyping.

Spectral karyotyping (SKY) is based on the simultaneous hybridization of a set of 24 chromosome-specific DNA painting probes, each labeled with a different fluor combination. Automatic classification, based on the measurement of the spectrum for each chromosome, was applied to metaphases obtained from the affected bone marrow of a neuroblastoma case. Spectral karyotyping allowed the identification of chromosomal aberrations that could not be identified by the use of the G-banding technique, and revealed a number of gains and unbalanced translocations.

[Glucose phosphate isomerase deficiency with congenital nonspherocytic hemolytic anemia].

Glucose phosphate isomerase (GPI) deficiency is an unusual cause of hereditary nonspherocytic hemolytic anemia described in Israel in 2 families of Arab ancestry. The disease, inherited as an autosomal recessive disorder, manifests itself by symptoms and signs of chronic hemolysis which are often ameliorated by splenectomy. A variety of defective GPI variants, characterized by modified physicochemical and/or kinetic properties of the enzyme have been reported, suggesting extensive polymorphism for this enzyme deficiency. We recently diagnosed GPI deficiency in a 23-year-old Jewish Ashkenazi man. Since the age of 1 year, when a diagnosis of hemolytic anemia of undetermined etiology was made, he has required frequent blood transfusion. Since splenectomy, performed when he was 6 years old, the requirement for blood transfusions diminished drastically, restricted to hemolytic crises following intercurrent febrile illnesses. To the best of our knowledge, this is the first report of GPI deficiency in an Israeli family of Ashkenazi-Russian origin.