Molecular analysis of PML-RAR alpha fusion mRNA detected by reverse transcription-polymerase chain reaction assay in long-term disease-free acute promyelocytic leukaemia patients

By use of RT-PCR of PML/RAR alpha, we evaluated bone marrow aspirates in 10 patients with APL in long-term disease-free status after induction chemotherapy and consolidation (median 54 months: range 33-101 months from complete remission). All patients were in clinical and cytogenetic remission at the time of molecular evaluation (range 32-96 months from CR). All patients but one were found to be RT-PCR negative at the molecular level for the expression of PML-RAR alpha transcript, confirming that the majority of the patients with long-term survival of APL are characterized by the eradication of the neoplastic clone.

Fludarabine treatment in resistant Waldenstrom's macroglobulinemia

Fludarabine (FLU) is a fluorinated purine analogue with a promising antineoplastic activity in lymphoproliferative disorders. In this study, we evaluated the efficacy of FLU in 12 previously treated (primary refractory and refractory relapse) patients with Waldenstrom's macroglobulinemia. All patients were treated at a dosage of 25 mg/m2 per day for 5 consecutive days for a total of six courses. Of the 12 patients, 5 (41%) achieved partial response (PR), and the remaining 7 showed no benefit from the treatment. An increased response rate was obtained in the 4 primary refractory patients in which 2 PR were documented. Treatment was well-tolerated and there were no Fludarabine-related fatalities. With a mean follow-up of 10 months, only 1 PR patient has relapsed. Fludarabine is an interesting new salvage agent effective against recurrent/resistant Waldenstrom's macroglobulinemia and should be evaluated in further studies in untreated patients with Fludarabine in monochemotherapy or in combination with other active modalities.

Factor VIII inhibitor prior to and during secondary acute nonlymphocytic leukemia in a patient with cured Hodgkin's disease

We report a 54-year-old patient with Hodgkin's disease who achieved a complete remission after combined modality treatment. Three years later the patient developed a severe hemorrhagic syndrome, concomitant with the onset of a factor VIII inhibitor in plasma. The control of very proteiform bleedings was extremely difficult, even with plasmaphereses, as well as with immunosuppressive and substitutive therapies. Two years later, a secondary acute nonlymphocytic leukemia (ANLL) was diagnosed. Two courses of chemotherapy with fludarabine, cytosine arabinoside and G-CSF (FLAG) were able to obtain a complete remission. Hemorrhagic complications were mainly linked to thrombocytopenia and continued until recovery of thrombopoiesis. Factor VIII inhibitor levels and related clinical symptoms decreased progressively. In conclusion, we suggest that FLAG succeeded in inhibiting an abnormal lymphoid clone responsible for factor VIII inhibitor production, suggesting a possible role for intensive chemotherapy in similar situations, which are often refractory to conventional immunosuppressive and depletive therapy.

Does the type of BCR/ABL junction predict the survival of patients with Ph1-positive chronic myeloid leukemia?

The prognostic value of the site of DNA rearrangement within the M-BCR on chromosome 22 or of the type of transcript has been debated in the last years. The majority of the studies do not support the hypothesis of a predictive value of such molecular parameters. Results coming from a multicentric, prospective trial, based on alpha-IFN therapy, seem to indicate a better karyotypic response in 3' rearranged patients. The possibility of evoking a cytotoxic immune response directed towards peptides originating from each of the different BCR/ABL junctions constitute an important challenge for the future.

Vitamin C reduces ischemia-reperfusion injury in a rat epigastric island skin flap model

Free radicals have been implicated in the cause of ischemia-reperfusion injury. Various agents have been used in an attempt to reduce ischemia-reperfusion injury pharmacologically, including free radical scavengers. Vitamin C (ascorbic acid), a well-known free radical scavenger, has not, to the best of our knowledge, been evaluated in this respect. Previous work at our institution has shown that vitamin C decreases capillary permeability, thus significantly reducing fluid resuscitation requirements in postburn cases. Because this is due in part to the scavenging effect of vitamin C on free radicals, we investigated the role, if any, of vitamin C on ischemia-reperfusion injury in a rat epigastric island skin flap model. Twenty-four adult Sprague-Dawley rats were divided into control and vitamin C groups. Superficial epigastric island skin flaps measuring 6.0 x 3.5 cm were raised. Pedicles were isolated and occluded with microvascular clamps for 6 hours. The flaps were then sutured back to their beds over Steri-Drape barriers. Fifteen minutes before reperfusion, the control group flaps were perfused via femoral artery cannulation with normal saline (2.5 ml/kg). The vitamin C-treated group was perfused in a similar fashion with 2.5 ml/kg of a vitamin C/normal saline solution (27 mg/ml). The animals were observed for 7 days, and the percentage of flap survival was determined using a paper template technique. The vitamin C-treated group demonstrated a significantly higher percentage of flap survival than did the control group (25.8% mean vs. 7.5% mean, p < 0.025). In this animal model, vitamin C reduced or limited reperfusion injury after 6 hours of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Apoptosis induction with three nucleoside analogs on freshly isolated B-chronic lymphocytic leukemia cells

The cytotoxic effects and the induction of programmed cell death (apoptosis) by Fludarabine (FLU), 2-chlorodeoxyadenosine (2-CdA), and deoxycoformycin (DCF) with/without alpha-interferon (alpha-IFN) were evaluated in vitro against freshly isolated B-chronic lymphocytic leukemia (B-CLL) cells. Cytotoxicity was evaluated according to the soluble tetrazolium/formazan assay. Regarding the cytotoxicity, FLU, 2-CdA, and DCF showed a mean antitumor activity of 45% +/- 3.39 (mean +/- S.D.), 55% +/- 4.72, and 20% +/- 3.16, respectively. alpha-IFN alone showed a mean cytotoxic activity of 10% +/- 2.72. The cytotoxicity of these purine analogues in combination with alpha-IFN was 52% +/- 2.97, 75% +/- 3.41, and 26% +/- 7.09, respectively. We observed a statistically significant increase of cytotoxicity compared to controls in FLU alone (P < 0.05), 2-CdA (P < 0.05), and their combination with alpha-IFN (P < 0.05). Apoptosis was evaluated by electrophoresis gel of DNA oligonucleosomal fragments and by a cytofluorimetric method. Only FLU and 2-CdA activated the apoptosis and DCF showed a minor apoptotic pathway amount. These apoptosis data were confirmed by both gel electrophoresis of DNA and by propidium iodide cytofluorimetric method. FLU and 2-CdA show activity in B-CLL cells by direct cytotoxic action and the induction of cell death by apoptosis; in the future, it would be interesting to utilize these in vitro assays in monitoring chemosensitivity and predicting response for the clinical use.

Persistence of non clonal hematopoietic progenitor cells in blastic phase chronic myelogenous leukemia (CML). Working Party on Severe Aplastic Anemia (WPSAA) of the European Group of Bone Marrow Transplantation (EBMT)

Normal and clonal hematopoietic progenitor cells have been demonstrated to coexist in chronic-phase chronic myelogenous leukemia (CML), but few data are available on the presence of non neoplastic hematopoiesis during the blastic transformation phase. We used reverse transcription-polymerase chain reaction (RT-PCR) to investigate expression of the BCR/ABL transcript of individual hematopoietic progenitors from a CML patient in blastic phase. We demonstrate that non clonal hematopoiesis is induced to re-emerge by conventional chemotherapy containing fludarabine. In addition, we confirm that some pluripotent CD34+/CD33-/DR- cells circulating in the peripheral blood are not clonal. Our data provide an encouraging basis for further studies of in vitro purification of normal hematopoietic stem cells in advanced stage CML and of their use in the context of autologous bone marrow transplantation.

Increased expression of myeloid antigen markers in adult acute lymphoblastic leukaemia patients: diagnostic and prognostic implications

By applying direct immunofluorescence with a dual-staining technique we were able to demonstrate that 20/37 (54%) patients with acute lymphoblastic leukemia (ALL) expressed both lymphoid and myeloid antigens on the same leukaemic cells. CD13 and CD33 myeloid antigens were detected in 18/20 and in 15/20 cases respectively, and both in 13. Molecular studies confirmed that the four patients with T-cell phenotype had molecular rearrangement of T-cell receptor (TcR) beta chain, and 26 ALL patients with 'B-cell' phenotype showed JH rearrangement. Two ALL patients without (ALL/My-) and three with myeloid antigens (ALL/My+) also demonstrated bcr/abl rearrangement. Both groups of patients had similar presenting features such as age, sex, Hb level, white blood cells, platelet counts and cytogenetic features. Complete response was achieved in 16/17 (94%) ALL/My- patients and in 15/18 (83%) ALL/My+ patients (two deaths occurred during induction) with a mean duration of 17 and 16 months respectively and with similar survival and event-free survival curves. Myeloid antigen expression in adult ALL patients may occur more frequently than previously reported. The presence of myeloid antigen does not identify, in our series, a higher-risk subgroup of patients, although lack of any statistical evidence of prognostic significance needs to be confirmed in a larger case study.

Induction of "in vitro" apoptosis by fludarabine in freshly isolated B-chronic lymphocytic leukemia cells

The cytotoxic effects and apoptosis (programmed cell death) induced by fludarabine (FLU), interleukin-2 (IL-2), interleukin-4 (IL-4), IL-2 plus IL-4, alpha-interferon (alpha-IFN), and mafosfamide were evaluated "in vitro" on freshly isolated B-cell chronic lymphocytic leukemia (B-CLL) cells. Cytotoxicity was evaluated according to the soluble tetrazolium/formazan assay. Treatment with mafosfamide, fludarabine, and IL-4 resulted in significant anti-tumor activity against all the freshly isolated samples. On the other hand, no significant cytotoxic activity was observed with alpha-IFN, IL-2, and the combination of IL-2 and IL-4. Apoptosis was evaluated by electrophoresis gel of DNA oligonucleosomal fragments and only FLU significantly activated apoptosis in all the samples. It appears that fludarabine is active against B-CLL cells acting by an direct cytotoxic effect and/or the induction of cell death by apoptosis.

Four-chromosomes complex translocations in acute promyelocytic leukemia: description of two cases

Two cases of acute promyelocytic leukemia with variant translocation involving 4 chromosomes are described. The karyotypes were 47,XX, +8,t(13;15;17;20)(q22;q22;q12;q13) and 46,XY,t(5;15;16;17)(q22;q22;p13;q12), respectively. Variant translocations in APL apparently do not follow any preferential routes since no recurrent breakpoint additional to those of chromosomes 15 and 17 has been found in any of the cases reported in the literature and in those described here. Moreover, it seems that the translocation of the RAR alpha gene from chromosome 17 to chromosome 15 is directly involved in the pathogenesis of the disease, while the reciprocal one is not, as demonstrated by variant translocations where 15q migrates to chromosomes other than 17.

FLAG (fludarabine+cytosine arabinoside+G-CSF) induces complete remission in acute-phase chronic myeloid leukaemia: a case report

The adenine nucleoside analogue fludarabine phosphate in combination with cytosine-arabinoside (Ara-C) and granulocyte-colony stimulating factor (G-CSF) has recently proved effective in the treatment of poor-prognosis acute non-lymphoid leukaemia. We used this triple combination in a case of Ph1+ chronic myeloid leukaemia (CML) unresponsive to alpha interferon that had progressed to acute phase after 5 months of treatment with 6-mercaptopurine plus hydroxyurea. The patient was treated with four courses of fludarabine 30 mg/m2 + Ara-C 2 g/m2 (days 1-5) and G-CSF (from day 0 to polymorphonuclear (PMN) recovery). Bone marrow blasts decreased from 80% to less than 5%, and karyotyping showed a progressive clearance of Ph1+ metaphases (from 100% to 9% after the fourth course). The patient is presently receiving autologous bone marrow transplantation (ABMT). This therapeutic success in a patient for whom conventional treatment would usually be ineffective makes this combination worthy of further studies, in view of its wider use as a preparative regimen to ABMT in CML.

In vitro amplification of hypervariable DNA regions for the evaluation of chimerism after allogeneic BMT

The role of mixed hematopoietic chimerism in engraftment and relapse after allogeneic BMT remains unclear. To better evaluate post-transplant chimerism we used polymerase chain reaction (PCR) in vitro amplification of four single locus simple repetitive DNA sequences, all of which vary extensively in their repeat number among different individuals: variable number of tandem repeats D1S80, APOB and D17S5, and the tetranucleotide repeat F8VWF. We tested 13 cases of CML, four of multiple myeloma (MM), three of ANLL and one of B-CLL. In a sequential analysis protocol with the different loci, the donor could be distinguished from the recipient in 14 of 20 (70%) pairs with the first marker used (D1S80). When a donor of opposite sex was involved, karyotyping and Y chromosome-specific PCR were also used. With the use of the four markers, chimerism was identified in all the pairs. Mixed chimerism was present in 5 patients, and complete chimerism in 15. No patients relapsed. The application of PCR for documenting post-transplant chimerism has several advantages over Southern blotting: increased sensitivity, use of small amounts of sample, ease of preparation of DNA, elimination of restriction enzyme analysis and of radioisotopes, and speed.

The type of BCR/ABL junction does not predict the survival of patients with Ph1-positive chronic myeloid leukaemia

The prognostic value of the location of the breakpoint on chromosome 22 in patients with Ph1+ chronic myeloid leukaemia (CML) is still controversial. We analysed both DNA rearrangement and transcript type in a new continuous series of CML patients. By Southern blotting analysis, we found that, out of 72 patients, 43 had a 5' rearrangement and 29 a 3' one, of the 43 5'-rearranged patients, 35 carried an a2b2 transcript and eight an a2b3 one, while, of the 29 patients rearranged in the 3' part of the M-BCR area, 26 had an a2b3 transcript, one had an a2b2 transcript and two carried both types of transcript. Thus, mRNA studies allow to detect an a2b3 transcript in 17.7% of 5' rearranged patients. However, no correlation was observed between type of transcript and survival, as after DNA studies.

t(8;14)(q11;q32) in acute lymphoid leukemia: description of two cases

An 8;14 chromosome translocation with breakpoints at q11 and q32, respectively, is described as the sole abnormality in bone marrow cells of two adult patients with common acute lymphoblastic leukemia (ALL). The Southern blot analysis revealed a rearrangement after BamHI and HindIII digestion and hybridization with a JH probe, thus demonstrating the involvement of the gene coding for the heavy chains of the immunoglobulins (IgH). Therefore, a pathogenetic mechanism similar to that observed in Burkitt's lymphoma and its variants, or in other lymphomas with t(11;14) or t(14;18), may be hypothesized. In all these cases IgH is juxtaposed to an oncogene (c-MYC, BCL-1, and BCL-2, respectively). A similar structure, with oncogene type potential, could be present on 8q11. The patients underwent a complete remission after induction therapy.

Structural organization of BCR-ABL gene in chronic phase and blast transformation in chronic myeloid leukemia patients

We studied 36 DNA samples of 18 patients affected with chronic myeloid leukemia (CML) for the presence of mutations in the first exon of the BCR gene was divided into four regions amplified by polymerase chain reaction (PCR). By single strand conformation polymorphism analysis (SSCP) and direct sequencing of amplified fragments, we found different banding profiles in 9 out of 18 patients in the PCR fragment spanning nucleotide 506-826. In one patient, sequence analysis revealed the presence of a point mutation at nucleotide 669 (A-T; Gln-Leu). No difference was found between DNA samples collected during the chronic phase and the blastic transformation. No different mobility shifts of single stranded PCR products were found in the other amplified fragments. The activation of BCR-ABL involves direct interaction between BCR first exon sequences and the tyrosine kinase regulatory domains of ABL. In the first BCR exon, and around the mutated sequences two SH-2-binding sites, are retained. These domains are essential for BCR-ABL-mediated transformation. Our results demonstrate the presence of point mutation in this regulatory region, which may suggest a role for the altered BCR sequence in activation of the BCR-ABL oncogene.

Will molecular biology contribute to refine prognosis and to select treatment? The Molecular Biology Committee. Italian Cooperative Study Group on Chronic Myeloid Leukemia

The possible prognostic value of the position of the breakpoint within the M-BCR in patients with Ph1+ CML is still being debated. We analyzed the DNA rearrangements and the transcript types of 244 patients and tried to correlate the data obtained with prognostic features, defined according to Sokal's risk index, and with chronic phase and/or survival duration. The exact location of the breakpoint, either 5' or 3' to the Hind III restriction site within the M-BCR was identified. Moreover, the exact M-BCR subregion was also identified. As a whole, 150 pts were rearranged in the 5' part and 94 in the 3' part of the M-BCR. No correlation was observed between the site of rearrangement on the one hand and the Sokal's prognostic index and survival, on the other. Transcript analysis was performed in 130 patients; 59 carried an a2b2 and 69 an a2b3 pattern. Two patients carried both transcripts. Of the patients rearranged in the 5' area, according to Southern blotting, 29.2% showed an a2b3 transcript. Therefore, RT-PCR analysis allowed a better definition of the breakpoint. However, also the type of transcript did not show any correlation either with risk categories or survival. No difference in response to therapy, either chemotherapy or alpha interferon, was observed between 5' and 3' rearranged patients.

Host origin of bone marrow fibroblasts following allogeneic bone marrow transplantation for chronic myeloid leukemia

We investigated the origin of the fibroblastic compartment of stromal hematopoietic microenvironment in eight chronic myeloid leukemia (CML) patients following allogeneic BMT. At the time of the study, all eight CML patients showed complete and long-lasting (14-87 months) engraftment of donor hematopoiesis and absence of clonal Ph-positive hematopoiesis. The study was carried out using in vitro amplification of informative DNA sequences: a Y chromosome specific DNA fragment in three patients who received a sex-mismatched allograft, and locus D1S80, a variable number of tandem repeats polymorphism, in five patients who received a sex-matched allograft. In all cases bone marrow fibroblasts were of recipient origin. These data indicate that with current BMT procedures the stromal compartment of hematopoiesis is not transplantable in humans.

Minimal residual disease status in transplanted chronic myelogenous leukemia patients: low incidence of polymerase chain reaction positive cases among 48 long disease-free subjects who received unmanipulated allogeneic bone marrow transplants

Forty-eight long-term disease-free chronic myelogenous leukemia (CML) patients, who had received unmanipulated allogeneic bone marrow transplants (BMT) for eradication of the Philadelphia (Ph1)-positive clone were studied by polymerase chain reaction (PCR), using a very sensitive PCR procedure and very stringent criteria for preventing and revealing contamination. Nine patients (18%) were positive at the first PCR examination, but only one patient remained PCR positive four years after. However, a second PCR analysis performed on new bone marrow samples obtained at a median interval of 14 months (range 6-16) after the first specimen collection from six of nine originally positive cases, and from 16 of 39 originally negative cases, showed that only one of the six positive cases remained positive, whereas negativity was confirmed in all the originally negative patients. These data are evidence that the Ph1-positive clone is apparently completely eradicated in the majority of CML patients who survive disease-free long-term after an unmanipulated allogeneic BMT and that only sporadic cases remain PCR-positive four years post-BMT. The data also show that at least two sequential bone marrow samples for each patient must be analyzed before drawing conclusions regarding the stable persistence of BCR/ABL transcripts and the minimal residual disease status.

Somatostatin analog in managing postgastrectomy duodenal stump leak

Somatostatin and its long-acting analog have a host of activities and potential applications in medicine today. Somatostatin is a naturally occurring peptide containing 14 amino acids. The following is one example of the many uses of somatostatin in the surgical patient.