Contribution of JAK2 mutations to T-cell lymphoblastic lymphoma development.

The JAK-STAT pathway has a substantial role in lymphoid precursor cell proliferation, survival and differentiation. Nonetheless, the contribution of JAK2 to T-cell lymphoblastic lymphoma (T-LBL) development remains poorly understood. We have identified one activating TEL-JAK2 translocation and four missense mutations accumulated in 2 out of 16 T-LBL samples. Two of them are novel JAK2 mutations and the other two are reported for the first time in T-LBL. Notably, R683G and I682T might have arisen owing to RNA editing. Mutated samples showed different mutated transcripts suggesting sub-clonal heterogeneity. Functional approaches revealed that two JAK2 mutations (H574R and R683G) constitutively activate JAK-STAT signaling in γ2A cells and can drive the proliferation of BaF3-EpoR cytokine-dependent cell line. In addition, aberrant hypermethylation of SOCS3 might contribute to enhance the activation of JAK-STAT signaling. Of utmost interest is that primary T-LBL samples harboring JAK2 mutations exhibited increased expression of LMO2, suggesting a mechanistic link between JAK2 mutations and the expression of LMO2, which was confirmed for the four missense mutations in transfected γ2A cells. We therefore propose that active JAK2 contribute to T-LBL development by two different mechanisms, and that the use of pan-JAK inhibitors in combination with epigenetic drugs should be considered in future treatments.

Absence of influence of prior treatment with interferon on the outcome of allogeneic bone marrow transplantation for chronic myeloid leukemia.

Timing of transplantation in the chronic phase of chronic myeloid leukemia (CML) and previous treatment with interferon remains controversial. We have tried to discover what influence pretreatment with interferon alpha (IFN-A) has on the results of allogeneic bone marrow transplantation for CML patients treated in a single institution. Fifty-one consecutive patients with chronic phase Ph-positive CML who received an allogeneic bone marrow transplantation from a HLA-identical familial donor were evaluated. Thirty had been treated with IFN-A (IFN+ group) prior to BMT and twenty-one had not (IFN- group). Both groups were homogeneous for clinical characteristics such as age, sex, previous chemotherapy, disease status, and time from diagnosis to transplant. No difference was found in neutrophil and platelet count recovery between the IFN+ and IFN- group. The incidence of acute and chronic GVHD, VOD and severe mucositis was not significantly different. Relapse and both overall survival and DFS were similar for both groups. No adverse effects of prior IFN exposure on the outcome of HLA-identical sibling donor BMT for chronic phase CML patients were found in this study.

Comparison of peripheral blood progenitor cell mobilization in patients with multiple myeloma: high-dose cyclophosphamide plus GM-CSF vs G-CSF alone.

The best method for peripheral blood progenitor cell (PBPC) mobilization in patients with multiple myeloma (MM) remains controversial. We report the results of two different methods of PBPC collection for autologous transplantation in 40 patients with stage II or III MM. In group I (n = 18), HD-CY, 4 g/m2 i.v., was administered followed by GM-CSF, 8 microg/kg/day s.c., until the end of collection, starting the leukaphereses after hematological recovery (>1 x 10(9)/l WBC). In group II (n = 22), G-CSF, 10 microg/kg/day s.c., was used alone until the last day of collection, starting consecutive aphereses on the 5th day. A minimum of two aphereses were performed to collect at least 2 x 10(6)/kg CD34+ cells. Both patient groups were comparable for age, sex and clinical prognostic features as well as previous therapies. In group I, the median yields per pheresis were: MNC 1.47 (1.38-2.32) x 10(8)/kg, CFU-GM 0.82 (0.18-13.2) x 10(4)/kg and CD34+ cells 1.98 (0.96-6.96) x 10(6)/kg. In group II these results were: MNC 2.44 (2.06-3.6 x 10(8)/kg) (P = 0.03), CFU-GM 0.75 (0.16-7.8) x 10(4)/kg and CD34+ 1.05 (0.32-3.4) x 10(6)/kg (P = 0.02). The median number of aphereses performed in each group was 5 (4-12) with a median of 5.24 +/- 2.51 in group I and 3 (2-6) with a median of 3.1 (+/- 0.91) in group II (P = NS). Hospitalization for PBPC mobilization was required in all patients in group I and the treatment-related toxicity was greater in this group: 12 patients (66%) developed fever requiring antibiotics during the neutropenic period after HD-CY and six (33%) patients required transfusion support. After receiving busulfan 12 mg/kg p.o. and melphalan 140 mg/m2 i.v., as the conditioning regimen, the median periods to reach granulocytes (>0.5 x 10(9)/l) and platelet (>20 x 10(9)/l) engraftment were 12 and 11 days respectively (ranges 8-20 and 10-16) in group I (HD-CY plus GM-CSF group), and 11 and 13 days respectively (ranges 7-42 and 10-38) in group II (G-CSF group) (P = NS). In conclusion, these data suggest that although HD-CY plus GM-CSF is superior to G-CSF alone based on mean CD34+ cell yield per pheresis, adequate CD34+ cell collections can be achieved with G-CSF alone in most MM patients with less toxicity and with simplification of the procedure.

Results of a pilot study of 40 patients using high-dose therapy with hematopoietic rescue after standard-dose adjuvant therapy for high-risk breast cancer.

The study was designed to determine the toxicity, feasibility, and effectiveness of high-dose cyclophosphamide (6 g/m2), thiotepa (500 mg/m2) and carboplatin (800 mg/m2 (CTCb) with hematopoietic rescue as consolidation after standard-dose adjuvant chemotherapy treatment of primary high-risk breast cancer. From October 1991 to September 1994, 40 patients with stage II or III breast cancer involving 10 or more nodes were treated with CTCb after six cycles of adjuvant therapy with an anthracycline-containing regimen. Bone marrow (BM) was used as the source hematopoietic stem cell in the first 23 patients and G-CSF-mobilized peripheral blood progenitor cells (PBPC) in the other 17. No therapy-related deaths occurred, but three life-threatening Complications were recorded which resolved: bilateral pulmonary hemorrhage, veno-occlusive disease of the liver and pulmonary thromboembolism. PBPC result in faster hemopoietic reconstitution with significantly lower transfusion requirements. With a median follow-up of 35 months (23-59) actuarial event-free survival for the study patients at 3 years is 72% (CI 95%: 66-81%). Even in patients over 50-60 years, CTCb is a relatively well tolerated regimen which appears, after a median follow-up of nearly 3 years, to decrease relapse frequency as compared with historical series, although a definite role of HDT in the treatment of high-risk primary breast cancer needs confirmation in prospective randomized trials.

[Imipenem combined with teicoplanin or vancomycin in the initial empirical treatment of febrile neutropenia. Analysis of the primary response and of a global sequential strategy in 126 episodes]. / Imipenem combinado con teicoplanina o vancomicina en el tratamiento empírico inicial de la neutropenia febril. Análisis de la respuesta primaria y de una estrategia secuencial global en 126 episodios.

The results of empiric antibiotic therapy in 126 episodes of febrile neutropenia in patients with hematologic neoplasms postchemotherapy and bone marrow transplantation are presented. The main objective of this work was the study of the initial control of infection comparing two glycopeptidic antibiotics: vancomycin and teicoplanin combined with imipenem in first line of empiric therapy. The secondary objective was to analyze the overall control of infection during the complete episode of neutropenia using a sequential empiric antibiotic therapy course which included the addition of amikacin followed by intravenous amphotericin B when fever persisted or recurred without microbiological documentation. Both initial courses (no guidelines), imipenem + vancomycin (arm A) and imipenem + teicoplanin (arm B) resulted in a similar percentage of response at 72 hours, both in episodes of fever of unknown origin (FUO) (55% and 68%, respectively; p = NS) and in those microbiologically documented (54% and 34.5%, p = NS); 58% and 79% of these episodes, respectively, were caused by gram-positive organisms. About 60% of patients in both arm ultimately required the empiric addition of amikacin, with or without amphotericin B, because of persistence or recurrence of fever; the percentage of overall responses in both arm did not differ significantly, both in FUO (70% and 86%, p = NS) and in microbiologically documented episodes (71% and 45%, p = NS). The overall infectious mortality for the whole group was 1.58%. In conclusion, no significant differences were observed in the clinical response or in toxicity between the combination of imipenem with any of the two glycopeptides: vancomycin or teicoplanin, for the initial empiric therapy of febrile neutropenia. The sequential empiric use of amikacin followed by amphotericin B assured an adequate overall control of infection in a group of patients with prolonged severe neutropenia.

Autologous or allogeneic bone marrow transplantation for acute myeloblastic leukemia in second complete remission. Importance of duration of first complete remission in final outcome.

Between May 1983 and March 1994, 31 patients with AML in second CR underwent BMT. Fifteen underwent allogeneic BMT from an HLA-identical sibling donor and 16 without a donor, unpurged ABMT. Two different preparative regimens were used: CY (120 mg/kg) and 12 Gy of fractioned TBI (19 patients), and Bu (16 mg/kg) and Cy (120 mg/kg) (BuCy2) in 12 patients. Main clinical characteristics including age, sex, length of first remission, FAB type, and number of leukocytes at diagnosis were similar in both groups. A combination of MTX and CsA was used in 13 cases whereas either CsA or MTX alone was employed in the other two patients. With a median follow-up of 5 years the actuarial 5 year probability of disease-free survival (DFS) for the whole group was 39.8% (95% CI: 29.5-50.1%). The 5 year DFS was equivalent for those who received either ABMT (41.6 +/- 14.2%) or allogeneic BMT (40 +/- 15%). Probabilities of relapse and non-relapse mortality for ABMT and allo BMT patients were 48.7 +/- 16.1 and 18.7 +/- 14.3, and 30.1 +/- 19.2 and 40.7 +/- 16.9, respectively. DFS was better in those patients with a longer duration of first CR (> 18 months) 62.5 +/- 14.4 vs 30.4 +/- 17.9%, attributable to a significantly lower relapse rate in this group of patients 16.6 +/- 12.8 vs 57.8 +/- 22.7 (P 0.05). In conclusion, similar results were observed when ABMT and allo BMT were compared for AML in CR2. A higher antileukemic effect associated with the allo BMT is balanced by an increase in transplant-related mortality. Duration of first remission was the most important factor affecting DFS and better outcome was observed for patients with longer CR1.

Fludarabine in resistant or relapsing B-cell chronic lymphocytic leukemia: the Spanish Group experience.

Fludarabine produces high response rates in patients with B-cell chronic lymphocytic leukemia (CLL). Nevertheless, response to fludarabine of patients with previously treated CLL varies from 17% to 74% (0% to 38% CR). In 68 patients with heavily pretreated and advanced CLL, an overall response rate to fludarabine of 28% (4% CR) was observed. Response correlated with sensitivity of the disease to previous treatments (relapsing vs. refractory disease) (62% vs. 20%; p = 0.005) and, albeit not significantly, with the number of cycles of fludarabine (>3 vs. < or = 3) that patients could receive (36% vs. 15%; p = NS). Responding patients had a longer survival (median, not reached) than those not responding (median, 11 months) (p = 0.03). Severe toxicity was observed in some cases. It is concluded that fludarabine is a highly useful agent in CLL. However, in order to improve its effectiveness and decrease its toxicity, fludarabine should be given as soon as a lack of response to front-line therapy is observed and before the disease becomes completely resistant to therapy.