ALBERT

Description: Seven patients with hairy cell leukemia were treated by intensive chemotherapy because they were considered to have a progressive disease and a poor short-term prognosis. The mean age was 47 years (range, 36 to 58). Six of seven patients had prior splenectomies with minor or transient hematologic responses. One patient had no spleen enlargement. The seven patients had never received any cytotoxic drugs and had prolonged granulocytopenia (less than 300/microL) with recurrent, severe infectious episodes. Chemotherapy included Rubidazone (zorubicine hydrochloride) 450 mg/m2 on day 1, arabinosyl cytosine 200 mg/m2/d from day 1 to day 5, and cyclophosphamide, 2,000 mg/m2 on day 5. Responses were assessed through examination of repeat bone marrow biopsy specimens and blood counts. A complete response was defined as normal blood counts associated with the disappearance of hairy cell infiltration and fibrosis on the bone marrow biopsy specimens. A partial response was defined as normal blood counts with persistence of leukemic cells in the bone marrow. Three patients achieved a complete response, and one patient had a partial response. Three patients died of infectious complications during induction chemotherapy. For the responding patients, the mean duration of aplasia was 37 +/- 5 days. Follow-up for the responding patients has been 44+, 24, 32+, and 23+ months. One patient with a complete response died while on maintenance therapy. We conclude that complete and prolonged histologic remission of hairy cell leukemia can be obtained with intensive chemotherapy. The toxicity of chemotherapy is such, however, that progressive disease after splenectomy needs to be more clearly defined.

Description: A series of 21 patients (5 refractory anemias with an excess of blasts in transformation and 16 acute leukemias) were treated with small doses of ARA-C (10 mg/sq m/12 hr for 15–21 days). Improvement was noted in 15 cases (71%) and complete remission observed in 12 (57%). Complete remission was obtained after one course of treatment in 8 cases. The fact that these patients entered remission relatively slowly and did not suffer marrow aplasia suggests that low-dose ARA-C may function in vivo as it does in vitro, i.e., by inducing differentiation of leukemic blasts.

Description: Twenty-two patients with acute promyelocytic leukemia were treated with all-trans retinoic acid (RA, 45 mg/m2 per day) for 90 days. Of the 22, four patients were previously untreated, two were resistant after conventional chemotherapy, and 16 were in first (n = 11), second (n = 4), or third (n = 1) relapse. We observed 14 complete response, four transient responses, one failure, and three early deaths. Length of hospitalization and number of transfusions were notably reduced in complete responders. Correction of coagulation disorders and an increase of WBCs were the first signs of all-trans RA efficacy. Morphologic analysis performed at days 0, 15, 30, 45, 60, and 90 showed that complete remissions were obtained without bone marrow (BM) hypoplasia. Presence of Auer rods in the maturing cells confirmed the differentiation effect of the treatment. At remission, the t(15;17) initially present in 20 patients was not found. The in vitro studies showed a differentiation in the presence of all-trans RA in 16 of the 18 tested cases. The single nonresponder to all trans RA in vitro did not respond in vivo. Adverse effects of RA therapy--skin and mucosa dryness, hypertriglyceridemia, and increase of hepatic transaminases-- were frequently noted. We also observed bone pain in 11 patients and hyperleukocytosis in four patients. Whether maintenance treatment consisted of low-dose chemotherapy or all-trans RA, early relapses were observed. Five patients are still in complete remission (CR) at 4 to 13 months. Our study confirms the major efficacy of all-trans RA in M3, even in relapsing patients. Remissions are obtained by a differentiation process.

Description: Background: Outcome of relapsing AML pts aged 〉 50 yrs is considered poor but remains incompletely studied and is important to analyse, especially with new therapeutic perspectives like targetted drugs and non myeloablative allogeneic SCT (ASCT). Methods: we analyzed the outcome of pts included in ALFA 9801 trial (reported in detail in another abstract) who had relapsed. This trial included, between 2001 and 2006, de novo AML aged 50 to 70 years, randomized for induction to conventional dose AraC and high dose DNR or IDA, followed by 2 courses of intermediate dose AraC with the same anthr, and finally randomization between no maintenance or 1 year of IL2. Results: 468 pts were included (median age: 60 years).360 (77%) achieved CR. With a median follow up of 40 months, 232 (64% of CR) pts had relapsed. Their median age was 60 years and M/F 132/100. Duration of first remission was ≤6 mo (41pts), 〉6mo and ≤12 mo (102 pts), 〉12 mo (89 pts). Treatment received for relapse was proposed at the discretion of physicians in charge of the patient: 97 (42%) pts received intensive chemotherapy (anthr-AraC, n=89, HD AraC n=5, FLAG, n= 3),) (IC group), 47 (20%) received Gemtuzumab (GO) alone (n= 25) or a GO containing regimen (n=22)(GO group), 12 patients (5%) received LD AraC, and 60 (28%) were treated with supportive care (SC). 8 pts were lost to follow up, 3 pts had CNS relapse, 1 pt received ASCT as relapse tratment, and 4 received investigational drugs. 52/110 pts aged 〈 60 received IC or GO combining regimen versus 39/122 pts〉 60 (p 60 were treated with SC versus 12/110 pts 60. A second CR was obtained in 39%: 57% in the IC group, 59% in the GO group (60% for pts treated with GO alone), 25% in the LDAraC group and none in the SC group. Median duration of second CR was 260 days. Median overall survival of the 232 patients from first relapse was 233 days (IC95%:202–281). Age 〈 60 years (p= 0.02), duration of first CR〉 12 months (median 451 d vs 205 d for 1st CR〈 12 months, p=0.001), salvage with IC or GO (median 340 days vs 140 for non IC +GO group, p

Description: Interferons (IFNs) initiate their effects by interacting with specific high-affinity cell surface receptors, but little is known about the physiology of IFN receptor interaction in vivo. Treatment of patients suffering from hairy cell leukemia (HCL) with human recombinant alpha IFN results in significant tumor regression, with clinical improvement in a high percentage of cases. To investigate a possible relevance of binding parameters as response markers, IFN receptor interaction on tumor cells responsive to IFN in vivo was studied. Binding of human alpha 2 IFN to circulating hairy cells was analyzed before and during IFN therapy in ten patients selected on the basis of high numbers of peripheral hairy cells. Binding experiments were carried out on Ficoll- Paque fractionated peripheral cell samples containing a majority of hairy cells. All patients reacted to recombinant alpha IFN treatment with a striking decrease in binding capacity within 12 hours after the first injection. As demonstrated by using a monoclonal antibody able to recognize alpha 2 IFN bound to its receptor, this decreased binding capacity was not due to blocking by circulating IFN but rather to a decrease in receptor number. This receptor “down-regulation” was partially reversible after the first IFN injection. However, upon prolonged IFN therapy, all patients displayed a stable state of decreased receptor expression. Down-regulation of IFN receptors can be regarded as a response marker to IFN treatment. This response marker, however, was not correlated with the clinical response within the first months of IFN therapy.

Description: A series of 21 patients (5 refractory anemias with an excess of blasts in transformation and 16 acute leukemias) were treated with small doses of ARA-C (10 mg/sq m/12 hr for 15–21 days). Improvement was noted in 15 cases (71%) and complete remission observed in 12 (57%). Complete remission was obtained after one course of treatment in 8 cases. The fact that these patients entered remission relatively slowly and did not suffer marrow aplasia suggests that low-dose ARA-C may function in vivo as it does in vitro, i.e., by inducing differentiation of leukemic blasts.

Description: Since vimentin intermediate filament (IF) expression in hemopoietic cells varies with the cell lineage as well as the state of differentiation of the cells, we studied the vimentin cytoskeleton by direct immunofluorescence and electron microscopy in 50 cases of acute nonlymphocytic leukemias. We found that malignant cells tend to reproduce the vimentin organization characteristic of their normal cellular counterpart. Thus, in M2 and M3 leukemias (French-American- British classification), vimentin was often reduced to a juxtanuclear bundle of filaments contrasting with the rich filamentous network expressed by M4 or M5 leukemias. In erythroblastic leukemias (M6) and megakaryoblastic leukemias, both identified by the expression of lineage-specific antigens, the absence of vimentin IFs could be correlated with the level of differentiation reached by the blasts. M1 leukemias displayed an abnormal pattern of vimentin organization with aggregated filaments giving a ring-like structure. However, no abnormality of the vimentin polypeptide could be detected by two- dimensional electrophoresis. These results show that the expression of the vimentin IF cytoskeleton may be a useful marker of differentiation in the study of leukemic cells.

Description: Low-dose interferon-alpha (IFN-alpha) therapy is consistently effective in the treatment of hairy cell leukemia (HCL). In two cases of resistance to IFN-alpha administration, we diagnosed variant HCL, a form of HCL with intermediate features between typical HCL and B cell prolymphocytic leukemia. We tried to distinguish variant and typical hairy cells (HCs) by Northern blot analysis of the oncogenes expressed in vivo. We report that variant HCs contain c-myc transcripts in contrast to typical HCs, whereas c-fos transcripts are detected in both cell types. We also report that the mRNA levels of c-myc are not modified in variant HCs by IFN-alpha treatment, whereas the level of c- fos mRNA is modulated in both types of HCs. Our findings suggest that the failure to modulate c-myc expression in vivo might indicate the limits of low-dose IFN-alpha therapy.

Description: Interferons (IFNs) initiate their effects by interacting with specific high-affinity cell surface receptors, but little is known about the physiology of IFN receptor interaction in vivo. Treatment of patients suffering from hairy cell leukemia (HCL) with human recombinant alpha IFN results in significant tumor regression, with clinical improvement in a high percentage of cases. To investigate a possible relevance of binding parameters as response markers, IFN receptor interaction on tumor cells responsive to IFN in vivo was studied. Binding of human alpha 2 IFN to circulating hairy cells was analyzed before and during IFN therapy in ten patients selected on the basis of high numbers of peripheral hairy cells. Binding experiments were carried out on Ficoll- Paque fractionated peripheral cell samples containing a majority of hairy cells. All patients reacted to recombinant alpha IFN treatment with a striking decrease in binding capacity within 12 hours after the first injection. As demonstrated by using a monoclonal antibody able to recognize alpha 2 IFN bound to its receptor, this decreased binding capacity was not due to blocking by circulating IFN but rather to a decrease in receptor number. This receptor “down-regulation” was partially reversible after the first IFN injection. However, upon prolonged IFN therapy, all patients displayed a stable state of decreased receptor expression. Down-regulation of IFN receptors can be regarded as a response marker to IFN treatment. This response marker, however, was not correlated with the clinical response within the first months of IFN therapy.

Description: Acute promyelocytic leukemia (APL) is a homogeneous subgroup of acute myeloid leukemias (AMLs) characterized by the presence of the t(15,17) translocation and the resulting promyelocytic myeloid leukemia/retinoic acid receptor alpha (PML/RAR alpha) fusion proteins. To date APL is the only AML that is sufficiently sensitive to all-trans retinoic acid's (ATRA) differentiating effect. In vivo ATRA alone achieves complete remission in most APL patients. However, failure or partial responses are observed and the molecular basis of the absence of ATRA response in these patients has not been determined. To gain insights in the cell growth and differentiation of APL cells, expression of hematopoietic growth factors (HGF) shown to be produced by leukemic cells (interleukin-1 beta [IL-1 beta], IL-6, tumor necrosis factor alpha (TNF alpha), granulocyte colony-stimulating factor [G-CSF], granulocyte- macrophage colony-stimulating factor [GM-CSF], and IL-3) was studied in 16 APL samples. Twelve APL cases expressed IL-1 beta, IL-6, and TNF alpha, but not G-CSF, GM-CSF, and IL-3. These cases achieved complete remission with ATRA therapy. The four remaining patients (either TNF alpha negative or G-CSF, GM-CSF or IL-3 positive) did not achieve complete remission with ATRA. In all cases, in vivo response to ATRA therapy was correlated to the in vitro differentiation effect of all- trans retinoic acid 10(-6) mol/L. Thus, ATRA differentiation induction was strongly correlated to the HGF expression (P 〈 .0001). These results suggest that the presence or absence of HGF's expression by APL cells may contribute to the therapeutic effect of ATRA in this disease.