Treatment of 11 patients with chronic myelogenous leukemia with interferon-alpha-2C and low-dose cytosine arabinoside.

Patients with Philadelphia (Ph) chromosome-positive chronic myelogenous leukemia (CML) and on interferon (IFN)-alpha-2c treatment for at least two months were entered in the present pilot study. IFN-alpha treatment was maintained identically and cytosine arabinoside (Ara-C) was added at monthly cycles of 10 mg/m2/day for ten days subcutaneously. In the case of a leukocyte nadir above 10 G/l, the Ara-C dose was increased to 20 mg/m2/day for 10 days per month. Ten of the eleven patients entered in this study were evaluable for toxicity and response. They received a total of 87 IFN-alpha/Ara-C cycles (3-14/patient). Five patients received 1-5 cycles with Ara-C dose intensification to 20 mg/m2/day. The following gastrointestinal and hematological toxicities were attributable to Ara-C, as they had not been observed in these patients during the preceding IFN-alpha monotherapy period. Gastrointestinal side effects consisted of nausea grade 1 (n = 5) and diarrhea grade 2 (n = 1). Hematotoxicity was observed in eight patients, grade 1 in five patients and grades 2, 3 and 4 in one of the patients each. Both episodes of grades 3 and 4 toxicity were seen during dose escalation to 20 mg/m2. Small cytogenetic responses (4-14%) were observed in 3 patients and a larger one (50%) in one patient, hematological improvement or stable disease in an additional three patients. These preliminary data suggest that the combination of IFN-alpha and low-dose Ara-C is active in inducing cytogenetic responses in CML patients at an acceptable rate of toxicity and therefore warrant further investigation.

Treatment of patients with advanced chronic myelogenous leukemia with interferon-alpha-2b and continuous oral cytarabine ocfosfate (YNK01): a pilot study.

The efficacy of continuous oral cytarabine ocfosfate (YNK01) (300 mg/day) in combination with interferon alpha (IFNalpha, 5x10(6) IU/day) was evaluated in patients with advanced chronic myelogenous leukemia, who previously failed to respond to IFNalpha-based therapies. Dose escalations up to 900 mg YNK01 were allowed in patients who failed to respond. In view of our results, four patients developed a complete hematological response after YNK01 was started. Among those who initially responded to YNK01, one complete cytogenetic response was achieved 18 months later. Although the data are preliminary, this is the first study showing that continuous administration of YNK01 along with IFNalpha is effective in patients with advanced chronic myelogenous leukemia.

Interferon-alpha for the treatment of elderly patients with chronic myeloid leukaemia.

The present retrospective analysis is based on data of 213 patients with chronic myeloid leukaemia (CML). They were treated with interferon (IFN)alpha-2C (Berofor) at daily doses of 3.5 MU subcutaneously (s.c.), alone or in combination with low-dose ara-C or hydroxyurea, according to four consecutive studies of the Austrian CML Study Group. Comparisons were made between 41 patients aged > or = 60 years and 172 younger patients. The elderly patients (median: 64 years; range: 60-73) showed similar pretreatment characteristics compared with the younger group, but included a higher percentage of Sokal Stage three (51 vs 20%). Median observation periods were similar (38 vs 39 months), whereas the duration of IFNalpha treatment was shorter in the elderly group (median 57 vs 42 weeks). The rate of overall haematological responses (73 vs 78%) and complete haematological response (44 vs 54%), was similar in both cohorts. Differences seen in partial (5 vs 12%) and complete cytogenetic response (10 vs 13%), were not statistically significant, but a tendency in favour of the younger cohort had to be noted. Summing up, in elderly patients acceptable rates of haematological and cytogentic response can be expected after treatment with IFNalpha alone or in combination with LD ara-C or HU.

A randomized study comparing interferon (IFN alpha) plus low-dose cytarabine and interferon plus hydroxyurea (HU) in early chronic-phase chronic myeloid leukemia (CML).

This multicenter randomized phase III study was designed to compare the efficacy and toxicity of IFN alpha-2c (3.5 MU/d) in combination with either araC (10 mg/m(2) d1-10) or hydroxyurea (HU: 25 mg/kg per day) in newly diagnosed CML patients. A total of 114 patients were randomized. Following a median observation period of 36 (range 1-73) months the major cytogenetic response rates were 25 and 27% and the 4-year survival probabilities 62.5 and 63% for the araC and HU group, respectively. While the overall toxicity profile was comparable between both groups, patients in the HU arm exhibited a slightly higher degree of WHO grades 3 and 4 non-hematological toxicities.

Interferon-alpha-2C and LD ara-C for the treatment of patients with CML: results of the Austrian multi-center phase II study.

Small pilot studies of patients with CML have reported on encouraging response rates after treatment with interferon-alpha (IFNalpha) in combination with low-dose cytosine arabinoside (LD ara-C). We therefore initiated a multi-center phase II trial in order to investigate the efficacy and tolerability of this combination in newly diagnosed patients with Ph-positive chronic myelogenous leukemia (CML). Eighty-four patients were treated with IFN-alpha-2c at daily subcutaneous doses of 3.5 MU and LD ara-C added subcutaneously for 10 days every month at a dose of 10 mg/m2, following an initial reduction of WBC to less than 20 x 10(9)/l with hydroxyurea (HU). Within a median observation period of 28 (5-59) months the patients received a median of 7 (1-35) IFNalpha and LD ara-C cycles. Treatment was stopped due to side effects in 16 cases (19%) and to primary or secondary treatment failure in 38 cases (45%). In 45 patients (54%) complete hematological response (CHR) was achieved; in 39 patients (46%) cytogenetic responses including 15 (18%) complete cytogenetic responses (CHR) were observed. Median duration of cytogenetic responses was 15 months. Relapses were seen in 8/15 patients (53%) with complete cytogenetic remission (CCR), in 3/6 patients (50%) with partial cytogenetic response and in 9/18 patients (50%) with minor cytogenetic response. In conclusion, the combination of IFNalpha and LD ara-C resulted in encouraging rates of hematological and cytogenetic responses in patients with CML with low to moderate toxicity.

Bone marrow lymphocyte subsets in myelodysplastic syndromes.

AIM: To examine lymphocyte subsets in patients with myelodysplastic syndromes (MDS); and to correlate immunohistological variables with prognosis. METHODS: Bone marrow trephine biopsy specimens from 65 patients with MDS were immunophenotyped using a panel of antibodies. A minimum of 1000 cells from representative areas of marrow sections were counted at light microscopy. The association between immunohistological variables and prognosis was assessed. RESULTS: Compared with normal control marrows (n = 23) no major abnormalities of T cells (CD3), T cell subsets (CD4, CD8, CD25, TCR gamma/delta) or natural killer cells (CD56, CD57) were seen in the 65 patients. In high risk MDS (RAEB, RAEB-t) 19% of the cases showed increased numbers of B lymphocytes compared with none in the low risk group (RA, RARS) (p < 0.0090). Only percentages of B cells above 3% significantly correlated with poor survival (p = 0.0121 for CD19, p = 0.046 for CD22). CONCLUSIONS: The deviations in T lymphocyte counts seen in peripheral blood and in bone marrow aspirates could not be verified in bone marrow biopsy specimens.

Dose escalation of ara-c may improve response rates in a subgroup of chronic myeloid leukemia patients with poor response to interferon-alpha and low-dose ara-C.

The present analysis was performed to evaluate the impact of cytosine arabinoside (ara-C) dose escalation on hematological and cytogenetic responses in patients with chronic myelogenous leukemia (CML) who failed to respond to low-dose ara-C (LD ara-C) at a dose of 10 mg/m2/d over 10 days per month and interferon-alpha (IFNalpha, 3.5 MU/d). Following the same administration schedule, dose escalation of ara-C to 15 and 20 mg/m2/d 1-10 was performed in 36 of 119 patients (30%) due to inadequate hematological response and/or disease progression. As a result, improvement of hematological and cytogenetic responses was achieved in 22 (61%) and nine (25%) patients, respectively. Escalated ara-C dose levels were usually well tolerated, although some patients experienced deterioration of preexisting side effects. Our results support the critical role of ara-C dose towards a better disease control in CML.

Independent measurement of the total active 8B solar neutrino flux using an array of 3He proportional counters at the Sudbury Neutrino Observatory.

The Sudbury Neutrino Observatory (SNO) used an array of 3He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active (nu_x) 8B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54_-0.31;+0.33(stat)-0.34+0.36(syst)x10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields Deltam2=7.59_-0.21;+0.19x10(-5) eV2 and theta=34.4_-1.2;+1.3 degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.

Genetics of the quantitative Lp(a) lipoprotein trait. II. Inheritance of Lp(a) glycoprotein phenotypes.

Lp(a) glycoprotein exhibits an apparent size polymorphism that is associated with genetically controlled Lp(a) lipoprotein concentrations in plasma (Utermann et al. 1988). We have tested the hypothesis that this polymorphism is genetically controlled by studying 15 matings with a total of 44 offspring. This confirmed our conclusion that Lp(a) types are controlled by a series of codominant alleles LpF, LpB, LpS1, LpS2, LpS3 and LpS4 and by a null allele LpO. Together with the data from the accompanying paper this indicates that the structural gene for the Lp(a) protein is the major gene locus determining Lp(a) lipoprotein concentrations in plasma.

The gene for the Lp(a)-specific glycoprotein is closely linked to the gene for plasminogen on chromosome 6.

We have studied the segregation of the Lp(a) glycoprotein phenotypes and of the plasminogen (PLG) polymorphism in three two-generation families. The inheritance of the Lp(a) gene was followed using the Lp(a) glycoprotein size polymorphism and that of the plasminogen gene, using protein and DNA polymorphisms. In the three families studied, no recombination was observed in 18 meioses. The lod score for linkage between the Lp(a) glycoprotein locus and the plasminogen locus in these families is greater than 5.0 at a recombination fraction of theta = 0. Our results show that the structural gene for the Lp(a) glycoprotein is closely linked to the gene for plasminogen on chromosome 6.

Dendritic cells generated from blood precursors of chronic myelogenous leukemia patients carry the Philadelphia translocation and can induce a CML-specific primary cytotoxic T-cell response.

Dendritic cells (DC) are professional antigen-presenting cells specialized in the initiation of primary immune responses. We were interested to know whether mature DC can be grown in vitro from peripheral blood mononuclear cells (PBMC) of patients with chronic myelogenous leukemia (CML), and whether they carry the Philadelphia (Ph) translocation. Using a method recently described, DC were generated from PBMC precursors of 12 patients with CML using GM-CSF, IL-4, and monocyte-conditioned medium. DC exhibited the typical morphology with thin cytoplasmatic processes and expressed high levels of MHC class II, CD86, and CD83 typical for mature DC. After sorting with the monoclonal antibody CD83, a cell population of more than 95% CD83 positive cells was obtained. The presence of the Ph translocation was analyzed in these cells, in PBMC, lymphoblastoid cell lines (LCL), and in phytohemagglutinin (PHA)-induced T blasts from the same patients by fluorescence in situ hybridization (FISH). In contrast to all other cells analyzed, the vast majority of DC (95.9 +/- 0.7%) displayed the Ph translocation, irrespective of disease stage or therapy. PBMC were predominantly positive for the Ph chromosome (67.6 +/- 7.3%), whereas only 11.4 +/- 1% of the B cells and 4.4 +/- 1.1% of the PHA blasts carried the Ph translocation. Using such leukemic DC as antigen-presenting cells, a primary CML-directed cytotoxic immune response in vitro was obtained, as shown by the specific recognition of Ph chromosome positive cells. We conclude that DC can be generated from blood progenitors of CML patients in vitro and exhibit, to a large extent, the Ph translocation. Such DC, which in a preliminary experiment have been able to induce a primary CML-directed cytotoxic immune response in vitro, might be ideal candidates for adoptive immunotherapy either by direct transfer of DC for in vivo generation of a T-cell response or by in vitro generation of CML-specific cytotoxic autologous or HLA-matched normal T-cell clones for use in vivo.

[Recombinant interferon alpha-2c in Ph-positive chronic myeloid leukemia. Results of a multicenter phase II study]. / Rekombinantes Interferon alpha-2c bei Ph-positiver chronischer myeloischer Leukämie. Ergebnisse einer multizentrischen Phase-II-Studie.

In a Phase II study, 82 patients with Philadelphia chromosome(Ph)-positive chronic myelogenous leukaemia were treated with 3.5 million I.U./d of recombinant interferon alpha-2c (rIFN). 73 patients have so far been evaluated (42 male, 31 female, mean age 50 [12-87] years). At the start of therapy, 10 were in the accelerated phase (group 1) and 63 in the chronic phase, of whom 19 had received previous treatment with cytotoxics (group 2), while the remainder (group 3, n = 44) had received primary treatment with rIFN. There was short-term stabilization in 7 of the 10 group 1 patients, but none had complete haematological or cytogenetic remission. In contrast, the remission rate (complete or partial haematological remission) was 63% in the previously treated (group 2) and 66% in the previously untreated chronic phase patients (group 3). There was a reduction in the proportion of Ph-positive metaphases in 7 group 2 patients (11%) and in 10 group 3 patients (23%). Complete cytogenetic remission has so far been seen in 2 patients. Cytogenetic improvement occurred after 3 months at the earliest, and in some patients only after 12 to 19 months treatment. Differences in response to treatment were related to stage (prognostic staging system of Kantarjian et al.) in group 3 patients: complete or partial haematological remission was seen in 22 out of 25 patients with stage 1 disease, in 4 out of 7 in stage 2, and in only 3 out of 12 in stages 3 and 4.

Chromosomal localization of the genes (CLNS1A and CLNS1B) coding for the swelling-dependent chloride channel ICln.

ICln is a cloned chloride channel paramount for regulatory volume decrease. Two different loci that carry the coding region for ICln were identified in the human genome. By PCR strategies an intronless copy of the gene was located on chromosome 6 at position 6p12.1-6q13 (CLNS1B). By fluorescence in situ hybridization a copy carrying introns with a putative length of 19 kb was located at chromosome 11 on position 11q13.5-q14.1 (CLNS1A). The characterization and chromosomal localization of the ICln gene offer the opportunity to study the regulatory sites of this gene in greater detail and could be helpful in establishing linkages between ICln and potential human diseases.

Interferon alpha-2c therapy of patients with chronic myelogenous leukemia: long-term results of a multicenter phase-II study. Austrian Biological Response Modifier (BRM) Study Group.

In a prospective multicenter phase-II trial 80 patients with Philadelphia (Ph)-positive chronic myelogenous leukemia (CML) were treated with recombinant interferon (IFN) alpha-2c, administered subcutaneously at an absolute dose of 3.5 megaunits (MU)/day. Complete hematological remission was achieved in 29 (39%) and partial hematological remission in 26 (35%) of the 74 patients evaluable for response. Major cytogenetic responses were observed in ten (13%) and minor cytogenetic responses in 11 patients (15%). Median duration of cytogenetic response was 33 months (range, 2-90); relapses were seen in all of the 11 patients with minor and in three of the ten patients with major cytogenetic responses. Median survival estimates for pretreated (n = 19) and untreated (n = 58) patients were 51 months (95% confidence interval [CI], 30-72) and 77 months (95% CI, 43-111), and the survival probabilities at 5 years were 45% and 54% for the two groups, respectively. Hematological response after 3 months of treatment demonstrated a clear-cut discriminative capacity with 5-year survival probabilities of 100%, 67% and 24% for patients achieving CHR (n = 6), PHR (n = 34), and less than PHR (n = 35), respectively. Landmark analysis at 12, 18, and 24 months after start of IFN therapy and an analysis treating time to cytogenetic response as a time-dependent covariate showed that cytogenetic response was associated with longer survival. The impact of a low-dose IFN regimen on survival in CML patients is unclear and requires further clarification by randomized clinical trials. Early hematological and cytogenetic response to IFN-alpha treatment identifies patients with a favorable long-term prognosis.

Constraints on nucleon decay via invisible modes from the Sudbury Neutrino Observatory.

Data from the Sudbury Neutrino Observatory have been used to constrain the lifetime for nucleon decay to "invisible" modes, such as n-->3nu. The analysis was based on a search for gamma rays from the deexcitation of the residual nucleus that would result from the disappearance of either a proton or neutron from 16O. A limit of tau(inv)>2 x 10(29) yr is obtained at 90% confidence for either neutron- or proton-decay modes. This is about an order of magnitude more stringent than previous constraints on invisible proton-decay modes and 400 times more stringent than similar neutron modes.

Measurement of the total active 8B solar neutrino flux at the Sudbury Neutrino Observatory with enhanced neutral current sensitivity.

The Sudbury Neutrino Observatory has precisely determined the total active (nu(x)) 8B solar neutrino flux without assumptions about the energy dependence of the nu(e) survival probability. The measurements were made with dissolved NaCl in heavy water to enhance the sensitivity and signature for neutral-current interactions. The flux is found to be 5.21 +/- 0.27(stat)+/-0.38(syst) x 10(6) cm(-2) s(-1), in agreement with previous measurements and standard solar models. A global analysis of these and other solar and reactor neutrino results yields Deltam(2)=7.1(+1.2)(-0.6) x 10(-5) eV(2) and theta=32.5(+2.4)(-2.3) degrees. Maximal mixing is rejected at the equivalent of 5.4 standard deviations.

Measurement of the rate of nu(e) + d --> p + p + e(-) interactions produced by (8)B solar neutrinos at the Sudbury Neutrino Observatory.

Solar neutrinos from (8)B decay have been detected at the Sudbury Neutrino Observatory via the charged current (CC) reaction on deuterium and the elastic scattering (ES) of electrons. The flux of nu(e)'s is measured by the CC reaction rate to be straight phi(CC)(nu(e)) = 1.75 +/- 0.07(stat)(+0.12)(-0.11)(syst) +/- 0.05(theor) x 10(6) cm(-2) s(-1). Comparison of straight phi(CC)(nu(e)) to the Super-Kamiokande Collaboration's precision value of the flux inferred from the ES reaction yields a 3.3 sigma difference, assuming the systematic uncertainties are normally distributed, providing evidence of an active non- nu(e) component in the solar flux. The total flux of active 8B neutrinos is determined to be 5.44+/-0.99 x 10(6) cm(-2) s(-1).

Direct evidence for neutrino flavor transformation from neutral-current interactions in the Sudbury Neutrino Observatory.

Observations of neutral-current nu interactions on deuterium in the Sudbury Neutrino Observatory are reported. Using the neutral current (NC), elastic scattering, and charged current reactions and assuming the standard 8B shape, the nu(e) component of the 8B solar flux is phis(e) = 1.76(+0.05)(-0.05)(stat)(+0.09)(-0.09)(syst) x 10(6) cm(-2) s(-1) for a kinetic energy threshold of 5 MeV. The non-nu(e) component is phi(mu)(tau) = 3.41(+0.45)(-0.45)(stat)(+0.48)(-0.45)(syst) x 10(6) cm(-2) s(-1), 5.3sigma greater than zero, providing strong evidence for solar nu(e) flavor transformation. The total flux measured with the NC reaction is phi(NC) = 5.09(+0.44)(-0.43)(stat)(+0.46)(-0.43)(syst) x 10(6) cm(-2) s(-1), consistent with solar models.

Measurement of day and night neutrino energy spectra at SNO and constraints on neutrino mixing parameters.

The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8B spectrum, the night minus day rate is 14.0%+/-6.3%(+1.5%)(-1.4%) of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0%+/-4.9%(+1.3%)(-1.2%). A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.