A stem cell-like gene expression signature associates with inferior outcomes and a distinct microRNA expression profile in adults with primary cytogenetically normal acute myeloid leukemia

Acute myeloid leukemia (AML) is hypothesized to be sustained by self-renewing leukemia stem cells (LSCs). Recently, gene expression signatures (GES) from functionally defined AML LSC populations were reported, and expression of a 'core enriched' (CE) GES, representing 44 genes activated in LCSs, conferred shorter survival in cytogenetically normal (CN) AML. The prognostic impact of the CE GES in the context of other molecular markers, including gene mutations and microRNA (miR) expression alterations, is unknown and its clinical utility is unclear. We studied associations of the CE GES with known molecular prognosticators, miR expression profiles, and outcomes in 364 well-characterized CN-AML patients. A high CE score (CE(high)) associated with FLT3-internal tandem duplication, WT1 and RUNX1 mutations, wild-type CEBPA and TET2, and high ERG, BAALC and miR-155 expression. CE(high) patients had a lower complete remission (CR) rate (P=0.003) and shorter disease-free (DFS, P<0.001) and overall survival (OS, P<0.001) than CE(low) patients. These associations persisted in multivariable analyses adjusting for other prognosticators (CR, P=0.02; DFS, P<0.001; and OS, P<0.001). CE(high) status was accompanied by a characteristic miR expression signature. Fifteen miRs were upregulated in both younger and older CE(high) patients, including miRs relevant for stem cell function. Our results support the clinical relevance of LSCs and improve risk stratification in AML.

Phase 2 study of subcutaneous omacetaxine mepesuccinate for chronic-phase chronic myeloid leukemia patients resistant to or intolerant of tyrosine kinase inhibitors

Omacetaxine mepesuccinate (omacetaxine) is a first-in-class cephalotaxine with a unique mode of action, independent of BCR-ABL, that has shown promising activity in patients with chronic myeloid leukemia (CML). This multicenter, noncomparative, open-label phase 2 study evaluated the efficacy and safety of subcutaneous omacetaxine in CML patients with resistance or intolerance to two or more tyrosine kinase inhibitors (TKIs); results in patients in chronic phase are reported here. Patients received subcutaneous omacetaxine 1.25 mg/m² twice daily days 1-14 every 28 days until hematologic response (up to a maximum of six cycles), then days 1-7 every 28 days as maintenance. Primary endpoints were rates of hematologic response lasting >8 weeks and major cytogenetic response (MCyR). Forty-six patients were enrolled: all had received imatinib, 83% had received dasatinib, and 57% nilotinib. A median 4.5 cycles of omacetaxine were administered (range, 1-36). Hematologic response was achieved or maintained in 31 patients (67%); median response duration was 7.0 months. Ten patients (22%) achieved MCyR, including 2 (4%) complete cytogenetic responses. Median progression-free survival was 7.0 months [95% confidence interval (CI), 5.9-8.9 months], and overall survival was 30.1 months (95% CI, 20.3 months-not reached). Grade 3/4 hematologic toxicity included thrombocytopenia (54%), neutropenia (48%), and anemia (33%). Nonhematologic adverse events were predominantly grade 1/2 and included diarrhea (44%), nausea (30%), fatigue (24%), pyrexia (20%), headache (20%), and asthenia (20%). Subcutaneous omacetaxine may offer clinical benefit to patients with chronic-phase CML with resistance or intolerance to multiple TKI therapies.

Molecular epidemiology and risk factors for colonization by vancomycin-resistant Enterococcus in patients with hematologic malignancies

OBJECTIVE

To study the molecular epidemiology of vancomycin-resistant Enterococcus (VRE) colonization and to identify modifiable risk factors among patients with hematologic malignancies.

SETTING

A hematology-oncology unit with high prevalence of VRE colonization.

PARTICIPANTS

Patients with hematologic malignancies and hematopoietic stem cell transplantation recipients admitted to the hospital.

METHODS

Patients underwent weekly surveillance by means of perianal swabs for VRE colonization and, if colonized, were placed in contact isolation. We studied the molecular epidemiology in fecal and blood isolates by pulsed-field gel electrophoresis over a 1-year period. We performed a retrospective case-control study over a 3-year period. Cases were defined as patients colonized by VRE, and controls were defined as patients negative for VRE colonization. Case patients and control patients were matched by admitting service and length of observation time.

RESULTS

Molecular genotyping demonstrated the primarily polyclonal nature of VRE isolates. Colonization occurred at a median of 14 days. Colonized patients were characterized by longer hospital admissions. Previous use of ceftazidime was associated with VRE colonization (P < .001), while use of intravenous vancomycin and antibiotics with anaerobic activity did not emerge as a risk factor. There was no association with neutropenia or presence of colonic mucosal disruption, and severity of illness was similar in both groups.

CONCLUSION

Molecular studies showed that in the majority of VRE-colonized patients the strains were unique, arguing that VRE acquisition was sporadic rather than resulting from a common source of transmission. Patient-specific factors, including prior antibiotic exposure, rather than breaches in infection control likely predict for risk of fecal VRE colonization.

A randomized phase II study of sapacitabine, an oral nucleoside analogue, in elderly patients with AML previously untreated or in first relapse or previously treated MDS

7021

Background: Sapacitabine is a novel nucleoside analogue with a unique ability to cause irreparable single-strand DNA breaks and induce G2 cell cycle arrest. It is orally administered and has demonstrated promising anti-leukemic activity against relapsed or refractory AML and MDS in a phase 1 trial. We are conducting a multi-center, open-label, randomized phase 2 study to evaluate 3 dosing regimens of this drug. Methods: Eligible patients must be ≥70 years with AML previously untreated or in first relapse or ≥60 years with MDS previously treated with hypomethylating agents. The planned sample size is 60 AML patients and 60 MDS patients. Patients are to be randomized 1:1:1 to receive one of the 3 dosing regimens. The primary efficacy endpoint is 1-year survival. Secondary efficacy endpoints include rate of CR, CRi, or hematological improvement (HI) and response durations. Results: As of December 2008, 60 AML and 13 MDS patients were enrolled and had ≥ 30 days of follow-up. Preliminary efficacy data were available for the AML stratum. Overall response rate is 31% (13% CR/CRp, 5% PR and 13% HI). Median time to CR/CRp is 3–4 cycles (range 1–7). Eight deaths of all causes occurred within 30 days of randomization and all were in the AML stratum (13%). One death was considered to be possibly related to sapacitabine. Common adverse events (all grades, regardless of causality) included fatigue, nausea, vomiting, diarrhea, constipation, anemia, leukopenia, febrile neutropenia, neutropenia, thrombocytopenia, dyspnea and peripheral edema, most of which were mild to moderate in intensity. Conclusions: These interim data suggest that sapacitabine is safe and active across all 3 dosing schedules. Updated data will be presented at the meeting.

[Table: see text]

No significant financial relationships to disclose.

Subcutaneous omacetaxine mepesuccinate in chronic myeloid leukemia (CML) patients resistant or intolerant to two or more tyrosine kinase inhibitors (TKIs): Data from an ongoing phase II trial

7027

Background: Omacetaxine (OM), a first-in-class cetaxine, shows clinical activity against Ph+ CML with a mechanism of action independent to tyrosine kinase inhibition. Patients (Pts) who have failed multiple TKIs may benefit from an alternative therapy for CML. Methods: Pts include adult CML following resistance or intolerance to at least 2 TKIs. T315I+ Pts are enrolled in a separate trial. Pts receive OM induction at 1.25 mg/m2 subcutaneous (SC) BID for 14 days every 28 days followed by maintenance at 1.25 mg/m2 SC BID for 7 days every 28 days (maintenance after at least one induction cycle and achievement of hematologic response). Results: 60 pts (30 chronic phase [CP], 14 accelerated phase [AP], and 16 blast phase [BP] have been enrolled with 51% having failed at least 3 prior TKIs. Median age: 58 yrs; 50% male. Median disease duration: 74 months. At baseline, 38.5% of pts had Bcr-Abl mutations including 9.6% with compound mutations. The most frequently observed mutations were F317L (11.5%) and V299L (5.8%). OM is well tolerated with transient myelosuppression as the primary toxicity. Grade 3/4 non-hematologic events are rare with pyrexia occurring in 4.3% of patients. Efficacy data are available for 30 Pts: Conclusions: Omacetaxine in multi-TKI resistant or intolerant CML is well tolerated and has achieved hematologic and cytogenetic responses in these heavily pre-treated Pts.

[Table: see text]

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Biologic features and treatment outcome of secondary acute lymphoblastic leukemia--a review of 101 cases

BACKGROUND

Secondary acute lymphoblastic leukemia (sALL) is a rare disease and its biologic features are not well characterized.

PATIENTS AND METHODS

We describe a cohort of seven patients and discuss 94 additional cases from the literature for whom biological parameters were described. Cases with incomplete data were excluded.

RESULTS

Hodgkin's disease (HD) was more common in the 18-59 age group while breast and prostate cancers were prevalent only in the >or=18-year-old patients. The time interval to develop sALL was similar among all age groups but was significantly longer for HD and neuroblastoma primary diagnoses and sALL with complex karyotype. T-cell immunophenotype was more common in the <18 age group. Complete remission was infrequent in the >or=60 age group. The overall survival was poor for all sALL regardless of age, primary diagnoses, cytogenetic subgroups, or immunophenotype. Allogeneic transplantation most probably represents the only chance of cure.

CONCLUSION

Better identification of prognostic factors to prevent the occurrence of sALL is indicated.

A phase III randomized trial of intensive induction and consolidation chemotherapy ± oblimersen, a pro-apoptotic Bcl-2 antisense oligonucleotide in untreated acute myeloid leukemia patients >60 years old

7012

Background: Overexpression of Bcl-2, an inhibitor of apoptosis, may render AML cells resistant to chemotherapy and has been associated with unfavorable outcome. Genasense is a phosphorothioate 18-mer antisense oligonucleotide directed against the first 6 codons of Bcl-2. In a phase I study of older (≥60 yrs) AML patients (pts) treated with Genasense in combination with cytarabine (Ara-C) and daunorubicin (DNR) induction and with high-dose cytarabine (HiDAC) consolidation, no antisense-related toxicity was reported. Furthermore, overexpression of Bcl-2 at diagnosis and down-regulation of the Bcl-2 target after antisense treatment was shown in pts achieving complete remission (CR). Methods: A phase III trial (CALGB 10201) randomized untreated older AML pts to induction treatment with Ara-C (100 mg/m2/d by CIVI on days 4–10) and DNR (60 mg/m2/d on days 4–6) followed by consolidation therapy with HiDAC (2 g/m2/d on days 4–8) with (Arm A) or without (Arm B) Genasense (7 mg/m2/d CIVI on days 1–10 for induction and days 1–8 for consolidation). The study was powered to identify a survival advantage for pts receiving Genasense. Results: 503 pts enrolled between 12/03 and 10/06; 76 had prior MDS and 24 prior chemoradiotherapy for unrelated cancers. The arms were balanced for age, sex, race, and performance status. No differences in toxicities were observed between the 2 arms. An interim futility analysis performed at 34 months from initiation of the study showed no differences in CR rates (48% vs 52%; p=0.75) or overall survival (OS; p=0.83) between the 2 arms. Estimated OS at 1 yr was 36% for Arm A and 40% for Arm B. Similarly, there were no differences in disease-free survival from date of CR (DFS; p=0.78) or event-free survival (EFS; p=0.77). DFS and EFS rates at 1 yr were 40% and 25% for Arm A, and 43% and 7% for Arm B, respectively. Conclusions: Addition of Genasense to induction and consolidation chemotherapy failed to improve the outcome of older AML pts. Pretreatment levels and post-antisense treatment changes in Bcl-2 expression are now being measured and correlated with outcome.

No significant financial relationships to disclose.

Sequential imatinib and chemotherapy yield reverse-transcriptase polymerase chain reaction (RT-PCR)-negative peripheral stem cell collections in Philadelphia (Ph) chromosome positive acute lymphoblastic leukemia (ALL)—Preliminary results of CALGB 10001

6549

Background: Ph+ ALL has a short complete remission duration and survival. Allogeneic stem cell transplantation (SCT) is recommended. We hypothesized that imatinib plus sequential chemotherapy will result in greater leukemia cell cytoreduction than previously achieved with chemotherapy alone, allowing collection of large numbers of normal hematopoietic stem cells uncontaminated by residual t(9;22) lymphoblasts and thus reduce the likelihood of relapse after autologous SCT for patients without donors. Methods: Treatment consisted of a 4–5 drug induction regimen followed by imatinib 400 mg BID for 4 weeks, CNS prophylaxis with high-dose methotrexate, another month of imatinib, and ideally allogeneic SCT following fractionated total body irradiation (FTBI) and etoposide. Those without donors received high-dose cytarabine, etoposide, and G-CSF for stem cell mobilization, leukapheresis, and autologous SCT after FTBI, etoposide and cyclophosphamide. Imatinib maintenance continues until RT-PCR negative for 12 months. Patients had to be < 60 years old. Results: 18 patients have enrolled to date; so far 3 underwent allogeneic SCT and 5 completed peripheral stem cell collections of whom 4 have undergone autologous SCT. Median stem cell yield was 55.74×106/kg (range, 34.8–94.4). Peripheral stem cells were assayed from 3 patients for RT-PCR with a sensitivity of 1:105-106. All 3 samples were negative for BCR-ABL. Of the 3 patients who underwent allogeneic SCT, 1 failed to engraft and died, 1 died due to respiratory failure on day 70, and 1 relapsed on day 113. Of the 4 patients who underwent autologous SCT, all achieved neutrophil engraftment (> 0.5×109/L) between days 8–10 and platelet engraftment (> 50×109/L) between days 7–17. Two patients relapsed (simultaneous CNS and marrow) on days 164 and 309, and 2 patients are alive in continuous remission on days +297 and +359 following autologous SCT. Conclusions: Sequential imatinib and chemotherapy can achieve RT-PCR negativity in Ph+ ALL, allowing autologous SCT. Ongoing accrual will evaluate the efficacy of this approach in adults with Ph+ ALL.

[Table: see text]

Simultaneous presentation of acute monoblastic leukemia and mantle cell lymphoma: case report and review of the literature

This paper reports a 73-year old woman with simultaneous presentation of acute monoblastic leukemia (acute myeloid leukemia (AML), French-American-British (FAB) type M5a) and mantle cell lymphoma. The patient presented with wasting, generalized lymphadenopathy, an extensive infiltrative rash and pancytopenia. Bone marrow and lymph node histopatholology showed extensive infiltration by leukemic monoblasts. Marrow cytogenetics revealed a complex karyotype, including t(8;16)(p11;p13). Flow cytometric immunophenotyping of peripheral blood, lymph node and bone marrow demonstrated two populations, expressing CD5, CD19, CD20 and CD22 and CD45, HLA-DR, CD13, CD33, CD14 and CD38, respectively. A focus of abnormal lymphocytes in the lymph node biopsy demonstrated BCL1 expression and t(11;14)(p11;p13) by fluorescence in situ hybridization and immunoglobulin heavy chain gene rearrangement by the polymerase chain reaction. The patient received infusional cytarabine, daunorubicin and etoposide chemotherapy, with complete remission of both the AML and the mantle cell leukemia. To the authors' knowledge, this is the first report of simultaneous presentations of AML, FAB M5a and mantle cell lymphoma. The case is discussed and the literature is reviewed.

A prognostic model for prolonged event-free survival after autologous or allogeneic blood or marrow transplantation for relapsed and refractory Hodgkin's disease

There are several prognostic models for Hodgkin's disease (HD) patients, but none evaluating patient characteristics at time of blood and marrow transplantation (BMT). We developed a prognostic model for event-free survival (EFS) post-BMT based on HD patient characteristics measured at the time of autologous (auto) or allogeneic (allo) BMT. Between 1/1991 and 12/2001, 64 relapsed or refractory HD patients received an auto (n=46) or allo (n=18) BMT. A multivariate prognostic model was developed measuring time to relapse, progression or death. Median follow-up was 51.7 months; median EFS for auto and allo BMT was 36 and 3 months, respectively (P=0.001). Significant multivariate predictors of shorter EFS were chemotherapy-resistant disease, KPS <90 and > or =3 chemotherapy regimens pre-BMT. Patients with two to three adverse factors had significantly shorter EFS at 2 years (58 vs 11% in auto; 38 vs 0% in allo BMT patients). Despite a selection bias favoring auto BMT, the model was valid in both auto and allo BMT groups. We were able to differentiate patients at high vs low risk for adverse outcomes post-BMT. This prognostic model may prove useful in predicting patient outcomes and identifying high-risk patients for novel treatment strategies. Validation of this model in a larger cohort of patients is warranted.

Acute renal failure requiring dialysis after allogeneic blood and marrow transplantation identifies very poor prognosis patients

We examined the incidence, risk factors and associated mortality of acute renal failure requiring dialysis (Renal Bearman Grade [BG] 3) in a 3-year cohort of 97 consecutive allogeneic blood and marrow transplantation (alloBMT) patients. In all, 20 (21%) developed Renal BG3 (all died by day +132) and 77 (79%) developed renal insufficiency (Renal BG1-2). Renal BG3 was a contributing or primary cause of death in 18 (90%) patients who continued to require dialysis at time of death. The two Renal BG3 patients whose deaths were not related to renal failure died on day +103 of hemorrhage and day +132 of underlying disease. By univariate analysis, age, unrelated donor, veno-occlusive disease (VOD) and grade III-IV acute graft-versus-host disease with hepatic involvement were significantly associated with Renal BG3. The multivariate model of time to Renal BG3 determined only a prior diagnosis of severe acute GVHD (RR=4.1, 95% CI 1.6-10.3, P=0.003) and VOD (RR=9.1, 95% CI 3.5-23.7, P<0.001) as significant independent predictors. Renal BG3 is generally considered a conditioning regimen-related toxicity. This study demonstrates that Renal BG3 is most commonly a complication of hepatic co-morbidities after allogeneic blood and marrow transplantation and identifies patients with a very poor prognosis.

Use of nonvolume-reduced (unmanipulated after thawing) umbilical cord blood stem cells for allogeneic transplantation results in safe engraftment

Volume reduction of umbilical cord blood (UCB) units before infusion is standard in most transplant centers. We examined 26 patients who underwent transplantation from May 1997 to December 2001 with unmanipulated (n=18) or volume-reduced (n=8) UCB units for engraftment. Of 18 unmanipulated UCBT patients, 16 achieved ANC >500/mm(3), a median of 26 days (range, 16-104) post-UCBT; two died before engraftment on days +2 and +14. Of 18 unmanipulated UCBT patients, 10 achieved platelet recovery, a median of 60.5 days (range, 41-144) post-UCBT; eight patients died before platelet recovery +2 to +255 days post-UCBT. These results are similar to several reported studies and our series utilizing volume-reduced UCB units for UCBT. At a median follow-up of 29.5 months, the 100-day and 3-year overall survivals of unmanipulated UCBT were 61.1% (95% CI, 38.6-83.6) and 48.6% (95% CI, 24.8-72.4) and of volume-reduced UCBT were 60% (95% CI, 24.4-95.6) and 22.5% (95% CI, 0-58.7). There was no serious toxicity from UCB infusion using unmanipulated UCB units. We conclude that unmanipulated UCB units may be infused safely into UCBT patients with adequate engraftment and survival.

HLA-DR antigen-negative acute myeloid leukemia

Human leukocyte antigen (HLA) Class II antigens are variably expressed on acute myeloid leukemia (AML) blasts. The biological and clinical significance of HLA Class II antigen expression by AML cells is not known. Therefore, we sought to characterize cases of AML without detectable HLA-DR expression. Samples from 248 consecutive adult AML patients were immunophenotyped by multiparameter flow cytometry at diagnosis. HLA-DR antigens were not detected on AML cells from 43 patients, including 20 with acute promyelocytic leukemia (APL), and 23 with other subtypes of AML. All APL cases had t(15;17), but there were no characteristic chromosome abnormalities in non-APL cases. No direct expression of other antigens was identified in HLA-DR-negative APL and non-APL cases. Interestingly, cells from three HLA-DR-negative non-APL patients had similar morphology to that of the hypogranular variant of APL. This morphology, however, was not present in any HLA-DR-positive AML cases. Treatment response was similar in the 23 HLA-DR-negative non-APL and the 205 HLA-DR-positive patients. Finally, relapse was infrequently associated with changes in HLA-DR antigen expression, as the HLA-DR antigen was lost at relapse in only 4% of HLA-DR-positive cases, and was gained at relapse in only 17% of HLA-DR-negative cases. We conclude that HLA-DR-negative AML includes approximately equal numbers of APL and non-APL cases, and that the morphology of HLA-DR-negative non-APL cases can mimic the hypogranular variant of APL. The diagnosis of APL cannot be based on morphology and lack of HLA-DR antigen expression; rather, it requires cytogenetic or molecular confirmation.

Remarkable spectator ligand effect on the rate constant of ligand substitution of (aqua)ruthenium(II) complexes

The influence of two different di(1-pyrazolyl)alkane ligands on the rate constant of aqua ligand substitution of ruthenium(II) complexes with the formula [Ru(H2O)(L2)(tpmm)]2+ (L2 = di(1-pyrazolyl)methane (DPMet) or 2,2-di(1-pyrazolyl)propane (DPPro)) was investigated. A 9.4 x 10(5)-fold increase in the rate constant of ligand substitution at pH = 6.86 was observed when DPMet was replaced with DPPro. This remarkable increase was unexpected, considering that these bidentate ligands appear quite similar. To help lend insight into this dramatic spectator ligand effect, the activation parameters for the ligand substitution reactions were determined, and single-crystal X-ray data were collected on the structurally analogous (chloro)ruthenium(II) complexes, [Ru(Cl)(L2)(tpmm)]+. These results are discussed in the context of a heteroscorpionate effect exerted by the DPPro ligand.

Acute myeloid leukemia in the setting of low dose weekly methotrexate therapy for rheumatoid arthritis

Methotrexate is in widespread use as second-line therapy for rheumatoid arthritis. Treatment with methotrexate in this and other settings has not been associated with the development of therapy-related leukemias. Four patients with rheumatoid arthritis are reported who developed acute myeloid leukemia (AML) while receiving low dose weekly methotrexate therapy in the absence of previous or concomitant treatment with known leukemogenic agents. AML in these four patients was of different morphologic subtypes and was associated with heterogeneous cytogenetic abnormalities, cell surface marker expression and multidrug resistance protein expression. None of the recognized features of therapy-related leukemia were present in these four nor in five previously-reported patients. It is likely that the occurrence of AML in patients with rheumatoid arthritis in the setting of methotrexate therapy represents the coincidence of these two diseases, and does not reflect a causal relationship.

High-dose cytosine arabinoside and idarubicin treatment of chronic myeloid leukemia in myeloid blast crisis

Chronic myeloid leukemia in myeloid blast crisis (CML-MBC) is highly resistant to standard induction chemotherapy regimens. Anecdotal results from previous clinical trials support the concept of dose escalation in patients with CML-MBC. Eight patients with CML-MBC were treated with cytosine arabinoside (Ara-C) 1.5-3.0 g/m2 intravenously over 1 hr every 12 hr for 12 doses and idarubicin 12 mg/m2 intravenously daily for 3 days. Sixteen previous reports describing the use of Ara-C-based chemotherapy regimens in patients with CML-MBC were also reviewed. Our patients' median age was 62 years (range, 42-69 years). One patient achieved complete hematologic remission (95% confidence interval, 0.3%, 53%). The median survival for our patients was 7.3 months. These results were not different from previous published reports using Ara-C-based chemotherapy regimens to treat CML-MBC. In summary, the combination of high-dose Ara-C and idarubicin did not improve the overall prognosis of patients with CML-MBC. Innovative approaches need to be explored for this patient population.

Truncated STAT proteins are prevalent at relapse of acute myeloid leukemia

Signal transducer and activator of transcription (STAT) proteins are implicated in the control of cell survival, proliferation and differentiation in response to hematopoietic cytokines. C-terminally truncated STAT isoforms (STATbeta), as opposed to the full length form (STATalpha), have a competitive or even transdominant negative effect on gene induction mediated by the STAT pathway. We have previously demonstrated that while constitutively active STAT proteins were detected in ten of 36 (28%) for STAT3 and eight of 36 (22%) for STAT5 in pretreatment samples from newly diagnosed acute myeloid leukemia (AML) patients, a significantly larger fraction of samples [21 of 27 (78%)] expressed STATbeta proteins. To determine whether STATbeta expression was maintained or increased after relapse in AML, we compared STAT activity and isoform expression at diagnosis and at relapse in 17 patients. In this selected group, constitutively active STAT3 was detected in 13 of 17 (76%) AML samples at diagnosis but was detected in only four of these patients at relapse. Constitutively active STAT5 was detected in three of 17 (18%) AML samples at diagnosis; but only two at relapse. In contrast, STATbeta protein expression was observed in 12 of the 17 pretreatment samples (71%) and in 16 of 17 samples at relapse. Only one patient did not express STATbeta at relapse. Our results suggest that STATbeta isoform expression, rather than level of constitutive activity, may be involved in disease progression in AML.

Thiotepa-associated cardiomyopathy during blood or marrow transplantation: association with the female sex and cardiac risk factors

Thiotepa (TT) has not been reported to cause cardiomyopathy, whereas cyclophosphamide (Cy)-related cardiomyopathy is well characterized. To search for cases of acute onset cardiomyopathy associated with TT, we retrospectively reviewed 171 patients who received TT-containing conditioning regimens for blood or marrow transplantation (BMT). Nine of 171 patients (5.3%) developed clinical congestive heart failure in the post-BMT period. The median time to onset of heart failure was 15 days after BMT (range 5-30). The median pre-BMT left ventricular ejection fraction (LVEF) was 50% (range 42-65%) as determined by two-dimensional echocardiogram, or gated blood pool scan. At the time of cardiomyopathy onset, LVEF was 30%. Six patients died of causes unrelated to heart failure. All affected patients who developed congestive heart failure following administration of TT had some evidence of cardiac dysfunction prior to transplantation. Significant risk factors for the development of cardiomyopathy included low pre-BMT-LVEF and female sex--particularly in females receiving allogeneic transplantation. The incidence of congestive heart failure with TT-containing regimens was similar to the incidence using other regimens with and without Cy. The mean time to clinical evidence of TT-associated cardiomyopathy was longer than the mean time reported with Cy. We recommend caution in using high-dose TT-containing regimens for patients with histories of cardiac dysfunction.

Retrospective multivariate analysis of hepatic veno-occlusive disease after blood or marrow transplantation: possible beneficial use of low molecular weight heparin

This retrospective cohort study of 462 consecutive adult allogeneic and autologous blood or marrow transplantation (BMT) patients compared the incidence of hepatic veno-occlusive disease (VOD) after BMT with three prophylactic regimens. Patients receiving heparin (Hep), heparin + prostaglandin E1 (Hep + PGE1) or low molecular weight heparin (LMWH) as a prophylactic VOD regimen were compared to a historical cohort receiving no VOD prophylaxis. Of 462 BMT patients, VOD was diagnosed in 22% (31 of 142) of the no prophylaxis group, 11% (11 of 104) of the Hep, 12% (13 of 110) in the Hep + PGE1 and 4% (four of 106) of the LMWH group (P = 0.0002). VOD was the primary cause of death in 20% (12 of 59). By multivariate logistic regression, independent risk factors for developing VOD were: no VOD prophylactic regimen, unrelated allogeneic BMT, Karnofsky performance score (KPS) < 80 and aspartate aminotransferase (AST) > or =50 U/l. There was no increase in the rate of death due to hemorrhagic events or VOD in any prophylaxis group compared to the control group. Prospective randomized trials of Hep vs LMWH vs placebo are warranted to assess the efficacy of heparin compounds in the prevention of VOD.

A novel serine-dependent proteolytic activity is responsible for truncated signal transducer and activator of transcription proteins in acute myeloid leukemia blasts

Hematopoietic cytokine receptor signaling involves activation of signal transducer and activator of transcription (STAT) proteins that are thought to control cellular differentiation. Truncated STAT isoforms (beta forms, rather than the normal alpha forms) have been described and found to block the normal signaling function of the alpha isoforms. We recently demonstrated STATbeta isoforms in bone marrow samples from 21 of 27 (78%) acute myeloid leukemia (AML) patients. We sought to determine the mechanism by which the STATbeta forms were generated. Samples from eight newly diagnosed AML patients were studied; four expressed predominantly STATalpha, and four expressed predominantly STATbeta. The reverse transcription-PCR generated identical products in the two groups, suggesting that alternate mRNA splicing is not responsible for the genesis of STATbeta. Extracts from cells expressing predominantly STATbeta incubated with cell extracts from the MO7E cell line, which expresses predominantly STATa, caused a decrease of the alpha isoforms and an increase of the beta isoforms, suggesting the presence of proteolytic activity. This proteolytic activity was: (a) specific for STAT3 and STAT5, but not for STAT6; (b) serine dependent; (c) equally present in nuclear and cytoplasmic fractions of the leukemic blasts; and (d) different than the activity detected in a murine hematopoietic cell line. The cleaved beta isoforms retained their DNA-binding activity. Because expression of truncated STATs may be involved in blocking differentiation of AML blasts, elucidation of the regulation of the proteolytic activity may contribute to our understanding of leukemogenesis.

HLA class I antigen cell surface expression is preserved on acute myeloid leukemia blasts at diagnosis and at relapse

Human leukocyte antigens (HLA) class I molecules restrict the interaction between cytotoxic T cells and target cells. Abnormalities in HLA class I antigen expression and/or function may provide tumor cells with a mechanism for escaping immune surveillance and resisting T cell-based immunotherapies. The potential for applying T cell-based immunotherapy in the treatment of acute myeloid leukemia (AML) has stimulated interest in analyzing HLA class I antigen expression on leukemic blasts in this disease. Little information is available in the literature. We have analyzed HLA class I antigen expression on bone marrow samples from 25 newly diagnosed AML patients by indirect immunofluorescence staining with monoclonal antibodies. Five of these patients were also studied at relapse. Leukemic blasts were resolved from normal lymphocytes by staining with antiCD45 antibody; CD45 expression is dim on leukemia cells, but bright on lymphocytes. HLA class I antigen expression was higher on leukemic blasts than on autologous lymphocytes in all but one case. Moreover, there was no significant change in HLA class I antigen expression at relapse. These results suggest that abnormalities in HLA class I antigens are infrequent in AML and should not represent a major obstacle to the application of T cell-based immunotherapies in this disease.

Cytogenetics in adult acute lymphocytic leukemia

The outcome of adult ALL patients has improved over the years, with an increase in median DFS from 0.9 years before 1988 to 1.7 years alter 1988. There is still ample room for improvement. Cytogenetic analysis at diagnosis can assist in developing risk-adapted therapeutic strategies and in devising new treatment modalities by an understanding of the molecular basis of the aberrations. Moreover, therapy can be intensified when residual disease is detected.

Cytoplasmic and nuclear localization of the 130 and 160 kDa Bcr proteins

Formation of the Bcr-Abl chimeric protein is the molecular hallmark of Philadelphia-positive leukemia. Normal Bcr is a complex protein which has been found in the cytoplasm, has serine kinase activity, and has been implicated in cellular signal transduction. However, we have recently demonstrated that Bcr can also associate with condensed chromatin. Since two major Bcr proteins have been characterized (p160Bcr and p130Bcr), we sought to determine if different forms of Bcr localized to the nucleus vs the cytoplasm. Metabolic labeling and Western blotting experiments were performed using nuclear and cytoplasmic extracts of three human Philadelphia-negative leukemia/lymphoma cell lines (KG-1, HL-60, and Jurkat). Both methodologies showed that p160Bcr and p130Bcr localized to the cytoplasm, but the p130 form predominated in the nucleus. These results suggest that Bcr serves both nuclear and cytoplasmic functions, and that different forms of Bcr may be preferentially involved in these distinct activities.

Tissue plasminogen activator (tPA) as therapy for hepatotoxicity following bone marrow transplantation

The treatment of established veno-occlusive disease (VOD) of the liver with tissue plasminogen activator (tPA) has been disappointing. In attempts to improve upon these results we identified a subgroup of patients with consistently elevated bilirubin levels who did not meet conventional criteria for VOD (Susp VOD) but who had a significant risk of later developing clinical VOD. In January 1994 we began to treat patients who developed Susp VOD with tPA rather than waiting until they developed clinical VOD. We now report on the results of the first 37 patients who ultimately developed clinical VOD and received tPA therapy prior to Susp VOD, or at the time they had established VOD. Significant bleeding complications occurred in 13 (35%) patients but resolved with discontinuation of therapy in all but one. We found that patients treated early in the course of hepatotoxicity prior to the development of overt VOD had a significantly higher response rate and 100 day survival than patients treated at the time of established VOD. Given the poor results seen in treating late VOD, we suggest that early treatment with tPA may improve the outcome in patients who develop signs of hepatotoxicity following marrow transplantation.

Modulation of hepatic acute phase gene expression by epidermal growth factor and Src protein tyrosine kinases in murine and human hepatic cells

As part of systemic inflammatory reactions, interleukin 6 (IL-6) induces acute phase protein (APP) genes through the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. Epidermal growth factor (EGF), which contributes to the regenerative process after liver injury and also activates STATs, does not induce but attenuates IL-6-stimulated expression of several APP genes in primary mouse hepatocytes. The APP-modifying action of EGF receptor (EGFR) was characterized in HepG2 cells. Although EGF less effectively engages STAT proteins in these cells, it reduces expression of fibrinogen and haptoglobin, but stimulates production of alpha(1)-antichymotrypsin and induces transcription through the alpha(1)-antichymotrypsin and C-reactive protein promoter. The stimulatory EGFR signal is insensitive to inhibition of JAKs and appears to involve Src kinases and STAT proteins as shown by inhibition through overexpression of C-terminal Src kinase (Csk) and transdominant negative STAT3, respectively. A mediator role of Src is supported by the ability of c-Src and v-Src to activate STATs and induce transcription through APP promoters. Src kinases have been observed in association with the IL-6 receptor; however, inhibition of Src kinases by Csk enhances IL-6-induced transcription. The Csk effect is attributed to prevention of Src kinases from phosphorylating gp130 at the docking site for the signal-moderating protein tyrosine phosphatase SHP-2. The inhibitory EGFR signal on APP expression correlates with the activation of Erk1 and Erk2. The study shows a dual signaling function for EGFR and suggests that the ratio of receptor-activated STATs and Erks influence the level of stimulated or inhibited expression of individual APPs.

Prospective karyotype analysis in adult acute lymphoblastic leukemia: the cancer and leukemia Group B experience

The Cancer and Leukemia Group B (CALGB) has been conducting a prospective cytogenetic companion study (CALGB 8461) to all CALGB treatment protocols for newly diagnosed adults with acute lymphoblastic leukemia (ALL). These protocols underwent a significant change in 1988 when a new intensive chemotherapy program was introduced (CALGB 8811). We asked whether karyotype continued to represent a significant prognostic factor in adult ALL patients after the change. A total of 256 patients had adequate pretreatment cytogenetic analyses: 67 before 1988 and 189 subsequently. The complete remission (CR) rate for the whole group was 80%. Patients with t(9;22), t(4;11), -7, or +8 had significantly lower probabilities of continuous CR and survival at 5 years (.11 and.12) than patients with a normal karyotype (.38 and.37) and patients with miscellaneous cytogenetic abnormalities (.52 and.49; P <.001 for each comparison). When analyzed by treatment period, the CR rate before CALGB 8811 was 63%; subsequently, it was 86% (P <.001). Patients with cytogenetic abnormalities other than t(9;22), t(4;11), -7, or +8 had better CR rates, disease-free survival (DFS), and survivals (P =.001, P =.04, and P =.004, respectively) after the change to the more intensive chemotherapy regimens. Patients with normal cytogenetics had improved CR rate but no improved DFS or survival, whereas no significant benefit for patients with t(9;22), t(4;11), -7, or +8 was seen. In a multivariate analysis, karyotype retained its prognostic significance for DFS but not for survival; it remained the most important factor for DFS. We conclude that cytogenetic analysis at diagnosis should be used to guide treatment decisions in adults with ALL.

Interferon-alpha-associated focal segmental glomerulosclerosis with massive proteinuria in patients with chronic myeloid leukemia following high dose chemotherapy

BACKGROUND

Acute renal failure, with or without massive proteinuria, is a rare idiosyncratic toxicity of interferon (IFN)-alpha therapy. The authors sought to review their experience with this toxicity as well as the world literature on the subject.

METHODS

The authors describe two patients with chronic myeloid leukemia treated with IFN-alpha following high dose chemotherapy who developed renal failure and proteinuria after 3 and 4 weeks of IFN-alpha therapy, respectively. Fifteen previously reported cases of renal failure and proteinuria associated with IFN-alpha therapy are also reviewed.

RESULTS

Renal biopsies performed on the authors' two patients revealed focal segmental glomerulosclerosis. However, the other reported patients with IFN-alpha-associated renal failure and massive proteinuria had an assortment of pathologic findings.

CONCLUSIONS

The specific renal pathology associated with proteinuria may be a consequence of the condition and not its cause; differences in renal pathology may be caused by other predisposing factors. Patients treated with IFN-alpha following high dose chemotherapy, with or without autologous transplantation, should be followed for the development of proteinuria and renal failure.

Expression and function of the megakaryocyte growth and development factor receptor in acute myeloid leukemia blasts

The receptor for megakaryocyte growth and development factor (MGDF), also known as thrombopoietin, has recently been cloned. MGDF stimulates platelet production and maturation both in vitro and in vivo. MGDF may thus have a role in attenuating the thrombocytopenia associated with acute myeloid leukemia (AML) and its therapy. However, there is concern that MGDF might induce AML blast proliferation and thereby increase the risk of treatment failure. To address this concern, we studied the expression of c-mpl mRNA and c-Mpl protein by blasts from AML patients. In addition we examined the in vitro effect of MGDF as well as the combined effect of MGDF and granulocyte colony-stimulating factor (G-CSF) or stem cell factor (SCF) on leukemic blast proliferation, recruitment into S-phase, induction of programmed cell death and activation of signal transducers and activators of transcription (STAT) proteins. Our results demonstrate that blasts from a substantial proportion of cases of AML express the receptor at either the mRNA or protein level. Moreover, the function of the MGDF receptor was demonstrated by activation of STAT proteins following exposure to MGDF. Nevertheless, blast proliferation in response to MGDF was rare, and the proliferative effect of MGDF was less than that of G-CSF or SCF. Furthermore, MGDF did not prevent programmed cell death induced by cytarabine. Finally, there appeared to be no correlation between receptor expression by AML blasts and functional response to MGDF. Based on these data, it would appear that clinical trials of MGDF may be undertaken safely in patients with AML.

Expression of signal transducers and activators of transcription proteins in acute myeloid leukemia blasts

Hematopoietic cytokine receptor signaling pathways involve activation of signal transducers and activators of transcription (STAT) proteins, which are postulated to be involved in cellular differentiation. Aberrant STAT isoforms (beta forms rather than the normal alpha forms) have been described and have been found to block the normal signaling pathway from the receptor. Bcr/Abl proteins have been suggested to directly activate STATs, without exposure to growth factors. We asked whether STATs play a role in leukemogenesis. We analyzed constitutive and induced patterns of STAT activity in pretreatment blasts from 36 newly diagnosed acute myeloid leukemia (AML) patients and studied protein tyrosine kinases (PTKs) that may be involved in STAT activity, using in vitro and in-gel kinase assays. The beta forms were expressed in 21 of 27 samples (78%). Constitutive STAT3 and STAT5 activity was found in samples from 28 and 22% of patients, respectively. Response to exogenous cytokines identified two groups. STAT activity in one group was modulated by exogenous cytokines: constitutive STAT activity increased in some patients but decreased or disappeared in response to cytokines in others. The second group was cytokine insensitive. Additionally, we found constitutive PTK activity in two patients whose blasts demonstrated constitutive STAT activity, suggesting that PTKs use cytokine receptor signal pathways to activate STATs in AML blasts without exposure to exogenous cytokines. Our data suggest that (a) constitutive expression of aberrant STATs may be involved in blocking differentiation of AML blasts, (b) exogenous cytokines may activate STAT-inhibitory pathways, and (c) STATs may be activated by PTKs in some AML blasts.

The orthopedic and social outcome of open tibia fractures in children

To determine whether the accepted principles of management of open tibia fractures apply to children, 40 consecutive open fractures of the tibial shaft in skeletally immature patients were retrospectively reviewed. Attempts were made to evaluate the functional and social impact of open tibia fractures in children. All open fractures were initially treated by rapid irrigation and debridement which was repeated every 48 hours until soft tissues stabilized. The average age was 10.1 years and average follow up was 26 months (range: 18 to 84). There were 16 grade I, 10 grade II, and 14 grade III open fractures. The grade III fractures were further subdivided into 6 grade IIIA, 7 grade IIIB, and 1 grade IIIC. The average time to union was 7.5 and 11.0 weeks in the grade I and II fractures respectively, with no infections and no delayed unions. In grade III fractures, the average time to union was 15 weeks, with 1 infection and 3 delayed unions. Bone grafting using autogenous iliac crest was performed on 2 patients. The children surveyed missed an average of 4.1 months of school and 33% had to repeat a year. Twenty-five percent of the children complained of nightmares involving the events of the accident. Chronic pain despite solid union was found in 30% of patients. Forty percent of those surveyed (7 grade III fractures) complained of a limp. The low incidence of soft tissue complications and infections in the study population supports applying in children the same basic soft tissue management principles of open fracture treatment as used in adults. While bone stabilization options are limited in children, the rate of successful union without adjunctive bone grafting is much higher than that of adults treated under similar protocols. Routine early iliac crest bone grafting is unnecessary. The prevalence of gait abnormality despite fracture union should be taken into account during the patient's rehabilitation. The extensive time missed from school and resulting scholastic setback should not be underestimated.

Suppressed formation of bone marrow adherent layers derived from acute myeloid leukemia patients after in vitro exposure to interleukin-4

Long-term bone marrow cultures from ten acute myeloid leukemia (AML) patients exposed to recombinant human (rhu) interleukin (IL) 4 from culture initiation failed to develop adherent layers at 5 weeks as compared to controls. The adherent layers from two of our patients expressed IL-1 beta transcripts constitutively, and all produced IL-6 and leukemia inhibitory factor (LIF) proteins. Our results demonstrate that rhuIL-4 markedly inhibited AML-derived adherent layer formation in a time- and dose-dependent manner, and this effect was not mediated through enhanced apoptosis and did not correlate with IL-1 beta, IL-6 or LIF production.