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Gordon AC, Oakervee HE, Kaya B, Thomas JM, Barnett MJ, Rohatiner AZS, Lister TA, Cavenagh JD, Hinds CJ. Incidence and outcome of critical illness amongst hospitalised patients with haematological malignancy: a prospective observational study of ward and intensive care unit based care. Anaesthesia 2005; 60:340-7. [PMID: 15766336 DOI: 10.1111/j.1365-2044.2005.04139.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
To determine the incidence and outcome of critical illness amongst the total population of hospital patients with haematological malignancy (including patients treated on the ward as well as those admitted to the intensive care unit), consecutive patients with haematological malignancy were prospectively studied. One hundred and one of the 1437 haemato-oncology admissions (7%) in 2001 were complicated by critical illness (26% of all new referrals). Fifty-four (53%) of these critically ill patients survived to leave hospital and 33 (34%) were still alive after 6 months. The majority (77/101) were not admitted to the intensive care unit but were managed on the ward, often with the assistance of the intensive care team. Independent risk factors for dying in hospital included hepatic failure (odds ratio 5.3, 95% confidence intervals 1.3-21.2) and central nervous system failure (odds ratio 14.5, 95% confidence intervals 1.7-120.5). No patient with four or more organ failures or a Simplified Acute Physiology Score II >/= 65 survived to leave hospital. There was close agreement between actual and predicted mortality with increasing Simplified Acute Physiology Score II for all patients, including those not admitted to intensive care.
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Eisterer W, Jiang X, Christ O, Glimm H, Lee KH, Pang E, Lambie K, Shaw G, Holyoake TL, Petzer AL, Auewarakul C, Barnett MJ, Eaves CJ, Eaves AC. Different subsets of primary chronic myeloid leukemia stem cells engraft immunodeficient mice and produce a model of the human disease. Leukemia 2005; 19:435-41. [PMID: 15674418 DOI: 10.1038/sj.leu.2403649] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Xenograft models of chronic phase human chronic myeloid leukemia (CML) have been difficult to develop because of the persistence of normal hematopoietic stem cells in most chronic phase CML patients and the lack of methods to selectively isolate the rarer CML stem cells. To circumvent this problem, we first identified nine patients' samples in which the long-term culture-initiating cells were predominantly leukemic and then transplanted cells from these samples into sublethally irradiated NOD/SCID and NOD/SCID-beta2microglobulin-/- mice. This resulted in the consistent and durable (>5 months) repopulation of both host genotypes with similar numbers of BCR-ABL+/Ph+ cells. The regenerated leukemic cells included an initial, transient population derived from CD34+CD38+ cells as well as more sustained populations derived from CD34+CD38- progenitors, indicative of a hierarchy of transplantable leukemic cells. Analysis of the phenotypes produced revealed a reduced output of B-lineage cells, enhanced myelopoiesis with excessive production of erythroid and megakaropoietic cells and the generation of primitive (CD34+) leukemic cells displaying an autocrine IL-3 and G-CSF phenotype, all characteristics of primary CML cells. These findings demonstrate the validity of this xenograft model of chronic phase human CML, which should enable future investigation of disease pathogenesis and new approaches to therapy.
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Kaboli PJ, McClimon BJ, Hoth AB, Barnett MJ. Assessing the accuracy of computerized medication histories. THE AMERICAN JOURNAL OF MANAGED CARE 2004; 10:872-7. [PMID: 15609741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
OBJECTIVE To determine the accuracy of computerized medication histories. STUDY DESIGN Cross-sectional observational study. PATIENTS AND METHODS The study sample included 493 Department of Veterans Affairs primary care patients aged 65 years or older who were receiving at least 5 prescriptions. A semistructured interview confirmed medication, allergy, and adverse drug reaction (ADR) histories. Accuracy of the computerized medication lists was assessed, including omissions (medications not on the computer record) and commissions (medications on the computer record that were no longer being taken). Allergy and ADR records also were assessed. RESULTS Patients were taking a mean of 12.4 medications: 65% prescription, 23% over-the-counter products, and 12% vitamins/herbals. There was complete agreement between the computer medication list and what the patient was taking for only 5.3% of patients. There were 3.1 drug omissions per patient, and 25% of the total number of medications taken by patients were omitted from the electronic medical record. There were 1.3 commissions per patient, and the patients were not taking 12.6% of all active medications on the computer profile. In addition, 23.2% of allergies and 63.9% of ADRs were not in the computerized record. CONCLUSIONS Very few computerized medication histories were accurate. Inaccurate medication information may compromise patient care and limit the utility of medication databases for research and for assessment of the quality of prescribing and disease management.
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Kaboli PJ, Barnett MJ, Rosenthal GE. Associations with reduced length of stay and costs on an academic hospitalist service. THE AMERICAN JOURNAL OF MANAGED CARE 2004; 10:561-8. [PMID: 15352532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
BACKGROUND Prior studies of hospitalist services have suggested improved efficiency and quality of care compared with traditional inpatient services. OBJECTIVES To compare outcomes of patients on a new hospitalist service with those on traditional inpatient services and to determine the impact of hospitalists on particular patient subgroups. STUDY DESIGN Prospective, quasiexperimental, observational. METHODS The study was conducted on the general medicine service at an academic teaching hospital, staffed by hospitalist physicians (HP) and nonhospitalist physicians (NHP), and included 1706 consecutive, directly admitted patients over 1 year. RESULTS The 447 HP patients and 1259 NHP patients had similar rates of in-hospital mortality (1.3% vs 2.1%, respectively; P = .29) and 30-day readmission (7.8% vs 8.7%, respectively; P= .55). Mean hospital length of stay (LOS) was 1 day shorter for HP patients in unadjusted analyses (5.5 vs 6.5 days, respectively; P = .009) and in multivariable analyses adjusting for clustering and patient factors. Physician experience was not correlated (P < .2) with LOS. In stratified analyses, differences in LOS between HP and NHP patients were greater for patients residing closer to the hospital. Mean total costs were $917 less for HP patients (P = .08) and 10% less (P= .04) in multivariable analyses. Decreases in costs were significant (P < .05) for nursing ($604; P = .002) and laboratory services ($126; P = .04). Nonetheless, mean costs per day were $122 higher (P= .003) for HP patients. CONCLUSIONS Patients managed by hospitalists had shorter LOS and lower costs than patients managed by nonhospitalists, but had higher costs per day. These results suggest that hospitalists increase the intensity of care and may have their greatest impact on specific types of patients and classes of hospital costs.
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Forrest DL, Nevill TJ, Naiman SC, Le A, Brockington DA, Barnett MJ, Lavoie JC, Nantel SH, Song KW, Shepherd JD, Sutherland HJ, Toze CL, Davis JH, Hogge DE. Second malignancy following high-dose therapy and autologous stem cell transplantation: incidence and risk factor analysis. Bone Marrow Transplant 2004; 32:915-23. [PMID: 14561993 DOI: 10.1038/sj.bmt.1704243] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
To establish incidence and risk factors for development of second malignant neoplasms after high-dose chemo/radiotherapy (HDT) and autologous hematopoietic stem cell transplantation (AHSCT), the case files of 800 consecutive patients who underwent AHSCT at our institution between June 1982 and December 2000 were reviewed. In all, 26 patients developed 29 second malignancies (nine myelodysplastic syndrome (MDS)/acute myelogenous leukemia (AML), 16 solid tumors and four lymphoproliferative disorders (LPDs)) for a 15-year cumulative incidence of 11% (95% confidence interval (CI), 5-18%). These second tumors occurred at a median of 68 (range 1.5-177) months following AHSCT. The relative risk (RR) compared to the general population of developing a second malignancy following AHSCT was 3.3 (CI 2.2-4.7) P<0.001. The RR of developing MDS/AML, LPD and a solid tumor was 47.2 (CI 21.5-89.5) P<0.001, 8.1 (2.2-20.7) P=0.002 and 1.98 (1.1-3.2) P=0.009, respectively. In multivariate analysis, age >or=35 years at the time of AHSCT (P=0.001) and an interval from diagnosis to AHSCT >or=36 months (P=0.03) were associated with a greater risk of developing a second malignancy. Patients who have undergone HDT and AHSCT are at significant risk for developing a second malignancy and should receive indefinite follow-up.
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Zickmund S, Hillis SL, Barnett MJ, Ippolito L, LaBrecque DR. Hepatitis C virus-infected patients report communication problems with physicians. Hepatology 2004; 39:999-1007. [PMID: 15057904 DOI: 10.1002/hep.20132] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We examined the prevalence and nature of perceived problems in the interaction between physicians and patients diagnosed with hepatitis C virus (HCV) infection. This cross-sectional study included 322 outpatients diagnosed with chronic HCV infection and treated at a tertiary referral hospital's hepatology clinic. Patients were asked to provide demographic information and to complete a semistructured interview, the Sickness Impact Profile (SIP) and Hospital Anxiety Depression (HAD) scale. A team of two blinded coders analyzed the interviews. A total of 131 (41%) study patients reported communication difficulties with physicians involved in their care. The main difficulties were the poor communication skills of physicians (91 [28%]), physician incompetence regarding the diagnosis and treatment of HCV infection (74 [23%]), feelings of being misdiagnosed, misled, or abandoned (51 [16%]), or being stigmatized by their physician (29 [9%]). Patients were twice as likely to report difficulties with subspecialists as compared with generalists. Nonresponse with antiviral therapy correlated with perceived physician conflict even after adjusting for treatment in relation to the time of interview, whereas previous or ongoing substance abuse and mode of acquisition did not. In a multivariate model, patients' psychosocial problems were the best predictors of communication difficulties. In conclusion, a substantial number of patients with HCV infection report difficulties when interacting with physicians, which may be due to coexisting emotional or social problems. However, perceived stigmatization by physicians and a sense of abandonment reflect the need for further educational efforts. These should target both specialists and primary care providers to inform them about the psychosocial challenges facing these patients.
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Wahls TL, Barnett MJ, Rosenthal GE. Predicting Resource Utilization in a Veterans Health Administration Primary Care Population. Med Care 2004; 42:123-8. [PMID: 14734949 DOI: 10.1097/01.mlr.0000108743.74496.ce] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Valid methods of predicting resource utilization in primary care populations are needed. We compared the predictive validity of a method based on diagnoses from administrative data (Adjusted Clinical Groups [ACGs]) and a method using medication profiles (Chronic Disease Index [CDI]). METHODS This retrospective cohort study included 31,212 primary care patients in a Veterans Health Administration (VA) network who received outpatient medication prescriptions in 1999 and who had VA utilization in 1999 and 2000. ACG and CDI classifications were determined using 1999 data. Analyses compared the predictive validity with respect to outpatient clinic visits and days of hospital care. RESULTS Both ACGs and CDI explained a higher proportion of the variance in outpatient visits than demographic data alone. However, explained variance was higher for ACGs. For example, ACGs explained 30.2% of the variance in total visits in 1999, compared with 8.8% for the CDI. Results were similar for 2000, although the explained variance declined for both methods (eg, 16.3% and 5.7%, respectively, for total visits). Results were similar in analyses examining the discrimination of the 2 methods to predict hospital use; for example, c statistics for ACGs and CDI scores were 0.86 versus 0.70, respectively (P <0.05), for 1999 and 0.72 and 0.65, respectively (P <0.05), for 2000. CONCLUSION Among VA patients, ACGs had superior predictive validity than the CDI, a newer nonproprietary method based on pharmacy data. The findings suggest that diagnosis-based measures could be preferable for ambulatory case-mix adjustment and are valid across a wide range of populations.
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Taussig DC, Davies AJ, Cavenagh JD, Oakervee H, Syndercombe-Court D, Kelsey S, Amess JAL, Rohatiner AZS, Lister TA, Barnett MJ. Durable remissions of myelodysplastic syndrome and acute myeloid leukemia after reduced-intensity allografting. J Clin Oncol 2003; 21:3060-5. [PMID: 12915594 DOI: 10.1200/jco.2003.02.057] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To evaluate the use of reduced-intensity (RI) conditioning with allogeneic hematopoietic stem cell transplantation (HSCT) from HLA-identical family donors in patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). PATIENTS AND METHODS Sixteen patients (median age, 54 years; range, 37 to 66 years) underwent RI-HSCT using a conditioning regimen of fludarabine 25 mg/m2 daily for 5 days and either cyclophosphamide 1 g/m2 daily for 2 days (14 patients) or melphalan 140 mg/m2 for 1 day (two patients). The median number of CD34+ cells and CD3+ cells infused per kilogram of recipient weight was 4.5 x 106 (range, 1.8 to 7.3 x 106 cells) and 2.9 x 108 (range, 0.1 to 9.6 x 108 cells), respectively. RESULTS There was no transplant-related mortality (TRM) within 100 days of HSCT. Grade 1 to 2 acute graft-versus-host disease (GVHD) occurred in three patients, but neither grade 3 nor grade 4 disease was observed. Chronic GVHD occurred in 10 patients. One patient had cytomegalovirus (CMV) reactivation but did not develop CMV disease. With a median follow-up of 26 months (range, 15 to 45 months), 11 patients are alive (nine in continuous complete remission and one in complete remission after a second transplantation), and five have died (four from disease progression and one from bone-marrow aplasia induced by cyclosporine withdrawal). The 2-year actuarial overall and event-free survival rates were 69% (95% confidence interval [CI], 40% to 86%) and 56% (95% CI, 30% to 68%), respectively. CONCLUSION This strategy of RI-HSCT resulted in reliable engraftment with low incidence of acute GVHD and TRM. Durable remissions were observed in patients with MDS and AML consistent with a graft-versus-leukemia effect.
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Rosenthal GE, Kaboli PJ, Barnett MJ. Differences in length of stay in Veterans Health Administration and other United States hospitals: is the gap closing? Med Care 2003; 41:882-94. [PMID: 12886169 DOI: 10.1097/00005650-200308000-00003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Compare risk-adjusted length of stay (LOS) in VA and other United States (non-VA) hospitals and determine if relative differences in LOS have changed in recent years. RESEARCH DESIGN Retrospective cohort study. PATIENTS Patients with ten common medical diagnoses admitted to all VA hospitals and to non-VA hospitals included in the National Hospital Discharge Survey (NHDS) during 1996 through 1999. DATA Comparable data elements were obtained from VA administrative databases and the NHDS. LOS was adjusted for age, gender, marital status, and comorbidity. Comorbidity was assessed using a validated methodology that considers 30 conditions. RESULTS Unadjusted mean LOS was longer in VA than non-VA patient for all 4 years, in aggregate (7.1 vs. 4.9 days, respectively; P < 0.001), and for each year individually. However, the difference in mean LOS in VA and non-VA patients declined from 2.9 days in 1996 to 1.6 days in 1999. LOS in VA patients remained longer (P < 0.001) in linear regression analyses, adjusting for demographics and comorbidity. However, the difference in LOS declined from 28.5% (95% CI, 28.1%-29.0%) in 1996 to 17.0% (95% CI, 16.6%-17.4%) in 1999. These results were similar in analyses of individual geographic regions. CONCLUSIONS Risk-adjusted LOS was longer in VA hospitals than in other United States hospitals. However, differences in LOS narrowed between 1996 and 1999. These findings suggest that changes in the organization and delivery of VA health care in the mid-1990s may be closing the gap between the VA and other healthcare systems in hospital utilization.
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Seftel MD, Barnett MJ. Hematopoietic stem cell transplantation: the Vancouver experience. Hematology 2002; 7:145-9. [PMID: 12243976 DOI: 10.1080/1024533021000008191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Hematopoietic stem cell transplantation has been available as a therapeutic modality for selected adult patients in Vancouver, British Columbia since 1981. We report on the history, progress, and future prospects of the Leukemia/Bone Marrow Transplantation Program of British Columbia. The basic mechanisms and indications for hematopoietic stem cell transplantation are outlined. Limitations of this procedure are also examined, particularly that of associated toxicities such as graft-versus-host-disease.
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Rosenthal GE, Kaboli PJ, Barnett MJ, Sirio CA. Age and the risk of in-hospital death: insights from a multihospital study of intensive care patients. J Am Geriatr Soc 2002; 50:1205-12. [PMID: 12133014 DOI: 10.1046/j.1532-5415.2002.50306.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES To determine independent relationships between age and the risk of in-hospital death. DESIGN Retrospective cohort study. SETTING Thirty-eight intensive care units (ICUs) in 28 hospitals in a large Midwest metropolitan region. PARTICIPANTS One hundred fifty-six thousand, one hundred thirty-six consecutive admissions to medical, surgical, neurological, and mixed medical/surgical ICUs between March 1, 1991, and March 31, 1997. MEASUREMENTS In-hospital death rates were compared at successive 5-year age intervals, adjusting for gender, diagnosis, admission source, comorbidity, and acute physiology scores. Acute physiology scores were determined using a validated methodology based on abnormalities in 17 physiological measures collected during the first 24 hours of ICU admission. RESULTS The adjusted odds of death increased with each 5-year age increment. For example, relative to patients younger than 35, adjusted odds of death in patients aged 40 to 44, 50 to 54, 60 to 64, 70 to 74, 80 to 84, and 90 and older were 1.51, 1.73, 2.38, 2.98, 3.86, and 4.74, respectively. In stratified analyses, age-related increases in the odds of death were somewhat higher in surgical than medical patients or patients with lower severity of illness at admission. Although acute physiology scores had excellent discrimination in all age groups, discrimination decreased with age (e.g., c-statistics of 0.928 and 0.835 in patients younger than 45 and 85 and older, respectively). CONCLUSION Our findings demonstrate incremental increases in the risk of hospital death associated with age that was independent of severity of illness and other prognostic factors. Although the current results may be less biased by differences in treatment goals than studies of general hospitalized patients, the lower discrimination of physiology scores in older patients suggests that unmeasured factors (e.g., functional status, patient preferences for care, differences in physician practices) may be of greater prognostic importance in older than in younger patients.
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Barnett MJ, Kaboli PJ, Sirio CA, Rosenthal GE. Day of the week of intensive care admission and patient outcomes: a multisite regional evaluation. Med Care 2002; 40:530-9. [PMID: 12021679 DOI: 10.1097/00005650-200206000-00010] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Relationships between day of the week of admission to hospitals and hospital outcomes have been poorly studied. Intensive care units (ICUs) appear to be uniquely suited to examine such a question given the unpredictability of ICU admissions and the clinical instability of their patient populations. METHODS This retrospective cohort study included 156,136 patients admitted to 38 ICUs in 28 hospitals in a large Midwestern metropolitan area during 1991 to 1997. Demographic and clinical data were collected from patients' medical records and used in multivariable risk-adjustment models that examined the risk for in-hospital death and ICU length of stay. RESULTS The adjusted odds of in-hospital death were 9% higher (OR 1.09; 95% CI, 1.04-1.15; P <0.001) for weekend admissions (Saturday or Sunday) than in patients admitted midweek (Tuesday through Thursday). However, the adjusted odds of death were also higher (P <0.001) for patients admitted on Monday (OR 1.09) or Friday (OR 1.08). Findings were generally similar in analyses stratified by admission type (medical vs. surgical), hospital teaching status, and illness severity. Adjusted ICU length of stay was 4% longer (P <0.001) for weekend or Friday admissions, compared with midweek admissions. CONCLUSIONS Patients admitted to an ICU on the weekend have a modestly higher risk for death and ICU length of stay. However, the similar risk for death in patients admitted on Friday and Monday suggests that "weekend effects" may be more related to unmeasured severity of illness and/or selection bias than to differences in quality of care.
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Kaboli PJ, Barnett MJ, Fuehrer SM, Rosenthal GE. Length of stay as a source of bias in comparing performance in VA and private sector facilities: lessons learned from a regional evaluation of intensive care outcomes. Med Care 2001; 39:1014-24. [PMID: 11502958 DOI: 10.1097/00005650-200109000-00011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Compare intensive care unit (ICU) mortality and length of stay (LOS) in a VA hospital and private sector hospitals and examine the impact of hospital utilization on mortality comparisons. RESEARCH DESIGN Retrospective cohort study. SUBJECTS Consecutive ICU admissions to a VA hospital (n = 1,142) and 27 private sector hospitals (n = 51,249) serving the same health care market in 1994 to 1995. MEASURES Mortality and ICU LOS were adjusted for severity of illness using a validated method that considers physiologic data from the first 24 hours of ICU admission. Mortality comparisons were made using two different multivariable techniques. RESULTS Unadjusted in-hospital mortality was higher in VA patients (14.5% vs. 12.0%; P = 0.01), as was hospital (28.3 vs. 11.3 days; P <0.001) and ICU (4.3 vs. 3.9 days; P <0.001) LOS. Using logistic regression to adjust for severity, the odds of death was similar in VA patients, relative to private sector patients (OR 1.16, 95% CI 0.93-1.44; P = 0.18). However, a higher proportion of VA deaths occurred after 21 hospital days (33% vs. 13%; P <0.001). Using proportional hazards regression and censoring patients at hospital discharge, the risk for death was lower in VA patients (hazard ratio 0.70; 95% CI 0.59-0.82; P <0.001). After adjusting for severity, differences in ICU LOS were no longer significant (P = 0.19). CONCLUSIONS Severity-adjusted mortality in ICU patients was lower in a VA hospital than in private sector hospitals in the same health care market, based on proportional hazards regression. This finding differed from logistic regression analysis, in which mortality was similar, suggesting that comparisons of hospital mortality between systems with different hospital utilization patterns may be biased if LOS is not considered. If generalizable to other markets, our findings further suggest that ICU outcomes are at least similar in VA hospitals.
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Barnett MJ, Fisher RF, Jones T, Komp C, Abola AP, Barloy-Hubler F, Bowser L, Capela D, Galibert F, Gouzy J, Gurjal M, Hong A, Huizar L, Hyman RW, Kahn D, Kahn ML, Kalman S, Keating DH, Palm C, Peck MC, Surzycki R, Wells DH, Yeh KC, Davis RW, Federspiel NA, Long SR. Nucleotide sequence and predicted functions of the entire Sinorhizobium meliloti pSymA megaplasmid. Proc Natl Acad Sci U S A 2001; 98:9883-8. [PMID: 11481432 PMCID: PMC55547 DOI: 10.1073/pnas.161294798] [Citation(s) in RCA: 208] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The symbiotic nitrogen-fixing soil bacterium Sinorhizobium meliloti contains three replicons: pSymA, pSymB, and the chromosome. We report here the complete 1,354,226-nt sequence of pSymA. In addition to a large fraction of the genes known to be specifically involved in symbiosis, pSymA contains genes likely to be involved in nitrogen and carbon metabolism, transport, stress, and resistance responses, and other functions that give S. meliloti an advantage in its specialized niche.
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Galibert F, Finan TM, Long SR, Puhler A, Abola P, Ampe F, Barloy-Hubler F, Barnett MJ, Becker A, Boistard P, Bothe G, Boutry M, Bowser L, Buhrmester J, Cadieu E, Capela D, Chain P, Cowie A, Davis RW, Dreano S, Federspiel NA, Fisher RF, Gloux S, Godrie T, Goffeau A, Golding B, Gouzy J, Gurjal M, Hernandez-Lucas I, Hong A, Huizar L, Hyman RW, Jones T, Kahn D, Kahn ML, Kalman S, Keating DH, Kiss E, Komp C, Lelaure V, Masuy D, Palm C, Peck MC, Pohl TM, Portetelle D, Purnelle B, Ramsperger U, Surzycki R, Thebault P, Vandenbol M, Vorholter FJ, Weidner S, Wells DH, Wong K, Yeh KC, Batut J. The composite genome of the legume symbiont Sinorhizobium meliloti. Science 2001; 293:668-72. [PMID: 11474104 DOI: 10.1126/science.1060966] [Citation(s) in RCA: 835] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The scarcity of usable nitrogen frequently limits plant growth. A tight metabolic association with rhizobial bacteria allows legumes to obtain nitrogen compounds by bacterial reduction of dinitrogen (N2) to ammonium (NH4+). We present here the annotated DNA sequence of the alpha-proteobacterium Sinorhizobium meliloti, the symbiont of alfalfa. The tripartite 6.7-megabase (Mb) genome comprises a 3.65-Mb chromosome, and 1.35-Mb pSymA and 1.68-Mb pSymB megaplasmids. Genome sequence analysis indicates that all three elements contribute, in varying degrees, to symbiosis and reveals how this genome may have emerged during evolution. The genome sequence will be useful in understanding the dynamics of interkingdom associations and of life in soil environments.
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Brümmendorf TH, Rufer N, Holyoake TL, Maciejewski J, Barnett MJ, Eaves CJ, Eaves AC, Young N, Lansdorp PM. Telomere length dynamics in normal individuals and in patients with hematopoietic stem cell-associated disorders. Ann N Y Acad Sci 2001; 938:293-303; discussion 303-4. [PMID: 11458518 DOI: 10.1111/j.1749-6632.2001.tb03598.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The telomere length in nucleated peripheral blood (PB) cells indirectly reflects the mitotic history of their precursors: the hematopoietic stem cells (HSCs). The average length of telomeres in PB leukocytes can be measured using fluorescence in situ hybridization and flow cytometry (flow FISH). We previously used flow FISH to characterize the age-related turnover of HSCs in healthy individuals. In this review, we describe results of recent flow FISH studies in patients with selected hematopoietic stem cell-associated disorders: chronic myelogenous leukemia (CML) and several bone marrow failure syndromes. CML is characterized by a marked expansion of myeloid Philadelphia chromosome positive (Ph+) cells. Nevertheless, nonmalignant (Ph-) HSCs typically coexist in the bone marrow of CML patients. We analyzed the telomere length in > 150 peripheral blood leukocytes (PBLs) and bone marrow samples of patients with CML as well as samples of Ph- T-lymphocytes. Compared to normal controls, the overall telomere fluorescence in PBLs of patients with CML was significantly reduced. However, no telomere shortening was observed in Ph- T-lymphocytes. Patients in late chronic phase (CP) had significantly shorter telomeres than those assessed earlier in CP. Our data suggest that progressive telomere shortening is correlated with disease progression in CML. Within the group of patients with bone marrow failure syndromes, we only found significantly shortened telomeres (compared to age-adjusted controls) in granulocytes from patients with aplastic anemia (AA). Strikingly, the telomere length in granulocytes from AA patients who had recovered after immunosuppressive therapy (recAA) did not differ significantly from controls, whereas untreated patients and nonresponders with persistent severe pancytopenia (sAANR) showed marked and significant telomere shortening compared to healthy donors and patients with recAA. Furthermore, an inverse correlation between age-adjusted telomere length and peripheral blood counts was found in support of a model in which the degree of cytopenia and the amount of telomere shortening are correlated. These results support the concept of extensive proliferation of HSCs in subgroups of AA patients and suggest a potential use of telomere-length measurements as a prognostic tool in this group of disorders as well.
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MESH Headings
- Anemia, Aplastic/blood
- Anemia, Aplastic/pathology
- Animals
- Blood Cells/ultrastructure
- Cell Division
- Cellular Senescence
- Fanconi Anemia/blood
- Fanconi Anemia/pathology
- Flow Cytometry
- Hemoglobinuria, Paroxysmal/blood
- Hemoglobinuria, Paroxysmal/pathology
- Humans
- In Situ Hybridization, Fluorescence
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/blood
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Mice
- Mice, Knockout
- Myelodysplastic Syndromes/blood
- Myelodysplastic Syndromes/pathology
- Neoplastic Stem Cells/ultrastructure
- Telomere/ultrastructure
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Barnett MJ, Hung DY, Reisenauer A, Shapiro L, Long SR. A homolog of the CtrA cell cycle regulator is present and essential in Sinorhizobium meliloti. J Bacteriol 2001; 183:3204-10. [PMID: 11325950 PMCID: PMC95222 DOI: 10.1128/jb.183.10.3204-3210.2001] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During development of the symbiotic soil bacterium Sinorhizobium meliloti into nitrogen-fixing bacteroids, DNA replication and cell division cease and the cells undergo profound metabolic and morphological changes. Regulatory genes controlling the early stages of this process have not been identified. As a first step in the search for regulators of these events, we report the isolation and characterization of a ctrA gene from S. meliloti. We show that the S. meliloti CtrA belongs to the CtrA-like family of response regulators found in several alpha-proteobacteria. In Caulobacter crescentus, CtrA is essential and is a global regulator of multiple cell cycle functions. ctrA is also an essential gene in S. meliloti, and it is expressed similarly to the autoregulated C. crescentus ctrA in that both genes have complex promoter regions which bind phosphorylated CtrA.
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68
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Eaves AC, Barnett MJ, Ponchio L, Cashman JD, Petzer AL, Eaves CJ. Differences between normal and CML stem cells: potential targets for clinical exploitation. Stem Cells 2000; 16 Suppl 1:77-83; discussion 89. [PMID: 11012149 DOI: 10.1002/stem.5530160809] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder in which there is a deregulated amplification of CML progenitors at intermediate stages of their differentiation along the myeloid, erythroid and megakaryocyte pathways. Such cell populations are routinely quantified using standard in vitro colony-forming cell (CFC) assays. The excessive production of leukemic CFC that is seen in most CML patients at diagnosis may be explained at least in part by their increased proliferative activity. An anomalous cycling behavior in vivo has also been found to extend to more primitive CML progenitor populations detectable as long-term culture-initiating cells (LTC-IC). Although the molecular basis of these changes in CML progenitor regulation is not fully understood at the level of the primitive CFC compartment, a selective inability of CML progenitors to be inhibited by certain -C-C-type chemokines has been demonstrated. Failure of the CML stem cell compartment to expand in vivo at the same rate as later progenitor cell types may be explained by their unique additional possession of an intrinsically upregulated probability of differentiation. Such a mechanism would be consistent with the observed loss of LTC-IC activity by CML cells incubated in vitro under conditions that sustain or expand normal LTC-IC populations. Initial clinical studies undertaken at our center established the feasibility of exploiting the differential behavior of primitive normal and CML cells in vitro as a potential purging strategy for reducing the leukemic stem cell content of CML marrow autografts. The results of a larger, second trial now in progress on a group of unselected patients are encouraging. Future studies of nonobese diabetic/severe-combined immunodeficiency mice engrafted with CML cells should provide another useful preclinical model for evaluating treatments that may more effectively eradicate the neoplastic clone in vivo.
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69
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Lohrisch CA, Nevill TJ, Barnett MJ, Hogge DE, Connors JM, Keown PA, Gascoyne RD. Development of a biologically distinct EBV-related lymphoproliferative disorder following autologous bone marrow transplantation for an EBV-negative post-renal allograft Burkitt's lymphoma. Leuk Lymphoma 2000; 39:195-201. [PMID: 10975399 DOI: 10.3109/10428190009053554] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Post-transplant lymphoproliferative disorder (PTLD) is a known complication of both solid organ transplantation and allogeneic bone marrow transplantation (BMT) but is rarely seen following autologous BMT. We report the case of a 45 year-old female who developed Burkitt's lymphoma eight years after a renal allograft. This PTLD was found to have lambda light chain restriction, contained del(8)(q24) and add(14)(q32), and was negative for EBV on immunohistochemical and DNA-based PCR analyses. Immunoglobulin heavy chain (IgH) PCR studies revealed a prominent clonal rearrangement. She responded to intravenous cyclophosphamide and proceeded to high-dose chemoradiotherapy and mafosfamide-purged autologous BMT. Thirty-nine days post-BMT she presented with cough and fever and developed hepatic dysfunction; abnormal lymphoplasmacytoid cells were noted in the peripheral blood. Investigations revealed kappa light chain restriction, an oligoclonal IgH rearrangement, a normal karyotype and PCR studies for EBV were positive, consistent with a clinically and biologically distinct PTLD. She initially improved following discontinuation of immunosuppression, but then deteriorated abruptly and died 58 days post-BMT. It is likely that the two separate episodes of PTLD in this patient, one of which was atypical, arose as a result of both the chronic use of cyclosporine and the impairment of cell-mediated immunity associated with autologous BMT. The sequence of events in this patient should contribute to a better understanding of late-onset, EBV-negative PTLD.
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Reece DE, Brockington DA, Phillips GL, Barnett MJ, Klingemann HG, Nantel SH, Sutherland HJ, Shepherd JD. Prolonged survival after intensive therapy and purged ABMT in patients with multiple myeloma. Bone Marrow Transplant 2000; 26:621-6. [PMID: 11041567 DOI: 10.1038/sj.bmt.1702574] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Despite numerous strategies, the cure of multiple myeloma remains a difficult challenge. Recent approaches have involved dose-intensive therapy followed by stem cell transplantation, most often with autologous stem cells (ASCT). Although ASCT is of benefit, it is not considered curative. Between 1988 and 1995, we utilized an aggressive three-drug conditioning regimen followed by ABMT using marrow purged with either 4-hydroperoxycyclophosphamide (4-HC) or mafosphamide (MAF). Twenty-nine of 42 patients who had first received VAD (14 patients) or VAD followed by cyclophosphamide (7 g/m2 i.v.) + dexamethasone (40 mg/day p.o. x4) + GM-CSF (15 patients) met the eligibility criteria needed to undergo bone marrow harvest and ABMT, ie < or =10% marrow plasma cells and > or =50% decrease in paraprotein level. Alpha-interferon maintenance therapy was given post ABMT. Median follow-up is 7.5 years (range 5.0-11.25). Six early and two late non-relapse deaths occurred; 15 patients have relapsed. Seven patients remain in continuous CR (five) or PR (two), including three with stage IIIB disease at diagnosis. One patient developed a soft tissue sarcoma 8 years post ASCT. Although this protocol produced excessive toxicity compared with current approaches, the results demonstrate that dose-intensive therapy and ASCT can produce durable remission in this disease. Further development of dose-intensive strategies is warranted.
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Barnett MJ, Oke V, Long SR. New genetic tools for use in the Rhizobiaceae and other bacteria. Biotechniques 2000; 29:240-2, 244-5. [PMID: 10948423 DOI: 10.2144/00292bm08] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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McCaul KG, Nevill TJ, Barnett MJ, Toze CL, Currie CJ, Sutherland HJ, Conneally EA, Shepherd JD, Nantel SH, Hogge DE, Klingemann HG. Treatment of steroid-resistant acute graft-versus-host disease with rabbit antithymocyte globulin. JOURNAL OF HEMATOTHERAPY & STEM CELL RESEARCH 2000; 9:367-74. [PMID: 10894358 DOI: 10.1089/15258160050079470] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Acute graft-versus-host disease (A-GVHD) is a life-threatening complication of allogeneic stem cell transplantation (SCT), and primary therapy consists of high-dose corticosteroids. Patients who fail to respond adequately to corticosteroids require salvage treatment, with anti-T cell antibodies being the most commonly utilized group of agents. We report our institution's experience treating steroid-resistant GVHD in 36 adult patients (median age 39 years, range 24-55) with a rabbit antithymocyte globulin product (thymoglobulin). Eleven patients had undergone sibling SCT (10 histocompatible, 1 one-antigen mismatched) and 25 patients had received unrelated donor bone marrow (17 matched, 8 one-antigen mismatched); 32 patients (89%) had grade III or IV A-GVHD. Thymoglobulin was administered in two different regimens; group 1 patients (n = 13) received 2.5 mg/kg/day x 4-6 consecutive days with maintenance of all other immunosuppressives. Group 2 patients (n = 21) were given the same dose of thymoglobulin on days 1, 3, 5, and 7 with discontinuation of cyclosporine for 14 days, during which the corticosteroid dose was held at 2-3 mg/kg/day. Two patients had severe adverse reactions to thymoglobulin (hypoxemia and hypotension) and could not complete treatment, however, in the other patients, aside from transient leukopenia (25%) and and hepatic dysfunction (25%), the antibody preparation was well tolerated. Of the 34 evaluable patients, 13 patients had a complete response (38%) and 7 patients (21%) had a partial response, for an overall response rate of 59%. Response rate was higher in group 1 patients (77%) compared to group 2 patients (48%), (p = 0.15); skin GVHD was more responsive (96% of patients) than gut GVHD (46% of patients) or hepatic GHVD (36% of patients). Opportunistic infections were a significant complication, with 11 patients developing systemic fungal infections and 9 patients serious viral infections; there were seven episodes of bacteremia following thymoglobulin treatment and one fatal protozoal infection. There were 9 patients (25%) who developed post-SCT lymphoproliferative disorder (PTLD) and 4 patients who had a relapse of underlying primary malignancy; none of these patients survived. Of the 36 patients entered on the study, only 2 patients (6%) survive, at 15+ and 34+ months post-unrelated donor SCT. Although thymoglobulin is associated with an impressive response rate when administered for advanced steroid-resistant GVHD, long-term survival is uncommon, even in responders, primarily due to the high risk of developing either an opportunistic infection or a PTLD.
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Zhou Y, Barnett MJ, Rivers JK. Clinical significance of skin biopsies in the diagnosis and management of graft-vs-host disease in early postallogeneic bone marrow transplantation. ARCHIVES OF DERMATOLOGY 2000; 136:717-21. [PMID: 10871932 DOI: 10.1001/archderm.136.6.717] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To determine the value of skin biopsies in the management of suspected graft-vs-host disease (GVHD) within 30 days of allogeneic bone marrow transplantation (BMT). DESIGN Retrospective study based on review of a BMT database. SETTING Leukemia/BMT ward of a tertiary care, university teaching hospital. PATIENTS One hundred and eighty-seven consecutive patients who received allogeneic BMT between January 1, 1994, and June 30, 1997, at Vancouver General Hospital, Vancouver, British Columbia. MAIN OUTCOME MEASURES (1) Skin biopsy frequency for patients with rashes suggestive of acute GVHD; (2) clinical significance of skin biopsy in the management of patients with suspected acute GVHD after BMT; (3) relationship between severity of clinical GVHD and the likelihood to receive GVHD therapy; and (4) relationship between biopsy status or biopsy result and outcome of BMT (acute and chronic GVHD, transplant-related mortality, and overall and event-free survival). RESULTS During the early post-BMT period (<30 days after BMT), 88 patients had rashes suggestive of acute GVHD; of these, 51 (58%) underwent skin biopsy to confirm the diagnosis. Skin biopsies were performed more often for higher clinical stages of cutaneous GVHD. There was no significant difference between the patients with positive biopsy findings and those with negative findings, either in the clinical severity of acute GVHD or in likelihood to receive treatment for GVHD. Most (85%) of the patients who underwent biopsies and received GVHD therapy had treatment initiated before skin biopsies were performed or before the results were available. The higher the clinical grade of overall acute GVHD, the more likely it was that the patients were treated for GVHD (P<.001). The outcome of BMT was not influenced by the skin biopsy status or biopsy result. CONCLUSIONS The biopsy findings correlated poorly with the clinical severity of skin rash suggestive of acute GVHD soon after BMT. The decision to treat suspected acute GVHD depended not on skin biopsy findings but rather on clinical severity of acute GVHD. In this regard, skin biopsy has a limited role in the management of patients early after allogeneic BMT.
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Neumark-Sztainer D, Rock CL, Thornquist MD, Cheskin LJ, Neuhouser ML, Barnett MJ. Weight-control behaviors among adults and adolescents: associations with dietary intake. Prev Med 2000; 30:381-91. [PMID: 10845747 DOI: 10.1006/pmed.2000.0653] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND This study aimed to assess the prevalence of weight-control behaviors and their associations with overall dietary intake among adults and adolescents. METHODS Participants included 3,832 adults and 459 adolescents from four regions of the United States. Cross-sectional data were collected on energy and nutrient intake, weight-control behaviors, body mass index (BMI), and sociodemographics. RESULTS Current weight-control behaviors were reported by 52.7% of the study population (adult women, 56.7%; adult men, 50.3%; adolescent girls, 44.0%; adolescent boys, 36.8%). Weight-control behaviors were consistently and positively associated with socioeconomic status among adults, but not among adolescents. Among "dieters," unhealthy practices were reported by 22.7% of adult women, 21.3% of adult men, 30.4% of adolescent girls, and 18.5% of adolescent boys. Adults trying to control their weight reported healthier nutrient intakes than those not trying to control their weight, in particular when moderate weight-control methods were employed. Among adolescents, there were fewer differences across dieting status and these were not suggestive of healthier intakes among dieters than nondieters. CONCLUSIONS Weight-control behaviors are reported by a large percentage of the population. Weight-control behaviors tend to be healthier among adults than among adolescents, in terms of the types of behaviors used and their impact on nutrient intakes. Obesity prevention interventions should emphasize the importance of using healthy weight-control practices.
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Toze CL, Shepherd JD, Connors JM, Voss NJ, Gascoyne RD, Hogge DE, Klingemann HG, Nantel SH, Nevill TJ, Phillips GL, Reece DE, Sutherland HJ, Conneally EA, Barnett MJ. Allografting for indolent lymphoid neoplasms. Ann Oncol 2000; 11 Suppl 1:59-61. [PMID: 10707781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
BACKGROUND Allogeneic bone marrow transplantation (BMT) has been used in patients with low-grade lymphoma (LGL) and chronic lymphocytic leukemia (CLL) with the goal of achieving long-term disease-free survival. PATIENTS AND METHODS Twenty-nine patients with these diagnoses (LGL = 19, CLL = 10) received allogeneic BMT between September 1995 and January 1999. Median age was 42 (range 20-52) years. Twenty-three of twenty-nine patients (79%) were Ann Arbor or Rai stage IV at the time of transplant; twenty-four (83%) had never achieved complete remission (CR). Donor source was HLA-matched sibling (20), unrelated (8) and syngeneic (1). RESULTS Seventeen patients are currently alive, a median of 29 months (range 1-85) post-BMT with a median KPS of 90%. Twenty-three of twenty-seven evaluable patients (85%) achieved CR post-BMT. Six patients had refractory/recurrent disease. Death occurred related to transplant complications in eight patients and underlying disease in four. Overall and event-free survival for the whole group is 51% and 44%, respectively. CONCLUSIONS Allogeneic BMT for young patients with advanced stage LGL or CLL is a feasible strategy that can result in achievement of long-term disease-free survival.
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