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Biomedical subjects

H J Deeg

Publications and source records attributed to H J Deeg.

At least 73 records · Page 4Linked to original sources
PubMed1999

Dose rate-dependent marrow toxicity of TBI in dogs and marrow sparing effect at high dose rate by dose fractionation.

We evaluated the marrow toxicity of 200 and 300 cGy total-body irradiation (TBI) delivered at 10 and 60 cGy/min, respectively, in dogs not rescued by marrow transplant. Additionally, we compared toxicities after 300 cGy fractionated TBI (100 cGy fractions) to that after single-dose TBI at 10 and 60 cGy/min. Marrow toxicities were assessed on the basis of peripheral blood cell count changes and mortality from radiation-induced pancytopenia. TBI doses studied were just below the dose at which all dogs die despite optimal support. Specifically, 18 dogs were given single doses of 200 cGy TBI, delivered at either 10 (n=13) or 60 (n=5) cGy/min. Thirty-one dogs received 300 cGy TBI at 10 cGy/min, delivered as either single doses (n=21) or three fractions of 100 cGy each (n=10). Seventeen dogs were given 300 cGy TBI at 60 cGy/min, administered either as single doses (n=5) or three fractions of 100 cGy each (n=10). Within the limitations of the experimental design, three conclusions were drawn: 1) with 200 and 300 cGy single-dose TBI, an increase of dose rate from 10 to 60 cGy/min, respectively, caused significant increases in marrow toxicity; 2) at 60 cGy/min, dose fractionation resulted in a significant decrease in marrow toxicities, whereas such a protective effect was not seen at 10 cGy/min; and 3) with fractionated TBI, no significant differences in marrow toxicity were seen between dogs irradiated at 60 and 10 cGy/min. The reduced effectiveness of TBI when a dose of 300 cGy was divided into three fractions of 100 cGy or when dose rate was reduced from 60 cGy/min to 10 cGy/min was consistent with models of radiation toxicity that allow for repair of sublethal injury in DNA.

Animals↗
PubMed1999

Marrow transplantation from unrelated donors for patients with severe aplastic anemia who have failed immunosuppressive therapy.

Allogeneic marrow transplantation offers curative therapy for patients with aplastic anemia. We analyzed retrospective results in 141 patients with severe aplastic anemia who received transplants between 1988 and 1995 from an unrelated volunteer donor identified through the National Marrow Donor Program (NMDP). All patients had failed one or more courses of immunosuppressive therapy. Of the patients, 121 (86%) received a radiation-containing conditioning regimen, and 20 (14%) were given chemotherapy only. Based on serologic human leukocyte antigen (HLA) typing (class I and II), 105 patients (74%) received HLA-matched marrow, and 36 (26%) received marrow mismatched for at least one HLA-A, -B, or -DR antigen. Allele-level (molecular) typing for HLA-DRB1 was available in 108 donor-recipient pairs; 77 patients received DRB -matched and 31 DRB1-mismatched transplants. All but 13% of patients were given a cyclosporine-containing regimen for graft-vs.-host disease (GVHD) prophylaxis, and 45 patients (32%) received marrow that was T cell-depleted. Among 131 evaluable patients, 116 (89%) achieved sustained engraftment and 15 (11%) did not. Among patients with engraftment, acute GVHD of grades II-IV developed in 60 patients (52%) and extensive chronic GVHD in 24 patients at risk (31%). Currently, 51 patients (36%) are surviving at 11-94 months (median 36) after transplantation. All but five have Karnofsky scores > or =80. Patients who received a serologically matched transplant fared somewhat better than did patients given a serologically mismatched transplant p = 0.03). Patients with donors matched by both serology and allele-level DRB1 typing had significantly better survival than DRB1-mismatched patients with 56 vs. 15% surviving at 3 years p = 0.001). Outcome in patients transplanted within 3 years of diagnosis was superior to that among patients transplanted with greater delay. Major causes of death were graft failure, GVHD, and infections. These data suggest that unrelated marrow transplantation offers successful therapy for a proportion of patients who have failed immunosuppressive therapy.

Adolescent↗
PubMed1999

Increased incidence of Hodgkin's disease after allogeneic bone marrow transplantation.

PURPOSE: Immune dysregulation associated with allogeneic bone marrow transplantation (BMT) is linked to an increased risk of posttransplant lymphoproliferative disorders (PTLD); however, reports of Hodgkin's disease (HD) after transplantation are rare. PATIENTS AND METHODS: We evaluated the risk of HD among 18,531 persons receiving allogeneic BMT between 1964 and 1992 at 235 centers. The number of HD cases was compared with that expected in the general population. Risk factors were identified using Poisson regression and a nested case-control study. RESULTS: Risk of HD was increased in the postBMT population compared with the general population with an observed-to-expected incidence ratio (O/E) of 6.2 (observed cases, n = 8; 95% confidence interval [CI], 2.7 to 12). A significantly increased risk of HD remained after excluding two human immunodeficiency virus-positive patients (observed cases, n = 6; O/E = 4.7, 95% CI, 1.7 to 10.3). Mixed cellularity subtype predominated (five of eight cases, 63%). Five of six assessable cases contained Epstein-Barr virus (EBV) genome. Posttransplant HD differed from PTLD by later onset (> 2.5 years) and lack of association with established risk factors (such as T-cell depletion and HLA disparity). Patients with HD were more likely than matched controls to have had grade 2 to 4 acute graft-versus-host disease (GVHD), required therapy for chronic GVHD, or both (P =.002), although analysis included small numbers of patients. CONCLUSION: The increased incidence of HD among BMT recipients adds support to current theories which link overstimulation of cell-mediated immunity and exposure to EBV with various subtypes of HD. The long latency of HD after transplant and lack of association with risk factors for PTLD is noteworthy and should be explored further for possible insights into pathogenesis.

Adolescent↗
PubMed1999

Allogeneic bone marrow transplantation for secondary leukemia or myelodysplasia.

BACKGROUND AND OBJECTIVE: Marrow transplantation results in disease-free survival for less than one-third of patients treated for secondary leukemia. The objective of this report is to review results following allogeneic marrow transplantation for treatment of secondary leukemia or myelodysplasia at a single tertiary referral center to determine the patient characteristics which lead to better survival and lower relapse. DESIGN AND METHODS: The medical records of 99 patients with secondary leukemia or myelodysplasia transplanted consecutively at the Fred Hutchinson Cancer Research Center between 1971 and 1997 were reviewed. Prior to development of secondary leukemia or myelodysplasia, the patients' original diagnoses were hematopoietic malignancies, solid tumors, aplastic anemia, or miscellaneous individual disorders previously treated by chemotherapy alone, radiation alone, chemoradiotherapy, or immunosuppressive therapy. At the time of transplantation, at each stage of myelodysplasia the numbers of patients were 52 with acute myelogenous leukemia (AML), 15 with refractory anemia with excess blasts in transition (RAEB-T), 18 with refractory anemia with excess blasts (RAEB), 11 with refractory anemia (RA), 1 with refractory anemia with ringed sideroblasts (RARS), and 2 with hypoplastic unclassifiable hematologic disorders. Sixty-five patients received marrow from an HLA identical or partially identical family member, and 34 received marrow from an HLA identical unrelated donor after conditioning with chemotherapy and total body irradiation or chemotherapy alone. RESULTS: The Kaplan-Meier probability of survival after transplantation for all patients was 13%, and by stage of disease was 33% for RA/RARS, 20% for RAEB, and 8% for RAEB-T/AML. The probability of relapse for all patients was 47%, was 34% for RAEB, and 58% for RAEB-T/AML. None of the patients with RA/RARS has relapsed. The overall probability of non-relapse mortality was 78%, divided equally among infection or organ failure-related causes of death. INTERPRETATION AND CONCLUSIONS: The main impediments to long-term survival after transplantation for secondary leukemia or myelodysplasia are relapse and mortality from infections or organ failure. The survival is better when transplantation is done during the early stages of myelodysplasia because it is then associated with a lower relapse rate. These data suggest that patients at risk of secondary myelodysplasia should be followed prospectively to detect the early stages of myelodysplasia, and be considered for transplantation at that time.

Adolescent↗
PubMed1998

New somatic mutation in the PIG-A gene emerges at relapse of paroxysmal nocturnal hemoglobinuria.

We report a detailed longitudinal study of the first patient to be treated (in 1973) for paroxysmal nocturnal hemoglobinuria (PNH) with syngeneic bone marrow transplantation (BMT). The patient subsequently relapsed with PNH in 1983, and still has PNH to date. Analysis of the PIG-A gene in a recent blood sample showed in exon 6 an insertion-duplication causing a frameshift. Polymerase chain reaction (PCR) amplification of the PIG-A exon 6 from bone marrow (BM) slides obtained before BMT showed that the duplication was not present; instead, we found several single base pair substitutions in exons 2 and 6. Thus, relapse of PNH in this patient was not due to persistence of the original clones; rather, it was associated with the emergence of a new clone. These findings support the notion that the BM environment may create selective conditions favoring the expansion of PNH clones.

Adolescent↗
PubMed1998

Current and future preparative regimens for bone marrow transplantation in thalassemia.

Preparative regimens for marrow allografts in thalassemia have two objectives. One is eradication of diseased marrow and the other suppression of host-versus-graft (HVG) reactions so that the allograft survives. A common regimen to accomplish these goals has combined high-dose busulfan with cyclophosphamide. Postgrafting immunosuppression with cyclosporine/methotrexate has been used for GVHD prevention. Some patients may die from regimen-related toxicity. Overall event-free survival is 75%. Occasional patients have become mixed donor/host hematopoietic chimeras and, yet, disease symptoms have abated. This has raised the possibility of developing safer and less toxic transplant programs that result in stable mixed hematopoietic chimerism. We have devised such a program in dogs consisting of a nonlethal dose of total body irradiation (200 cGy) before and a novel combination of mycophenolate mofetil and cyclosporine after transplant. Mixed donor/host chimerism (> or = 50% donor cells in all lineages) has persisted for > 80 weeks, even though immunosuppression was discontinued after five weeks.

Animals↗
PubMed1998

Long-term outcome after marrow transplantation for severe aplastic anemia.

We reviewed the records and reevaluated 212 patients with aplastic anemia transplanted at the Fred Hutchinson Cancer Research Center (FHCRC) between 1970 and 1993 who survived >/=2 years and who have been followed for up to 26 years. Parameters analyzed included hematopoietic function, chronic graft-versus-host disease (GVHD), skin disease, cataracts, lung disease, skeletal problems, posttransplant malignancy, depression, pregnancy/fatherhood, and the return to work or school, as well as patient self-assessment of physical and psychosocial health, social interactions, memory and concentration, and overall severity of symptoms. Survival probabilities at 20 years were 89% for patients without (n = 125) and 69% for patients with chronic GVHD (n = 86) (the status was uncertain in 1 surviving patient). All patients had normal hematopoietic parameters. Skin problems occurred in 14%, cataracts in 12%, lung disease in 24%, and bone and joint problems in 18% of patients. Eleven patients (12%) developed a solid tumor malignancy and 19% of patients experienced depression. Chronic GVHD was the dominant risk factor for late complications. Seventeen patients died at 2.5 to 20.4 years posttransplant; 13 of these had chronic GVHD and related complications. At 2 years, 83% of patients had returned to school or work; the proportion increased to 90% by 20 years. At least half of the patients preserved or regained the ability to become pregnant or father children. Patients rated their quality of life as excellent and symptoms as minimal or mild. In conclusion, marrow transplantation in patients with aplastic anemia established long-term normal hematopoiesis. No new hematologic disorders occurred. The major cause of morbidity and mortality was chronic GVHD. However, the majority of patients who survived beyond 2 years returned to a fully functional life.

Anemia, Aplastic↗
PubMed1998

Synergism between mycophenolate mofetil and cyclosporine in preventing graft-versus-host disease among lethally irradiated dogs given DLA-nonidentical unrelated marrow grafts.

Mycophenolate mofetil (MMF) was evaluated either alone or combined with cyclosporine (CSP) for preventing graft-versus-host disease (GVHD) in dogs given 9.2 Gy total body irradiation and DLA-nonidentical unrelated marrow grafts. Marrow autograft studies showed gut toxicity as limiting MMF side effects. Four groups were studied for GVHD prevention: six dogs in group 1 received MMF 10 mg/kg twice daily subcutaneously (SC) on days 0 to 27. They died between 8 to 28 days from infection or GVHD; survival was better than that of 72 controls given no immunosuppression (P = .04), but not different from 19 dogs given CSP. Four dogs in group 2 received MMF as described, along with CSP at 10 to 15 mg/kg twice daily on days 0 to 27. They died at 6 to 98 days from CSP-associated toxicity, weight loss, or infection. Nine dogs in group 3 received MMF SC twice daily 6 mg/kg/d for 3 days, followed by 10 mg/kg twice daily until day 27, along with CSP as described; four died between 7 to 106 days with intussusception, infection, or GVHD, and five became long-term survivors. Six dogs in group 4 received shortened MMF (21 days) and reduced doses of CSP given through day 100. Three died with GVHD or infection between days 38 to 119, and three became long-term survivors. Results support the notion of synergism between MMF and CSP, as evidenced by stable graft-host tolerance in greater than 50% of dogs.

Animals↗
PubMed1998

Dose rate-dependent sparing of the gastrointestinal tract by fractionated total body irradiation in dogs given marrow autografts.

PURPOSE: We compared gastrointestinal toxicity of single vs. fractionated total body irradiation (TBI) administered at dose rates ranging from 0.021 to 0.75 Gy/min in a canine model of marrow transplantation. METHODS AND MATERIALS: Dogs were given otherwise marrow-lethal single or fractionated TBI from dual 60Co sources at total doses ranging from 8-18 Gy and delivered at dose rates of 0.021, 0.05, 0.10, 0.20, 0.40, and 0.75 Gy/min, respectively. They were protected from marrow death by infusion of previously stored autologous marrow cells and they were given intensive supportive care posttransplant. The study endpoint was 10-day mortality from gastrointestinal toxicity. Logistic regression analyses were used to jointly evaluate the effects of dose rate, total dose, and delivery regimen on toxicity. RESULTS AND CONCLUSION: With increasing dose rates, mortality increased for either mode of delivery of TBI. With dose rates through 0.10 Gy/min, mortality among dogs given single vs. fractionated TBI appeared comparable. Beginning at 0.20 Gy/min, fractionation appeared protective for the gastrointestinal tract. Results in dogs given TBI at 0.40 and 0.75 Gy/min, respectively, were comparable, and dose fractionation permitted the administration of considerably higher total doses of TBI than were possible after single doses, an increment that was on the order of 4.00 Gy. The data indicate that the impact of fractionating the total dose at high dose rates differs from the effect of fractionation at low dose rates.

Animals↗
PubMed1998

Reproducibility in retrospective grading of acute graft-versus-host disease after allogeneic marrow transplantation.

We have undertaken a formal study to evaluate the reproducibility of retrospective assessments for grading the severity of acute GVHD. Using criteria previously established by the Seattle group, three reviewers independently assigned GVHD severity grades for a set of 100 marrow transplant patients. Significant differences were found in the distribution of GVHD grades assigned by one of the reviewers as compared to the other two reviewers. In only 40% of cases did all three reviewers assign the same GVHD grade, and in only 68-71% of cases did all three reviewers assign the same grade within 0-I vs II-IV or 0-II vs III-IV categories. Despite the high rate of disagreement between any two reviewers, at least two reviewers assigned the same overall GVHD grade in 93% of cases. These results suggest that current criteria for assessing the severity of GVHD by a single reviewer are not sufficiently reliable for rigorous clinical studies. As an alternative to the original criteria, we have developed and tested simplified criteria that summarize the clinical course of GVHD as reflected by the progression of disease and the amount of immunosuppressive treatment used to control the disease. Our results suggest that the revised criteria might yield more reproducible retrospective grading than the original criteria. Although the original criteria and the revised criteria might produce different results for individual patients, the overall distributions of grades with the two systems were similar. The proposed revised criteria could be implemented without disrupting the continuity and consistency with previous grading assigned by the original criteria.

Bone Marrow Transplantation↗
PubMed1998

A role for tumour necrosis factor-alpha, Fas and Fas-Ligand in marrow failure associated with myelodysplastic syndrome.

Apoptosis of haemopoietic cells in the marrow of patients with myelodysplastic syndrome (MDS) has been suggested as a mechanism for peripheral cytopenias. We determined the expression of Fas (CD95), Fas-Ligand (Fas-L) and TNF-alpha factors known to be involved in apoptosis, in the marrow of 44 patients with MDS and characterized their functional relevance in in vitro assays of haemopoiesis. Multidimensional flow cytometry revealed phenotypically aberrant blasts as defined by orthogonal light scatter and CD45 expression in the marrow of 24/44 patients. Among those blasts Fas expression was increased on CD34-positive cells and on cells co-expressing HLA-DR. In addition, Fas-L was expressed on some CD34+ cells of MDS patients but was never detected on CD34+ cells in normal marrow. Fas and Fas-L mRNAs as well as mRNA for TNF-alpha, known to increase Fas expression in normal marrow, were up-regulated in patients with MDS. TNF-alpha protein and sTNF-R1 levels in marrow plasma were higher in MDS patients than in controls (P<0.002 and <0.003, respectively). However, results were dependent upon disease category: TNF-alpha levels were significantly higher in patients with refractory anaemia (RA) than in patients with RA with excess blasts (RAEB) or RAEB in transformation (RAEB-T) (P=0.043). Conversely, the proportion of Fas-L-positive cells was lowest in patients with RA (P=0.037). In marrow cultures, Fas-Ig, rhuTNFR:Fc or anti-TNF-alpha antibody, by blocking Fas or TNF mediated signals, respectively, significantly increased the numbers of haemopoietic colonies compared to untreated cells (P<0.001, P<0.003, P<0.001, respectively). These results show significant dysregulation in the expression of TNF-alpha, Fas and Fas-L in the marrow from MDS patients. Altered expression of these molecules appears to be of functional relevance in the dysregulation of haemopoiesis in MDS and may be amenable to therapeutic interventions.

Adolescent↗
PubMed1998

MHC class II and negative regulators of hematopoiesis.

HLA-DR antigens a side from their antigen-presenting function have recently been shown to allow for transmembrane signaling. Findings in several models suggest that such a signaling function may occur in hematopoietic tissues. Signals generated via HLA-DR result in upregulation of tumor necrosis factor alpha (TNF-alpha) and nitric oxide as well as an enhanced expression of Fas and its natural ligand (Fas-L), all molecules associated with programmed cell death (apoptosis). While a role of HLA-DR in hematopoietic failure remains hypothetical, the data presented here can be accommodated into a model of hematopoietic failure initiated by HLA-DR mediated signals.

Animals↗
PubMed1997

HLA-DR-triggered inhibition of hemopoiesis involves Fas/Fas ligand interactions and is prevented by c-kit ligand.

The function of MHC class II (HLA-DR) Ags in hemopoiesis is not well defined. Here we investigated the effect of anti-HLA-DR mAb H81.9 on human marrow cells. mAb H81.9 inhibited colony formation from purified CD34+ marrow cells in long term culture-initiating cell assays. Inhibition was prevented, however, if c-kit ligand (stem cell factor (SCF)) was added to cultures concurrently with H81.9. DNA histograms from cultured untreated marrow mononuclear cells showed 2+/-1.2% apoptotic nuclei, whereas 14.1+/-5.4% were apoptotic after 12-h exposure to mAb H81.9. The apoptotic peak was reduced to 1.2+/-0.8% when SCF was added to cultures concurrently with mAb H81.9. The addition of Fas-Ig, a fusion protein that neutralizes Fas ligand (Fas-L), also prevented mAb H81.9-induced apoptosis. As determined by terminal deoxynucleotidyl transferase assays, agonistic anti-Fas mAb also induced apoptosis (in 13+/-4% of cells), and combined treatment with anti-Fas mAb and H81.9 was additive (27% apoptotic nuclei). The extent of apoptosis induced by anti-Fas mAb was significantly reduced by SCF. After H81.9 exposure, Fas was up-regulated on CD34+ cells, and Fas-L expression was 2.5-fold higher than in controls or CD34- cells, particularly within a small cell window with low orthogonal scatter (lymphocyte gate). These findings show that HLA-DR-mediated signals inhibit hemopoiesis in human marrow by a mechanism involving Fas/Fas-L-dependent signals that are blocked by c-kit ligand. These data suggest a possible role for MHC class II molecules in the regulation of hemopoiesis.

Antibodies, Monoclonal↗
PubMed1997

HLA-DR-mediated signals for hematopoiesis and induction of apoptosis involve but are not limited to a nitric oxide pathway.

Cross-linking of major histocompatibility complex (MHC) class II antigens by anti-HLA-DR monoclonal antibody (MoAb; H81.9; IgG2a) results in inhibition of hematopoiesis in canine and human models. Inhibition of hematopoiesis is associated with apoptosis in a proportion of marrow cells. Since in murine macrophages class II cross-linking triggers nitric oxide (NO) production, and NO is thought to affect regulation of hematopoiesis, we investigated whether NO was involved in our models. In murine J774 monocytes/macrophages, MoAb H81.9 did induce NO. NO production was blocked by N(G)-monomethyl-L-arginine (NMMA), an inhibitor of NO synthase (NOS), and by the antioxidant N-acetylcysteine (NAC). In human and canine long-term marrow cultures (LTMCs) and in enriched marrow monocytes, however, no measurable increase in NO production was noted after H81.9 exposure. Nevertheless, NAC protected LTMCs against H81.9 induced inhibition of hematopoiesis. Therefore, we determined the effect of an exogenous NO donator, sin-1 (3-morpholinosydnonimine), on canine and human LTMCs and on apoptosis. Sin-1 at concentrations > or =100 microg/mL inhibited LTMCs and induced apoptosis; at low concentrations (1 microg/mL), however, sin-1 stimulated the generation of colony-forming unit granulocyte-macrophage. Combined treatment with sin-1 at 100 microg/mL and MoAb H81.9 resulted in profound inhibition of hematopoiesis in both canine and human LTMCs, and had an additive effect on apoptosis. At 1 microg/mL sin-1 counteracted the effect of H81.9 on hematopoiesis. The effect of sin-1 on apoptosis and hematopoiesis in LTMC was largely prevented by NAC. These results are consistent with the hypothesis that HLA-DR mediated apoptosis and inhibition of hematopoiesis involve oxidative stress. However, the biphasic response of hematopoiesis to sin-1 suggests a complex regulatory network possibly related to differences in NO sensitivity of distinct subpopulations of cells. Signals in addition to NO appear to be involved in the effect of anti-HLA-DR MoAb on hematopoiesis.

Animals↗