Immunogenicity of Ly5 (CD45)-antigens hampers long-term engraftment following minimal conditioning in a murine bone marrow transplantation model

Various techniques are available for distinguishing donor from host cells evaluating the efficacy of conditioning regimen for experimental bone marrow transplantation (BMT). Techniques include the use of extracellular immunological markers, such as Ly5 (CD45), and intracellular biochemical markers, such as glucose-phosphate-isomerase (Gpi). Because Ly5 is an extracellular protein, the disparity between donor (Ly5.1) and host (Ly5.2) antigens may induce a weak immune response whereas with Gpi, no immune response is expected. This difference may be of particular concern in experimental transplantation approaches that use minimal conditioning such as low-dose total body irradiation (TBI). Such mild conditioning may not induce the immunosuppression required to overcome host rejection of Ly5 disparate cells. To compare the relative engraftment of Ly5.1 and Gpi-1(a) donor marrow, B6 (Gpi-1(b)/Ly5.2) mice were irradiated with low-level TBI (0-6 Gy) and transplanted with several bone marrow (BM) doses (2 x 10(6)-5 x 10(7) cells). At 8, 26, and 52 weeks post-BMT, the level of donor engraftment was measured using flow cytometry (Ly5) or Gpi-electrophoresis. Lower engraftment levels were found in mice transplanted with Ly5 congenic BM in groups given low-dose TBI (< or = 4 Gy) and/or low doses of BM cells (BMC) (2 x 10(6)). However, when higher TBI or BMC doses were used, similar engraftment levels were found, suggesting sufficient immune suppression to allow equal engraftment of both sources of BM. These data suggest that even a minor phenotypic disparity between donor and host, such as Ly5, may necessitate high-dose TBI to prevent rejection. The combination of low-dose TBI or other nonmyeloablative conditioning strategies with small numbers of BMC may lead to reduced engraftment when extracellular immunological markers such as Ly5 are used for transplantation studies. Therefore, small immunological differences must be considered when using the Ly5 marker for engraftment.     

Long-Term Outcomes of Patients with Acute Myelogenous Leukemia Treated with Myeloablative Fractionated Total Body Irradiation TBI-Based Conditioning with a Tacrolimus- and Sirolimus-Based Graft-versus-Host Disease Prophylaxis Regimen: 6-Year Follow-Up from a Single Center

Cyclophosphamide (Cy)/etoposide combined with fractionated total body irradiation (FTBI) or i.v. busulfan (Bu) has been the main conditioning regimens for allogeneic hematopoietic cell transplantation (alloHCT) for young patients with acute myelogenous leukemia (AML) eligible for a myeloablative conditioning (MAC) regimen. Recent data has suggested that i.v. Bu could be the preferred myeloablative regimen in patients with myeloid malignancies. However, Bu-based regimens are associated with higher rates of sinusoidal obstruction syndrome. Here we report long-term survival outcomes of patients with AML receiving FTBI combined with Cy or etoposide before undergoing alloHCT at City of Hope (COH). We obtained a retrospective review of a prospectively maintained institutional registry of clinical outcomes in 167 patients (median age, 41 years; range, 18 to 57 years) with AML in first or second complete remission who underwent alloHCT at COH between 2005 and 2015. Eligible patients received a MAC regimen with FTBI (1320 cGy) and Cy (120 mg/kg) for unrelated donor transplantation or etoposide (60 mg/kg) for related donor transplantation. Graft-versus-host disease (GVHD) prophylaxis was provided with tacrolimus and sirolimus. In this retrospective study, 6-year overall survival was 60% and nonrelapse mortality was 15%. The GRFS rate was 45% at 1 year and 39% at 2 years. We also describe late metabolic effects and report the cumulative incidence of secondary malignancies (9.5%). Overall, in this young adult patient population, our results compare favorably to chemotherapy-based (i.v. Bu) conditioning regimens without significant long-term toxicity arising from TBI-based regimens.     

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.     

Relapse after allogeneic bone marrow transplantation for refractory anemia is increased by shielding lungs and liver during total body irradiation.

Patients with the refractory anemia (RA) subtype of myelodysplastic syndrome who undergo allogeneic bone marrow transplantation (BMT) have a low risk of relapse, but they have a high risk of nonrelapse mortality when prepared with conventional preparative regimens. To try to reduce nonrelapse mortality, we treated 14 RA patients with a modified approach to total body irradiation (TBI) followed by cyclophosphamide (CY) and HLA-identical sibling BMT. Median patient age was 44 years (range, 28 to 65 years). Patients received TBI with shielding of the right lobe of the liver and both lungs followed by electron beam boosts to shielded ribs. Total radiation exposure in nonshielded areas was 12 Gy (n = 10), 10 Gy (n = 3), or 6 Gy (n = 1). After TBI, patients received CY at 120 mg/kg over 2 days, followed by transplantation of unmanipulated bone marrow. All patients initially achieved engraftment with donor cells, although 2 patients had subsequent reemergence of host hematopoiesis without evidence of disease relapse. Five patients died of transplantation-related causes between 22 and 1262 days post-BMT. Four patients relapsed between 157 and 1096 days post-BMT. These 14 patients were compared with 46 historical controls with RA who received conventional CY/TBI or busulfan/CY preparative regimens. Patients in the experimental group had a similar nonrelapse mortality rate compared with the historical control group (29% versus 37%, respectively; P = .8), but a higher relapse rate (34% versus 2%, P = .0004) and a lower disease-free survival (38% versus 61%, P = .16). We conclude that this modified TBI approach is associated with an unacceptably high risk of relapse for patients with RA undergoing BMT.     

Lymphohematopoietic graft-vs.-host reactions can be induced without graft-vs.-host disease in murine mixed chimeras established with a cyclophosphamide-based nonmyeloablative conditioning regimen.

Mixed hematopoietic chimerism can be induced in mice receiving allogeneic bone marrow transplantation (BMT) after nonmyeloablative host conditioning with depletion T cells with of anti-T cell monoclonal antibodies (mAbs), low-dose (3 Gy) total-body irradiation (TBI), and local thymic irradiation (7 Gy). These mice are specifically tolerant to donor and host antigens. When nontolerant donor T cells are given to chimeras several months after BMT, full donor-type chimerism develops, but graft-vs.-host disease (GVHD) does not occur. The induction of such lymphohematopoietic GVH reactions without GVHD could provide an approach to separating graft-vs.-leukemia (GVL) from GVHD in patients with hematologic malignancies. To make the nonmyeloablative conditioning regimen described above more cytoreductive for such malignancies, we have now modified it by replacing TBI with cyclophosphamide (CP). Treatment with anti-CD4 and anti-CD8 mAbs on day -5, 200 mg/kg CP on day -1, and 7 Gy thymic irradiation on day 0 was only slightly myelosuppressive and allowed fully major histocompatibility complex (MHC)-mismatched (with or without multiple minor antigen disparities) allogeneic bone marrow to engraft and establish long-term mixed chimerism in 40 to 82% of recipients in three different strain combinations. The administration of nontolerant donor spleen cells at 5 weeks or at 5, 8, and 11 weeks posttransplant was capable of eliminating host hematopoietic cells, leading to full or nearly full donor chimerism in six of six and two of four chimeric animals in two different strain combinations. No clinical evidence of GVHD was observed in any recipients of these donor leukocyte infusions (DLI). These studies demonstrate that induction of mixed chimerism with nonmyeloablative conditioning followed at appropriate times by DLI might allow lymphohematopoietic GVH reactions, and hence GVL effects, to eliminate chronic hematologic malignancies without causing clinically significant GVHD.     

Optimizing the Conditioning Regimen for Hematopoietic Cell Transplant in Myelofibrosis: Long-Term Results of a Prospective Phase II Clinical Trial

Optimal conditioning regimens for older patients with myelofibrosis undergoing allogeneic hematopoietic cell transplant are not known. Likewise, the role of dose intensity is not clear.We conducted a nonrandomized, prospective, phase II trial using low-dose, later escalated to high-dose (myeloablative conditioning), busulfan with fludarabine (Bu-Flu) in myelofibrosis patients up to age 74 years. The first 15 patients received i.v. busulfan 130 mg/m²/day on days –3 and –2 (“low dose”); 31 patients received high-dose conditioning, either 100 mg/m²/day (days –5 to –2; n = 4) or pharmacokinetic-guided area under the curve of 4000 μmol/min (days –5 to –2; n = 27). The primary endpoint was day 100 nonrelapse mortality (NRM).Median age was 58 years (interquartile range [IQR], 53-63). Dynamic international prognostic scoring system-plus was intermediate (n = 28) or high (n = 18). Donors were related (n = 19) or unrelated (n = 27). Cumulative incidence of NRM was 9.7% (95% confidence interval [CI], 0-20.3) at day 100 and at 3 years in the high-dose group and 0% in the low-dose group at day 100, which increased to 20% (95% CI, 0-41.9) at 3 years. With a median follow-up of 5.1 years (IQR, 3.8-6), 3-year relapse was 32.3% (95% CI, 15.4-49.1) in high dose versus 53.3% (95% CI, 26.6-80.1) in low dose. Event-free survival was 58% (95% CI, 43-78) versus 27% (95% CI, 12-62), and overall survival was 74% (95% CI, 60-91) versus 60% (95% CI, 40-91). In multivariate analysis, high-dose busulfan had a trend toward lower relapse (hazard ratio, .44; 95% CI, .18-1.07; P = .07), with no impact on NRM.Intensifying the Bu-Flu regimen using pharmacokinetic-monitoring appears to be promising in reducing relapse without increasing NRM.     

Low-dose (550 cGy), single-exposure total body irradiation and cyclophosphamide: consistent, durable engraftment of related-donor peripheral blood stem cells with low treatment-related mortality and fatal organ toxicity.

On the basis of observations of dog models and from earlier studies with humans, we hypothesized that a low-dose (550 cGy) TBI-based conditioning regimen would result in sustained engraftment of HLA-matched sibling peripheral blood stem cells (PBSC) with low treatment-related mortality (TRM) and low serious organ toxicity if the TBI was given as a single dose and at a high dose rate. The regimen included 550 cGy TBI administered as a single dose at 30 cGy/min and cyclophosphamide. Cyclosporine was given as GVHD prophylaxis. Twenty-seven good-risk (acute leukemia in first remission and chronic-phase chronic myelogenous leukemia) and 53 poor-risk (other) patients were accrued. Complete donor engraftment occurred in 93% to 100% of evaluable patients at each scheduled assessment and was durable through 4 years. Mixed chimerism (50% to 98% donor) was observed in 9 patients (11%). Without further intervention, all patients had complete donor engraftment on subsequent assessments. Graft failure did not occur. TRM through at least 2 years was 7% in the good-risk and 19% in the poor-risk diagnostic groups. Grade 4 (fatal) organ toxicity occurred in only 2 patients (2.5%). Other causes of TRM included infection and GVHD. Median follow-up for the surviving patients was 1234 days (range, 780-1632 days). Current status includes 39 patients (49%) alive and in complete remission, 2 alive in relapse, and 39 dead. Relapse occurred in 15% of the good-risk group and 45% of the poor-risk group. The Kaplan-Meier estimates of 3-year disease-free and overall survival of the good-risk group were 77% and 85%, respectively, and of the poor-risk group were 34% and 36%, respectively. Low-dose (550 cGy), single-exposure TBI given at a high dose rate with cyclophosphamide resulted in consistent durable engraftment of HLA-matched sibling PBSC with a low risk of fatal organ toxicity and TRM.     

Transplant Conditioning with Treosulfan/Fludarabine with or without Total Body Irradiation: A Randomized Phase II Trial in Patients with Myelodysplastic Syndrome and Acute Myeloid Leukemia

In this prospective, randomized, phase II “pick the winner” trial we assessed the efficacy of transplant conditioning with treosulfan/fludarabine?±?2?Gy total body irradiation (TBI) in reducing post-transplant relapse in 100 patients, aged 2 to 70 years (median, 57), with myelodysplastic syndrome (MDS)/chronic myelomonocytic leukemia (n?=?51) or acute myeloid leukemia (AML; n?=?49). Patients received i.v. treosulfan, 14?g/m²/day on days –6 to –4 and i.v. fludarabine, 30?mg/m²/day on days –6 to –2, alone or combined with 2?Gy TBI (day 0). Donors were related (n?=?43) or unrelated (n?=?57). When a planned interim analysis showed superior progression-free survival in the TBI arm (P?=?.04), all subsequent patients received TBI. With a follow-up of 12 to 40 months (median, 20), the 1-year overall survival was 80% for the TBI arm and 69% for the non-TBI arm. The 1-year cumulative incidence of relapse was 22% and 34%, respectively (P?=?.06). Among patients with low-risk disease the 1-year relapse incidence was 15% and 31% (P?=?.20) and for patients with high-risk disease, 26% and 36% (P?=?.18), respectively. Among MDS patients the 1-year relapse incidence was 27% versus 33% (P?=?.49) and among AML patients 16% versus 35% (P?=?.05), respectively. The largest difference was among patients with unfavorable cytogenetics, with 1-year relapse incidences of 31% and 63% (P?=?.18), respectively. Nonrelapse mortality in this high-risk patient population was 9% at 6 months and did not differ between arms. Thus, treosulfan/fludarabine/low-dose TBI provided effective conditioning for allogeneic hematopoietic cell transplantation in high-risk patients up to 70 years of age. The addition of TBI had a more profound effect in patients with AML than in those with MDS. High-risk disease features were associated with a lower overall success rate. Further studies are warranted.     

Long-Term Follow-up of Allogeneic Hematopoietic Stem Cell Transplantation for De Novo Acute Myelogenous Leukemia with a Conditioning Regimen of Total Body Irradiation and Granulocyte Colony-Stimulating Factor-Combined High-Dose Cytarabine

We retrospectively evaluated the efficacy and safety of total body irradiation (TBI) and granulocyte colony-stimulating factor (G-CSF)-combined high-dose cytarabine as a conditioning regimen for allogeneic hematopoietic stem cell transplantation (HSCT) in patients with de novo acute myelogenous leukemia (AML). The conditioning regimen consisted of 12 Gy of TBI followed by high-dose cytarabine (3 g/m²) every 12 hours for 4 days in combination with the continuous administration of G-CSF. Stem cell sources included bone marrow or peripheral blood stem cells (PBSC) from human leukocyte antigen (HLA)-identical siblings (n = 24), or bone marrow from HLA serologically matched unrelated donors (n = 26). Fifty patients (median age, 38 years) were evaluated. At HSCT, 35 patients were in the first or second complete remission (CR1/2), and 15 patients were not in remission (n = 14) or in the third CR (n = 1). Thirty-six of 50 patients are currently alive, with a median follow-up period of 5.6 years (range: 1.1-12.1 years). The 5-year estimated overall survival (OS) and disease-free survival (DFS) rates were 85.5% (95% confidence interval [CI], 73.7%-97.3%) and 82.1% (95% CI, 69.0%-95.2%) in patients with AML in the first or second CR, 46.7% (95% CI, 21.4%-72.0%), and 40.0% (95% CI, 15.3%-64.7%) in patients with AML in other stages. The 2-year cumulative incidence of treatment-related mortality (TRM) of all patients was 10.4% (95% CI, 1.8%-18.6%). The only factors affecting the OS and DFS were disease status at transplant and cytogenetics by multivariate analysis. These results suggest that G-CSF-combined high-dose cytarabine could be a promising component of the conditioning regimen for allogeneic HSCT for AML, providing a high DFS and low TRM.     

A comparison of cyclophosphamide and total body irradiation with etoposide and total body irradiation as conditioning regimens for patients undergoing sibling allografting for acute lymphoblastic leukemia in first or second complete remission.

We compared the outcomes of 298 patients with acute lymphoblastic leukemia in first or second complete remission (CR1 or CR2) receiving HLA-matched sibling allografts after cyclophosphamide and total body irradiation (Cy-TBI) conditioning with 204 patients receiving etoposide and TBI. Consequently, 4 groups were compared: Cy-TBI <13 Gy (n = 217), Cy-TBI > or =13 Gy (n = 81), etoposide-TBI <13 Gy (n = 53), and etoposide-TBI > or =13 Gy (n = 151). Analyses of relapse, leukemia-free survival (LFS), and survival were performed separately for CR1 and CR2 transplantations. Transplant-related mortality did not differ by conditioning regimen. In CR1, there were also no significant differences in relapse, LFS, or survival by conditioning regimen. In CR2, these outcomes differed among conditioning groups. In comparison with Cy-TBI <13 Gy, the risks of relapse, treatment failure (inverse of LFS), and mortality tended to be lower with etoposide (regardless of TBI dose) or with TBI doses > or =13 Gy. For both CR1 and CR2 transplantations, causes of death were similar among the groups; disease recurrence accounted for 47% of deaths. We conclude that for HLA-identical sibling allografts for acute lymphoblastic leukemia in CR2, there is an advantage in substituting etoposide for Cy or, when Cy is used, in increasing the TBI dose to > or =13 Gy.     

Tumorigenesis in high-dose total body irradiated rhesus monkeys--a life span study

In the early sixties, studies have been performed at the TNO-Institutes for Health Research on acute effects of high dose total body irradiation (TBI) with X-rays and fission neutrons in Rhesus monkeys and the protective effect of autologous bone marrow transplantation (BMT). The surviving animals of this study were kept to investigate late radiation effects, ie, tumorigenesis. TBI in combination with chemotherapy, followed by rescue with BMT is increasingly used for the treatment of hematological malignancies and refractory autoimmune disease. The risk of radiation carcinogenesis after this treatment is of growing concern in man. Studies on tumor induction in nonhuman primates are of relevance in this context since the response of this species to radiation does not differ much from that in man. The group of long-term surviving monkeys comprised nine neutron irradiated animals (average total body dose 3A Gy, range 2.3-4.4 Gy) and 20 X-irradiated monkeys (average total body dose 7.1 Gy, range 2.8-8.6 Gy). A number of 21 age-matched nonirradiated Rhesus monkeys served as a control-group. All animals wereregularly screened for the occurrence of tumors. Complete necropsies were performed after natural death or euthanasia. At postirradiation intervals of 4-21 years an appreciable number of malignant tumors was observed. In the neutron irradiated group eight out of nine animals died with 1 or more malignant tumors. In the X-irradiated group this fraction was 10 out of 20. The tumors in the control group, in seven out of 21 animals, appeared at much older age compared with those in the irradiated cohorts. The histogenesis of the malignant tumors was diverse, as was the case for benign tumors. The observed shortening of latency periods and life span, as well as, the increase of mean number of tumors per tumor bearing animal for benign neoplasms parallels the trend observed for malignant tumors. The results of this study were compared to other radiation late effects after TBI followed by different BMT treatment modalities in Rhesus monkeys. The observation that the carcinogenic risk of TBI in the Rhesus monkeys is similar to that derived from the studies of the Japanese atomic bomb survivors and the increase of the risk by a factor of 8 emphasizes the need for regular screening for secondary radiation-induced tumors in long-term surviving patients after TBI followed by BMT.     

Updated Clinical Outcomes of Hematopoietic Stem Cell Transplantation Using Myeloablative Total Body Irradiation with Ovarian Shielding to Preserve Fertility

Myeloablative conditioning regimens are associated with severe gonadal toxicity. To preserve ovarian function, we have been investigating ovarian shielding during total body irradiation (TBI) with a myeloablative dose. In this report, we update the clinical outcomes. Female patients with standard-risk hematologic diseases, aged 40 years or younger, who desired to have children, were included (n = 19). The conditioning regimen consisted of TBI at 12 Gy with ovarian shielding and cyclophosphamide (120 mg/kg) or cytarabine (24 g/m²). Ovarian shielding reduced the actual irradiation dose applied to the ovaries from 12 Gy to 2 to 3 Gy. The median age at hematopoietic stem cell transplantation (HSCT) was 24 years (range, 19 to 33 years). With a median follow-up period of 1449 days (range, 64 to 3694) after HSCT, 5-year overall survival and 1- and 5-year relapse rates were 67%, 17%, and 31%, respectively. Only 2 of 14 patients with acute myeloid or lymphoid leukemia in remission have relapsed thus far. The 6-month and 1-year cumulative rates of menstrual recovery were 42% and 78%, respectively. In all patients with menstrual recovery, menstruation recovered within 1 year. The serum anti-Müllerian hormone (AMH) level tended to gradually increase after menstrual recovery. Three patients with extensive chronic graft-versus-host disease experienced delayed recovery of menstruation and serum AMH. Five pregnancies in 3 patients resulted in normal delivery in 1, selective cesarean operation in 1, current pregnancy in 1, and natural abortion in 2. These results suggest that a myeloablative TBI regimen with ovarian shielding could preserve fertility after HSCT without an apparent increase in relapse in standard-risk patients. Because serum AMH recovered gradually over time, the AMH level during the early phase after HSCT may have little value as a marker of ovarian reserve.     

Total Body Irradiation Is Safe and Similarly Effective as Chemotherapy-Only Conditioning in Autologous Stem Cell Transplantation for Mantle Cell Lymphoma

Autologous stem cell transplant (ASCT) consolidation has become a standard approach for patients with mantle cell lymphoma (MCL), yet there is little consensus on the role of total body irradiation (TBI) as part of high-dose transplantation conditioning. We analyzed 75 consecutive patients with MCL who underwent ASCT at our institution between 2001 and 2011 with either TBI-based (n?=?43) or carmustine, etoposide, cytarabine, melphalan (BEAM; n?=?32) high-dose conditioning. Most patients (97%) had chemosensitive disease and underwent transplantation in first remission (89%). On univariate analysis, TBI conditioning was associated with a trend toward improved PFS (hazard ratio [HR], .53; 95% confidence interval [CI], .28-1.00; P?=?.052) and similar OS (HR, .59; 95% CI, .26-1.35; P?=?.21), with a median follow-up of 6.3 years in the TBI group and 6.6 years in the BEAM group. The 5-year PFS was 66% in the TBI group versus 52% in the BEAM group; OS was 82% versus 68%, respectively. However, on multivariate analysis, TBI-based conditioning was not significantly associated with PFS (HR, .57; 95% CI .24-1.34; P?=?.20), after controlling for age, disease status at ASCT, and receipt of post-transplantation rituximab maintenance. Likewise, early toxicity, nonrelapse mortality, and secondary malignancies were similar in the 2 groups. Our data suggest that both TBI and BEAM-based conditioning regimens remain viable conditioning options for patients with MCL undergoing ASCT.     

Bone marrow transplantation for chronic granulocytic leukaemia

Summary Twenty-one patients with chronic granulocytic leukaemia underwent marrow transplantation. The donors were human-lymphocyte antigen-identical siblings in 19 cases. In the remaining 2 cases the donor was a parent in one and an identical twin in the other. The preparatory regimen included cyclophosphamide and 8.6 Gy total body irradiation given at either a dose of 0.1 Gy/min or 0.04 Gy/min. Five patients were in the accelerated phase of the disease, one was in remission following blast crisis, and the rest were all in the chronic phase. After chemotherapy and irradiation, all patients received bone marrow transplants. To date, nine patients are still alive, with a median survival of 64 days (range 28–683 days). One patient continued to have leukaemic cells and in another, the leukaemia recurred 18 months following transplantation. Interstitial pneumonitis was the cause of death of eight patients (38%). Graft-versus-host disease occurred in ten patients (47%).Abbreviations accel. accelerated phase - Bl.c. blast crisis - BMT bone marrow transplantation - BN barrier nursing - CGL chronic granulocytic leukaemia - chr. chronic phase - GvHD graft versus host disease - Gy Gray - HLA human lymphocyte antigen - IP interstitial pneumonitis - MLC mixed lymphocyte culture - neg. negative - Ph¹ Philadelphia chromosome - pos. positive - Rem. remission - rob.t. congenital Robertsonian translocation - sec.A. secondary anomalies - TBI total body irradiation - UPN unique patient number Gefördert durch die Deutsche Forschungsgemeinschaft SFB 102.     

High-dose therapy and autologous hematopoietic-cell transplantation for follicular lymphoma beyond first remission: the Stanford University experience.

A retrospective analysis was performed to investigate the outcome of high-dose therapy (HDT) and autologous hematopoietic cell transplantation in patients with follicular lymphomas beyond first remission. Ninety-two patients with primary induction failure or relapsed follicular low-grade lymphoma (FLGL), follicular large cell lymphoma (FLCL), and transformed follicular lymphoma (TFL) were treated with myeloablative therapy consisting of etoposide (60 mg/kg), cyclophosphamide (100 mg/kg), and either carmustine (BCNU;15 mg/kg) or fractionated total body irradiation (FTBI; 1200 cGy) followed by transplantation of purged autologous bone marrow or peripheral blood hematopoietic cells. For the 49 patients with relapsed FLGL, the median age was 49 years and the median interval from diagnosis to HDT was 30 months. The 4-year estimate of overall survival (OS) was 60% (95% confidence interval [CI], 45%-75%) and of disease-free survival (DFS) was 44% (95% CI, 29%-59%). Treatment with the FTBI-containing HDT regimen was associated with significantly longer DFS (P = .04) and OS (P = .04) in our multivariate analysis. OS was also significantly longer among those treated with 3 or fewer chemotherapy regimens. For the 26 FLCL patients, the median age was 51 years and in 31% the indication for HDT was primary induction failure. For FLCL patients, the 4-year estimate of OS was 58% (95% CI, 37%-79%) and of DFS was 51% (95% CI, 30%-72%). Among the 17 patients with TFL, 13 (76%) transformed at first relapse, and only 6 patients (35%) achieved complete remission with salvage therapy prior to HDT. For TFL patients, the 4-year estimate of OS was 50% (95% CI, 24%-76%) and of DFS 49% (95% CI, 20%-78%). There were 3 occurrences of myelodysplasia (1 after treatment with TBI, 2 after BCNU treatment), yielding an estimated incidence of 7% (95% CI, 0%-16%) at 56 months. This analysis shows that relapsed FLGL patients treated with 3 or fewer different chemotherapy regimens show inferior survival. The HDT regimen containing FTBI appears to be superior to the BCNU-based regimen for relapsed FLGL, although longer follow-up is needed to evaluate late effects. Lastly, patients with TFL or induction failure and relapsed FLCL can achieve survival outcome comparable to those observed with the indolent follicular lymphomas.     

Induction of a cytogenetic adaptive response in germ cells of irradiated mice with very low-dose rate of chronic {gamma}-irradiation and its biological influence on radiation-induced DNA or chromosomal damage and cell killing in their male offspring

In earlier studies we have shown that either a single exposureor multiple exposures to a low dose of X-rays (0.05 Gy) induceda significant cytogenetic adaptive response in mouse germ cells.In this paper, a very low-dose rate (20 µGy/min) of chronic⁶⁰Co     

Immunomodulation of autoimmunity in MRL/lpr mice with syngeneic bone marrow transplantation (SBMT).

MRL-lpr/lpr mice spontaneously develop a severe autoimmune syndrome, characterized by massive generalized lymphadenopathy, arthritis, arteritis, dermatitis and immune complex-mediated glomerulonephritis. Bone marrow transplantation (BMT) from MHC-matched systemic lupus erythematosus (SLE)-resistant donors to susceptible recipients has proved effective in correcting autoimmune manifestations in autoimmune-prone mice. We investigated the effect of syngeneic BMT from MRL/lpr (donor) to immunocompromised MRL/lpr (recipient), after purging the bone marrow inoculum with MoAbs against mature T cells (anti-Thy 1.2). All the untreated mice developed lymphadenopathy and by the age of 36 weeks five of the eight were dead; in contrast, all the mice which underwent syngeneic BMT following acute immunosuppression with total body irradiation (900 cGy) (TBI) remained disease-free. In an additional experiment, it was found that conditioning with cyclophosphamide (CY) before BMT was more effective than TBI in inhibiting delayed-onset autoimmune manifestations (mean survival 350 days in the CY group and 305 days in the TBI group, versus 197 days in untreated controls). Under both immunosuppressive regimens T cell-depleted bone marrow grafts produced far better results than did unmanipulated BMT. Following syngeneic BMT the incidence of proteinuria and the level of serum anti-DNA (dd) antibodies were significantly reduced, compared with that of the age-matched untreated controls. CY was more effective than TBI in reducing the anti-DNA titres. Likewise, T depletion of bone marrow inocula before BMT induced a more drastic drop in autoantibodies, following both CY and TBI conditioning protocols. After syngeneic BMT (either CY or TBI) no signs of lymphadenopathy were observed even at an advanced age. Upon histopathological examination, the BMT-treated mice displayed normal glomeruli with occasional minimal signs of glomerulonephritis. Syngeneic T cell-depleted BMT following acute cytoreduction of anti-self immune lymphocytes may represent a new therapeutic approach for drug-resistant autoimmune diseases.     

Low incidence of transplantation-related acute complications in patients with chronic myeloid leukemia undergoing allogeneic stem cell transplantation with a low-dose (550 cGy) total body irradiation conditioning regimen.

Although allogeneic transplantation is a curative therapy for chronic myeloid leukemia (CML), treatment-related mortality is still a major cause of posttransplantation mortality, especially for patients older than 40 years. We investigated, in a phase II trial, the role of a low-dose (550 cGy) high-dose rate (35 cGy/min) single-exposure total body irradiation (TBI) conditioning regimen for allogeneic peripheral blood stem cell (PBSC) transplantation in patients with CML. Between June 1997 and August 2000, 30 adult patients with CML underwent cytokine-mobilized allogeneic PBSC transplantation from HLA-matched siblings following administration of cyclophosphamide (60 mg/kg per day intravenously on days -2 and -1) and single-dose TBI (550 cGy delivered at 30 cGy/min on day 0). Cyclosporine A alone was administered for prophylaxis against graft-versus-host disease (GVHD). Median patient age was 47 years (range, 21-63 years), with 23 patients (77%) older than 40 years. The preparative regimen was well tolerated. Grade 4 toxicities and oral mucositis were not observed. Graft failure did not occur. Severe acute GVHD was observed in 5 patients (17%). The median follow-up was 23 months (range, 6-39 months). Cytogenetic or hematologic relapse was detected in 3 patients (10%), 2 of whom subsequently entered remission following a taper of immunosuppression. Nonrelapse mortality occurred in 5 patients (17%), and the Kaplan-Meier estimate of survival at 2 years was 83% (95% confidence interval, 70%-97%). In summary, this low-dose TBI-based preparative regimen resulted in uniform donor engraftment, with markedly reduced organ toxicity and nonrelapse mortality, in this relatively older cohort of patients with CML.     

Intracellular fluorescent labelling of cells for analysis of lymphocyte migration

Since conventional methods of inducing depletion of polymorphonuclear granulocytes (PMNs) in mice, such as treatment with cytostatic drugs and anti-PMN sera, proved to be insufficient to induce a stable PMN depletion for several days, and were accompanied by considerable toxic side effects, we induced neutrophil depletion in mice by total body irradiation (TBI) in a single dose of 6.0 Gy (600 rads.) at a dose rate of 0.20 Gy/min. This treatment reduced the number of PMNs in the peripheral circulation to values below 150/microliter from day 3-10 after irradiation. The number of lymphocytes fell simultaneously. Platelet counts remained above 60% of normal values during the first 7 days after irradiation. Complement levels were not significantly affected by TBI. The results show that TBI of 6.0 Gy induces pronounced and stable PMN depletion in mice for at least 7 days. Furthermore, under an aseptic regimen the mice can be kept in good condition and losses are less than 5%.     

不同分割剂量同步推量调强放疗治疗肺癌脑转移瘤的安全性分析

目的:分析不同分割剂量同步推量调强放疗治疗肺癌脑转移瘤的安全性及生存情况。方法:选取肺癌脑转移瘤患者75例,随机分为3组,均实施同步推量调强放疗,其中A组放疗方案为全脑40 Gy/20f（2.0 Gy/f）+瘤区同步推量46 Gy/20f（2.3 Gy/f）,B组方案为全脑40 Gy/20f（2.0 Gy/f）+瘤区同步推量52 Gy/20f（2.6 Gy/f）,C组方案为全脑40 Gy/20f（2.0 Gy/f）+瘤区同步推量58 Gy/20f（2.9 Gy/f）。放疗开始后,对3组患者危及器官（眼球、晶体、视神经、脑干）平均剂量及最大剂量和3组患者放疗相关不良反应进行比较。治疗结束后定期复查颅脑MRI评价疗效,观察3组患者1年生存率。结果:A、B、C组危及器官平均剂量及最大剂量差异不显著（P>0.05）;A、B、C组急性放疗不良反应发生率差异不显著（P>0.05）,晚期神经系统不良反应发生率亦差异不显著（P>0.05）,3级放疗不良反应低于5%,无4级放疗不良反应发生。随访1年,C组生存率高于A、B组（P<0.05）。结论:同步推量调强放疗治疗肺癌脑转移瘤是一种安全有效的方法,随着放疗剂量增加,疗效有增加趋势。