Interleukin-12 prevents severe acute graft-versus-host disease (GVHD) and GVHD-associated immune dysfunction in a fully major histocompatibility complex haplotype-mismatched murine bone marrow transplantation model

BACKGROUND: We have recently reported that interleukin (IL)-12 prevents acute graft-versus-host disease (GVHD)-induced mortality in a full major histocompatibility complex- plus multiple minor antigen-mismatched A/J-->B10 bone marrow transplantation (BMT) model. Because most patients have access to a haploidentical, one haplotype-mismatched donor, we have now investigated the protective effect of IL-12 against GVHD and GVHD-associated immune dysfunction in a haploidentical CBD2F1 (H2kxd) --> B6D2F1 (H2bxd) strain combination. METHODS: GVHD was induced by injecting CBD2F1 marrow and spleen cells into lethally irradiated B6D2F1 mice. RESULTS: In untreated control mice, GVHD resulted in 87% mortality by day 8 after BMT, with no survivors beyond day 17. Treatment with a single injection of IL-12 on the day of BMT led to 87% long-term survival, with no significant weight loss, diarrhea or GVHD skin changes. The majority of T cells recovering in these mice showed the CD62L+, CD44low, CD45RBhigh naive phenotype. These T cells showed specific tolerance to both host and donor histocompatibility antigens, but normal anti-third party (H2s) alloresponses in vitro. B-cell proliferative responses to lipopolysaccharide were also normal in IL-12-protected mice. Moreover, normal negative selection of thymocytes bearing T cell receptors with Vbeta that recognize endogenous superantigens was observed among CD4+CD8- thymocytes, indicating a lack of GVHD-associated thymic selection abnormalities in IL-12-protected allogeneic BMT recipients. CONCLUSIONS: IL-12 provides permanent protection against an otherwise severe, rapidly lethal GVHD, with no clinical manifestations of chronic GVHD, immunosuppression or autoimmune features, in a full major histocompatibilty complex haplotype-mismatched murine BMT model.     

Differential effects of the absence of interferon-gamma and IL-4 in acute graft-versus-host disease after allogeneic bone marrow transplantation in mice

Graft-versus-host disease (GVHD), in which immunocompetent donor cells attack the host, remains a major cause of morbidity after allogeneic bone marrow transplantation (BMT). To understand the role of cytokines in the pathobiology of GVHD, we used cytokine knockout (KO) mice as a source of donor T cells. Two different MHC-disparate strain combinations were examined: BALB/c (H2(d)) donors into lethally irradiated C57BL/6 (H2(b)) recipients or C57BL/6 (H2(b)) donors into B10.BR (H2(k)) recipients. Donor cells were from mice in which either the interferon-gamma (IFN-gamma) or the IL-4 gene was selectively disrupted to understand the role of these cytokines in acute GVHD. In both strain combinations the same pattern was noted with regard to GVHD onset and morbidity. All mice exhibited the classic signs of acute GVHD: weight loss with skin, gut, and liver pathology resulting in morbidity and mortality. Surprisingly, donor cells obtained from mice lacking IFN-gamma gave rise to accelerated morbidity from GVHD when compared with cells from wild-type control donors. Similar results were obtained using normal donors when neutralizing antibodies to IFN-gamma were administered immediately after the BMT. These results suggest that IFN-gamma plays a role in protection from acute GVHD. In marked contrast, cells obtained from IL-4 KO mice resulted in protection from GVHD compared with control donors. Splenocytes from IFN KO mice stimulated with a mitogen proliferated to a significantly greater extent and produced more IL-2 compared with splenocytes obtained from IL-4 KO or control mice. Additionally, there was increased IL-2 production in the spleens of mice undergoing GVHD using IFN-gamma KO donors. These results therefore indicate, with regard to the TH1/ TH2 cytokine paradigm, the absence of a TH1-type cytokine can be deleterious in acute GVHD, whereas absence of a TH2 cytokine can be protective.     

Host reactive donor T cells are associated with lung injury after experimental allogeneic bone marrow transplantation

Noninfectious lung injury is common after allogeneic bone marrow transplantation (BMT), but its association with acute graft-versus-host disease (GVHD) is unclear. Using a murine BMT system where donor and host differ by multiple minor histocompatibility (H) antigens, we investigated the nature of lung injury and its relationship both to systemic GVHD and host-reactive donor T cells. Lethally irradiated CBA hosts received syngeneic BMT or allogeneic (B10.BR) T-cell-depleted (TCD) bone marrow (BM) with and without the addition of T cells. Six weeks after BMT, significant pulmonary histopathology was observed in animals receiving allogeneic BMT compared with syngeneic controls. Lung damage was greater in mice that received allogeneic T cells and developed GVHD, but it was also detectable after TCD BMT when signs of clinical and histologic acute GVHD were absent. In each setting, lung injury was associated with significant alterations in pulmonary function. Mature, donor (Vbeta6(+) and Vbeta3(+)) T cells were significantly increased in the broncho-alveolar lavage (BAL) fluid of all allogeneic BMT recipients compared with syngeneic controls, and these cells proliferated and produced interferon-gamma (IFN-gamma) to host antigens in vitro. These in vitro responses correlated with increased IFN-gamma and tumor necrosis factor-alpha (TNF-alpha) in the BAL fluid. We conclude that alloreactive donor lymphocytes are associated with lung injury in this allogeneic BMT model. The expansion of these cells in the BAL fluid and their ability to respond to host antigens even when systemic tolerance has been established (ie, the absence of clinical GVHD) suggest that the lung may serve as a sanctuary site for these host reactive donor T cells. These findings may have important implications with regard to the evaluation and treatment of pulmonary dysfunction after allogeneic BMT even when clinical GVHD is absent.     

Interleukin-12 preserves the graft-versus-leukemia effect of allogeneic CD8 T cells while inhibiting CD4-dependent graft-versus-host disease in mice

We have recently demonstrated that a single injection of 4,900 IU of interleukin-12 (IL-12) on the day of bone marrow transplantation (BMT) markedly inhibits acute graft-versus-host disease (GVHD) in a fully major histocompatibility complex plus minor antigen-mismatched BMT model (A/J --> B10, H-2(a) --> H-2(b)), in which donor CD4(+) T cells are required for the induction of acute GVHD. We show here that donor CD8-dependent graft-versus-leukemia (GVL) effects against EL4 (H-2(b)) leukemia/lymphoma can be preserved while GVHD is inhibited by IL-12 in this model. In mice in which IL-12 mediated a significant protective effect against GVHD, marked GVL effects of allogeneic T cells against EL4 were observed. GVL effects against EL4 depended on CD8-mediated alloreactivity, protection was not observed in recipients of either syngeneic (B10) or CD8-depleted allogeneic spleen cells. Furthermore, we analyzed IL-12-treated recipients of EL4 and A/J spleen cells which survived for more than 100 days. No EL4 cells were detected in these mice by flow cytometry, tissue culture, adoptive transfer, necropsies, or histologic examination. Both GVL effects and the inhibitory effect of IL-12 on GVHD were diminished by neutralizing anti-interferon-gamma (IFN-gamma) monoclonal antibody. This study demonstrates that IL-12-induced IFN-gamma production plays a role in the protective effect of IL-12 against GVHD. Furthermore, IFN-gamma is involved in the GVL effect against EL4 leukemia, demonstrating that protection from CD4-mediated GVHD and CD8-dependent anti-leukemic activity can be provided by a single cytokine, IFN-gamma. These observations may provide the basis for a new approach to inhibiting GVHD while preserving GVL effects of alloreactivity.     

Prevention of graft-versus-host disease and the induction of transplant tolerance by low-dose UV-B irradiation of BM cells combined with cyclosporine immunosuppression

GVHD is prevented and stable chimerism is induced in the rat BMT model by 700 J/m2 but not 100-500 J/m2 UV-B irradiation of allogeneic BM cells. Paradoxically, CsA which prevents GVHD in clinical BMT causes an aggressive autoimmune disease termed syngeneic GVHD in irradiated syngeneic BMT recipients after its withdrawal. Recently, we have shown that while 500-700 J/m2 UV-B irradiation of syngeneic BM cells combined with a 30-day course of CsA recipient immunosuppression impairs hemopoiesis due to lack of hemopoietic factors, a low dose of 100-300 J/m2 UV-B is effective in preventing CsA-induced autoimmune disease without endangering BM engraftment. This study extends these findings to the P-to-F1 hybrid and fully allogeneic rat BMT models and examines the effectiveness of low-dose UV-B irradiation of BM cells combined with a short course of CsA treatment in the prevention of GVHD and induction of transplant tolerance. Lethally gamma-irradiated (10.5 Gy) LBNF1 recipients of naive or UV-B irradiated (100-700 J/m2) BMT were treated with CsA (12.5 mg/kg/day) for 30 consecutive days after BMT. All lethally irradiated LBNF1 that did not receive BMT died in < 16 days, while animals transplanted with UV-B (700 J/m2) BMT survived > 1 year without GVHD. In contrast, all recipients of naive BMT died of lethal GVHD in < 50 days. Similarly, all recipients of naive BMT that received a 30-day course of CsA therapy developed severe GVHD with 60% mortality after cessation of CsA therapy. CsA-treated recipients of BMT irradiated with 700 J/m2 died between 12 and 25 days from failure of hemopoiesis. In contrast, CsA-treated recipients of 100-200 J/m2 UV-B irradiated BMT showed full BM engraftment without GVHD after cessation of CsA and survived > 1 year. These results were reproducible in the fully allogeneic UV-B BMT model. To test for donor-specific tolerance, the animals challenged 100 days after BMT with cardiac allografts accepted permanently (> 100 days) Lewis but not BN (non-BMT parental donor) cardiac allografts. Our results confirm that 700 J/m2 UV-B irradiation of BM cells combined with CsA recipient immunosuppression impairs the recovery capacity of stem cells while the use of lower UV-B (100-200 J/m2) is effective in preventing CsA-induced autoimmune disease without endangering BM engraftment and leads to induction of transplant tolerance.     

Interleukin-2 inhibits graft-versus-host disease-promoting activity of CD4+ cells while preserving CD4- and CD8-mediated graft-versus-leukemia effects

We have recently shown that a short course of high-dose interleukin-2 (IL-2) can markedly inhibit the graft-versus-host disease (GVHD)-promoting activity of donor CD4+ T cells. The difficulty in dissociating GVHD-promoting from graft-versus-leukemia (GVL) effects of alloreactive donor T cells currently prevents clinical bone marrow transplantation (BMT) from fulfilling its full potential. To test the capacity of IL-2 treatment to promote such a dissociation, we have developed a new murine transplantable acute myelogenous leukemia model using a class II major histocompatibility complex-positive BALB/c Moloney murine leukemia virus-induced promonocytic leukemia, 2B-4-2. BALB/c mice receiving 2.5 x 10(5) 2B-4-2 cells intravenously 1 week before irradiation and syngeneic BMT died from leukemia within 2 to 4 weeks after BMT. Administration of syngeneic spleen cells and/or a 2.5-day course of IL-2 treatment alone did not inhibit leukemic mortality. In contrast, administration of non-T-cell-depleted fully allogeneic B10 (H-2b) spleen cells and T-cell-depleted B10 marrow led to a significant delay in leukemic mortality in IL-2-treated mice. In these animals GVHD was inhibited by IL-2 treatment. GVL effects were mediated entirely by donor CD4+ and CD8+ T cells. Remarkably, IL-2 administration did not diminish the magnitude of the GVL effect of either T-cell subset. This was surprising, because CD4-mediated GVHD was inhibited in the same animals in which CD4-mediated GVL effects were not reduced by IL-2 treatment. These results suggest a novel mechanism by which GVHD and GVL effects of a single unprimed alloreactive T-cell subset can be dissociated; different CD4 activities promote GVHD and GVL effects, and the former, but not the latter activities are inhibited by treatment with IL-2.     

Use of anti-CD3 epsilon F(ab')2 fragments in vivo to modulate graft-versus-host disease without loss of graft-versus-leukemia reactivity after MHC-matched bone marrow transplantation

The use of T cell-specific mAb in vivo for prevention and treatment of graft-vs-host disease (GVHD) and its impact on graft-vs-leukemia (GVL) reactivity was examined in a murine model of MHC-matched bone marrow transplantation (BMT). F(ab')2 fragments of a CD3 epsilon-specific mAb were administered to irradiated AKR (H-2k) hosts after transplantation of BM plus spleen cells from B10.BR donors (BMS chimeras). The effects on GVH and GVL reactivity were Ab dose- and schedule-dependent. A short course of mAb (qe2d, days 0 to 8) prevented clinical evidence of GVHD and mortality. Anti-CD3 F(ab')2 mAb reversed clinical symptoms of acute GVHD when delayed up to 18 days post-transplant. Anti-host (Mls-1a)-specific V beta 6+ cells were absent from the spleens of GVH-negative control mice, but persisted in Ab-treated BMS chimeras despite the absence of GVHD. Leukemic mice given 16.7 micrograms of Ab on days 0, 2, and 4 survived leukemia-free without developing severe GVHD. A longer course of Ab completely prevented GVHD, but led to leukemia relapse in tumor-bearing hosts, despite engraftment of donor T cells. The GVL effect was quantitatively stronger when Ab was used for GVH therapy as compared with GVH prevention. Some Ab-treated, GVH-free chimeras relapsed with lymphomas in unusual sites, suggesting that occult tumor cells may persist in nonlymphoid tissues. These experiments demonstrate that T cell-specific mAb can be used successfully in vivo to avoid severe GVHD, but that excessive or ill-timed administration of Ab may eliminate GVL reactivity.     

Keratinocyte growth factor administered before conditioning ameliorates graft-versus-host disease after allogeneic bone marrow transplantation in mice

Keratinocyte growth factor (KGF) is important in tissue repair and wound healing and its administration can abrogate chemical- and radiation-induced tissue damage in rodents. We investigated KGF as a therapeutic agent for the prevention of graft-versus-host disease (GVHD)-induced tissue damage, morbidity, and mortality in an established murine allogeneic bone marrow transplantation (BMT) model. B10.BR (H2(k)) recipient mice were lethally irradiated and transplanted with C57BL/6 (H2(b)) bone marrow (BM) with spleen cells (BMS) as a source of GVHD-causing T cells. KGF-treated mice (5 mg/kg/d subcutaneously days -6, -5, and -4 pre-BMT) receiving BMS exhibited better survival than those not receiving KGF (P =.0027). Cyclophosphamide (Cy), a common component of total body irradiation (TBI)-containing regimens, was administered to other cohorts of mice at a dose of 120 mg/kg/d intraperitoneally on days -3 and -2 before BMT. KGF-treated mice again exhibited a better survival rate than those not receiving KGF (P =.00086). However, KGF-treated recipients receiving TBI or Cy/TBI BMS were not GVHD-free, as shown by lower body weights compared with BM groups. GVHD target tissues were assessed histologically during a 38-day post-BMT observation period. KGF ameliorated GVHD-induced tissue damage in the liver, skin, and lung (completely in some recipients) and moderately so in the spleen, colon, and ileum, even with Cy conditioning. These studies demonstrate that KGF administration, completed before conditioning, has potential as an anti-GVHD therapeutic agent.     

Nonmitogenic anti-CD3F(ab')2 fragments inhibit lethal murine graft-versus-host disease induced across the major histocompatibility barrier

We have investigated the in vivo administration of nonmitogenic anti-CD3F(ab')2 fragments for the prevention of lethal graft-vs-host disease (GVHD) in irradiated recipients of fully allogeneic bone marrow cells plus splenocyte (BMS) inocula. Recipients of anti-CD3F(ab')2 fragments administered for 1 mo post-bone marrow transplantation (BMT) had 100% survival without clinical or histopathological evidence of GVHD. Controls given saline injections succumbed by 39 days post-BMT. Similar results were obtained in groups of recipient mice given BMS in which T cells were depleted by in vitro anti-Thy-1.2 plus C' treatment. Further studies were undertaken to define mechanistic differences in the two approaches. Using Ly-5 congenic sources of donor bone marrow and spleen, we determined that anti-CD3F(ab')2 fragments induced TCR modulation and T cell depletion. Mature splenic-derived CD4+ cells were depleted to a greater extent than CD8+ cells. Early post-BMT, recipients receiving injections with control saline had the highest number of CD4+ and CD8+ cells (which may cause GVHD) followed by recipients of anti-CD3F(ab')2 fragments, with the fewest CD8+ cells observed in the anti-Thy-1.2 + C' treated group. CD3+CD4-CD8- cells (which may suppress GVHD generation) were present in higher numbers early post-BMT in recipients given anti-CD3F(ab')2 fragments as compared to recipients given anti-Thy-1.2 + C'-treated BMS. In long term survivors, a mononuclear T cell containing infiltrate without evidence of destruction was observed in sites of GVHD (lung and liver), consistent with a "Quilty" effect, which was not observed in either of the other two groups. Although survivors were tolerant of donor skin grafts and rejected third party grafts, recipients given anti-CD3F(ab')2 fragments but not anti-Thy-1.2 + C'-treated BMS had vigorous anti-host proliferative responses. These results demonstrate that although in vitro anti-Thy-1.2 + C' treatment of BMS (which is highly depletionary) and in vivo administration of anti-CD3F(ab')2 fragments (which is modulatory and less depletionary) are both effective strategies for GVHD, the cellular events involved in achieving GVHD prevention are indeed different.     

Allogeneic bone marrow transplantation vs filgrastim-mobilised peripheral blood progenitor cell transplantation in patients with early leukaemia: first results of a randomised multicentre trial of the European Group for Blood and Marrow Transplantation

In a multicentre trial involving 20 transplant centres from 10 countries haematopoietic stem cells were obtained either from the bone marrow of 33 sibling donors or from the peripheral blood of 33 such donors after administration of filgrastim (10 microg/kg/day). The haematopoietic stem cells were infused into their HLA-identical recipients suffering from acute leukaemias in remission or chronic myeloid leukaemia in chronic phase. PBPC donors tolerated filgrastim administration and leukapheresis well with the most frequent side-effects being musculoskeletal pain, headache, and mild increases of LDH, AP, Gamma-GT or SGPT. Pain and haematoma at the harvest site and mild anaemia were the most frequent complaints of BM donors. Severe or life-threatening complications were not seen with any type of harvest procedure. Time to platelet recovery greater than 20 x 10(9)/l was 15 days (95% confidence interval (CI) 13-16 days) in the PBPCT group and 19 days (CI 16-25) in the BMT group. Time to neutrophil recovery greater than 0.5 x 10(9)/l was 14 days (CI 12-15 days) in the PBPCT group as compared to 15 days (CI 15-16 days) in the BMT group. The numbers of platelet transfusions administered to PBPCT and BMT patients were 12 (range: 1-28) and 10 (range: 3-39), respectively. Sixteen patients (48%) transplanted with bone marrow and 18 patients (54%) transplanted with PBPC developed acute GVHD of grades II-IV; acute GVHD of grades III or IV developed in six (18%) and seven (21%) patients, respectively. Kaplan-Meier plots for transplant-related mortality until day 100 and leukaemia-free survival at a median of 400 days after BMT or PBPCT showed no significant differences. Administration of filgrastim and leukapheresis in normal donors were feasible and well tolerated. The number of days with restricted activity and of nights spent in hospital was lower in donors of PBPC. Transplantation of PBPC to HLA-identical siblings with early leukaemia resulted in earlier platelet engraftment. The incidence of moderate to severe acute GVHD, transplant-related mortality, and leukaemia-free survival did not show striking differences. Further investigation of allogeneic PBPCT as a substitute for allogeneic BMT is warranted.     

Prevalence of antibodies to Rickettsia conorii Ricketsia africae, Rickettsia typhi and Coxiella burnetii in Mauritania

A 24-year-old male developed cytogenetic relapse of chronic myeloid leukemia (CML) four years after allogeneic BMT. After a year of treatment with IFN-alpha, he achieved a partial cytogenetic response. Treatment with donor leukocyte infusions (DLI) was given (total dose 1 x 10(8) T lymphocytes/kg). Two months later, he developed acute GVHD (skin and liver), that improved with CsA and methylprednisolone and resulted in cytogenetic remission with complete donor chimerism. One month later he developed rhinocerebral mucormycosis and was successfully treated with surgical debridement and liposomal amphotericin B (total dose 12 g). This is the first case of mucormycosis described after DLI.     

Long-term safety of GM-CSF (molgramostim) administration after allogeneic bone marrow transplantation for hematologic malignancies: five-year follow-up of a double-blind randomized placebo-controlled study

In a double-blind, randomized study performed between 1988 and 1990, 40 patients undergoing allogeneic BMT from HLA-identical siblings for hematologic malignancies received 8 mg/kg/d rHuGM-CSF (molgramostim, n = 20) for 14 days. The median neutrophil count on day 14 was significantly higher in the GM-CSF group (1.90 vs 0.46 yen 10(9)/L, P < .0001). The incidence of acute GVHD and transplant-related mortality were comparable. Only two deaths occurred after 6 months; one due to pulmonary fibrosis in the GM-CSF group on day 1591, and one due to relapse on day 1590 in the placebo group. The Karnofsky score of the 10 survivors, 3 in the placebo group and 7 in the GM-CSF group, is 90-100% (median 100%), and none has chronic GVHD requiring therapy. There was no evidence of increased relapse in the GM-CSF group with only two relapses occurring; both in the placebo group. With a follow-up of 4.5-6.8 years (median 5.5 years), these patients are amongst the longest surviving patients to have received a recombinant growth factor post-allograft. We conclude that the administration of GM-CSF after allogeneic BMT does not appear to be associated with an increased incidence of chronic GVHD or relapse, or of other adverse effects such as the development of myelodysplasia.     

An MHC-compatible allogeneic bone marrow donor with a distinct role of T cell subsets in graft-versus-leukemia effect and lethal graft-versus-host disease

Our previous results in a murine model indicated that the GVL effect against radiation-induced leukemias could be induced in not only MHC-incompatible but also MHC-compatible allogeneic BMT, and that the intensity of the GVL effect induced in MHC-compatible allogeneic BMT varied among different leukemias and the donor/host strain combinations used. With the use of a radiation-induced T cell leukemia which followed the induction of the GVL effect in both MHC-compatible and -incompatible, allogeneic BMT, the role of T cell subsets in the development of the GVL effect and GVHD was studied. The results indicated that Lyt2+ T cells contaminating donor BM were consistently critical for the induction of the GVL effect in MHC-incompatible (B10) and -compatible (B10.BR and AKR) allogeneic BMT of leukemia-bearing C3H mice, but the depletion of L3T4+ T cells had no effect. In contrast, lethal GVHD induced by AKR donor lymph node cells was totally dependent on L3T4+ T cells, but the depletion of Lyt2+ T cells had no effect. On the other hand, both T cell subsets could cause lethal GVHD induced by MHC-incompatible (B10) and -compatible (B10.BR) allogeneic donors. The distinct roles of T cell subsets of AKR donors were confirmed by the preferential induction of the GVL effect with the AKR donor bone marrow mixed with lymph node cells which had been depleted of L3T4+ T cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in lung and chest wall properties with abdominal insufflation of carbon dioxide are immediately reversible

There is increasing interest in blood cell transplants (BCT) from normal donors as an alternative to BMT. Ten patients with relapsed or persistent leukemia after BMT received intensive cytotoxic conditioning followed by allogeneic BCT. Three BCT were from single-antigen mismatched donors; two of the corresponding recipients had rejected a BMT from the same donor. Two patients received BCT from a different donor (one matched, one single-antigen mismatched). The other six BCT were from the same, fully matched, bone marrow donors. Donors were given G-CSF to mobilize progenitor cells which were collected by a single 2-4 h leukapheresis. Methotrexate, CsA and folinic acid were used for GVHD prophylaxis for all transplants but CsA was discontinued sooner after BCT than after BMT. One patient died without engraftment having rejected a BMT from the same single-antigen mismatched donor 4 years previously. Nine patients had granulocyte recovery at a median of 14 days, up to 6 days faster than with their previous BMT. Platelet recovery was also 2-6 days faster than with BMT in four previously engrafting patients. Four patients died without platelet recovery after BCT within a year of BMT, three of treatment-related toxicity and one of relapse. Two patients developed grade II acute GVHD. Of six patients given BCT more than a year from BMT, four, all with acute leukemia, survive 7, 14, 29 and 29 months after BCT and one relapsed at 7 months. All four survivors developed chronic GVHD. These results indicate that BCT may be useful therapy for relapse occurring more than a year after BMT.     

Interleukin-10 dose-dependent regulation of CD4+ and CD8+ T cell-mediated graft-versus-host disease

BACKGROUND: Endogenous interleukin (IL)-10 production has been associated with the lack of graft-versus-host disease (GVHD) in human recipients of MHC-disparate donor grafts. Paradoxically, we have shown that the exogenous administration of high doses (30 microg/dose) of IL-10 to murine recipients of MHC-disparate grafts accelerates GVHD lethality. METHODS: The effects of IL-10 on GVHD mediated by either CD4+ or CD8+ T cells was examined in studies involving exogenous IL-10 administration or the infusion of T cells from IL-10-deficient (-/-) donor mice. The role of interferon (IFN)-gamma on IL-10-induced GVHD acceleration was studied using IFN-gamma-deficient (-/-) donor mice or neutralizing monoclonal antibody. RESULTS: IL-10 was found to have a dose-dependent effect on the GVHD lethality mediated by either CD4+ or CD8+ T cells. High doses of exogenous IL-10 accelerated GVHD lethality. IFN-gamma release was not responsible for the IL-10 facilitation of GVHD lethality. Paradoxically, low doses of IL-10 protected mice against GVHD lethality. The GVHD protective effect of the bioavailability of small amounts of IL-10 was confirmed by demonstrating that the infusion of T cells from IL-10 -/- donors accelerated GVHD lethality. CONCLUSIONS: The results suggest that IL-10 has a dose-dependent effect on the GVHD lethality mediated by CD4+ or CD8+ T cells, such that high doses accelerate lethality, while low amounts of bioavailable IL-10 are protective.     

Cytokine gene expression after allogeneic bone marrow transplantation

Cytokines produced by T lymphocytes, monocytes/macrophages, and fibroblasts play a central role in the immune response and in the development of graft-versus-host disease (GVHD). Also, it has been reported that dysregulated production of cytokines maybe the primary mediator of clinical manifestation of acute GVHD. Regarding cytokine gene expression after human allogeneic bone marrow transplantation (allo BMT), we have demonstrated increased IL-1 beta, IL-6, and TNF-alpha mRNA expression in peripheral blood mononuclear cells during the development of acute and chronic GVHD and that the degree of the increase was dependent on the severity of the disease. Furthermore, overexpression of these cytokine mRNAs could be detected before the clinical manifestations of GVHD developed. In contrast, IL-2 mRNA expression was not detected in peripheral blood mononuclear cells in GVHD patients. On the other hand, we have reported that increased mRNA expression and protein product of IL-2 and IFN-gamma were evident in the mixed lymphocyte culture of the cases who developed severe lethal transplantation-related complications. Therefore, the detection of increased IL-2 and IFN-gamma gene expression in MLC appeared to be useful for predicting transplantation-related complications in BMT patients. Furthermore, we found increased IL-2 receptor alpha subunit mRNA expression in the peripheral blood mononuclear cells during GVHD. These findings may indicate the important role of inflammatory cytokines such as IL-1 beta, IL-6 and TNF-alpha in the development of the clinical manifestation of GVHD and also may be indicative of the important role of IL-2 and the IL-2 receptor in allo response perhaps mainly as an autocrine effect.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immunotherapy with donor leukocyte infusions for patients with relapsed acute myeloid leukemia following partially mismatched related donor bone marrow transplantation

Donor leukocyte infusions (DLI) were used to treat 2 patients with AML who relapsed within 4 months of treatment with partially mismatched related donor (PMRD) BMT representing 1-2 HLA-mismatches. No other form of cytoreductive therapy was given to these patients. Both patients developed GVHD (grade II-III) following DLI requiring steroid therapy. One of these patients went into complete remission following development of GVHD and immunophenotypic analysis of peripheral blood showed increased numbers of CD3+/CD8+ T cells, CD56+/CD8+ lymphokine activated killer (LAK) cells and CD16+/CD56+ natural killer (NK) cells expressing intermediate affinity IL-2 receptor P75. Unfortunately, the response was of short duration and the patient relapsed 8 weeks later ultimately resulting in death. The second patient did not show any response to DLI and died of progressive leukemia in conjunction with active GVHD. We conclude that DLI from PMRD carries a high risk for the development of GVHD and may have an anti-leukemia effect for relapsed AML. The anti-leukemic effect from PMRD DLI may be mediated by cytotoxic T lymphocytes, LAK cells and NK cells.     

Impact of previous aspergillosis on the outcome of bone marrow transplantation

A retrospective analysis of 48 patients with documented or probable invasive aspergillosis (IA) prior to bone marrow transplantation (BMT) was conducted in 16 centers. Treatment of primary IA was medical in all 48 patients and surgical in 20; clinicoradiological resolution of IA occurred in 30 of 48 patients. Pretransplantation risk factors for relapse IA, total mortality, and IA-related mortality were analyzed by multivariate logistic regression with the following dichotomous risk factors: surgery as part of the initial treatment, resolution of IA by the time of BMT, donor type, conditioning regiment, total-body irradiation, T cell depletion, immunosuppressive therapy, type of antifungal prophylaxis, and growth factor prophylaxis. Conditioning with busulfan/cyclophosphamide was associated with a beneficial outcome for total survival and reduced IA-related mortality. Posttransplantation risk factors such as the development of graft-vs.-host disease (GVHD), therapy for GVHD, and the duration of neutropenia did not have a significant effect on relapse IA, IA-related mortality, or total mortality. The overall incidence of relapse IA was lower than expected (33% [16 of 48 patients]), but the mortality rate among relapsed patients was 88% (14 of 16). Patients receiving prophylaxis with absorbable or intravenous antifungals had less relapses of IA than did those not receiving prophylaxis (12 of 41 vs. four of seven, respectively). This finding reflects the need for better prophylaxis and new antifungal treatments for patients undergoing BMT who have a history of IA.     

A novel antithrombin gene mutation: slippage and mispairing as a mechanism of genetic disease

Treatment options for acute leukemia relapsing after allogeneic BMT include conventional chemotherapy or a second transplant; however, results are rather discouraging, the first option being associated with poor survival and the second with a high mortality rate. More recently, donor leukocyte infusion (DLI) from the original donor has been used for relapsed patients in an attempt to induce a graft-versus-leukemia (GVL) effect. This procedure is partially devoid of the toxicity inherent to a second BMT. At our Institution, a 36-year-old patient with biphenotypic AML in second complete remission after relapse following allogeneic BMT was treated with peripheral blood stem cell (PBSC)-enriched donor leukocytes, obtained after in vivo priming with rhG-CSF. The patient experienced extensive cGVHD but developed a testicular relapse while in full hematologic remission. After irradiation of the sanctuary site he remains free of disease, still with chronic GVHD, 21 months after bone marrow relapse. This case suggests that immunologically privileged sites are inaccessible to GVHD/GVL effect. This should be considered when planning salvage transplants procedures in patients at risk for extramedullary involvement.     

Total body irradiation and acute graft-versus-host disease: the role of gastrointestinal damage and inflammatory cytokines

The influence of bone marrow transplantation (BMT) conditioning regimens on the incidence and severity of graft-versus-host disease (GVHD) has been suggested in clinical BMT. Using murine BMT models, we show here an increase in GVHD severity in several donor-recipient strain combinations after intensification of the conditioning regimen by increasing the total body irradiation (TBI) dose from 900 cGy to 1,300 cGy. Increased GVHD was mediated by systemic increases in tumor necrosis factor alpha (TNF alpha). Histologic analysis of gastrointestinal tracts showed synergistic damage by increased TBI and allogeneic donor cells that permitted increased translocation of lipopolysacharide (LPS) into the systemic circulation. In vitro, LPS triggered excess TNF alpha from macrophages primed by the GVH reaction. In addition, macrophages isolated within 4 hours of conditioning were primed in proportion to the TBI dose itself to secrete TNF alpha. Thus, the higher TBI dose increased macrophage priming and increased gut damage after allogeneic BMT, causing higher systemic levels of inflammatory cytokines and subsequent severe GVHD. These data highlight the importance of conditioning in GVHD pathophysiology and suggest that interventions to prevent LPS stimulation of primed macrophages may limit the severity of GVHD after intensive conditioning for allogeneic BMT.