Acute graft-versus-host disease after allogeneic bone marrow transplantation.

In 25 patients receiving allogeneic bone marrow transplants methotrexate was used to prevent acute graft-versus-host disease (GVHD). Acute GVHD, grades 2 to 4, developed in only 5 (20%) of the patients. The incidence of acute GVHD in other series of recipients of bone marrow transplants has ranged from 5% to 76%. A review of the literature suggests that this variation cannot be completely accounted for by age, type of disease treated by transplantation or type of GVHD prophylaxis. However, transfusion of allogeneic lymphocytes that have not been completely inactivated by irradiation (e.g., in platelet and granulocyte preparations) and inadequate isolation-decontamination procedures may increase the probability of GVHD following bone marrow transplantation.     

Endotoxin tolerance in rats treated with antilymphocyte serum.

Rats were treated with rabbit anti-rat lymphocyte serum (ALS). The subsequent selective immunosuppressive effect on the immune response of thymus dependent antigen was shown by immunization with sheep red blood cells (SRBC). Endotoxin tolerance could be evoked in ALS treated animals. This suggests that the establishment of endotoxin tolerance is independent of thymus function and makes it possible to enhance the nonspecific resistance of immunosuppressed patients with a transplanted organ.     

Allogeneic T cells treated with amotosalen prevent lethal cytomegalovirus disease without producing graft-versus-host disease following bone marrow transplantation

Infusion of donor antiviral T cells can provide protective immunity for recipients of hemopoietic progenitor cell transplants, but may cause graft-vs-host disease (GVHD). Current methods of separating antiviral T cells from the alloreactive T cells that produce GVHD are neither routine nor rapid. In a model of lethal murine CMV (MCMV) infection following MHC-mismatched bone marrow transplantation, infusion of MCMV-immune donor lymphocytes pretreated with the DNA cross-linking compound amotosalen prevented MCMV lethality without producing GVHD. Although 95% of mice receiving 30 x 10(6) pretreated donor lymphocytes survived beyond day +100 without MCMV disease or GVHD, all mice receiving equivalent numbers of untreated lymphocytes rapidly died of GVHD. In vitro, amotosalen blocked T cell proliferation without suppressing MCMV peptide-induced IFN-gamma production by MCMV-primed CD8(+) T cells. In vivo, pretreated lymphocytes reduced hepatic MCMV load by 4-log(10) and promoted full hemopoietic chimerism. Amotosalen-treated, MCMV tetramer-positive memory (CD44(high)) CD8(+) T cells persisted to day +100 following infusion, and expressed IFN-gamma when presented with viral peptide. Pretreated T cells were effective at preventing MCMV lethality over a wide range of concentrations. Thus, amotosalen treatment rapidly eliminates the GVHD activity of polyclonal T cells, while preserving long-term antiviral and graft facilitation effects, and may be clinically useful for routine adoptive immunotherapy.     

Elimination of leukemia in the absence of lethal graft-versus-host disease after allogenic bone marrow transplantation

Donor T cells are able to effect a graft-vs-leukemia (GVL) response but also induce graft-vs-host disease (GVHD) after allogeneic bone marrow transplantation. We used an AKR leukemia murine transplant model, analogous to human acute lymphoblastic leukemia, in which donor T cells expressed a thymidine kinase suicide gene, to test whether separation of GVL and graft-vs-host (GVH) responses was feasible by selectively eliminating alloactivated donor T cells at defined time points posttransplant. Under experimental conditions where untreated mice could not be cured of disease without dying from GVHD, mice transplanted with thymidine kinase-positive T cells and subsequently administered ganciclovir (GCV) could eliminate leukemia without lethal GVHD. Timing of GCV administration, donor T cell dose, and preexisting leukemia burden were observed to be critical variables. Eradication of leukemia without lethal GVHD in GCV-treated mice implied that the kinetics of GVL and GVH responses were asynchronous and could therefore be temporally dissociated by timely GCV administration. That this strategy was feasible in a murine leukemia model in which GVHD and GVL reactivity are tightly linked suggests that this approach may be relevant to the treatment of selected human leukemias where similar constraints exist. This strategy represents an alternative approach to separating GVL and GVH reactivity and challenges the current paradigm that separation of these responses is dependent upon the administration of donor T cells with restricted specificity for leukemia as opposed to host Ags.     

Cytokine gene polymorphism and graft-versus-host disease: a survey in Iranian bone marrow transplanted patients

Graft versus host disease (GVHD) is a major complication of bone marrow transplantation (BMT). Numerous studies have shown the potential role of cytokine genotypes in the occurrence of GVHD. In this retrospective, case–control study we aimed to investigate the association between 13 cytokine genes and acute GVHD (aGVHD) after HLA-identical sibling BMT in 91 Iranian subjects. Negative association was found between aGVHD and donor IL-10/GCC haplotype or donor IL-4Ra-A allele in the population study. When compared within the leukemia subgroup, we observed positive association between recipient IL-1α ?889/C allele and aGVHD. Also there were negative association between recipient IL-10/CAA haplotype and donor IL-4Ra/A allele and development of aGVHD. Among the different genotypes only donor IL-4Ra and donor IL-12 showed significant association. We conclude that several cytokine polymorphisms are positively and negatively associated with aGVHD in Iranian HLA matched siblings, of which IL-4Ra and IL-12 may play important roles.     

Activation of bone marrow cells treated with Canova in vitro

Canova is a Brazilian complex homeopathic medication produced from Aconitum, Thuya, Bryonia, Lachesis and Arsenicum. Previous studies demonstrated that Canova induces up-regulation in numbers of leukocytes. The bone marrow microenvironment is composed of growth factors, stromal cells, extracellular matrix, and progenitor cells that differentiate into mature blood cells. As it is the major site of blood cell formation, we studied in vitro Canova effects on bone marrow cells of mice. Swiss mouse femurs were dissected, cleaned, and the marrow was flushed. The cells were plated, treated or not, incubated for different times and processed for light, scanning electron, and confocal microscopy, and also flow cytometry. The treatment did not modify the expression of the analyzed surface markers or cytokine production. All microscopy techniques showed that a monocytic lineage (CD11b(+)) and stromal cells (adherent cells) were activated by treatment. Canova also increased cell clusters over adherent cells, suggesting proliferation areas.     

Different subsets of T cells in the adult mouse bone marrow and spleen induce or suppress acute graft-versus-host disease.

Fractionation of normal adult mouse spleen and bone marrow cells (C57BL/Ka) was performed by discontinuous Percoll density gradients. The fractionated low density (1.050-1.060 g/ml) C57BL/Ka spleen cells completely suppressed acute lethal graft vs host disease (GVHD) when coinjected with unfractionated C57BL/Ka spleen cells into sublethally irradiated (400 rad) BALB/c mice. In dose response experiments, as few as 0.5 x 10(6) low density cells from the spleen fractions suppressed acute GVHD induced by 2.5 x 10(6) unfractionated allogeneic spleen cells. Although the low density spleen fractions inhibited acute GVHD, the high density (1.075-1.090 g/ml) spleen fractions induced acute GVHD in sublethally irradiated BALB/c recipients. Fractionation of C57BL/Ka bone marrow cells showed that none of the high or low density fractions or unfractionated cells induced lethal GVHD. When these fractions were tested for their capacity to suppress GVHD by coinjection with C57BL/Ka unfractionated spleen cells, all fractions protected the BALB/c recipients. Unfractionated bone marrow cells showed modest protection. Evaluation of the dose response characteristics of the suppressive activity of the low and middle density (1.060-1.068 g/ml) bone marrow cell fraction showed that reproducible protection could be achieved at a 5:1 ratio of inducing to suppressing cells. The low density fractions of both bone marrow and spleen cells had a marked depletion of typical TCR(+)-alpha beta CD4+ or CD8+ T cells, and a predominant population of TCR(+)-alpha beta CD4- CD8- T cells. Purified populations of the latter cells suppressed GVHD. Recipients given unfractionated C57BL/Ka spleen cells and protected with low-density bone marrow or spleen cells were chimeras.     

T-cell depletion of allogeneic bone marrow prevents acceleration of graft-versus-host disease induced by exogenous interleukin 2

Highly purified human recombinant interleukin 2 (IL-2) markedly accelerated lethal GVHD in the H-2-identical B10.BR----CBA combination, but had no effect when the donor cells were depleted of mature (Thy-1.2-positive) T lymphocytes, indicating a strong immunopotentiating effect of IL-2 on mature T cells causing GVHD. In the same donor-host combination, IL-2 did not influence the recovery from the post-transplantation bone marrow aplasia. The results suggest that IL-2 could be considered for adjuvant hormonal therapy to enhance immune recovery in recipients of T-cell-depleted allogeneic marrow.     

Hemolytic uremic syndrome in renal allografted patients treated with cyclosporin

The classical triad of hemolytic uremic syndrome (microangiopathic hemolytic anemia, severe thrombopenia, and renal failure) developed de novo in three of our renal transplanted patients under cyclosporin A treatment. The predominant morphologic findings in the grafts consisted of glomerular and arteriolar thrombosis as well as arteriolonecrosis, all features of the syndrome. In one instance, ischemic bowel disease supervened after graft removal and was associated with persistent low grade microangiopathic process. De novo hemolytic uremic syndrome has been reported in patients treated with cyclosporin A following bone marrow or liver transplantation as well as in a few renal graft recipients. This peculiar form of cyclosporin A nephrotoxicity should not be confused with acute rejection of the renal transplant.     

Hemopoietic progenitor cell function after HLA-identical sibling bone marrow transplantation: influence of chronic graft-versus-host disease

We examined hemopoietic reconstitution during the first 12 months post-transplant in 31 patients given high-dose cyclophosphamide, total body irradiation and an HLA-identical sibling marrow transplant for hematological malignancy. Unexpectedly, we found marrow CFU-gm and marrow CFU-e cells to be denser than normal throughout the first year post-transplant. While functionally adequate neutrophil and platelet counts were achieved in the first six weeks post-transplant, there were defects in hemopoietic progenitor cell function during the first year post-transplant. Although we could detect no influence from acute graft-versus-host disease (GVHD), chronic GVHD adversely affected the growth of both myeloid and erythroid blood progenitor cells.