Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018133 (graft-versus-host disease)
 18,032 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Graft-versus-host disease (GVHD) was induced across the murine major histocompatibility complex by injecting C57BL/6 (H-2b) bone marrow and splenocytes into lethally irradiated B10.BR (H-2k) murine recipients. An immunotoxin (IT) composed of a pan T-cell monoclonal antibody called anti-Ly1 (the murine homologue to human anti-CD5) was conjugated to ricin toxin A chain (anti-Ly1-RTA) and used to treat recipient mice. In vitro, IT was as active as free RTA, bound selectively, and inhibited T-cell proliferation even in the absence of potentiators. Mice administered anti-Ly1-RTA in vivo during ongoing GVHD, at a dose of 10 micrograms/d for 5 days, showed lower numbers of splenic Thy1.2+ T cells and significantly improved survival as compared with mice given phosphate-buffered saline (PBS) or irrelevant control RTA IT. Protection was transient because GVHD and weight loss occurred when injections ceased. Survival could not be enhanced by crosslinking RTA30, a low oligosaccharide-containing fraction of purified RTA. Treatment with anti-Ly1-RTA caused a significant elevation in neutrophils, and higher doses were associated with mild hepatotoxicity. In contrast, infusion of identical doses and schedules of another pan T-cell immunotoxin, anti-Thy1.2-RTA, caused a significant decrease in lymphocytes, but not neutrophils; a precipitous increase in weight; a decrease in total plasma protein (TPP); and an increase in pleural and peritoneal effusions reminiscent of vascular leak syndrome (VLS). Although the toxic effects of anti-Thy1.2-RTA were too severe to show a survival advantage in a GVHD model, histopathologic studies showed a definite anti-GVHD effect. The most significant decline in GVHD as compared with the PBS-treated controls was observed in skin, and to a lesser extent, in liver and lung. To investigate the cause of IT toxicity, anti-Thy1.2-RTA was administered intraperitoneally to lethally irradiated B10.BR (H-2k) recipients of syngeneic bone marrow. These recipients showed the same weight gain, hypoproteinuria, and VLS observed in the GVHD model. Death occurred at higher anti-Thy1.2-RTA doses (30 or 50 micrograms/daily injections administered days 8 through 12 posttransplant). Anti-Thy1.2-RTA had a negligible effect on renal function, but histologic studies showed patchy dropout of the renal tubules. Treatment resulted in pulmonary vascular congestion, but there was no pathologic evidence of liver, brain, or colon toxicity. Weight gain was enhanced by irradiation because nonirradiated normal mice did not undergo such a precipitous weight increase.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Toxicity and efficacy of anti-T-cell ricin toxin A chain immunotoxins in a murine model of established graft-versus-host disease induced across the major histocompatibility barrier. 198 94

Acute steroid-resistant graft-versus-host disease (AGVHD) after allogeneic bone marrow transplantation is frequently fatal. A new treatment for this T-lymphocyte-mediated condition uses an immunotoxin, H65-RTA, comprised of a monoclonal antibody that recognizes the CD5 lymphocyte differentiation antigen coupled to ricin A chain, a cytotoxic enzyme that inhibits protein synthesis. The safety and efficacy of this lymphocyte-targeted immunotoxin was evaluated in patients with severe AGVHD in a phase I-II dose escalation study with group expansion at the two middle doses. Thirty-four patients received up to 14 daily intravenous infusions of the immunotoxin. The principal side effects were constitutional symptoms such as fatigue and myalgias, and hypoalbuminemia with weight gain was seen at all doses. Thirty-two patients were evaluated for improvement or resolution of disease. Durable complete or partial responses were not dose-related and were seen in 16 patients. Skin GVHD had the highest incidence of response (73%), although improvement or resolution in gastrointestinal tract (45%) and liver (28%) GVHD was also noted. Survival in responding patients was significantly prolonged at all times as compared with those with no response (P = .03). Treatment was associated with a rapid decrease in peripheral blood T lymphocytes, which persisted for greater than 1 month after therapy. Anti-immunotoxin antibodies were seen in 6 of the 23 patients tested; these were of low titer and did not block immunotoxin binding to T cells. Results of this study indicate that anti-T-lymphocyte immunotoxins may form a new class of immunosuppressive agents useful in T-lymphocyte-mediated diseases.
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PMID:Use of an anti-pan T-lymphocyte ricin a chain immunotoxin in steroid-resistant acute graft-versus-host disease. 218 Apr 94

Thirty-eight patients with haematological malignancies were treated with bone marrow transplantation using histocompatible immunotoxin T cell-depleted marrow siblings. All patients received conventional postgraft immunosuppression (methotrexate and/or cyclosporin A). Donor bone marrow was treated ex vivo with T101 Fab fragment coupled to ricin A-chain (T101 Fab-RTA) at a concentration of 10(-8) M of A-chain in association with NH4Cl (2 x 10(-2) M) in pH adjusted (7.8) incubation medium. A median cytoreduction of 99.5% (91-99.5) was obtained. The median of follow-up was 300 days. Only three patients developed grade II acute graft-versus-host disease (GVHD) (actuarial rate of acute GVHD: 9.1%). No chronic GVHD occurred. All patients but one engrafted. Six out of the 37 patients developed a documented bone marrow rejection (actuarial rate of graft failure: 18%). Ten patients relapsed (actuarial rate of relapse: 36.9%). These findings demonstrate that treatment of donor marrow with T101 Fab-RTA in association with NH4Cl at critical pH value can achieve a high level of mature T cell depletion and greatly reduce the incidence of bone marrow rejection and relapse after T cell-depleted allogeneic bone marrow transplantation.
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PMID:Donor bone marrow treatment with T101 Fab fragment-ricin A-chain immunotoxin prevents graft-versus-host disease. 278 84

Young adult rat thymus and lymph node cell subpopulations were obtained by differential flotation on discontinuous BSA density gradients and assayed for properties characteristic of mature thymus-derived lymphocytes. One such subpopulation (C) of thymocytes was enriched in its ability to respond mitotically to a hemiallogeneic MLR stimulus, to localize in the parenchyma of lymph nodes and spleen, and to initiate a GVH reaction in a suitable host. These cells did not respond well to mitotic stimulation by PHA, they were lighter in density than the majority of mature lymph node thymus-derived lymphocytes, and they possessed a thymus-specific antigen (RTA) not present on peripheral lymphoid cells. We conclude that the acquisition of peripheral properties occurs sequentially, during an intrathymic differentiation cycle or shortly after the cells leave the thymus.
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PMID:Cellular differentiation in the thymus. 3. Surface properties of rat thymus and lymph node cells separated on density gradients. 553 48

Despite the use of conventional chemoprophylaxis regimens, patients receiving unrelated-donor BMT are at high risk of developing severe acute GVHD. We evaluated a prophylactic regimen combining CsA, MTX and anti-CD5-ricin A chain immunotoxin (H65-RTA) in 31 patients; pentoxifylline was also given to reduce the anticipated nephrotoxicity of CsA. In most cases, planned doses of CsA, MTX and H65-RTA were given (i.e. to 77%, 77% and 93% of patients, respectively). Although fluid retention requiring diuretic therapy was frequent, only 1 patient had a > 10% unexplained increase in body weight during the first 21 days post-BMT. Also, while significant increase of the baseline serum creatinine was noted in 7 patients, none required dialysis. One patient suffered a reversible allergic reaction to the immunotoxin; no other side effects attributable to this regimen were observed. All but 2 patients engrafted (1 died of fungemia on d + 19 and the other had persistent leukemia) and no late graft failures were observed. Seventeen patients developed acute GVHD grade > or = II (probability, 58% [95% CI 41-76%]); 7 had grade > or = III (probability, 24% [95% CI 12-43%]). In the 27 patients who achieved stable engraftment and have survived beyond d + 100, the 3-year probability of developing chronic GVHD was 66% (95% CI 48-84%). As of the last follow-up prior to 01 May 1994, 13 patients are alive in CR and one in relapse; 9 of these patients are off all immunosuppressives and well. Four other patients relapsed and died, and 13 died of other transplant-related causes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Prophylaxis for acute graft-versus-host disease following unrelated donor bone marrow transplantation. 753 67

Six patients (five children < or = 12 years old and one young adult) underwent allogeneic BMT (not T lymphocyte-depleted) from sex-matched HLA-identical siblings. GVHD prophylaxis consisted of methylprednisolone (30 mg/m2) and anti-pan T lymphocyte ricin A chain immunotoxin (H65-RTA) (0.1 mg/kg) administered daily for 12 consecutive doses. H65-RTA was initiated at day +5 (n = 4) or day +2 (n = 2). All patients engrafted. Despite receiving the planned GVHD prophylaxis, all patients developed moderate to severe acute GVHD; five patients developed Grade III/IV GVHD. Four patients died 34 to 78 days post-transplant; GVHD was a contributory cause of death in each case. H65-RTA as used in this study was ineffective for the prophylaxis of acute GVHD.
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PMID:Anti-pan T lymphocyte ricin A chain immunotoxin (H65-RTA) and methylprednisolone for acute GVHD prophylaxis following allogeneic BMT from HLA-identical sibling donors. 843 9

Most patients requiring allogeneic bone marrow transplantation (BMT) lack a human leukocyte antigen genotypically identical sibling and require an alternative donor. This carries an increased risk of graft failure and acute graft-versus-host disease (GVHD). We sought to overcome these problems with transplants by using grafts obtained from the most readily available source: the haploidentical, partially mismatched, related donor. This study of 40 patients used a novel approach combining in vitro and in vivo T cell depletion with T lymphocyte targeted monoclonal antibodies (mAb) and intensified conditioning therapy, including fractionated total body irradiation before etoposide, cytoside arabinoside, cyclophosphamide, and methylprednisolone. Grafts were treated with T10B9.1A-31 mAb, directed against the alpha-beta heterodimer of the T cell receptor, and rabbit complement. In vivo depletion was attempted with an anti-CD5 mAb-Ricin A-chain (H65-RTA) immunotoxin (IT). Study patients were compared with a historical control group of 17 patients not given H65-RTA. Rates of engraftment were not significantly different (93% vs. 100%, P=0.12), although patients receiving IT engrafted more rapidly. The incidence of > grade I GVHD was significantly lower in the study group (36% vs. 100%, P=0.0001), as well as for severe grade III-IV GVHD (19% vs. 92%, P=0.0001). Five-year survival tended to be improved in the study group (40% vs. 18%, P=0.21). Transplant from haploidentical family members is indicated for patients without a matched sibling in whom allogeneic BMT offers the best opportunity to achieve cure.
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PMID:Combined in vitro and in vivo T lymphocyte depletion for the control of graft-versus-host disease following haploidentical marrow transplant. 860 77

Immunotoxins (ITs) are potent cytotoxic agents used in the treatment of cancer, autoimmune disease, and graft-versus-host disease. Results from clinical trials demonstrate that many IT-treated patients, especially those with an intact immune system, develop anti-IT antibodies that may prohibit repeated IT dosing. We, therefore, evaluated a panel of novel immunosuppressive (IS) agents for their ability to inhibit the antitoxin immune response in mice receiving multiple courses of a ricin A chain (RTA)-containing IT and also assessed whether this suppression would result in an increase in IT-mediated antitumor activity. The results indicate that a 3-day pretreatment, plus one additional boost 2 weeks later, of a combination of hCTLA4Ig + anti-CD40L, virtually eliminated the anti-RTA response in normal mice receiving six weekly injections of an IT. When tested in BCL1 tumor-bearing mice, the concomitant use of a combination of hCTLA4Ig + anti-CD40L and six doses of the IT resulted in a 1.5-fold increase in tumor cell killing, as compared with treatment with IT alone. We conclude that a combination of IS + IT therapy should facilitate the administration of multiple courses of IT, as well as enhance its antitumor activity.
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PMID:Effect of immunosuppressive agents on the immunogenicity and efficacy of an immunotoxin in mice. 960 90