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

Twenty-three patients with primary myelodysplasia (MDS) or secondary myelodysplasia/acute nonlymphocytic leukemia (MDS/ANLL) were treated with allogeneic or syngeneic bone marrow transplantation (BMT). Only one patient was in a chemotherapy-induced hematologic remission. Graft-versus-host disease prophylaxis included methotrexate, methotrexate plus cyclosporine, cyclosporine, or T-cell depletion using one of two anti-CD5 monoclonal antibodies. For patients with primary MDS, the median age was 19 years (range, 11 to 41 years) and the actuarial disease-free survival was 56% +/- 21% (median follow-up, 2 years; range, 0.8 to 5 years). There were three graft failures (two with autologous recovery) and two early deaths. Outcome appeared to be related to French-American-British (FAB) classification. For patients with secondary MDS/ANLL, the median age was 28 years (range, 3 to 16 years) and the actuarial disease-free survival was 27% +/- 13% (median follow-up, 5 years; range, 2.5 to 8.5 years). There were no graft failures, two relapses, and four early deaths. The presence of marrow fibrosis per se did not predict for graft failure (P = .21); however, the use of T-cell depleted marrow in patients with marrow fibrosis resulted in graft failure in three of five individuals. Our results suggest that in patients with primary MDS or secondary MDS/ANLL, BMT should be considered early in the course of the disease, and that attempts at inducing a remission prior to BMT appeared to be unnecessary. In MDS patients with marrow fibrosis, T-cell depletion should be avoided.
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PMID:Bone marrow transplantation for myelodysplasia and secondary acute nonlymphoblastic leukemia. 221 6

The lymphocyte cell surface molecule CD5 (T1, Leu 1, Tp67 in the human; Ly 1 in the mouse) is expressed on the majority of circulating T lymphocytes and a small population of B cells. We have analyzed CD5 expression on repopulating T cells in the peripheral blood of patients after allogeneic bone marrow transplantation (BMT). The frequency of CD3+ T cells that lack expression of CD5 is dramatically increased after BMT compared with the normal population. The percent of total CD3+ CD5- cells correlated with the presence of graft versus host disease and with time following transplant, but did not correlate with age, diagnosis, preparative regimen, T-cell depletion of the marrow, major histocompatibility complex compatibility, or the presence or absence of interstitial pneumonitis. Furthermore, the total number and percent of CD8+ CD5- cells was increased following BMT. CD3+ cells from BMT patients were sorted for the presence or absence of CD5 expression. CD3+ CD5- cells were capable of interleukin-2 production and of mediating cytolysis following lectin stimulation. We conclude that CD3+ CD5- T cells are functional and represent a significant proportion of circulating cells in patients after BMT.
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PMID:A large proportion of T lymphocytes lack CD5 expression after bone marrow transplantation. 246 8

71 leukaemic patients having HLA-matched bone-marrow transplants (BMT) were randomised to receive whole marrow (group A) or marrow depleted of T cells by treatment with monoclonal antibodies (anti CD4-CD5-CD8, group B; anti CD2-CD5-CD7, group C) plus complement. All patients received cyclophosphamide and total body irradiation before transplantation and cyclosporin after BMT. Marrow treatment removed 97% of T cells (median) in group B and 99% in group C. Although both serious and mild graft-versus-host disease (GVHD) were reduced in T-cell depleted patients, graft failure and relapse were increased. Graft failure was caused by GVHD and transplant complications in the controls and by rejection and relapse in the T-cell depleted groups; relapse-free survival did not differ between the groups. Without better control of host immunity and of the residual leukaemia T-cell depletion of the marrow, BMT should not be pursued in standard-risk patients.
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PMID:Impact of T-cell depletion on outcome of allogeneic bone-marrow transplantation for standard-risk leukaemias. 288 38

We studied optimal conditions for ex vivo elimination of mature T cells from human bone marrow by T101 immunotoxin (T101-IT) with criteria applicable to graft-versus-host disease (GVHD) prophylaxis prior to allogeneic marrow transplantation. T101-IT consisted of T101 anti-CD5 monoclonal antibody conjugated to purified ricin A-chain toxin. Marrow mononuclear cells isolated by Ficoll-Hypaque or by fractionation with soybean lectin (SBA- cells) were incubated with T101-IT at 37 degrees C with or without ammonium chloride and/or verapamil as potential enhancers of immunotoxin potency. As controls, competitive inhibition studies with unconjugated T101 or irrelevant IgG2a antibody were carried out. Residual T cells were quantified by limiting dilution in phytohemagglutinin (PHA)-interleukin 2 (IL-2) feeder-cell-containing microcultures and hematopoietic progenitors by CFU-GM assay. We demonstrated that T101-IT in the range of 1-100 nM does not affect early total cell viability; that its delayed cytotoxicity is T-cell-specific, greatly enhanced by ammonium chloride, and moderately by verapamil--which also is not synergistic with ammonium chloride; and that 10 nM X 3 fractionated doses (i.e., added at 0, 1.5, and 3 hr of incubation) in the presence of 10 mM ammonium chloride for 4 hr at pH 7.8 consistently induces 2 log T cell depletion. In addition, if the same T101-IT treatment is preceded by fractionation with soybean lectin (i.e., T101-IT treatment of SBA- marrow cells), 3 log T cell depletion is accomplished. We conclude that T101-IT is highly effective in eliminating T cells from donor grafts. However, data presented here indicate that T101-IT should be associated with additional methods, such as soybean lectin fractionation, to ensure more effective ex vivo T cell depletion and acute GVHD prevention.
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PMID:Specific ex-vivo depletion of human bone marrow T lymphocytes by an anti-pan-T cell (CD5) ricin A-chain immunotoxin. 310 75

Graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT) is initiated by immunocompetent T cells present in the graft. Selective elimination of distinct T-cell subsets or a sufficient, but not complete T-cell depletion, might abolish severe GVHD without graft rejection and loss of the anti-tumour potential. In this study we analysed the efficacy of different monoclonal antibodies (MoAb) WT32 (CD3), OKT4 (CD4), T101 (CD5), WT1 (CD7), and WT82 (CD8) with respect to their cytotoxicity to T cells either as immunotoxin (IT) or in combination with complement. The cytotoxic potential was assessed by protein synthesis inhibition and clonogenic assays. The ricin A conjugated MoAb exerted only a minor effect on blood or bone marrow T cells, although they were highly inhibitory to T-cell lines. However, in the presence of 20 mM ammonium chloride, IT directed against CD3, CD5, and CD7 were highly cytotoxic. IT directed against CD4 and CD8 were less effective, due to a low internalization. The complement-mediated cytotoxicity was efficient for all antigens used. The natural killer (NK) activity, as measured by cytotoxicity to K562, was hardly depressed by anti-CD3, anti-CD4, anti-CD5, and anti-CD8, but was eliminated by anti-CD7. All procedures used had only a minimal effect on haematopoietic progenitors as measured by CFU-GM and BFU-E assays. We concluded that, although the T-cell population can be eliminated with the combination of anti-CD3, anti-CD5, and anti-CD7 antibodies plus complement, IT with 20 mM NH4Cl appear to kill higher amounts of T cells. Selective elimination of CD4- and CD8-positive cells is effectively obtained by MoAb with complement.
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PMID:Human T lymphocyte differentiation antigens as target for immunotoxins or complement-mediated cytotoxicity. 326 84

The efficacy of bone marrow transplant (BMT) T-cell depletion for the prevention of acute graft-versus-host disease (GVHD) has been demonstrated in animal models and in clinical studies. The importance of T-cell depletion has to be evaluated with standardized methods suitable for routine purposes. We report herein an in vitro mature T-cell depletion using a cocktail of three monoclonal antibodies (CD2, CD5, and CD7) and baby rabbit complement in 38 histocompatibility leucocyte antigen (HLA)-identical BMT with no more than grade II acute GVHD. The T-cell depletion was quantified using three prestandardized immunological methods: immunofluorescence (IF) analysis, SRBC-rosetting assay, and PHA proliferation assay. A mean of 97.5% IF-assessed T-cell depletion was achieved in the 38 BMT. The immediate IF analysis using three distinct sets of anti-T-cell monoclonal antibodies allowed us to detect a mean of 1.2% residual T cells. The SRBC-rosetting assay was not useful to quantify T-cell depletion because no residual SRBC-rosette-forming cells could be detected in every case. The results of a prestandardized PHA-induced proliferation assay gave a mean 96.7% inhibition of proliferation, and they were correlated with the IF results although the IF threshold of detection was higher. From these data we conclude that our in vitro T-cell-depletion procedure is reproducible and that standardized simple immunological methods such as immediate immunofluorescence analysis and PHA proliferation assay provide good tools to assess a T-cell depletion effective in the prevention of acute GVHD.
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PMID:T-cell depletion of bone marrow transplants: assessment of standard immunological methods of quantification. 331 22

We evaluated the inhibitory effects of two immunotoxins (IT) synthesized by linking two different anti-CD2 (T, p50) murine monoclonal antibodies (MoAb) to intact ricin (R). Pretreatment with 1000 ng ml-1 35.1-R or OKT 11a-R inhibited PHA-induced T-cell proliferation by 93% and 86%, respectively. At this IT concentration generation of alloreactive cytotoxic T-cells (CTL) was inhibited by more than 99% by either IT. 35.1-R and OKT 11a were minimally toxic to natural killer (NK) effectors or pluripotent bone marrow progenitor cells (CFU-GEMM). Blocking experiments suggested that 35.1-R and OKT 11a-R might recognize different epitopes of the CD2 (T, p50) surface determinant. Our findings show that anti-CD2 IT may be useful for T-cell depletion in allogeneic bone marrow transplantation. We compared TU3, an equimolar mixture of T101 [anti-CD5]-R, UCHT-1 [anti-CD3]-R and 35.1 [anti-CD2]-R with the TUT-cocktail (a mixture of T101-R, UCHT-1-R and TA-1 [anti-CDw18]-R. TUT is currently under evaluation in Phase 1 clinical trials as a T-cell depletion regimen for GVHD prophylaxis. TU3 was as effective as TUT-cocktail in inhibition of PHA response and CTL generation but unlike TUT spared NK effectors. Cocktails of immunotoxins directed against subpopulations of lymphocytes may be useful for more effective anti-GVHD strategies, and to circumvent problems of graft failure/rejection associated with current purgation regimens.
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PMID:Anti-CD2 (T, p50) intact ricin immunotoxins for GVHD-prophylaxis in allogeneic bone marrow transplantation. 351 22

A cooperative study was done on ex vivo treatment of bone marrow for the prevention of acute graft-versus-host disease (GvHD), in which either CD2-CD5-CD7 (14 patients) or CD2-CD3 (15 patients) monoclonal antibody cocktail and complement were used. In this study, 29 patients (12 female, 17 male; average age, 22-1/2 yr) received T-cell-depleted allograft through complement cytolysis, 26 from HLA-identical donors and 3 from HLA-mismatched donors. All of the patients had malignant disease with poor prognosis; 21 had acute leukemia, 7 had chronic granulocytic leukemia, and 1 had multiple myeloma. After bone marrow transplantation (BMT), GvHD prophylaxis was maintained in 12 patients (group 1), was stopped at day 11 in 6 patients (group 2), and was not administered to 11 patients (group 3). The treatment removed 92.65 +/- 5.36% of donor bone marrow T-cells with one round of complement lysis. Of 3 patients who received mismatched transplant, 2 did not achieve engraftment. Engraftment was achieved in all of the patients who had matched BMT. Two patients had acute GvHD, 1 with grade 2 in group 1, and 1 with grade 3 in group 3. No patient has developed chronic GvHD; for 9 patients, the follow-up is longer than 6 months. Five patients relapsed within 6 months after BMT. Eighteen patients are alive and well in complete remission, with an average follow-up of 7.5, 10.6, and 2.7 months for patients in groups 1, 2, and 3, respectively.
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PMID:Depletion of T-lymphocytes in donor marrow with pan-T monoclonal antibodies and complement for prevention of acute graft-versus-host disease: a pilot study on 29 patients. 352 74

A new pharmacologic agent, anti-CD3F(ab')2-ricin toxin A chain (RTA), was synthesized for the purpose of targeting T cells and as a means of treating established graft-versus-host disease (GVHD). The Fc region of anti-CD3 monoclonal antibody (MoAb) was removed to prevent its ability to activate T cells. The resulting F(ab')2 fragments were conjugated to deglycosylated RTA (dgRTA), a catalytic and potent phytotoxin. The resulting immunotoxin (IT) was potent (greater than 95% inhibition) and selective in inhibiting T-cell mitogenesis in vitro. In vivo, the IT depleted 80% of T cells in mice receiving bone marrow (BM) transplants. Transplantation in an aggressive acute GVHD model using C57BL/6 donor cells and H-2 disparate B10.BR recipients resulted in an infiltration of CD3-expressing cells and a median survival time (MST) of 20 to 30 days. A 5-day course of anti-CD3F(ab')2-RTA (30 micrograms/d intraperitoneally) beginning 7 days after GVHD induction was beneficial in treating established GVHD in these mice, as evidenced by significantly prolonged survival (MST, greater than 80 days), superior mean weight values, and improved clinical appearance. Neither intact anti-CD3, unconjugated anti-CD3 F(ab')2 fragments, nor a mixture of anti-CD4 and anti-CD8 MoAbs (which are highly effective in prophylactic models) were as effective. F(ab')2 fragments made from anti-Lyt-1 (the murine homologue of human anti-CD5) linked to RTA were also not effective, despite the fact that both anti-CD3F(ab')2-RTA and anti-Lyt-1F(ab')2-RTA had similar half-lives of about 9 hours. The IT also increased MST in two aggressive models of GVHD across non-H-2 minor histocompatibility barriers, indicating that the usefulness of anti-CD3F(ab')2-dgRTA is not limited to a single-strain combination. This agent should be further investigated as an alternative to current strategies for treating steroid refractory GVHD.
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PMID:Therapy for ongoing graft-versus-host disease induced across the major or minor histocompatibility barrier in mice with anti-CD3F(ab')2-ricin toxin A chain immunotoxin. 749 98

Studies were designed to prospectively evaluate the effects of selective depletion for donor T cells strongly expressing the CD3 and CD5 pan-T antigens on the incidence of leukemia relapse following bone marrow transplantation. This evaluation was performed under controlled conditions in a mouse model for MHC-matched unrelated-donor transplantation, employing Rauscher leukemic SJL/J mice as the recipients and leukemia-resistant B10.S mice as the donors. Selective donor cell depletion for CD3 and CD5 was accomplished ex vivo prior to transplantation by incubation with the appropriate monoclonal antibody plus complement. When untreated, Rauscher leukemia resulted in a 97% fatality incidence. This was reduced to 30% by the transplant of non-depleted B10.S cells, with another 37% recipients dying from GVHD and graft failure. CD3 depletion reduced the GVHd deaths to 6% but increased relapse to 62%. Conversely, CD5 depletion had no effect on relapse or on GVHD but did significantly increase graft failure, thus negatively affecting survival. Evaluation of the results, done in conjunction with flow cytometry analysis of the effects of CD3 versus CD5 depletion on the donor cells, suggests that the T cells involved in suppressing leukemic relapse in these studies, and hence contributing to the GVL response, most probably had a phenotype of CD3+, CD5-.
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PMID:Comparison of the effects of CD3 and CD5 donor T cell depletion on graft-versus-leukemia in a murine model for MHC-matched unrelated-donor transplantation. 751 54


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