Cell-depleted Bone Marrow Transplantation Research Articles

Graft failure after T cell depleted HLA identical allogeneic bone marrow transplantation: risk factors in leukemic patients.

In a retrospective analysis of T cell depleted bone marrow transplantation, we have looked at different parameters in order to determine risk-factors of graft-failure after allogeneic bone marrow transplantation for leukemia. Fifty-one patients with acute leukemia or chronic myeloid leukemia have been analysed. For 33 of them, the pretransplant conditioning regimen consisted of fractionated total body irradiation (TBI) at 12 Gy prior to cyclophosphamide (120 mg/kg). The other patients received various reinforced preparative regimens. T-cell depletion consisted of treating marrow cells with pan-T monoclonal antibodies (CD2+CD3 or CD2-CD5-CD7) followed by complement mediated cytolysis. No post-transplant immunosuppressive prophylaxis was administered except for the first nine patients who received Methotrexate alone. In this group of 51 patients, 12 died within 3 months from graft-related complications and 10 developed graft failure (no engraftment or rejection). Among the possible risk factors associated with this failure, two graft-related parameters appeared significant: the number of CFU-GM progenitors and the number of viable T cells injected with the marrow inoculum. No correlation with graft failure was found with other parameters including diagnosis, disease status at transplant, conditioning regimen, age, sex, and CMV status of donor/host pairs. However, the interpretation must remain cautious because of the relatively small samples in each group.

Self-nonself discrimination and repertoire selection of human T cells differentiated in an HLA-semiallogeneic environment following bone marrow transplantation for severe combined immunodeficiency

We have analyzed allorecognition, HLA restriction and T cell receptor (TcR) diversity in an HLA-heterozygous (HLA-DRw6,7) severe combined immunodeficiency (SCID) patient whose T cell system had been repopulated by HLA-homozygous (HLA-DRw6) paternal T cells following T cell-depleted bone marrow transplantation (BMT). Donor origin of T cells and host origin of antigen-presenting cells (APC) in peripheral blood and BM is shown by HLA typing of separated cell populations and two-color immunofluorescence using an anti-HLA monoclonal antibody (mAb). Peripheral blood lymphocytes (PBL) from the chimeric patient proliferate normally against PHA, anti-TcR/CD3 mAb, pooled allogeneic PBL, and also against the recall antigen (Ag) tetanus toxoid and purified protein derivative of tuberculin (PPD) following immunization, suggesting recognition by donor (DRw6) T cells of Ag presented by host (DRw6,7) APC. PPD-specific cytotoxic T lymphocytes generated in vitro from patient PBL post-BMT display specific cytotoxicity against targets expressing DRw6 and DR7, but not against DR-mismatched targets, suggesting that HLA restriction of Ag recognition may occur through determinants expressed by the host and not by the donor. Donor T cells differentiated in the HLA-semiallogeneic host show specific proliferative and cytotoxic responses against HLA-mismatched stimulators, but not against stimulators taken from the host, expressing the host-specific HLA-haplotype, or expressing the host-specific HLA-DR7 antigens. Compared to T cells directly taken from the donor, differentiation of donor T cells in the host is associated with a significant decrease of T cells expressing TcR V beta 5 and V alpha 2 determinants, while no differences in the abundance of of TcR V beta 6, V beta 8 and V beta 12 subsets were noticed. We conclude that allorecognition, major histocompatibility complex (MHC) restriction and TcR diversity generation of human T cells can be modulated through differentiation in an MHC-different environment, as had been previously shown to be the case in murine model systems.

Cytogenetic analysis of chimerism and leukemia relapse in chronic myelogenous leukemia patients after T cell-depleted bone marrow transplantation

Serial cytogenetic studies were performed on 64 patients with chronic myelogenous leukemia (CML) after T cell-depleted allogeneic bone marrow transplantation (BMT). Forty patients with CML in chronic phase (CP) received cytoreduction followed by BMT with HLA-matched T cell-depleted allogeneic marrow. The remaining 24 patients were transplanted in second chronic, accelerated, or blastic phase, or received T cell- depleted grafts with a dose of T cells added back. The Y chromosome and autosomal heteromorphisms were used to distinguish between donor and host cells. Mixed hematopoietic chimerism (presence of donor and host cells) was identified in 90% of patients in first CP. The Philadelphia (Ph) chromosome reappeared in 16 of the 40 first CP CML patients. As expected, patients who had detectable Ph chromosome positive cells at any time during the posttransplant period had a high likelihood of subsequent clinical relapse. Transient disappearance of the Ph positive clone was rarely observed, and was followed by reappearance of the Ph chromosome or clinical relapse. A subset of engrafted patients with greater than 25% host cells within 3 months post-BMT had a significantly shorter survival time free of cytogenetic or clinical relapse compared with other patients. In patients who had received donor T cells added to the T cell-depleted graft, there was a higher proportion of complete chimerism. Clonal progression of Ph positive as well as negative cells was observed and may be the result of radiation induced breakage. Serial cytogenetic studies of patients post-BMT can provide useful information regarding the biologic and clinical behavior of CML.

Cytogenetic Analysis of Chimerism and Leukemia Relapse in Chronic Myelogenous Leukemia Patients After T Cell-Depleted Bone Marrow Transplantation

Serial cytogenetic studies were performed on 64 patients with chronic myelogenous leukemia (CML) after T cell-depleted allogeneic bone marrow transplantation (BMT). Forty patients with CML in chronic phase (CP) received cytoreduction followed by BMT with HLA-matched T cell-depleted allogeneic marrow. The remaining 24 patients were transplanted in second chronic, accelerated, or blastic phase, or received T cell-depleted grafts with a dose of T cells added back. The Y chromosome and autosomal heteromorphisms were used to distinguish between donor and host cells. Mixed hematopoietic chimerism (presence of donor and host cells) was identified in 90% of patients in first CP. The Philadelphia (Ph) chromosome reappeared in 16 of the 40 first CP CML patients. As expected, patients who had detectable Ph chromosome positive cells at any time during the posttransplant period had a high likelihood of subsequent clinical relapse. Transient disappearance of the Ph positive clone was rarely observed, and was followed by reappearance of the Ph chromosome or clinical relapse. A subset of engrafted patients with greater than 25% host cells within 3 months post-BMT had a significantly shorter survival time free of cytogenetic or clinical relapse compared with other patients. In patients who had received donor T cells added to the T cell-depleted graft, there was a higher proportion of complete chimerism. Clonal progression of Ph positive as well as negative cells was observed and may be the result of radiation induced breakage. Serial cytogenetic studies of patients post-BMT can provide useful information regarding the biologic and clinical behavior of CML.

Development of multiple monoclonal serum immunoglobulins (multiclonal gammopathy) following both HLA-identical unfractionated and T cell-depleted haploidentical bone marrow transplantation in severe combined immunodeficiency

We have identified five patients with severe combined immunodeficiency (SCID) who developed multiple monoclonal serum immunoglobulin components (multiclonal gammopathy) following bone marrow transplantation. Four patients received haploidentical bone marrow stem cells depleted of T cells and other mature marrow cells by soy lectin agglutination and/or sheep erythrocyte rosetting. One patient received unfractionated HLA-identical bone marrow. Twenty-one distinct paraproteins were detected: 14 IgG, 5 IgM, and 2 IgA, all containing either kappa or lambda light chains. In the haploidentical stem-cell recipients, these monoclonal immunoglobulins appeared immediately prior to, or concomitant with, a rise in T-cell numbers and function. Resolution or diminution of this multiclonal gammopathy occurred as T-cell function was established. Posttransplant karyotypic analyses revealed PHA-stimulated T cells to be of donor origin in all patients. Karyotyping of B-cell lines posttransplantation revealed them to be 100% donor in the patient receiving unfractionated HLA-identical marrow and 100% host (1/4), 100% donor (1/4), mixed (1/4), or not tested (1/4) in the patients receiving haploidentical marrow stem cells. There was no evidence of Epstein-Barr virus (EBV) infection in any of the patients. All patients are currently alive and well. Immunoglobulin synthesis is normal in the patient who received the HLA-identical marrow but remains below normal in the four patients who received T cell-depleted haploidentical stem cells. The posttransplantation development of monoclonal immunoglobulins in the absence of EBV infection did not adversely affect the outcome of either HLA-identical marrow or haploidentical stem-cell grafting.(ABSTRACT TRUNCATED AT 250 WORDS)

Lymphokine-activated killer cells in primary immunodeficiencies and acquired immunodeficiency syndrome

Cytotoxic mechanisms (e.g., natural killer (NK) lysis, antibody-dependent cellular cytotoxicity, and cytotoxic T lymphocyte lysis) play an important role in host defense against various infections and neoplasms. Lymphokine-activated killer (LAK) cytotoxicity, induced in vitro by incubating mononuclear cells with interleukin 2 (IL-2) for 2–5 days, may also represent an important component of the body's cytotoxic repertoire. In 10 patients with congenital cellular immunodeficiencies, including 5 with severe combined immunodeficiency, the mean LAK activity in a 3-hr chromium release assay against Raji target cells was 44 ± 8.1%, which is equivalent to that observed in normal adults and neonates. In only one case, a patient with reticular dysgenesis, was there absent LAK cell generation. Haploidentical T cell-depleted bone marrow transplantation (BMT) restored LAK activity in this patient. LAK activity was first observed in this patient and two other 3–6 weeks following BMT, prior to other evidence of immunologic engraftment such as lymphocyte proliferation to mitogens, NK activity, or interferon-γ production. One patient with adenosine deaminase deficiency showed normal levels of LAK activity despite absent NK activity. Three patients with chronic granulomatous disease also had normal LAK activity (57 ± 14% specific lysis). In 9 patients with acquired immunodeficiency syndrome (AIDS), IL-2 activation resulted in a mean cytotoxic activity of 56 ± 8.7% toward Raji targets. In addition, 9 patients with pre-AIDS complex also showed normal levels of cytotoxicity (37 ± 3.3% toward Raji targets), equivalent to that of 8 normal controls, including two healthy homosexual males (mean lysis 38 ± 3.9%). These results indicate that LAK cells appear early in immunologic ontogeny. Further, the mechanism of lysis is not oxygen dependent since LAK activity was present in the 3 patients with chronic granulomatous disease. The ability to generate LAK in a wide spectrum of immunodeficiences may indicate that IL-2 could be used in therapy of such disorders.

CARDIAC ALLOGRAFT SURVIVAL ACROSS MAJOR HISTOCOMPATIBILITY COMPLEX BARRIERS IN THE RHESUS MONKEY FOLLOWING T LYMPHOCYTE-DEPLETED AUTOLOGOUS MARROW TRANSPLANTATION

We have studied organ allograft survival in rhesus monkeys conditioned with myeloablative total-body irradiation and T cell-depleted autologous bone marrow transplantation then given a heterotopic MHC-mismatched cardiac allograft in the immediate postmyeloablative period. This model has enabled us to investigate the role of T cells in vascularized organ allograft rejection. We previously reported (1) that recipients of marrow depleted of T cells below a critical threshold (0.16% residual marrow T cells, or 0.14 x 10(5) infused T cells/kg) experienced a period of freedom from acute rejection associated with a profound nonspecific immune deficiency (determined by skin grafting). Resolution of the nonspecific immune deficiency was associated with late graft rejection. In the present report, we correlate the results of peripheral immune reconstitution studies and direct immunohistochemical analysis with allograft status in order to study T cell subsets involved in late rejection. We report that, in contrast with CD8+/CD28- T cells, CD16+ NK cells, and CD20+ B cells, late allograft rejection was associated with the return of peripheral CD4+ T cells and CD8+/CD28+ T cells, suggesting a critical role for one or both of these subsets in late allograft rejection in this model.

Mixed Blood Chimerism in T Cell-Depleted Bone Marrow Transplant Recipients: Evaluation Using DNA Polymorphisms

We have used DNA sequence polymorphism analysis to document engraftment after T cell-depleted bone marrow transplantation (BMT), with a selected panel of four DNA probes. In contrast to nondepleted BMT recipients, the patients who received T cell-depleted marrow exhibited a mixed blood chimerism. This mosaicism was observed before graft failure or relapse in six patients. However, in five other patients, this mixed chimerism was not followed by these complications with a follow-up of 9 to 31 months after transplantation. Our results support the hypothesis that transplanted bone marrow T cells may help to maintain engraftment by eliminating host cells that can cause graft failure.

Mixed blood chimerism in T cell-depleted bone marrow transplant recipients: evaluation using DNA polymorphisms

We have used DNA sequence polymorphism analysis to document engraftment after T cell-depleted bone marrow transplantation (BMT), with a selected panel of four DNA probes. In contrast to nondepleted BMT recipients, the patients who received T cell-depleted marrow exhibited a mixed blood chimerism. This mosaicism was observed before graft failure or relapse in six patients. However, in five other patients, this mixed chimerism was not followed by these complications with a follow-up of 9 to 31 months after transplantation. Our results support the hypothesis that transplanted bone marrow T cells may help to maintain engraftment by eliminating host cells that can cause graft failure.

Retarded Recovery of Functional T Cell Frequencies in T Cell–Depleted Bone Marrow Transplant Recipients

AbstractWe have studied the effect of removing donor T cells by treatment with the monoclonal antibody Leu-1 and complement before marrow transplantation on the regeneration of functionally competent T lymphocytes in the blood at selected times after transplant. Using sensitive limiting-dilution methods that allow us to enumerate helper, cytotoxic, and proliferating T lymphocyte precursors, we report that regeneration of a functional T cell compartment is more severely impaired for the first 180 days after transplantation in those patients given T cell–depleted bone marrow than in recipients of untreated marrow. After this first 6 months, however, patients given T cell–depleted bone marrow had blood T cell frequencies comparable to those observed in patients given untreated marrow. Diminished frequencies of reactive T cells in recipients of depleted marrow could leave them more susceptible to infection or to the recurrence of neoplastic cells.

Retarded recovery of functional T cell frequencies in T cell-depleted bone marrow transplant recipients

We have studied the effect of removing donor T cells by treatment with the monoclonal antibody Leu-1 and complement before marrow transplantation on the regeneration of functionally competent T lymphocytes in the blood at selected times after transplant. Using sensitive limiting-dilution methods that allow us to enumerate helper, cytotoxic, and proliferating T lymphocyte precursors, we report that regeneration of a functional T cell compartment is more severely impaired for the first 180 days after transplantation in those patients given T cell-depleted bone marrow than in recipients of untreated marrow. After this first 6 months, however, patients given T cell- depleted bone marrow had blood T cell frequencies comparable to those observed in patients given untreated marrow. Diminished frequencies of reactive T cells in recipients of depleted marrow could leave them more susceptible to infection or to the recurrence of neoplastic cells.

Human large granular lymphocytes induce immunoglobulin synthesis after bone marrow transplantation.

Following T cell-depleted bone marrow transplantation, helper T cell numbers remain depressed for some months. Nonetheless, functional B cells can be adoptively transferred to the recipients of such grafts, where they continue to secrete antibody. We now show that immunoglobulin production by these transferred B cells is induced by activated large granular lymphocytes (LGL) which circulate in the recipients in substantial numbers during the immediate post-transplant period. The LGL are CD3 negative and therefore provide help in an antigen-unlinked manner. Helper effects for autologous (donor) B cells are augmented by the addition of anti-LFA-2 (anti-CD2) which appears to act by blocking recruitment of LGL inhibitory to developing B cells. In contrast antibody to the beta chain of LFA-1, which effectively reduces natural killer activity of LGL, does not influence their helper function. The peripheral blood LGL fraction thus contains both helper and cytotoxic activity, which can be distinguished by appropriate monoclonal antibodies.

Clonable T Lymphocytes in T Cell-Depleted Bone Marrow Transplants Correlate With Development of Graft-v-Host Disease

Early clinical trials using T lymphocyte-depleted human marrow for transplantation have reported that such grafts reduce, to varying degrees, both the incidence and the severity of graft-v-host disease (GVHD). However, to date, no clear estimates have been made as to what degree of T cell depletion is necessary to prevent GVHD in every case. To address this problem, we used a limiting dilution assay (LDA) to quantitate residual clonable T lymphocytes in human T cell-depleted bone marrow in 31 HLA-identical transplants for leukemia. The number of phytohemagglutinin -interleukin 2-responsive T lymphocytes determined by LDA and expressed as T cell per kilogram recipient weight was found to correlate with the subsequent development of GVHD: no patients who received less than 1 X 10(5) T cell per kilogram developed GVHD (N = 24). Of the seven patients who received 1 X 10(5) to 4.4 X 10(5) T cell per kilogram, four patients developed grade I or II skin GVHD. This study thus provides a quantitative estimate of the number of T lymphocytes necessary to initiate clinically detectable GVHD in an HLA-identical host.

Clonable T lymphocytes in T cell-depleted bone marrow transplants correlate with development of graft-v-host disease

Early clinical trials using T lymphocyte-depleted human marrow for transplantation have reported that such grafts reduce, to varying degrees, both the incidence and the severity of graft-v-host disease (GVHD). However, to date, no clear estimates have been made as to what degree of T cell depletion is necessary to prevent GVHD in every case. To address this problem, we used a limiting dilution assay (LDA) to quantitate residual clonable T lymphocytes in human T cell-depleted bone marrow in 31 HLA-identical transplants for leukemia. The number of phytohemagglutinin -interleukin 2-responsive T lymphocytes determined by LDA and expressed as T cell per kilogram recipient weight was found to correlate with the subsequent development of GVHD: no patients who received less than 1 X 10(5) T cell per kilogram developed GVHD (N = 24). Of the seven patients who received 1 X 10(5) to 4.4 X 10(5) T cell per kilogram, four patients developed grade I or II skin GVHD. This study thus provides a quantitative estimate of the number of T lymphocytes necessary to initiate clinically detectable GVHD in an HLA- identical host.

A correlation between conditioning and engraftment in recipients of MHC-mismatched T cell-depleted murine bone marrow transplants.

We studied engraftment in a murine model of allogeneic bone marrow (BM) transplantation. Recipient C57BL/6 (H-2b) mice were conditioned with single-dose (9 or 7.5 Gy) total body irradiation (TBI), fractionated (4 X 3.3 Gy) TBI, hyperfractionated (8 X 1.65 Gy) TBI, 2 X 120 mg/kg cyclophosphamide (CY) followed by 7.5 Gy TBI, or 300 mg/kg CY followed by 9 Gy total lymphoid irradiation (TLI). Conditioned mice were transplanted with BALB/c (H-2d) BM supplemented with splenocytes (BMS) to facilitate graft-vs-host disease (GVHD). Ex vivo T cell depletion of the BMS with anti-Thy-1.2 antibody and complement protected recipients from lethal GVHD. Engraftment was measured in transplanted animals by serotyping peripheral blood mononuclear cells with anti-H-2-specific antibodies and complement. Mice that were given a T cell-depleted BMS transplant after conditioning with 9 Gy TBI, fractionated TBI, or CY plus TBI showed a 99 to 100% incidence of engraftment. However, if the T cell-depleted graft was given to mice conditioned with hyperfractionated TBI, 7.5 Gy TBI, or CY plus TLI, only 3 to 32% of the animals engrafted. BM which was not T cell-depleted engrafted in 63 to 100% of the mice regardless of the conditioning used. Nonengrafted mice tested with anti-host type antibody demonstrated autologous recovery. We conclude that engraftment or failure/rejection of BM in transplanted mice is determined in part by a dynamic equilibrium between T cells present in the donor graft and the surviving hemopoietic cells in the conditioned recipient. More intensive conditioning of the recipient allows engraftment of T cell-depleted, mismatched BMS. Such conditioning is not limited to a single modality, but can be achieved with single-dose TBI, fractionated TBI, or with TBI combined with CY. These findings have timely and important implications for the current understanding of engraftment in human allogeneic BM transplantation following T cell depletion.

Transplantation of Major ABO‐Incompatible Bone Marrow Depleted of Red Cells by Hydroxyethyl Starch1

23 bone marrow transplant recipients whose donors where major ABO-incompatible received marrow depleted of red cells prior to infusion utilizing gravity sedimentation in hydroxyethyl starch. The in vitro red cell-depletion procedure effectively removed 97.8% (mean) of the red cells from the harvested marrows and preserved 86.8% of the nucleated cells and 98.2% of the CFU-C activity in 25.4% of the original volume. All recipients had a significant quantity of isohemagglutinins of both IgM and IgG classes demonstrable in their serum at the time of the marrow infusion. Patients were premedicated and well-hydrated prior to the infusion and tolerated the infusion well. These patients demonstrated bone marrow engraftment at the same rate as did those patients whose marrow donors were either ABO-identical or minor ABO-incompatible. There was no difference in the incidence of or time to development of graft versus host disease, the incidence of graft rejection, or patient survival among the groups. Recipients of red cell-depleted major ABO-incompatible bone marrow transplants demonstrated production of donor-type red cells somewhat later and required slightly more red cell transfusion support that did the other groups of recipients. This red cell-depletion technique is safe and effective in the management of major ABO-incompatible bone marrow transplantation.

IgE antipolymyxin B antibody formation in a T cell-depleted bone marrow transplant patient

The production of IgE-class antibody specific for polymyxin B is documented in an 18-year-old white female acute myelocytic leukemic patient in relapse. The patient was rendered T cell-deficient by total body X-irradiation and antihuman thymocyte globulin for the purpose of bone marrow transplantation. Thereafter, symptoms of nasal congestion, rhinorrhea, and perinasal urtication produced by topical application of a polymyxin solution were noted. Reaginic activity mediated by an IgE antibody against polymyxin is documented by Prausnitz-Küstner-type passive transfer reactions and by an indirect hemagglutination technique developed for these studies. The occurrence of type I hypersensitivity to this topical antibiotic is rare. It is speculated that pharmaceuticals normally having a low sensitizing potential might demonstrate increased reaginic immunogenicity in a spontaneously or iatrogenically T cell-depleted patient.