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Biomedical subjects

R Hong

Publications and source records attributed to R Hong.

At least 109 records · Page 6Linked to original sources
PubMed1985

Relapse of host leukemic lymphoblasts following engraftment by an HLA-mismatched marrow transplant: mechanisms of escape from the "graft versus leukemia" effect.

Leukemic relapses and graft versus host disease (GvHD) remain major complications following allogeneic bone marrow transplantation for leukemia. We present clinical and laboratory details for an eight-year-old boy who received a T-cell-depleted HLA-mismatched marrow transplant as therapy for acute lymphoblastic leukemia (ALL) in second remission. Engraftment with donor marrow was prompt and without any acute GvHD. Nevertheless, the patient's original ALL recurred and proved fatal. The patient remained a chimera with persistent donor lymphocytes present at the time of posttransplant relapse and subsequent to treatment with unsuccessful reinduction chemotherapy. In vitro immune studies showed that these leukemic cells could be recognized and destroyed by the donor's lymphocytes. The relapse itself suggests, however, that the donor's lymphocytes did not effectively destroy the patient's histoincompatible ALL cells in vivo following establishment of the chimeric state. Potential mechanisms are presented to account for this presumed "escape" from the postulated "graft versus leukemia" effect.

Acute Disease↗
PubMed1985

Clinical trial depleting T lymphocytes from donor marrow for matched and mismatched allogeneic bone marrow transplants.

Nine patients received T-lymphocyte-depleted histocompatible bone marrow and 28 patients received T-lymphocyte-depleted histoincompatible bone marrow. Eight of nine patients receiving matched bone marrow quickly engrafted without severe graft-versus-host disease (GvHD). None of the eight patients received anti-GvHD prophylaxis medications. Two of these eight patients are currently alive. Nonengraftment and severe GvHD were problems seen in some of the patients given the histoincompatible bone marrow. Additional cytarabine pretransplant permitted engraftment in those patients undergoing histoincompatible transplants for treatment of malignancy, and prednisone and cyclosporine posttransplant reduced the incidence of acute GvHD in those given T-lymphocyte-depleted grafts. Seven of these 28 patients are currently alive. T-lymphocyte-depleted marrow can reduce the occurrence or prevent severe acute GvHD, especially when combined with additional prednisone and cyclosporine; however, the impact on relapse patterns and survival remains to be determined. The occurrence of nonengraftment and treatment-related lymphomas are formidable problems to overcome.

Adolescent↗
PubMed1985

Transplantation of HLA-haploidentical T-cell-depleted marrow for leukemia: addition of cytosine arabinoside to the pretransplant conditioning prevents rejection.

A total of 41 patients with hematologic malignancies (other than acute leukemia in relapse) received allogeneic bone marrow transplants at the University of Wisconsin from 1 April 1980 through 31 March 1984. In an effort to minimize graft-versus-host disease, marrow was depleted of T-lymphocytes in vitro with monoclonal anti-T-cell antibody and complement prior to infusion for seven of 19 recipients of marrow from HLA-identical, MLC-nonreactive siblings, and for all 22 recipients of marrow from MLC-reactive HLA-haploidentical donors. The recipients of HLA-identical T-depleted marrow all showed excellent engraftment following standard pre-BMT conditioning with cyclophosphamide and total body irradiation. In contrast, five of five recipients of T-depleted haploidentical marrow failed to engraft following this same conditioning regimen. The addition of cytosine arabinoside to the pretransplant conditioning appeared to correct this problem, allowing engraftment in 14 of 17 subsequent patients. These clinical results, coupled with prior in vitro data, demonstrate the need to adequately suppress residual host-versus-graft immunity in order to prevent the rejection of T-cell-depleted HLA-haploidentical bone marrow.

Adolescent↗
PubMed1985

Mismatched bone marrow transplantation in children with hematologic malignancy using T lymphocyte depleted bone marrow.

Twenty children with hematologic malignancies were treated with bone marrow transplantation using histoincompatible donor marrow depleted of T lymphocytes. CT-2 and complement were used to deplete the T lymphocytes. Engraftment was not a major problem in those receiving increased pre- and posttransplant immunosuppression. Five of the 20 children are currently alive and disease-free. Complications in the other children included engraftment problems, cyclosporin toxicity, infections, and bleeding. However, for most children, durable engraftment was seen. Thus, the nonavailability of histocompatible donors is no longer a contraindication to allogeneic bone marrow transplantation for those at high risk of relapse.

Adolescent↗
PubMed1984

Autoimmune hemolytic anemia as a manifestation of T-suppressor-cell deficiency.

This report describes two children in whom autoimmune hemolytic anemia was the initial clinical manifestation of an underlying T-cell deficiency. Further investigation revealed a profound deficiency of T suppressor cells in both children as detected by monoclonal T-cell antibody (OKT8) and/or functional assays. In vitro incubation of their lymphocytes with cultured thymus epithelium or thymic factors induced T suppressor cells. In vivo treatment with cultured thymus epithelium or calf thymosin fraction 5 resulted in increased T-suppressor-cell numbers and/or function in both and possibly decreased hemolytic activity in one. These results suggest that the autoimmune process in some patients with autoimmune hemolytic anemia is associated with T-suppressor-cell deficiency and that in vivo therapy with agents that modulate T-cell function may be of therapeutic value.

Adenosine Deaminase↗
PubMed1984

The in vivo distribution of indium-111 labeled in vitro alloactivated syngeneic lymphocytes in a patient with relapsed acute myelomonocytic leukemia: implications for adoptive chemoimmunotherapy.

A single patient who had a leukemic relapse six months after receiving a syngeneic bone marrow transplant was given "adoptive chemoimmunotherapy." Lymphocytes from the patients identical twin were alloactivated and grown in T cell growth factor in vitro. After receiving chemotherapy to reduce the number of relapsed leukemia cells, he received 1.1 X 10(10) in vitro alloactivated twin lymphocytes via intravenous and intraperitoneal injections. Although progressive Candidal pneumonia was fatal and prevented analysis of either efficacy or delayed toxicity of this potential form of therapy for this patient, radioactive 111In labelling and scanning showed dissemination of these lymphocytes following either injection route, with no clinical evidence of immediate toxicity.

Adult↗
PubMed1984

Total lymphatic irradiation and bone marrow in human heart transplantation.

Six patients, aged 36 to 59 years, had heart transplants for terminal myocardial disease using total lymphatic irradiation (TLI) and donor bone marrow in addition to conventional therapy. All patients were poor candidates for transplantation because of marked pulmonary hypertension, unacceptable tissue matching, or age. Two patients are living and well more than four years after the transplants. Two patients died of infection at six and seven weeks with normal hearts. One patient, whose preoperative pulmonary hypertension was too great for an orthotopic heart transplant, died at 10 days after such a procedure. The other patient died of chronic rejection seven months postoperatively. Donor-specific tolerance developed in 2 patients. TLI and donor bone marrow can produce specific tolerance to donor antigens and allow easy control of rejection, but infection is still a major problem. We describe a new technique of administering TLI with early reduction of prednisone that may help this problem.

Adult↗
PubMed1984

Idiopathic acute interstitial nephritis: characterization of the infiltrating cells in the renal interstitium as T helper lymphocytes.

A previously healthy 39-year-old man presented with acute renal failure. There was no history of exposure to drugs nor was there any infection. Renal biopsy revealed interstitial nephritis with extensive acute degenerative changes in the tubules and extensive interstitial infiltration with mononuclear cells and no eosinophils. Monoclonal antibody staining studies identified the cells in the renal interstitium to be a helper/inducer subset of T lymphocytes. We suggest that a delayed hypersensitivity mechanism played a pathogenetic role in this patient's idiopathic acute interstitial nephritis.

Acute Kidney Injury↗
PubMed1984

Transplantation of cultured thymic fragments: results in nude mice. V. Reconstitution with xenogeneic (rat) thymic tissue.

Transplantation of F344 rat cultured thymic fragments was able to restore immune function to nude mice. Approximately half of such animals displayed increased lifespan (7-8 months). These mice were also capable of rejecting allogeneic mouse skin and rat skin from a strain (Buffalo) unrelated to the thymus donor; however, they were incapable of rejecting rat skin from the thymus donor strain. Proliferative responses to T-cell mitogens were restored. Proliferative responses to alloantigens and xenoantigens in mixed leucocyte cultures were also restored and showed the same patterns of specific reactivity and non-reactivity as in skin graft rejection. The ability to make antibody responses to specific antigens was also restored, but the responsiveness was more variable than for cell-mediated responses. Some mice were able to make antibody to rabbit serum proteins; however, fewer mice made antibody to ovalbumin. The inability to respond to ovalbumin may be due to the fact that F344 rats are low responders to this protein. These results suggest that cultured xenogeneic thymus is effective in restoring two major differentiation functions of the normal thymus gland: development of specific antigen responsiveness and non-responsiveness.

Animals↗
PubMed1984

Depletion of T cells from human bone marrow with monoclonal antibody CT-2 and complement.

CT-2 mouse monoclonal antibody to the E-rosette receptor was used with complement to deplete bone marrow of E-rosette-positive cells (T cells). Depletion of E-rosette-positive cells was complete and nontoxic to hematopoietic progenitor cells. Depletion of E-rosette-positive cells with CT-2 may decrease the severity of graft-versus-host disease following bone marrow transplantation and extend the application of bone marrow transplantation to those without HLA-identical donors.

Antibodies, Monoclonal↗
PubMed1983

Transplantation of cultured thymic fragments: results in nude mice. IV. Effect of amount of thymic tissue.

Nude mice were transplanted with varying amounts of cultured thymic fragments equivalent to tissue derived from less than 1, 1 or 3 thymuses. All amounts of tissue preserved life, restored skin graft rejection, thymus-dependent allotolerance, anti-sheep erythrocyte antibody responses and serum IgG1 levels to near normal values. Serum IgA levels, IgE and hemagglutinating responses to ovalbumin as well as mitogen proliferation were shown to be more dependent upon the mass of thymus transplanted. In some cases, allogeneic CTF transplantation results showed a greater mass effect, but this was apparent only when less than 1 thymus equivalent was used. These data correlate well with the heterogeneity of the DiGeorge syndrome and variable results seen with human CTF transplantation.

Animals↗
PubMed1983

Pediatric bone marrow transplantation: current progress and future prospects.

Ongoing clinical and laboratory research is being directed at the many problems and complications associated with clinical bone marrow transplantation. The most important goals are to increase the long-term survival of patients receiving bone marrow transplants, decrease the morbidity associated with the process, and extend this therapeutic modality to patients in need of a transplant, but without an HLA identical sibling. In addition, as these problems are resolved, and the toxicity of BMT is controlled, this form of therapy may become the treatment of choice for a number of inherited and acquired hematologic, immunologic, and metabolic disorders that are chronically progressive but ultimately fatal, yet are not now routinely treated with BMT due to the acute morbidity and mortality associated with this major procedure.

Bone Marrow Transplantation↗
PubMed1982

Clear cell sarcoma and selective IgM deficiency: a case report.

A case of clear cell sarcoma of tendons and aponeuroses and a co-existent IgM deficiency is reported. The tumor arose in the Achilles tendon with metastases to the skin, bone, and lymph nodes. The tumor, examined by light and electron microscopy, consisted of glycogen-containing clear cells with melanotic and amelanotic features. There was no detectable serum IgM. The IgA levels were normal and IgG levels were elevated. Peripheral blood lymphocytes contained a normal amount (4.5%) of IgM-bearing cells. Cultured mononuclear cells from the patient suppressed production of IgM by normal lymphocytes, suggesting a role of suppressor cells in the IgM deficiency. The co-existence of soft tissue sarcomas and immunoglobulin deficiency states is reviewed.

Achilles Tendon↗
PubMed1982

Cellular enzyme-linked immunospecific assay (CELISA). I. A new micromethod that detects antibodies to cell-surface antigens.

A novel, indirect immunoassay capable of detecting human anti-HLA antibody bound to lymphocytes has been developed. This cellular enzyme-linked immunospecific assay (CELISA) utilizes an antiglobulin covalently linked to alkaline phosphatase to quantitate the amount of anti-HLA antibody bound to cell-surface HLA antigens. During the CELISA, V-bottom polyvinyl microplates served as the receptacle in which as little as 5 microliters of sera and as few as 25,000 lymphocytes per well were incubated. We devised a rapid and simple technique to transfer the cells from the original V-bottom plate to a flat-bottom plate before adding the enzyme substrate. Using this strategy, background noise because of the nonspecific adsorption of the different protein immunoreactants to plastic was eliminated. This strategy, the identification of an optimal cell concentration and an optimal conjugate source and dilution, enabled us to detect the anti-HLA activity in sera diluted out 250-fold more than their maximum titer as determined by the microdroplet cytotoxicity test. Since this assay is capable of sensitively and objectively quantitating antibody bound to cell-surface antigens, it may be of value in the areas of transplantation, blood banking, autoimmune disease, tumor immunology, and the study of cell-surface differentiation and viral antigens.

Alkaline Phosphatase↗
PubMed1982

Lymphocyte dysfunction in congenital hypoplastic anemia.

Congenital hypoplastic anemia (Diamond-Blackfan syndrome) is thought to involve the erythropoietic cell line alone. In this study, the evaluation of lymphocyte function in five patients with this syndrome revealed a number of abnormalities. Peripheral blood T lymphocyte percentages as assessed by monoclonal antibodies were decreased in three patients. T-helper/T-suppressor cell (OKT4:OKT8) ratios were almost unity in four of the five patients. We usually find a ratio of 2:1 in normal populations. Studies of lymphocyte-mediated suppression of lymphoproliferation demonstrated an inability to generate concanavalin A-induced suppressor cells in the same four patients and impaired prostaglandin-mediated suppression in two patients. Co-culture studies revealed a T lymphocyte-mediated suppression of erythropoiesis in a single patient, who also showed suppression of the mixed lymphocyte reaction. The four remaining patients showed no excessive suppressor effects either upon erythropoiesis or lymphoproliferation. These studies demonstrate that in congenital hypoplastic anemia, the cellular defect is not restricted to the erythroid progenitor cells, but extends to the lymphocytes.

Adolescent↗