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Biomedical subjects

R Storb

Publications and source records attributed to R Storb.

At least 793 records · Page 44Linked to original sources

Marrow transplantation in aplastic anemia and leukemia.

Human marrow transplantation has resulted in observations of fundamental significance in understanding both aplastic anemia and acute leukemia. For example, the observation that transplanted marrow can grow successfully in patients with aplastic anemia indicates that the disease is due to a defect in the marrow precursor cells and not in the marrow microenvironment. Similarly, the observation of recurrent leukemia in donor cells has important implications. Nonetheless, marrow transplantation is sufficiently established therapeutically to be considered the treatment of choice for patients with severe aplastic anemia, and a realistic alternative for patients with recurrent acute leukemia. We suggest that patients be managed with regard to marrow transplantation according to the general approach outlined in Table 3. Marrow transplantation and histocompatibility typing are available at increasing numbers of institutions throughout the world. More and more patients with either severe aplastic anemia or recurrent acute leukemia should have marrow transplantation available to them when it is indicated as part of optimal management of these no longer hopeless diseases.

Adult↗

Effect of six weekly transfusions on canine marrow grafts: tests for sensitization and abrogation of sensitization by procarbazine and antithymocyte serum.

We have previously shown that blood transfusions can immunize a dog and lead to rejection of a subsequent marrow graft despite lethal total body irradiation (TBI). Sensitization to histocompatibility antigens induced by two prior transfusions of whole blood could be overcome by a regimen of procarbazine and anti-thymocyte serum (ATS) preceding TBI. The current study investigated a) whether this regimen could abrogate sensitization induced by six weekly transfusions given from days --50 to --15 preceding a marrow graft, and b) whether platelet survival studies and two in vitro tests of immunity could predict marrow graft rejection. All donor-recipient pairs were histoincompatible, unrelated, and of different breed. Twenty-two recipients received platelet concentrate transfusions and eight received whole blood transfusions. Recipients were given 1200 R TBI and a graft of marrow and peripheral blood leukocytes from the transfusion donor on day 0. Three of 15 recipients (20%) given procarbazine, 12.5 mg/kg i.v. on days --8, --6, and --4, and ATS, 0.6 ml/kg subcutaneously on days --7, --5 and --3, Rejected their grafts, whereas 11 of 15 dogs (73%) not given procarbazine and ATS rejected their grafts (p less than 0.01). Serum lymphocytotoxic antibodies, peripheral leukocyte migration inhibition, and in vivo donor platelet recovery and survival were studied in those recipients receiving six weekly transfusions and in 18 other recipients receiving a single donor transfusion 3 months before marrow grafting. No significant correlation was found among these in vitro and in vivo tests of sensitization. Sensitization to marrow grafts was not reliably detected by the presence of cytotoxic antibodies or leukocyte migration inhibition. Platelet survival, however, was positively correlated with the results of marrow grafting in 12 of 15 (80%) evaluable recipients (p approximately 0.15).

Animals↗

Recovery from aplastic anemia following attempted marrow transplantation.

A 23-year-old man with severe idiopathic aplastic anemia was prepared for marrow transplantation by the administration of cyclophosphamide (CY) 50 mg/kg on each of 4 days. He then received an intravenous infusion of 9.5 x 10(9) marrow cells from an HL-A matched and mixed leukocyte culture non-reactive sister. The graft was successfully established as shown by cytogenetic studies but was rejected after approximately 4 weeks. In preparation for a second transplant he was given procarbazine 12.5 mg/kg and goat antihuman thymocyte globulin (ATG) 7 mg/kg administered on alternate days for a total of 4 doses of each agent. At the end of this therapy his white blood cell count was noted to be going up and the second transplant was not carried out. Complete hematologic recovery of host type marrow ensued and persists now 20 months later. The various pathophysiologic mechanisms that may be involved are discussed.

Adult↗

Infusion of donor lymphocytes into stable canine radiation chimeras: implications for mechanism of transplantation tolerance.

Canine radiation chimeras were used to investigate further mechanism(s) responsible for maintaining the stable chimeric state. Chimeras were studied 7 to 46 months after 1200 R total body irradiation and transplantation of marrow from a littermate donor matched at the major histocompatibility complex. An attempt was made to perturb the stable chimeric state by infusion of large numbers (0.6 to 13.7 x 10(8)/kg) of donor peripheral blood lymphocytes into each respective chimera. Two groups were studied: donors in Group A were normal; donors in Group B had been specifically sensitized against minor histocompatibility antigens of the chimera by repeated skin grafts. None of the nine chimeras in Group A developed significant clinical or histologic evidence of graft-vs-host disease (GVHD) after donor lymphocyte infusion. Eight of the 12 chimeras in Group B, however, developed GVHD which was transient in three and fatal in five. The results in Group A are not consistent with classical theories of tolerance, i.e., elimination or inactivation of potentially reactive cell clones, but suggest the presence of an active mechanism suppressing recognition of host antigens by the infused donor lymphocytes and development of GVHD. The results in Group B indicate that this mechanism can be overcome by infusion of sensitized donor cells. In an attempt to elucidate the nature of this postulated active mechanism, the cytotoxicity of donor lymphocytes for fibroblasts of the chimera and the presence or absence of serum-blocking factors were assessed in vitro by using a cellular inhibition (CI) assay. The presence of serum-blocking factors did not protect against the development of significant GVHD in two chimeras (fatal in one). GVHD did not occur in four other chimeras after infusion of cytotoxic donor lymphocytes despite the absence of serum-blocking factors. These and previous results suggest that serum-blocking factors are not the mechanisms suppressing the development of GVHD in canine radiation chimeras, and raise the possibility that a suppressor cell population may be responsible for preventing GVHD.

Animals↗

Severe aplastic anemia: a prospective study of the effect of early marrow transplantation on acute mortality.

A prospective randomized trial of therapy for severe aplastic anemia was designed to compare early bone marrow transplantation with conventional treatments. All patients with a sibling matched at the major histocompatibility region were transplanted. Transplantation was performed with 17-100 (median 33) days of original diagnosis. Conventional treatments included transfusion support with or without androgens. Twenty-four of 36 patients intered on the transplant arm are alive after 4-20 (median 9) mo with full marrow reconstitution. Only two are limited by chronic graft-versus-host disease. In contrast only 12 of 31 conventionally treated patients are alive. Six of these survivors have improved, five incompletely. The 19 nontransplant deaths have occurred within 1-11 (median 3) mo of diagnosis. Compared to nontransplant regimens, early transplantation more effectively restores normal marrow function and decreases the acute mortality of severe marrow aplasia (p = 0.006). Pending longer follow-up, early marrow transplantation appears to be the most effective available treatment for severe aplastic anemia.

Androgens↗

Experience with second marrow transplants.

This report summarizes the experience with 25 patients who received a second marrow transplant. The marrow donor for the first transplant was an identical twin in four cases and a sibling matched at the major histocompatibility complex in 21 instances. The donor for the second transplant was the same as the first except for three patients whose second donor was another matched sibling. Nine patients with aplastic anemia rejected their first graft. Four of these patients were prepared for the second graft with a regimen of procarbazine and antithymocyte globulin (ATG) followed by cyclophosphamide or total body irradiation and were successfully regrafted. One rejected the second graft, two died of septicemia and one is alive and well 10 months after the second graft. Twelve patients with hematologic malignancy had a recurrence of disease after the first transplant. Despite preparation for the second graft with a variety of intensive chemotherapeutic regimens, the five patients who did not succumb to infection showed an early recurrence of disease. Four patients with hematologic malignancy had a failure of the first graft for unknown reasons, possibly related to the administration of ATG or methotrexate. One patient prepared for the second graft with procarbazine and ATG showed evidence of engraftment but died of infection. Two out of three patients given no additional preparation were successfully grafted. One died of recurrent central nervous system leukemia after 18 months and one is alive and well 26 months after the second graft.

Anemia, Aplastic↗

Allogeneic marrow grafting for treatment of aplastic anemia: a follow-up on long-term survivors.

Eleven of twenty-four patients with severe aplastic anemia given marrow grafts from HLA-identical siblings between October 1970 and March 1973 are alive with normal marrow function and continued evidence of engraftment 3-5 yr later. Ten have been leading normal lives with no immunosuppressive or other drug therapy since day 100 postgrafting. One has had chronic graft-versus-host disease of the skin which is now slowly improving with no therapy. He returned to full-time employment in the summer of 1975. The long-term well-being of almost half of our initial patients emphasizes the importance of marrow transplantation for the treatment of severe aplastic anemia.

Anemia, Aplastic↗

Immunologic reactivity to soluble autochthonous tumor extracts in dogs with spontaneous malignancies.

The presence of tumor-associated antigens (TAA) in dogs with spontaneous lymphoma (L) or solid tumors (ST) was investigated by testing soluble tumor cell extracts for their ability to stimulate autochthonous in vitro lymphocyte blastogenesis and in vivo intradermal delayed hypersensitivity responses. Tumor extracts were prepared from tumor biopsies and control extracts were prepared from buffycoat cells of tumor dogs by hypertonic KCl solubilization. Blastogenic responses to intact, cryopreserved, autochthonous tumor cells were also determined. Fifteen of 26 (58%) L dogs and 23 of 32 (72%) ST dogs had positive blastogenic responses to at least one concentration of autochthonous tumor extracts. Blastogenic responses to tumor extract and to cryopreserved whole tumor cells correlated well when the tests were performed simultaneously. No consistent effect of autochthonous serum on the lymphocyte response to autochthonous tumor extract was observed. Two of 11 L dogs showed a positive skin test to autochthonous tumor extract and none reacted to control extract. Three of 21 ST dogs showed a positive skin test and two had a borderline response, while two ST dogs had a positive response to control extract. However, five of seven L and nine of 18 ST dogs were anergic as defined by failure to respond to intradermal PPD challenge after sensitization with Bacille Calmette-Guerin. In conclusion, lymphocytes from most dogs with spontaneous tumors underwent blastogenesis in vitro in response to autochthonous soluble tumor extracts, and these responses when tested simultaneously correlated well with responses to cryopreserved intact tumor cells. These results are compatible with the presence of TAA in extracts from cells of spontaneous canine tumors. Delayed skin test reactivity, however, was an uncommon and unpredictable finding, and does not appear to be useful in detecting TAA in the dog.

Animals↗