Joel M. Rappeport

Aberrations of Suppressor T Cells in Human Graft-versus-Host Disease

To determine whether imbalances in immunoregulatory T-cell subsets exist in patients with graft-versus-host disease, we analyzed T cells in three patients with acute and in six patients with chronic graft-versus-host disease after bone-marrow transplantation. The normal human peripheral-blood T-cell compartment is composed of 80 per cent TH2-and 20 per cent TH2+ T cells, and defined by reactivity with subset-specific heteroantiserums. Human suppressor cells are TH2+, whereas helper cells are TH2-. Patients with acute and chronic graft-versus-host disease had abnormalities in these populations, and their T cells frequently bore la-like antigens. Patients with acute disease lacked TH2+ cells, and the reappearance of this subset preceded the cessation of disease activity. Chronic disease, in contrast, was more heterogeneous. Suppressor cells were lacking in two patients but increased in the other four. Two of these four patients had TH2+, la+ T cells, suggesting in vivo activation of suppressor cells. Studies showing that these TH2+, la+ cells actively suppressed the in vitro immune response support this hypothesis and suggest that the immunoregulatory cells may profoundly affect the overall immune response.

Complete Correction of the Wiskott-Aldrich Syndrome by Allogeneic Bone-Marrow Transplantation

Two patients with the Wiskott-Aldrich syndrome had complete donor lymphoid and hematopoietic engraftment after successful allogeneic bone-marrow transplantation. One patient had had only a temporary donor T-lymphocyte graft after a previous transplantation, for which he had been prepared with cytarabine and cyclophosphamide; the patients own T lymphocytes returned six months later. A repeat transplant, for which the patient was prepared with anti-human thymocyte serum, total-body irradiation and procarbazine, resulted in complete donor engraftment. The second patient underwent a successful transplantation after similar preparation, except that procarbazine was omitted. At 11 and five months after transplantation both had normal hematopoiesis and no evidence of graft-versus-host disease. This treatment of the Wiskott-Aldrich syndrome may be a model for the correction of other genetically determined immune and hematologic bone-marrow disorders.

Acute graft-versus-host disease in recipients of bone-marrow transplants from identical twin donors.

Three patients with acute leukaemia received bone-marrow from identical twin donors after pre-transplant preparation with cyclophosphamide, cytosine arabinoside, and total body irradiation. Later clinical and microscopic changes in all three patients suggested cutaneous acute graft-versus host disease. In two of the recipients thrombolytic thrombocytopenia developed during the seventh week after transplantation, and platelet half-life was reduced to 9 h in one recipient (normal 3--4 days). It is suggested that acute graft-versus-host disease in bone-marrow recipients sometimes may result from an imbalance between autoreactive lymphocytes and lymphocytes which suppress their effect and not always from genetically determined histocompatibility differences between donor and recipient.

Bone-Marrow Transplantation in Severe Gaucher's Disease

We performed allogeneic bone-marrow transplantation of normal cells in an eight-year-old patient with Type 3 Gauchers disease in an attempt to alter his progressive deterioration. The procedure resulted in complete engraftment of the enzymatically normal donor cells. Donor monocyte precursors were present in the circulation of the recipient by 28 days after transplantation. Post-transplantation beta-glucocerebrosidase activity in mononuclear white cells in peripheral blood exceeded normal levels. Despite these early results no change in Gauchers-cell infiltration of the bone marrow was noted for at least 111 days, and Gauchers cells persisted in the marrow for at least 274 days. The plasma glucocerebroside concentration ultimately returned to normal. During the post-transplantation course, until the patient died from an episode of sepsis, there was no important change in his clinical status. However, this case demonstrates that the enzymatic abnormality in hematopoietic cells in Gauchers disease is correctable by bone-marrow transplantation, leading to normalization of plasma levels of glucocerebroside. We observed the long survival of Gauchers cells, which was consistent with the lack of clinical improvement. Intervention might have been more effective earlier in the course of the disease.

Correction of infantile agranulocytosis (Kostmann's syndrome) by allogeneic bone marrow transplantation

Allogeneic bone marrow transplantation has been unsuccessful as therapy for genetically determined bone marrow disorders. In patients prepared for transplantation with drugs alone long-term hematopoietic engraftment is not achieved due to the overgrowth of the infused donor bone marrow cells by residual recipient hematopoietic stem cells. Utilizing a combination of total body irradiation and antihuman thymocyte serum, the successful eradication of the abnormal hematopoietic stem cells of patients with the Wiskott-Aldrich syndrome and now infantile agranulocytosis has been achieved. Following preparation with total body irradiation and antihuman thymocyte serum a 20 month old patient with infantile agranulocytosis has complete donor hematopoietic and lymphoid engraftment one year after a histocompatible allogeneic bone marrow transplant. Prior to transplantation, this patient had no circulating or bone marrow granulocytes; following transplantation he has normal numbers of circulating granulocytes with normal in vivo and in vitro function. This therapeutic result demonstrates that genetic disorders of myeloid function can be corrected by allogeneic bone marrow transplantation following preparation with total body irradiation and antihuman thymocyte serum, and suggests that infantile agranulocytosis is due to an intrinsic defect of the pluripotent hematopoietic stem cell and not to a micro-environmental defect.

Bone marrow transplantation for myelodysplasia and secondary acute nonlymphoblastic leukemia.

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.

Origin of cell populations after bone marrow transplantation. Analysis using DNA sequence polymorphisms.

After successful bone marrow transplantation, patient hematopoietic and lymphoid cells are replaced by cells derived from the donor marrow. To document and characterize successful engraftment, host and donor cells must be distinguished from each other. We have used DNA sequence polymorphism analysis to determine reliably the host or donor origin of posttransplant cell populations. Using a selected panel of six cloned DNA probes and associated sequence polymorphisms, at least one marker capable of distinguishing between a patient and his sibling donor can be detected in over 95% of cases. Posttransplant patient peripheral leukocytes were examined by DNA restriction enzyme digestion and blot hybridization analysis. We have studied 18 patients at times varying from 13 to 1,365 d after marrow transplantation. Mixed lymphohematopoietic chimerism was detected in 3 patients, with full engraftment documented in 15. One patient with severe combined immunodeficiency syndrome was demonstrated to have T cells of purely donor origin, with granulocytes and B cells remaining of host origin. Posttransplant leukemic relapse was studied in one patient and shown to be of host origin. DNA analysis was of particular clinical value in three cases where failure of engraftment or graft loss was suspected. In two of the three cases, full engraftment was demonstrated and in the third mixed lymphohematopoietic chimerism was detected. DNA sequence polymorphism analysis provides a powerful tool for the documentation of engraftment after bone marrow transplantation, for the evaluation of posttransplant lymphoma or leukemic relapse, and for the comprehensive study of mixed hematopoietic and lymphoid chimeric states.

B lymphocyte reconstitution after human bone marrow transplantation. Leu-1 antigen defines a distinct population of B lymphocytes.

Differences in the expression of Leu-1 (CD5) define two populations of recovering B cells after human marrow transplantation, Leu-1+ and Leu-1- B cells. The Leu-1+ B cells were polyclonal, of donor origin, and did not express detectable interleukin 2 receptor. Leu-1+ B cells generally appeared 2-4 wk after marrow grafting and often preceded the recovery of Leu-1- B cells. Acute and chronic graft vs. host disease (GvHD) resulted in the recovery of significantly fewer Leu-1+ B cells, whereas Leu-1- B cells were only decreased in acute GvHD. Multivariate analysis showed no significant effect of age, disease, prednisone or azathioprine, or ex vivo treatment of the marrow with anti-Leu-1 and complement on recovery of Leu-1+ and Leu-1- B cells, independent of the effects of GvHD. Leu-1+ B cells are a major lymphocyte population posttransplant. They may reflect a stage of differentiation of normal B cells or a separate B cell lineage.

Regulation of human immunoglobulin E synthesis in acute graft versus host disease.

Immunoglobulin (Ig) E synthesis was studied in vitro in eight patients who had received transplants of allogeneic bone marrow. Seven of these patients developed acute graft vs. host disease (GVHD) and elevated serum IgE levels, whereas the eighth did not. In vitro synthesis of IgE, but not of IgG, was elevated in cultures of lymphocytes obtained during acute GVHD (17,923 +/- 14,607 pg/10(6) cells) but not in cultures of lymphocytes obtained after resolution of the acute GVHD when the serum IgE had returned to normal (106 +/- 31 pg/10(6) cells). In contrast, lymphocytes from the patient with no acute GVHD, like normal lymphocytes, failed to synthesize IgE in vitro. The increased in vitro IgE synthesis in acute GVHD was suppressed by normal allogeneic lymphocytes and by autologous lymphocytes obtained after the resolution of the acute GVHD, but not by allogeneic lymphocytes obtained from patients undergoing acute GVHD. The deficiency in functional IgE-specific suppressor cells in acute GVHD occurred in the face of normal or increased percentages of circulating T8+ cells, which in normal subjects contain the IgE-specific suppressor cells. In two patients studied, there was evidence of activated IgE-specific, circulating helper T cells. T cells from these two patients, but not normal T cells, secreted spontaneously upon culture in vitro a factor that induced IgE, but not IgG, synthesis by normal B cells. Finally, a survey of 21 bone marrow transplant recipients revealed that acute GVHD was a necessary requirement for the development of elevated serum IgE levels in recipients of bone marrow transplants. These results suggest that acute GVHD is accompanied by an imbalance in IgE-specific immunoregulatory T cells consisting of activated helper T cells and deficient suppressor cells.

Inhibition of Normal Murine Hematopoiesis by Leukemic Cells

Inhibition of normal mouse hemopoietic stem cells by leukemic cells (C1498) was observed with use of in vitro agar and in vivo diffusion-chamber cultures. The C1498 cells were unresponsive to colony-stimulating activity, and, above a critical threshold, they inhibited normal granulocyte progenitors in agar culture. C1498 cells added to normal marrow in diffusion chambers progressively reduced granulocyte progenitors. The larger, more rapidly growing, C1498 cells showed the most inhibitory effect. Transmembrane culture of C1498 cells adjacent to normal marrow in double diffusion chambers for five to 14 days led to reduction of recovery of granulocyte progenitors (72 +/- 7 per cent of control) and pluripotent stem cells (45 +/- 7 per cent of control) from the normal marrow chambers. These results indicate that leukemic mouse cells inhibit normal mouse-marrow stem cells by releasing a diffusible substance, and this inhibition occurs primarily at the level of the pluripotent stem cell.