Jeanne E. Anderson

A role for tumour necrosis factor-α, Fas and Fas-Ligand in marrow failure associated with myelodysplastic syndrome

Apoptosis of haemopoietic cells in the marrow of patients with myelodysplastic syndrome (MDS) has been suggested as a mechanism for peripheral cytopenias. We determined the expression of Fas (CD95), Fas‐Ligand (Fas‐L) and TNF‐α factors known to be involved in apoptosis, in the marrow of 44 patients with MDS and characterized their functional relevance in in vitro assays of haemopoiesis. Multidimensional flow cytometry revealed phenotypically aberrant blasts as defined by orthogonal light scatter and CD45 expression in the marrow of 24/44 patients. Among those blasts Fas expression was increased on CD34‐positive cells and on cells co‐expressing HLA‐DR. In addition, Fas‐L was expressed on some CD34+ cells of MDS patients but was never detected on CD34+ cells in normal marrow. Fas and Fas‐L mRNAs as well as mRNA for TNF‐α, known to increase Fas expression in normal marrow, were up‐regulated in patients with MDS. TNF‐α protein and sTNF‐R1 levels in marrow plasma were higher in MDS patients than in controls (P < 0.002 and <0.003, respectively). However, results were dependent upon disease category: TNF‐α levels were significantly higher in patients with refractory anaemia (RA) than in patients with RA with excess blasts (RAEB) or RAEB in transformation (RAEB‐T) (P = 0.043). Conversely, the proportion of Fas‐L‐positive cells was lowest in patients with RA (P = 0.037). In marrow cultures, Fas‐Ig, rhuTNFR:Fc or anti‐TNF‐α antibody, by blocking Fas or TNF mediated signals, respectively, significantly increased the numbers of haemopoietic colonies compared to untreated cells (P < 0.001, P < 0.003, P < 0.001, respectively). These results show significant dysregulation in the expression of TNF‐α, Fas and Fas‐L in the marrow from MDS patients. Altered expression of these molecules appears to be of functional relevance in the dysregulation of haemopoiesis in MDS and may be amenable to therapeutic interventions.

Unrelated donor marrow transplantation for myelodysplasia (MDS) and MDS‐related acute myeloid leukaemia

Allogeneic marrow transplantation using related marrow donors for myelodysplasia (MDS) and acute myeloid leukaemia (AML) arising from MDS results in 35–56% actuarial disease‐free survival. Because the use of unrelated donors has not been well‐characterized, we report on the outcome of 52 patients with MDS or MDS‐related AML consecutively treated between 1987 and 1993 with unrelated donor marrow transplantation. The median age was 33 (range 1–53) years. 33 patients received chemotherapy and total body irradiation and the remainder busulfan and cyclophosphamide. The donors were phenotypically identical at the HLA‐A, B and Dw/DRB1 loci in 34 cases and mismatched for one HLA locus in 17 cases and two loci in one case. Marrow was non‐T‐cell depleted and methotrexate with cyclosporine or FK506 was used for postgrafting immunosuppression. The 2‐year disease‐free survival, relapse, and non‐relapse mortality rates were 38%, 28% and 48%, respectively. One patient who relapsed survives disease‐free after withdrawal of immunosuppressive therapy. 16/19 survivors have a performance status of 90–100%. Patients with MDS in transformation or with AML had a significantly higher risk of relapse than patients with less advanced disease (P = 0.0014). Increased non‐relapse mortality was significantly associated with higher age, longer disease duration before transplant, lower neutrophil count on admission and, unexpectedly, being seronegative for cytomegalovirus. We conclude that the outcome with transplantation using unrelated donors is similar to reported results using related donors and that a meaningful proportion of eligible patients with an otherwise incurable disease may be cured with this treatment. However, mortality from the transplant procedure is high and future studies should focus on reducing toxicity.

Allogeneic marrow transplantation for myelodysplastic syndrome with advanced disease morphology: a phase II study of busulfan, cyclophosphamide, and total-body irradiation and analysis of prognostic factors.

PURPOSE To determine if an intensive preparative regimen of busulfan (BU), cyclophosphamide (CY), and total-body irradiation (TBI) could improve outcome after marrow transplantation for advanced morphology myelodysplasia (refractory anemia with excess blasts [RAEB], RAEB in transformation [RAEB-T], and chronic myelomonocytic leukemia [CMML]) compared with that obtained with conventional CY/TBI and to analyze prognostic factors for transplantation for myelodysplasia. PATIENTS AND METHODS A phase II study was conducted of 31 patients (median age, 41 years) treated with BU (7 mg/kg), CY (50 mg/kg), TBI (12 Gy), and human leukocyte antigen (HLA)-matched (n = 23) or -mismatched (n = 2) related or unrelated donor (n = 6) marrow transplantation. Results were compared with 44 historical control patients treated with CY (120 mg/kg) and TBI. RESULTS The 3-year actuarial disease-free survival (DFS) rate was similar for the BU/CY/TBI group and the CY/TBI group (23% v 30%, P = .6), but there were trends toward lower relapse rates (28% v 54%, P = .27) and higher nonrelapse mortality rates (68% v 36%, P = .12) among the current patients compared with historical controls. Multivariate analysis showed that a normal karyotype pretransplant and the use of methotrexate as part of posttransplant immunosuppression were associated with improved survival and reduced nonrelapse mortality. Univariate analysis showed significant differences in relapse rates based on marrow source (57% for HLA genotypically matched marrow v 18% for all others, P = .04) and on disease morphology (66% for RAEB-T v 38% for RAEB and CMML, P = .05). CONCLUSION Patients with advanced morphology myelodysplasia tolerated the intensified BU/CY/TBI preparative regimen and reduced posttransplant immunosuppression poorly. Novel transplant procedures are needed to reduce relapse rates without increasing nonrelapse mortality rates. In addition, transplantation before progression to RAEB-T, if possible, may reduce the risk of relapse.

Allogeneic marrow transplantation for primary myelofibrosis and myelofibrosis secondary to polycythaemia vera or essential thrombocytosis

Primary myelofibrosis is a clonal haemopoietic disorder, incurable with conventional therapy, and associated with a median survival of 4–5 years. Patients with polycythaemia vera and essential thrombocytosis who progress into a myelofibrotic picture also have a poor prognosis. Between 1980 and 1996, 13 patients with myelofibrosis due to one of these three myeloproliferative disorders (primary myelofibrosis [n=8], essential thrombocytosis [n=3], polycythaemia vera [n=2]) underwent allogeneic marrow transplantation in Seattle. The median age was 40 years (range 18–49). The median time from myeloproliferative diagnosis to transplantation was 39 months (range 5–192). Three patients received preparative regimens containing total body irradiation and 10 received busulphan–cyclophosphamide regimens. Nine patients received marrow from HLA‐matched related donors, one from a one antigen mismatched related donor, and three from HLA‐matched unrelated donors. The median time to both granulocyte and platelet engraftment was 21 d. Nine patients survive between 1.2 and 7.1 years post‐transplant. Two patients relapsed at 1 year post‐transplant, both of whom survive in a chronic myeloproliferative state. Four patients died of transplant‐related complications between 43 d and 2.2 years post‐transplant. At 1 year post‐transplant the majority of the disease‐free survivors have normal peripheral blood counts and none‐to‐minimal marrow fibrosis. These preliminary results are encouraging, and suggest that stem cell transplantation can be curative therapy for selected patients with myelofibrosis.

An Update on Allogeneic Marrow Transplantation for Myelodysplastic Syndrome

Ninety-three patients with myelodysplastic syndrome with either excess blasts or life-threatening cytopenia received cyclophosphamide and total body irradiation (88 patients) or busulfan (5 patients) followed by allogeneic (90 patients) or syngeneic (3 patients) marrow infusion. Thirty-eight patients are disease-free survivors between 1.8 and 11.3 years (median 6.1 years) after transplantation. The median Karnofsky performance status of the survivors is 100%, and only 2 have a performance status of < 80%. Eighteen patients relapsed and the remaining 37 died without evidence for relapse. The 5-year actuarial disease-free survival, relapse, and non-relapse mortality rates are 40%, 29%, and 44%, respectively. The actuarial relapse rate was higher among patients with excess blasts at the time of transplantation compared to those without excess blasts (49% vs. 4%, p = 0.0001), resulting in a lower disease-free survival (31% vs. 54%, p = 0.07). Increasing age was associated with a lower disease-free survival (p = 0.02). In a multivariate analysis, younger age, shorter disease duration, and absence of excess blasts were associated with improved outcome. We recommend that patients with myelodysplasia with appropriate marrow donors, especially patients less than age 40, undergo marrow transplantation early during the disease course, before the disease progresses or life-threatening complications develop.