Cecile du Toit

Thrombotic thrombocytopenic purpura after allogeneic stem cell transplantation: a survey of the European Group for Blood and Marrow Transplantation (EBMT)

Summary. A survey was carried out among the European Group for Blood and Marrow Transplantation (EBMT) centres to determine the incidence, risk factors, treatment and outcome of thrombotic thrombocytopenic purpura (TTP) following allogeneic haematopoietic stem cell transplantation. TTP was defined as the simultaneous occurrence of red cell fragmentation, laboratory findings of haemolysis, red cell transfusion requirement and de novo or persistant thrombocytopenia caused by consumption, in the absence of disseminated intravascular coagulation. Forty‐five centres reported all patients (n = 406) transplanted between July and December 1996. Twenty‐three patients developed TTP; the risk of developing TTP was 6·7% at 2 years (95% CI: 4·1% to 9·3%). The median time of onset was 44 d (range 13–319) post transplantation. Significant risk factors for the development of TTP were female gender (P = 0·005) and an unrelated donor (P = 0·046). To treat TTP, cyclosporin administration was discontinued in 10 cases, plasma exchanges were performed in five cases and 12 patients received plasma infusions without plasma exchange. TTP resolved in 13 of the 23 patients (57%). The only factor predictive of resolution of TTP was the absence of nephropathy. Seven patients (30%) were alive at follow‐up of 38–45 months from the onset of TTP. Sixteen patients died; the causes were multiple, only three patients had TTP as a central factor. The median time to death was 41 d (range 1–762 d) from the onset of TTP. TTP is a relatively frequent complication of allogeneic stem cell transplantation and it is associated with high mortality, though death is usually caused by multiple factors.

Thrombotic thrombocytopenic purpura in patients with retroviral infection is highly responsive to plasma infusion therapy

We prospectively studied presentation biological differences and the response to therapy in patients with thrombotic thrombocytopenic purpura (TTP) associated with, or unrelated to human immunodeficiency virus (HIV) infection. TTP patients underwent standard evaluations and were treated with prednisone 1 mg/kg in addition to infusions of fresh frozen plasma (FFP; 30 ml/kg/d) until normalization of the platelet count. Unresponsive patients were referred for plasma exchange. Compared with HIV− TTP patients (n = 23), in HIV+ subjects (n = 21) microangiopathy was dominant among Black females, who had lower presentation Hb (median 5·8 g/dl; P = 0·03), platelet count (13 × 109/l; P = 0·05) and a CD4 count of 0·096 × 109/l. HIV+ individuals responded to FFP faster than HIV− patients and none of them required apheresis. Ten HIV− TTP patients required apheresis (P = 0·03) and four died. Responses in the HIV+ and HIV− groups occurred after treatment with a median of 33 and 55 units (one unit = 320 ml) of FFP (P = 0·004) respectively. Response to this protocol was seen in 84% (95% response in HIV+ patients). Regression analysis showed that survival was associated with younger age (P = 0·001), rapid platelet (P = 0·001) and Hb (P = 0·0009) recovery, and fewer FFP units to normal lactate dehydrogenase levels (P = 0·006). We conclude that in HIV+ individuals, microangiopathy is highly responsive to plasma infusions. This observation is important particularly when apheresis is not available.

Increased apoptosis of bone marrow cells and preserved proliferative capacity of selected progenitors predict for clinical response to anti-inflammatory therapy in myelodysplastic syndromes

To determine the relation of apoptosis and clonal proliferation in the bone marrow (BM) to the effectiveness of a therapeutic protocol described to downmodulate monokine activity in patients with myelodysplastic syndromes (MDS). Prior to protocol therapy, BM stroma was cultivated and selected CD34(+) cells were studied in stroma and cytokine-dependent clonogenic assays. The TUNEL assay was used to establish the degree of apoptosis occurring in the marrow and CD34(+) population. The effectiveness of oral ciproloxacin 500 mg b. i.d., pentoxifylline 800 mg t.i.d., and dexamathasone 4 mg t.i.d. (CPD) antiinflammatory therapy was correlated with the intensity of cell apoptosis and proliferation of BM progenitor cells. Seventeen patients were studied. Twelve patients (10 transfusion dependent) received therapy for a median of 99 days (range 49-284). Toxicity caused four patients to discontinue the drug combination. Six patients fulfilled response criteria. Four patients became transfusion independent, and 50% reduction in the need for blood transfusions was noted in one patient. Blood parameters of one untransfused patient increased by >30%. Blood count remained unsupported in three patients, even at a median of 12 months after trial discontinuation. Apoptosis of marrow cells and selected CD34(+) progenitors was detected in a median of 49.5% (range 3. 6%-90%) and 10.6% (range 3.6%-100%; p < 0.01), respectively. In patients who responded to therapy, the median apoptosis rate in the bone marrow population was 71%, in contrast to the nonresponders rate of 13% (p = 0.002). Overall clonogenic growth of selected precursors corresponded significantly with response to CPD protocol (p = 0.004). In some patients with MDS, ineffective hematopoiesis is related to high apoptotic index despite proliferation of the CD34(+) precursors. These patients seem to benefit from CPD cytokine modulatory therapeutic strategy.

Is There a Role for Autologous Stem Cell Transplantation for Patients with Acute Myelogenous Leukemia? A Retrospective Analysis

For patients with acute myelogenous leukemia (AML) who are unable to secure an acceptable HLA donor, the role of autologous stem cell transplantation (auto-SCT) has remained controversial. Its effectiveness remains unclear as, when analyzed on intention-to-treat strategies, a significant number do not undergo the procedure, whereas others seem to fail therapy from pretransplant recurrences. To improve our counseling to our patients on these 2 therapeutic options, we compared the outcome of patients in first remission of AML who actually underwent autologous or allogeneic transplantation. The choice for the type of graft was based on availability of HLA identical siblings. Patients received myeloablative conditioning followed by allogeneic or autologous cytokine mobilized peripheral blood stem cell transplantation. For prophylaxis of graft-versus-host disease (GVHD), grafts were incubated ex vivo with anti-CD52 antibodies and patients were prescribed cyclosporin until day 90. Patients were stratified by clinical and laboratory factors as well as cytogenetic risk. The endpoints were treatment-related mortality (TRM), disease-free survival (DFS), and overall survival (OS). The median presentation age for both transplant groups was 35 (14-60) years. Of the 112 consecutive patients achieving remission, autologous or allogeneic grafts were transplanted to 43 and 32 patients, respectively. There was no significant difference in the presentation clinical features, laboratory parameters, marrow morphology, or proportion of low and intermediate cytogenetic risk for both transplant options. Treatment mortality as well as relapse rate was similar (14% and 15%; 39% and 27%, respectively). At a median of 1609 and 1819 posttransplant days, 56% and 63% in each group survived. In univariate analysis performance status, cytogenetic risk, morphologic features of dysplasia, blast count, and lactate dehydrogenase (LDH) were significant factors for survival. Although for the entire group there was no difference in survival between both modalities, all patients with unfavorable cytogenetics receiving an autologous graft died of disease recurrence (3-year survival 35% versus 0%; P = .05). We conclude that patients with AML who have low or intermediate cytogenetic risk undergoing myeloablative conditioning followed by autologous or allogeneic T cell-depleted stem cell transplantation appeared to have similar outcome. However, those with unfavorable karyotype are unlikely to be cured with autologous grafts and are candidates for experimental modalities.

Combined Submyeloablative and Myeloablative Dose Intense Melphalan Results in Satisfactory Responses with Acceptable Toxicity in Patients with Multiple Myeloma

We studied in patients with multiple myeloma (MM) the efficacy, cost-effectiveness, and toxicity of a strategy of submyeloablative doses of Mel and stem cell support in the ambulatory setting, followed by a standard myeloablative dose transplant. Patients with recently diagnosed symptomatic MM received dexamethazone to induce clinical response. Cytokine mobilized peripheral blood progenitor cells (PBPC) were split into 2 aliquots and cryopreserved. Patients then received Mel 100 mg/m(2) (Mel100) and infusion of the first PBPC aliquot in an ambulatory facility. Individuals received standard neutropenia prophylaxis and no growth factor support, but were seen regularly at the clinic until recovery. The cost of this step was calculated in a cohort of 23 patients where information for the expenditure was available. Six months later patients were conditioned in the hospital with Mel 200 mg/m(2) (Mel 200) followed by nfusion of the second aliquot. This study tested the cost, effectiveness, and the toxicity of out-patient-based transplantation, as well as the rate of response (complete remission [CR], very good partial remission [VGPR], partial remission [PR], and stable disease [SD]) and overall survival (OS) of this strategy. Twenty-six female and 16 male patients, with a median age of 53 years (range: 33-68 years) and median Salmon & Durie clinical disease stage III (range: II-III) were studied. The paraprotein was IgA in 17%, IgG in 52%, and light chains in 26%. The median harvested CD34(+) x 10(6) cells/kg was 12.03 (2.25-55.4). The median interval between the 2 transplant procedures was 239 (105-376) days. The median Karnofsky presentation score was 40%, but improved to 80% after the Mel 100 and was 90% following Mel 200. Subsequent to MEL 100 response was complete (CR) in 7 and it was VGPR in 9. Mel 100 grade 3-4 toxicity was mainly hematologic, but 15 (36%) required hospital admission for a median of 5 days. The median cost of MEL100 and corresponding supportive therapy was U.S.

GVL and GVHD following the infusion of a limited number of donor CD3 cells in the therapy of leukaemia relapse after bone marrow transplantation

2,142.35. In addition, the total median cost of those who needed admission to hospital was U.S.

In stem cell transplantation, by limiting the morbidity of graft-versus-host disease tolerance to myeloablative conditioning is improved.

6,042.78. Thus, pooling costs from patients who needed or did not need admissions the average cost of this strategy was U.S.

MULTIPLE MYELOMA: INFUSIONS OF LOW DOSES OF DONOR LYMPHOCYTES ARE ALSO EFFECTIVE IN REVERSING DISEASE RECURRENCE AFTER BONE MARROW TRANSPLANTATION

3,546.50 per patient. Among Mel 200 patients, except for hematologic toxicity, no patient had greater than grade 2 side effects. On completion of the program, 20 (48%) patients achieved CR, a further 14 (33%) had VGPR, whereas 6 had PR. At a median follow-up of 659 days there were 8 deaths, 1 (2%) was related to the treatment procedures and 6 from disease progression; thus, the 1000 days OS was 73%. Significant adverse factors included older age, lower presentation Hb, and lower Karnofsky %. Nonparametric testing confirmed that good performance scores and VGPR or CR were associated with more favorable outcome. Importantly, these satisfactory results were obtained in the absence of the new biologic cell modifiers. Mel 100 was well tolerated in the outpatient setting and the overall strategy seems to be effective in inducing durable responses with acceptable toxicity.

Increasing Anthracycline Dose during Induction Chemotherapy Leads to Higher Remission Rates in Acute Myelogenous Leukaemia (AML).

To the Editor: Allogeneic bone marrow (1) and the more recent introduction of cytokine mobilized blood stem cell (2) transplantation are currently the only curative approaches in CML. However, the initial mortality from GVHD (3) and later, disease recurrence, limit the success of these procedures. T cell depletion of the progenitor cell concentrates can effectively prevent GVHD (4), but in chronic myeloid leukaemia, reports have associated this procedure with increased recurrence of the malignancy due to the loss of the putative graft-versus-leukaemia (GVL) effect (5 ) . Consequently, the infusion of donor lymphocytes has resulted in the re-establishment of the GVL, leading to clinical, cytogenetic and even molecular responses, and is now the accepted alternative to re-transplantation (6, 7). Such adoptive immunotherapy can, however, also be complicated by clinically relevant GVHD, and both GVL and GVHD appear cell-dose-dependent. In a dose escalation study, anti-neoplastic responses could be elicited at CD3’ cell numbers starting at l-Sx107 cells/kg while GVHD was uncommon below Sx108/ kg (7). We report on a patient who received adoptive immunotherapy for disease recurrence following BMT, rapidly achieved a molecular remission, but developed severe GVHD at lower CD3 numbers than usually reported in the literature. A 37-yr-old male received a BMT from his HLA identical sister for Philadelphia chromosome positive (Ph+) chronic phase CML. Myeloablative preconditioning included 6 fractions (200 cGy) of total body irradiation over 3 d, 4 fractions of total nodal irradiation (150 cGy) and cyclophosphamide 120mg/kg. He received a bone marrow graft that had been depleted of T cells by the addition of Campath ZG (anti CD 52) “into the bag” (4). By 3 months from transplantation, the patient achieved normalization of the blood counts and bone marrow morphology. However, cytogenetic analysis demonstrated a chimeric state with 13/20 44 XX metaphases but 7 were 44 XU, t(9:22). Following informed consent, absolute CD 3’ cell numbers were collected by apheresis from the original donor, defined by standard flow cytometry and fractions of CD3’ starting at Sx106 to 1x10’ cells/kg patient’s body weight were aliquoted at %log steps, cryopreserved and stored in liquid nitrogen. Five months after transplantation the patient received the first infusion of 5x106 CD3’ cells/kg body weight but S wk later he presented with biopsy proven extensive cutaneous GVHD. The aspartate aminotransferase was 110 (normal: 7-25 U/l), alanine aminotransferase was 141 (normal: 125 U/l) and alkaline phosphatase was 351 (normal: 30-70 U/l), but there was no diarrhoea. Daily cyclosporin (10 mg/kg) and prednisone (1 mg/kg) were prescribed, resulting in good control of the GVHD. A bone marrow examination 6 wk after the lymphocyte infusion showed normal morphology and karyotype, while the BCR/ABL protein was not detected. At this time he became pyrexial with a detectable pp6S antigen in leucocytes for CMV. He later developed macroscopic haematuria and cultures confirmed adenovirus infection. Chest radiology revealed bilateral pulmonary infiltrates that on lung biopsy contained filamentous fungi. He was treated with cefapime, vancomycin, gancyclovir and amphotericin B, but his renal function deteriorated and he also became leucopenic, but white cells failed to recover despite daily G-CSF (5 pg/kg). The patient’s condition continued to deteriorate and he died on d 201 post-transplantation. The necropsy did not show evidence of leukaemia or graft vs. host disease, but confirmed pulmonary aspergillosis and CMV inclusions in pneumocytes as well as extensive ureteric obstruction caused by clots from the bladder extending into the caliceal system from adenovirus infection. This patient’s case history and responses to therapy illustrate 2 salient problems related to adoptive immunotherapy for relapsed CML. First, that the immune system has a potent anti-leukae-

In Patients with Aplastic Anaemia, Conditioning with Reduced Intensity Followed by Infusion of T-Cell Depleted Grafts Is Associated with Limited Transplant Related Morbidity and Universal Survival.

Myeloablative conditioning followed by T-cell depletion of grafts and reduced intensity conditioning (RIC) has both been shown to decrease treatment related mortality (TRM). However in RIC the incidence of graft vs. host disease (GvHD) is high and patients with aggressive diseases tend to relapse. Following myeloablative conditioning, patients with chemotherapy-responsive hematological malignancies underwent transplantation from HLA identical siblings. GvHD prophylaxis was by ex viva T-cell depletion with alemtuzumab. The outcome of these patients was analysed. At transplantation, the median age of 81 consecutive individuals was 45 years (range 15-60). GvHD was seen in 10% and was commonly associated with infections resulting in one and 3 year TRM of 15 and 20.5%. Fifteen patients relapsed, 10 who had myeloproliferative syndromes or lymphoma and two with myeloma responded to DLI. For the whole group, median follow up is 777 (range 7-2702) days and 73% remain disease free. Cox regression analysis for survival showed that only occurrence of GvHD was a significant adverse factor. Age order than median was not associated with worse outcome. By reducing the incidence and severity of GvHD, T-cell depletion of grafts leads to greater tolerance to myeloablative chemotherapy, resulting in acceptable TRM. This strategy should be compared with the RIC approaches.