Franca Vassallo

Factors predicting response and graft-versus-host disease after donor lymphocyte infusions: a study on 593 infusions

Summary:In the present study, we analyze factors predicting graft-versus-host disease (GvHD) and response after donor lymphocyte infusions (DLI). A total of 100 patients received 593 DLI between June 1990 and December 2000 in a bulk dose (n=14) or in escalating dose infusions (n=86). Patients were analyzed after stratification for type of relapse: (1) molecular relapse (n=6), (2) cytogenetic relapse (n=20), (3) chronic phase of chronic myeloid leukemia (CML) or complete remission of other disease post chemotherapy (n=24), (4) CML in accele-rated/blastic phase (n=14), (5) resistant disease not responding to chemotherapy (n=36). The proportion of responders to DLI in these five groups was 100, 90, 75, 36 and 0% (P<0.0001). Factors predicting response by multivariate analysis were type of relapse (P<0.0001), post-DLI GvHD (P=0.005), pancytopenia (P=0.008), and a diagnosis of CML (P=0.04). Acute GvHD (grades II—IV) occurred in 21 patients (21%), and correlated in multivariate analysis with pancytopenia and less than four DLI. Other predictors of GvHD were the number of CD3+cells/infusion and serum levels of gamma-glutamyl transferase (γGT). The actuarial probability of treatment-related mortality was 9% for HLA identical siblings and 44% for alternative donor transplants (P=0.006). Response to DLI is predicted by tumor burden and is associated with GvHD and pancytopenia.

Donor lymphocyte infusions (DLI) in patients with chronic myeloid leukemia following allogeneic bone marrow transplantation

Donor lymphocyte infusions (DLI) were given between June 1990 and March 1996 to 18 patients with chronic myeloid leukemia (CML) for the treatment of cytogenetic (n = 6) or hematologic relapse (n = 12) following an allogeneic bone marrow transplant (BMT). Patients were divided in two groups: patients in group A (n = 8) received a large dose of donor lymphocytes (⩾1 × 108/kg), whereas patients in group B (n = 10) received escalating numbers of cells (2 × 105 up to 2 × 108/kg). The median number of DLI in group A was 2 (range 1–3); the median number of infusions in group B was 7 (range 3–9). Acute GVHD occurred in 12 patients (grades I–III) and was a major cause of death in two. The risk of developing GVHD correlated with the number of cells infused: 37%, 14%, 5% and 0% for DLI with cells ⩾1 × 108, 2 × 107/kg, 2 × 106/kg, and 2 × 105/kg, respectively (P = 0.01). Median transaminase levels were found to be significantly increased in patients with, as compared to patients without, acute GVHD (GPT 412 vs 28 IU/l; P = 0.03). Severe aplasia occurred in four and was a contributing cause of death in two patients. Overall, four patients died as a consequence of DLI and all received >1 × 108/kg cells: the actuarial risk was 38% in group A and 14% in group B (P = 0.1). There were 10 complete and three partial cytogenetic responses: the actuarial probability at 5 years of being Ph negative was 69%: it was 46% for group A and 85% for group B (P = 0.1). The longest patient is now 6 years post-DLI, Ph negative, BCR-ABL negative. The actuarial 3 year survival is 38% in group A and 86% in group B (P = 0.06). The study confirms that DLI post-BMT is not innocuous and that there is a definite long-lasting antileukemic effect in patients with CML. It also suggests that: (1) the risk of developing GVHD correlates with the number of infused cells; (2) that significant elevations of serum GPT levels are associated with GVHD; and (3) that the use of escalating doses of cells may allow the identification of side-effects and discontinuation of infusions before life-threatening GVHD has developed.

Transplantation of HLA-mismatched CD34+ selected cells in patients with advanced malignancies: severe immunodeficiency and related complications.

This trial was designed to test the use of CD34+ selected haemopoietic stem cells (HSC) in HLA‐mismatched donor–recipient pairs, following intensive conditioning with thiotepa, antilymphocyte globulin (ALG), cyclophosphamide and single‐dose total‐body irradiation (sTBI). 10 patients aged 16–50 with advanced malignancies and a two‐ or three‐antigen mismatched family donor entered this study. Donor marrow and G‐CSF primed peripheral blood cells were processed separately on CD34 columns (Ceprate). The median number of infused CD34+ cells were 5.66 × 106/kg, with 0.55 × 106/kg CD3+ cells. Nine patients received cyclosporin for graft‐versus‐host disease (GvHD) prophylaxis. Median neutrophil counts on day 21 were 2 × 109/l with a median platelet count of 60 × 109/l, but CD4 counts remained extremely depressed throughout the study. Acute GvHD was scored as grade 0–I in two patients, as grade II in seven, and grade III in one. Eight patients died at a median interval of 72 d from HSCT (range 20–144) due to cytomegalovirus (CMV) associated interstitial pneumonitis (IP) (n = 5), renal failure (n = 1), GvHD (n = 1) and Aspergillus meningitis (n = 1). Two patients are alive 365–495 d post transplant, one in remission and one in relapse.

Quantitative competitive reverse transcriptase-polymerase chain reaction for BCR-ABL on Philadelphia-negative leukaphereses allows the selection of low-contaminated peripheral blood progenitor cells for autografting in chronic myelogenous leukemia

The Philadelphia (Ph) translocation t(9;22) results in the creation of the BCR-ABL gene, which is now regarded as central to the mechanism that underlies the chronic phase of chronic myelogenous leukemia (CML). From a clinical point of view, BCR-ABL mRNA detection has become the basis for the study of minimal residual disease in CML, particularly when a complete cytogenetic remission is achieved after interferon-alpha (IFN-α) therapy or allogeneic stem cell transplantation. We have recently demonstrated that it is possible to mobilize normal peripheral blood progenitor cells (PBPC) in higher rates if this procedure is performed during the early chronic phase. In an attempt to monitor the leukemic cell content of PBPC collections, we used quantitative-competitive RT-PCR (QC-RT-PCR). Thirty consecutive Philadelphia (Ph) chromosome positive patients were enrolled in this study. After chemotherapy and G-CSF, 14 patients achieved 100% Ph-negative metaphases, nine patients had 34% and seven patients >34% leukemic metaphases. A total of 116 collection samples were studied. For each sample, BCR-ABL transcript numbers and BCR-ABL/ABL ratio were evaluated. A highly significant correlation between Ph-positive metaphases and BCR-ABL transcript numbers (r = 0.84, P< 0.0001) or bcr-abl/abl ratio (r = 0.86, P < 0.0001) was found. for patients that underwent the procedure in early chronic phase, ph-negative collections showed different levels of bcr-abl expression. bcr-abl transcript numbers varied from a median of 100/μg rna in the first and second leukaphereses, to 500/μg rna in the third and fourth leukaphereses, and 1500/μg rna in the fifth leukapheresis (P = 0.002). BCR-ABL/ABL ratio values showed similar kinetics. We have also demonstrated that there is a correlation between low values in BCR-ABL/ABL ratio (≤0.01) in the reinfused PBPC and the achievement of cytogenetic remission after autografting (χ2 test, P = 0.01). In conclusion, this study demonstrates that QC-RT-PCR for BCR-ABL is a reliable and helpful method for monitoring residual leukemic load in mobilized PBPC, particularly in Ph-negative collections. Moreover, QC-RT-PCR allows selection of the best available collections for reinfusion into patients after myeloablative therapy.

Normal primitive haemopoietic progenitors are more frequent than their leukaemic counterpart in newly diagnosed patients with chronic myeloid leukaemia but rapidly decline with time

We carried out studies to quantify Ph‐negative progenitors both in steady state and during regeneration after chemotherapy and G‐CSF in 23 newly diagnosed chronic myeloid leukaemia (CML) patients (group A) and in 14 individuals more than a year from diagnosis (nine in chronic and five in accelerated phase, group B). In steady‐state bone marrow, Ph‐negative long‐term culture initiating cells (LTC‐IC) and Ph‐negative colony‐forming‐cells (CFC) were detected in 18/23 and 14/23 patients of group A versus 3/14 and 3/14 patients of group B (P < 0.001 and P < 0.02, respectively). The absolute number of mobilized Ph‐negative progenitors was markedly higher in group A versus group B (P < 0.02 for LTC‐IC, P < 0.003 for CFC). 12/16 newly diagnosed patients mobilized Ph‐negative LTC‐IC only and the yield was in the range of normal allogeneic donors. Overall the frequency of Ph‐negative LTC‐IC in the bone marrow predicted the yield of Ph‐negative LTC‐IC mobilized into peripheral blood (P < 0.001). The bone marrow frequency of Ph‐positive LTC‐IC was considerably lower than the normal counterpart. Taken together, these findings suggest that normal progenitors are relatively well preserved in newly diagnosed CML patients, but tend to rapidly decline with time. This observation helps in the understanding of the pathogenesis of CML and has potential implications for autografting. The optimal time for a successful collection of Ph‐negative circulating progenitors would appear to be soon after diagnosis.

Cytogenetic response to autografting in chronic myelogenous leukemia correlates with the amount of BCR-ABL positive cells in the graft.

OBJECTIVE An important step in successful autografting of patients with chronic myelogenous leukemia is the delivery of a leukemia-free graft. We conducted this study to determine whether the cytogenetic response after autografting was correlated with the number of BCR ABL-positive cells present within the stem cell grafts. MATERIALS AND METHODS By BCR-ABL mRNA quantification, we studied the serial pheresis products from 40 Philadelphia (Ph)-positive patients who received ICE/mini-ICE mobilization therapy and underwent autologous stem cell transplantation. We correlated the residual disease within the graft reinfused with the cytogenetic response following transplantation, taking into consideration those responses that lasted 12 months or more. RESULTS Thirty-two patients received a graft with 0-35% Ph-metaphases and 19 received a graft with BCR-ABL/ABL ratio < or =0.01. After a median of 27 months (range, 12-50) from transplant, 18 patients achieved complete or major cytogenetic response lasting at least 12 months, and 14 of them (78%) received a graft with BCR-ABL/ABL ratio < or =0.01 (range, 0.0003-0.01). Twenty-two patients experienced short-lived responses or had >35% Ph-positive cells in the marrow after transplant, but only 5 of them (23%) had a graft with BCR-ABL/ABL ratio < or =0.01 (range, 0.001-0.01). Therefore, we found a strong association between a BCR-ABL/ABL ratio less than or =0.01 and the achievement of complete or major cytogenetic remission after autografting (chi(2) test, p = 0.0001). Patients reinfused with grafts contaminated at low levels with leukemic cells also showed a longer duration of the response (log-rank test, p = 0.0009). Eleven patients were reinfused with the lowest level of contaminated stem cell collections, according to the BCR-ABL/ABL ratio. None of these patients experienced prolonged neutropenia or thrombocytopenia following stem cell reinfusion and nine of them had long-lasting complete or major cytogenetic responses after transplant. CONCLUSION This study demonstrates that the number of BCR-ABL positive cells present in a stem cell graft is an important predictive factor for the achievement and the duration of cytogenetic response after autografting. [corrected]

Spontaneous exodus of high numbers of normal early progenitor cells (Ph‐negative LTC‐IC) in the peripheral blood of patients with chronic myeloid leukaemia at the beginning of the disease

Elevated white blood cell counts are frequently found in patients with chronic myeloid leukaemia (CML). Although some studies have disclosed that bone marrow of CML patients may contain some normal Philadelphia‐negative early progenitor cells, it has been assumed that the dramatic increase of white blood cells was entirely related to the leukaemic cell expansion. In this study we attempted to quantify the number of normal and leukaemic progenitor cells in the bone marrow and peripheral blood of newly diagnosed CML patients. Bone marrow and peripheral blood cells of eight newly diagnosed CML patients were analysed for clonogenic colony‐forming cells (CFC) and very early progenitor cells, i.e. long‐term culture initiating cells (LTC‐IC). The leukaemic (Ph‐positive) or normal (Ph‐negative) origin of progenitor cells was revealed by cytogenetic analysis performed on single colonies arising from in‐vitro assays.

High-dose cyclophosphamide followed by autografting can improve the outcome of relapsed or resistant non-Hodgkin's lymphomas with involved or hypoplastic bone marrow.

We report our experience of high-dose cyclophosphamide (HDCY) followed by high-dose therapy (HDT) and peripheral blood progenitor cell (PBPC) autografting in patients with diffuse, intermediate and high-grade non-Hodgkins lymphomas who have failed conventional treatment. From 1991 to 1996, 54 consecutive patients pre-treated with a median of two chemotherapy lines entered the study. Eighteen patients (33%) were still responders to conventional chemotherapy (sensitive relapse), and 20 patients (37%) were in partial response (PR) after chemotherapy (CT). Sixteen patients (30%) were resistant to conventional CT either at presentation (non responder) or in relapse (resistant relapse). Thirty-nine patients had bone marrow involved by disease and fifteen had an hypoplastic marrow following conventional treatment. Patients received HDCY (7gr/m2) and G-CSF or GM-CSF in order to collect PBPC. Median collected CD34+ cells was 12.3 x 10(6)/Kg (range 0.7-197). After HDT (BEAM or Melphalan + TBI) 50 patients underwent PBPC autografting. According to intention to treat, 44 (81%) of 54 patients achieved complete remission (CR) (50% after HDCY and 31% after HDT). Procedure related death occurred in 6 patients (11%), one after HDCY and 5 after autografting. Twenty-nine (66%) of 44 patients are still in CR, 7 to 63 months (median 27 months) after the procedure. Three-year probability of survival, disease-free survival and progression-free survival are 63%, 64% and 52% respectively. In conclusion, HDCY is an effective procedure not only in mobilizing PBPC, but also in reducing tumour burden. HDT with PBPC support may further improve the outcome in this category of high-risk non-Hodgkins lymphomas.