Elizabeth Naparstek

T-cell-depleted allogeneic bone marrow transplantation for acute leukaemia using Campath-1 antibodies and post-transplant administration of donor's peripheral blood lymphocytes for prevention of relapse

One hundred and forty‐six patients with acute leukaemia (81 with ANLL and 65 with ALL) received allogeneic bone marrow transplantation from their fully matched siblings. 121 patients underwent T‐cell depletion (TCD) using Campath 1 monoclonal rat anti‐human lymphocyte (CDw52) antibodies; 67 with Campath 1M and 54 with Campath 1G isotypes. Patients were conditioned for transplant using either total body irradiation combined with chemotherapy (125 patients) or busulfan and cyclophosphamide (21 patients). 112 recipients of T‐cell depleted allografts received in addition total lymphoid irradiation (TLI) for prevention of rejection. Engraftment of neutrophils (>0.5 × 109/l) and platelets (>25 × 109/l) occurred on days 15 and 18, and on days 18 and 20 in recipients of Campath 1M and Campath 1G treated marrows respectively. Rejection was documented in 6.8% of T‐cell depleted transplants. Leukaemia relapse‐free survival at 2 years was 83% for patients transplanted in first CR, 76% in second CR (P2= 0.34) and 42% in advanced leukaemia (P2= 0.009). 81 marrow recipients, 38 with Campath 1M and 43 with Campath 1G treated marrow, received post‐transplant graded increments of donors peripheral blood lymphocytes (PBL) to induce graft‐versus‐leukaemia (GVL) effects. Administration of donors PBL was associated with clinically significant GVHD and with decreased relapse rate especially in patients with ALL. Our data suggest that in patients receiving marrow allografts depleted of T cells by Campath 1 monoclonal antibodies, rejection can be reduced by adequate pregrafting immunosuppression. In patients with advanced disease, post‐transplant cell‐mediated immunotherapy (CMI) using donors PBL may be beneficial; however, further studies are needed to define the optimal schedule of CMI for safe and effective prevention of relapse following TCD bone marrow transplantation in malignant haematological diseases.

The CXCR4 antagonist AMD3100 impairs survival of human AML cells and induces their differentiation

The chemokine stromal cell-derived factor-1 (SDF-1) and its receptor, CXCR4, participate in the retention of acute myeloblastic leukemia (AML) cells within the bone marrow microenvironment and their release into the circulation. AML cells also constitutively express SDF-1-dependent elastase, which regulates their migration and proliferation. To study the molecular events and genes regulated by the SDF-1/CXCR4 axis and elastase in AML cells, we examined gene expression profiles of the AML cell line, U937, under treatment with a neutralizing anti-CXCR4 antibody or elastase inhibitor, as compared with non-treated cells, using DNA microarray technology. Unsupervised hierarchical clustering analysis demonstrated similar gene expression profiles of anti-CXCR4 antibody or elastase inhibitor-treated cells, as compared with control. Pathway and functional analysis showed a greater tendency toward differentiation in cells under either one of both treatment modalities. Thus given, we further analyzed the effects of CXCR4 inhibition on AML cell growth and differentiation using the antagonist AMD3100. AMD3100 arrested proliferation in AML cell lines and triggered changes that mimicked differentiation, including morphological changes and the expression of myeloid differentiation antigens. Inhibition of elastase also triggered the differentiation of AML cells. Our study defines a new role for the SDF-1/CXCR4 axis in the regulation of leukemic cell survival and differentiation.

Diagnostic accuracy of PET⁄CT in patients with extranodal marginal zone MALT lymphoma

Background:  18Fluoro‐2‐deoxyglucose (18FDG) positron emission tomography (PET) is widely used for initial staging and follow‐up in patients with malignant lymphoma. While earlier studies suggested a limited role for PET in extranodal marginal zone mucosa‐associated lymphoid tissue (MALT) lymphoma patients due to their non‐FDG avidity, more recent reports have suggested that the issue is controversial. In the present study, we evaluated the diagnostic accuracy of PET integrated with CT (PETCT) in patients with MALT lymphoma and assessed its reliability in clinical staging and monitoring response.

Second allogeneic stem cell transplantation using nonmyeloablative conditioning for patients who relapsed or developed secondary malignancies following autologous transplantation

OBJECTIVE Second allogeneic stem cell transplants for hematological malignancies are associated with a high incidence of transplant-related mortality due to the cumulative incidence of toxicity of the high-dose chemoradiotherapy traditionally used as an essential component of the conditioning. We have demonstrated previously that nonmyeloablative conditioning for primary allogeneic transplants from both sibling and unrelated donors results in minimal transplant-related toxicity and excellent stem cell engraftment. This study explores the possibility of using nonmyeloablative conditioning to minimize transplant-related toxicity in patients who have undergone second allogeneic transplants. PATIENTS AND METHODS Twelve high-risk, heavily treated patients-five with acute myelogenous leukemia (AML); five with non-Hodgkins lymphoma (NHL); one with Burkitts lymphoma, and one with acute lymphoblastic leukemia (ALL)-underwent second allogeneic nonmyeloablative stem cell transplantation (NST) from human leukocyte antigen (HLA)-matched donors, 29 (median) (range 3-57) months following their first transplantation procedure. The conditioning consisted of fludarabine 30 mg/m(2) daily for 6 days, busulfan 4 mg/kg daily for 2 days, and anti-T-lymphocyte globulin 10 mg/kg daily for 4 days. Anti-graft-vs-host disease (anti-GVHD) prophylaxis consisted of cyclosporine A alone, 3 mg/kg. RESULTS Engraftment was observed in all recipients, with complete and stable chimerism. None of the patients developed veno-occlusive disease of the liver or multi-organ failure. Five very high-risk patients with NHL (n = 3), Burkitts lymphoma (n = 1), and AML (n = 1) relapsed 2 to 6 months post-transplant, and four of them died. Six patients appear to be disease-free after median follow-up of 23 months. One additional patient died from grade IV hemorrhagic cystitis. Actuarial survival and disease-free survival at 34 months are 56% and 50% respectively, with 95% confidence interval (25-78%). CONCLUSION These results suggest that nonmyeloablative conditioning significantly reduces transplant-related toxicity, thus making a second transplant feasible.

Hydrolytic and Nonenzymatic Functions of Acetylcholinesterase Comodulate Hemopoietic Stress Responses

Glucocorticoid-initiated granulocytosis, excessive proliferation of granulocytes, persists after cortisol levels are lowered, suggesting the involvement of additional stress mediator(s). In this study, we report that the stress-induced acetylcholinesterase variant, AChE-R, and its cleavable, cell-penetrating C-terminal peptide, ARP, facilitate granulocytosis. In postdelivery patients, AChE-R-expressing granulocyte counts increased concomitantly with serum cortisol and AChE activity levels, yet persisted after cortisol had declined. Ex vivo, mononuclear cells of adult peripheral blood responded to synthetic ARP26 by overproduction of hemopoietically active proinflammatory cytokines (e.g., IL-6, IL-10, and TNF-α). Physiologically relevant ARP26 levels promoted AChE gene expression and induced the expansion of cultured CD34+ progenitors and granulocyte maturation more effectively than cortisol, suggesting autoregulatory prolongation of ARP effects. In vivo, transgenic mice overexpressing human AChE-R, unlike matched controls, showed enhanced expression of the myelopoietic transcription factor PU.1 and maintained a stable granulocytic state following bacterial LPS exposure. AChE-R accumulation and the consequent inflammatory consequences can thus modulate immune responses to stress stimuli.

Nosocomial coagulase-negative staphylococcal infections in bone marrow transplantation recipients with central vein catheter. A 5-year prospective study.

The purpose of this study was to examine coagulase-negative staphylococcal infections in bone marrow transplantation (BMT) patients with central vein catheters by investigating incidence, clinical relevance, risk factors, methicillin resistance, clinical impact of initial empiric antimicrobial therapy without vancomycin, and management of documented catheter-related infections. A 5-year prospective study was conducted with daily evaluation of 242 BMT patients during hospitalization, including clinical assessment and blood culture via the Hickman/Broviac catheter. If fever or infected appearance occurred, peripheral blood cultures or exit site cultures, respectively, were done. Results showed a septicemia incidence of 7.0%, including in 6 patients following colonization, in 1 patient with tunnel infection, in 1 patient with thrombophlebitis, in 1 patient with exit site infection, and in 8 patients with septicemia of unknown origin. Total colonization incidence was 7%, with colonization only in 11 patients who had 16 episodes; incidence of exit site infection was 3.7%. Age > or = 18 years was the only identified risk factor for developing staphylococcal infection (P = 0.03). Despite a methicillin resistance rate of 45% and omission of vancomycin from the routine initial empiric antimicrobial regimen, the clinical course of coagulase-negative staphylococcal infections was relatively benign. A single patient, who experienced marrow rejection, died on day +31 with septicemia and only one patient experienced microbiological failure with recurrent colonization. Bacteria grown in both aerobic and anaerobic bottles were more likely true bacteremia than contaminant (P = 0.03). We conclude that the hazard of coagulase-negative staphylococcal infection does not mandate inclusion of a glycopeptide in the initial empiric antimicrobial regimen in BMT patients, even during febrile neutropenia. Hickman/Broviac-related staphylococcal infections, except for tunnel infection or thrombophlebitis, can usually be treated successfully without removing the catheter.

Immunotherapy of Minimal Residual Disease by Immunocompetent Lymphocytes and Their Activation by Cytokines

A murine model of minimal residual disease (MRD) was established utilizing the murine B-cell leukemia (BCL1). BALB/c mice inoculated with up to 10(4) BCL1 were cured (greater than 1 year disease-free survival) following administration of intraperitoneal injections of recombinant human IL-2 (10(5) Cetus units x 3/day intraperitoneally x 5 days). Lethally irradiated BALB/c or (BALB/c x C57BL/6)F1 recipients were reconstituted with syngeneic bone marrow cells or T-cell-depleted C57BL/6 bone marrow cells contaminated with 10(4), 10(5), or 10(6) BCL1 to simulate quantitative MRD. Untreated mice died of typical leukemia without exception, whereas a substantial anti-leukemia effect was noted in mice treated by allogeneic spleen cells, IL-2, or particularly a combination of allogeneic spleen cells and IL-2 given concomitantly. Increments of donor-type spleen cells (10(6), 10(7), and 5 x 10(7)) or IL-2 (10(4) U x 2/day x 3 days) were given alone or in combination on days +1, +5, and +9 following Thy 1.2-depleted allogeneic BMT. All adoptive recipients of 10(5) spleen cells obtained from mice inoculated with 10(4) and 10(5) BCL1 treated by a combination of allogeneic spleen cells and IL-2 showed no evidence of disease greater than 100 days. The antitumor effects of allogeneic spleen cells alone and IL-2 alone were also highly significant, although not totally curative in all mice. Allogeneic spleen cells seemed more effective as compared with low dose IL-2 (3 courses of 2 x 10(4) U x 2/day x 3 days). None of the recipients of 10(6) BCL1 could be completely cured under the experimental conditions described without additional chemotherapy, although significant antitumor effects could again be documented following concomitant administration of allogeneic spleen cells and IL-2. Using an experimental model of autologous BMT, recipients of 10(3) tumor cells could also be cured following transplantation of syngeneic spleen cells by high-dose IL-2 (10(5) U x 3/day x 5 days) given at the time lymphocytes were present, optimally at 3 weeks following BMT. Based on encouraging results from experiments using our animal model of MRD, in conjunction with autologous and allogeneic BMT, pilot clinical trials are currently underway, investigating the effect of cytokine-mediated immunotherapy (CMI) in MRD following conventional and high-dose cytoreductive anticancer therapy in conjunction with ABMT. In addition, we are attempting induction of cell-mediated cytokine-activated immunotherapy (CCI) in conjunction with autologous and allogeneic BMT. Prospective randomized clinical trials and longer observation periods are required to assess the full efficacy of these new therapeutic modalities.

Functional CXCR4-Expressing Microparticles and SDF-1 Correlate with Circulating Acute Myelogenous Leukemia Cells

Stromal cell-derived factor-1 (SDF-1/CXCL12) and its receptor CXCR4 are implicated in the pathogenesis and prognosis of acute myelogenous leukemia (AML). Cellular microparticles, submicron vesicles shed from the plasma membrane of various cells, are also associated with human pathology. In the present study, we investigated the putative relationships between the SDF-1/CXCR4 axis and microparticles in AML. We detected CXCR4-expressing microparticles (CXCR4(+) microparticles) in the peripheral blood and bone marrow plasma samples of normal donors and newly diagnosed adult AML patients. In samples from AML patients, levels of CXCR4(+) microparticles and total SDF-1 were elevated compared with normal individuals. The majority of CXCR4(+) microparticles in AML patients were CD45(+), whereas in normal individuals, they were mostly CD41(+). Importantly, we found a strong correlation between the levels of CXCR4(+) microparticle and WBC count in the peripheral blood and bone marrow plasma obtained from the AML patients. Of interest, levels of functional, noncleaved SDF-1 were reduced in these patients compared with normal individuals and also strongly correlated with the WBC count. Furthermore, our data indicate NH(2)-terminal truncation of the CXCR4 molecule in the microparticles of AML patients. However, such microparticles were capable of transferring the CXCR4 molecule to AML-derived HL-60 cells, enhancing their migration to SDF-1 in vitro and increasing their homing to the bone marrow of irradiated NOD/SCID/beta2m(null) mice. The CXCR4 antagonist AMD3100 reduced these effects. Our findings suggest that functional CXCR4(+) microparticles and SDF-1 are involved in the progression of AML. We propose that their levels are potentially valuable as an additional diagnostic AML variable.

Erythropoietin treatment in advanced multiple myeloma is associated with improved immunological functions : could it be beneficial in early disease?

Erythropoietin (Epo) is the main growth regulator of red blood cells, and recombinant human erythropoietin (rHuEpo) is thus used in clinical practice for the treatment of anaemia, primarily in kidney disease and cancer. rHuEpo treatment was found to be associated with prolonged survival of multiple myeloma (MM) patients. This clinical observation was then supported by studies on murine myeloma models. It thus appeared that rHuEpo had an anti‐myeloma effect, causally related to an immunomodulatory function of rHuEpo. The present study investigated whether rHuEpo‐treated MM patients acquire improved immunological functions. Treatment with rHuEpo, prescribed for anaemia that occurs in advanced disease, was associated with effects on a variety of immunological parameters and functions. This was expressed in an actual normalisation of the CD4:CD8 cell ratio, enhanced T cell phytohaemagglutinin‐mediated activation and proliferation potential, T cell expression of the costimulatory CD28 and inhibitory CTLA‐4 molecules, as well as reduced interleukin‐6 serum values to normal levels. Furthermore, it was demonstrated that immunological abnormalities manifest in patients even in the early stages of MM. Our findings thus suggest that rHuEpo treatment might be effective in the early stages of MM, before anaemia develops. It is expected that this would boost the immune system, consequently achieving an anti‐myeloma function; affecting disease progression and improving the prognosis.

Use of Fiberoptic Bronchoscopy in Bone Marrow Transplant Recipients

Bone marrow transplantation (BMT) has become the therapy of choice for a number of malignant and nonmalignant hematologic and nonhematologic disorders. A frequent complication after BMT is pulmonary disease which is associated with a high mortality rate. We examined the results of 79 bronchoscopies performed between May 1991 and May 1995 in 62 patients for the evaluation of pulmonary complications after BMT. In all cases bronchoalveolar lavage (BAL) was performed, in 10% transbronchial biopsy (TBB) was also carried out and in 13% bronchoscopy was followed by open lung biopsy. Positive results were found in 67% of bronchoscopies. Fungal infection (Candida and Aspergillus species) was the most common finding (18%), bacterial infection was found in 13%, mixed (fungal and bacterial) infection in 6%, cytomegalovirus in 11% and Pneumocystis carinii pneumonia in 4%. Diffuse alveolar hemorrhage was detected in 11% of cases. Idiopathic pneumonia syndrome (IPS) was diagnosed by TBB in 3% of procedures. We conclude that BAL is a safe and accurate procedure for the evaluation of pulmonary complications after BMT. TBB should be considered in the absence of thrombocytopenia for the diagnosis of IPS. If bronchoscopy findings are negative, open lung biopsy should be considered.