Yeh-Ching Linn

Generation of cytokine‐induced killer cells from leukaemic samples with in vitro cytotoxicity against autologous and allogeneic leukaemic blasts

Summary. Cytokine‐induced killer (CIK) cells are CD3+CD56+ non‐major histocompatibility complex (MHC)‐restricted immune effector cells. The present report demonstrates that it was possible to expand CIK cells obtained at diagnosis from patients with acute leukaemia. The percentage of CD3+CD56+ CIK cells generated following culture ranged between 7·6% and 65% (median of 35·3%) and these cells were able to kill the human natural killer target K562 cells. Although the same effector cells were able to lyse autologous acute myeloid leukaemia (AML) target cells, they were not able to lyse autologous acute lymphoblastic leukaemia target cells. Pre‐absorption of the CIK effector cells by K562 cells did not completely abrogate the cytotoxicity of CIK cells against autologous blasts in 9 out of 12 samples tested. Moreover, it was observed that the cytotoxicity generated by the CIK effector cells against allogeneic leukaemic blasts was similar to that against autologous blasts. The present study suggests the potential application of CIK cells in the immunotherapy of AML, either in minimal disease state, as donor lymphocyte infusion in relapse post allogeneic transplant, or in cases of chemotherapy refractory leukaemia.

Cytokine-induced Killer Cells: NK-like T Cells with Cytotolytic Specificity against Leukemia

Abstract Cytokine-induced killer (CIK) cells are a unique population of cytotoxic T lymphocytes (CTL) with the characteristic CD3+CD56+ phenotype. These cells have demonstrated higher proliferative and cytolytic activities in comparison to the reported CD3−CD56+ lymphokine activated killer (LAK) cells that are essentially activated natural killer (NK) cells. CIK cells are non-MHC-restricted in target cell recognition and killing. We have shown the feasibility of generating CIK cells from a series of marrow samples of patients with acute myeloid leukemia (AML) collected at diagnosis. At maturity, the CIK cells exhibit potent cytotoxicity against autologous AML targets as well as allogeneic myeloid leukemia cells, regardless of the HLA types of these targets. This observed cytotoxicity is not entirely due to NK cells as prior pre-absorption of the NK cells cytolytic activities does not abolish the subsequent cytotolytic activities against leukemic targets. It has also been reported by others that CIK cells are cytolytic against chronic myeloid leukemia (CML) cells, both in vitro and in the SCID mouse tumor model. In a mouse transplant model across MHC barrier, the CIK cells generated from the donor do not induce graft vs. host disease as observed for unfractionated donor splenocytes. In comparison to untreated control mice, the infusion of CIK cells results in the prolonged survival of murine leukemia-bearing mice. CIK cells also express CD94, part of the NK receptor comprising of CD94-NKG2 heterodimer. However, only low level of the killer immunoglobulin-like receptors are expressed by the CIK cells. In addition, as reported for the classical CTL, CIK cells could interact with dendritic cells (DC) to result in the enhancement of cytotolytic activities against tumor cells. The characteristic biological properties of the CIK cells would, therefore, enable them to be exploited for anti-leukemic therapy.

Fludarabine in comparison to alkylator-based regimen as induction therapy for chronic lymphocytic leukemia: A systematic review and meta-analysis

The superiority of Fludarabine over conventional therapy as primary induction therapy for patients with chronic lymphocytic leukemia (CLL) has been shown in several studies but no studies have yet reported a pooled estimate of the treatment effect. We performed a systematic review of evidence from 5 randomized controlled trials involving approximately 1300 patients with CLL, comparing Fludarabine with several alkylator-based combination regimens in the primary treatment of CLL. Complete response rate was significantly higher for Fludarabine compared to alkylator-based chemotherapy (RR 1.87, 95% CI 1.10 - 3.19, P = 0.02), while overall response, though superior, did not reach statistical significance (RR 1.22, 95% CI = 0.88 - 1.69, P = 0.24). Overall survival was similar for Fludarabine and alkylator-based therapy (the pooled log hazard ratio of death, HR =  − 0.05, 95% CI =  − 0.36 - 0.26, P = 0.75). Infection rate was significantly higher (RR 1.58, 95% CI = 1.10 - 2.27, P = 0.01), but there was no significant difference in the incidence of thrombocytopenia, neutropenia and anemia. Therefore, this meta-analysis supports the findings that Fludarabine as an induction agent for patients with CLL yields a better clinical response with acceptable toxicity when compared with alkylator-based combination therapy, but without a survival benefit by 5 - 6 years of follow up.

Risk of hepatitis B reactivation and the role of novel agents and stem-cell transplantation in multiple myeloma patients with hepatitis B virus (HBV) infection

BACKGROUND The purpose of the study is to analyse the prevalence of hepatitis B virus (HBV) infection and its incidence of reactivation among multiple myeloma (MM) patients treated in the era of novel therapy in an endemic Asian setting. PATIENTS AND METHODS From 2000 to 2008, 273 patients with newly diagnosed MM were screened for the presence of hepatitis B virus surface antigen and HBV core antibody. HBV-infected patients were prospectively followed for reactivation with serial monitoring of serum alanine transferase and HBV DNA load. The patterns of HBV reactivation in relation to treatment received, exposure to high-dose therapy with autologous stem-cell transplantation (HDT/ASCT) and novel agents were studied. RESULTS The prevalence of HBV infection was 5.5%. Three cases of HBV reactivation despite lamivudine prophylaxis were reported. Two patients reactivated 3-5 months after HDT/ASCT while receiving thalidomide maintenance and one reactivated 3 years after HDT/ASCT and shortly after bortezomib salvage therapy. Emergence of a mutant HBV strain was documented in one patient. CONCLUSIONS Use of prophylaxis may reduce but will not preclude HBV reactivation. Highest risk occurs during immune reconstitution phase of HDT/ASCT. The role of immunomodulatory agents in HBV reactivation needs to be further elucidated. Separate HBV prophylaxis and surveillance guidelines ought to be developed for patients with MM.

A phase I/II clinical trial of autologous cytokine-induced killer cells as adjuvant immunotherapy for acute and chronic myeloid leukemia in clinical remission

BACKGROUND AIMS Cytokine-induced killer (CIK) cells have shown remarkable cytotoxicity against various tumors in vitro and in animal studies. We report on the clinical outcome of autologous CIK cells for patients with acute (AML) and chronic (CML) myeloid leukemia in remission. METHODS Eleven of the 13 recruited AML patients undergoing autologous peripheral blood stem cell transplant (autoPBSCT) were given autologous CIK cell infusion upon engraftment post-transplant and followed-up for disease relapse. Eleven CML patients on Imatinib with residual disease detectable by polymerase chain reaction (PCR) were given infusion and monitored by quantitation of the bcr-abl transcript. RESULTS Despite the presence of interferon (IFN)-γ-secreting T cells against various AML- and CML-associated peptides at sporadic time-points and demonstration of in vitro cytotoxicity of CIK cells against autologous and allogeneic AML targets, there was no survival benefit in AML patients post-autoPBSCT given CIK cells compared with historical controls. For CML patients, all continued to have a detectable bcr-abl transcript fluctuating within a range comparable to their pre-treatment baseline, although two had a transient but non-sustainable disappearance of bcr-abl transcript. There were no adverse reactions except for fever within the first day of infusion. CONCLUSIONS Our small series, while confirming safety, failed to demonstrate a clinical benefit of autologous CIK cells given in its current form for AML and CML. Further manipulation of CIK cells to improve anti-leukemic potency and specificity, together with the preparation of patients to create a more conducive milieu for in vivo expansion and persistence of infused CIK cells, should be explored.

Clinical scale expansion of cytokine-induced killer cells is feasible from healthy donors and patients with acute and chronic myeloid leukemia at various stages of therapy

OBJECTIVE In our clinical studies involving cytokine-induced killer (CIK) cells for patients with hematological malignancies, starting cells came from a heterogeneous group of patients and donors. Here we study the feasibility of expansion and analyzed the characteristics of the end product from starting cells derived from different sources and at different disease states. MATERIALS AND METHODS Seventy-five clinical scale cultures were grown from 28 patients and 20 donors in Good Manufacturing Practices facilities under CIK condition. RESULTS CIK cells could be successfully expanded from healthy donors, patients with acute myeloid leukemia recovering from chemotherapy, untreated patients with acute myeloid leukemia or myelodysplastic syndrome with circulating leukemic blasts, and patients with chronic myeloid leukemia on imatinib. Furthermore, CIK cells of donor origin could be expanded from leukapheresis product collected from patients who relapsed post-allogeneic transplantation, thereby offering a useful method of obtaining activated donor cells in patients for whom further donor cells were unavailable. Interestingly, CIK cells cultured from patients with untreated acute myeloid leukemia and myelodysplastic syndrome had a significantly higher proportion of CD3(+)CD56(+) subset and higher fold expansion of CD3(+) cells as compared to other groups of patients or healthy donors. Multivariate analysis showed that fresh starting cells expanded better than frozen-thawed cells, while prior exposure to granulocyte colony-stimulating factor or imatinib before harvesting did not adversely affect CIK cell expansion. CONCLUSIONS Clinical scale expansion of CIK cells is feasible from both healthy donors and leukemia patients at various stages of treatment. This robust system allows clinical translation using CIK cells as immunotherapy in various clinical settings.

Subdural hematoma in two hematopoietic stem cell transplant patients with post-dural puncture headache and initially normal CT brain scan

Abstract. Subdural hematoma (SDH) is a rare complication in patients after lumbar puncture. We report two patients receiving hematopoietic stem cell transplantation (HSCT) who developed post-dural puncture headache (PDPH) and SDH following intrathecal methotrexate (MTX). Both patients initially had normal computed tomography (CT) scan findings at the onset of headache. The diagnosis was established only when a repeat CT brain scan was performed for deteriorating neurological signs coinciding with improving platelet counts. These cases demonstrate the importance of continued vigilance for the early recognition of this salvageable entity. A normal initial CT finding and platelet count do not exclude the occurrence of SDH. A repeat CT scan, or even magnetic resonance imaging (MRI), are indicated if the clinical suspicion remains strong.

Berberine-induced Haemolysis Revisited: Safety of Rhizoma coptidis and Cortex phellodendri in Chronic Haematological Diseases

Two commonly used berberine‐containing Chinese herbs, Rhizoma coptidis (RC) and Cortex phellodendri (CP), have been banned in Singapore for the past three decades due to implication of berberine in aggravating jaundice and kernicterus in neonates with glucose‐6‐phosphate dehydrogenase deficiency. Here we conducted a single arm, phase I/II clinical study on Chinese herbal medicine for patients with chronic cytopenic haematological conditions and we analysed a subset of 20 patients who also had RC, CP or both in their herbal concoction. We found no organ toxicity or electrolyte imbalance in these 20 patients where RC was administered for 1055 patient‐days and CP for 1252 patient‐days. In three patients with thalassemia intermedia, transient elevation in serum bilirubin level was observed but this was not associated with any aggravation of anaemia or liver dysfunction. A review of the literature found conflicting evidence of varying levels either supporting or refuting the allegation of neonatal jaundice and kernicterus caused by berberine. There were, however, very few clinical reports of adverse reaction attributable to RC or CP in oral TCM concoction. We conclude that based on traditional dosage and indication, the use of RC and CP in oral concoction is safe. Copyright

Successful treatment of primary granulocytic sarcoma by non-myeloablative stem cell transplant

Pre-leukemic granulocytic sarcoma (GS) may pose an initial diagnostic problem and its therapeutic approach has never been formally established. To our knowledge, non-myeloablative stem cell transplantation has been reported in cases of leukemic GS, but not in primary GS. We report a case of primary GS with extensive and aggressive presenting features and successfully treated with intensive chemotherapy followed by non-myeloablative allogeneic stem cell transplant. This resulted in complete remission with minimal complications. Our case demonstrates the potential of graft-vs.-tumour effect in the treatment of GS and suggests that non-myeloablative allogeneic stem cell transplant may be a feasible therapeutic approach for primary GS.

Imatinib mesylate (STI-571) given concurrently with nonmyeloablative stem cell transplantation did not compromise engraftment and resulted in cytogenetic remission in a patient with chronic myeloid leukemia in blast crisis

Summary:The main obstacles to successful hematopoietic stem cell transplantation for patients with chronic myeloid leukemia (CML) in blast crisis (BC) are increased post-transplant relapse and high treatment-related mortality. We report a patient with CML in BC who was treated initially with imatinib mesylate and was then concurrently treated with a nonmyeloablative stem cell transplant. Successful engraftment of donor cells followed by complete cytogenetic remission was achieved in the absence of severe therapy-related toxicities. This case demonstrates that imatinib mesylate given through nonmyeloablative transplant is a minimally toxic therapeutic approach, which does not compromise engraftment and may result in a favorable outcome in patients with CML in BC.