An exploration of the applicability of the refined disease risk index and its integration with other independent risk factors for individualized prognostication.

The refined disease risk index (DRI) is a powerful prognostic model based solely on the disease type and stage for predicting survival outcomes of various hematological malignancies after allogeneic transplant. Here, we analyzed our series of 690 patients transplanted over the past 15 years, and showed that besides overall survival (OS), the refined DRI is also able to segregate event-free survival and relapse mortality in our cohort of largely Southeast Asian patients with a long and complete follow-up. Stratification by refined DRI remains statistically significant even when broken down by specific diseases each with a smaller number of patients, as well as for a small subset of patients younger than 18 years old, providing a robust model for prognostication. Multivariable analysis shows that refined DRI, age, year of transplant and donor type are independent risk factors for OS. We further demonstrated here that prognostication for a given patient with a specific disease can be made more discriminating by integrating independent risk factors such as age and donor type with the refined DRI. The future development of prognostic system incorporating the refined DRI with patient- and transplant-related risk factors will provide a more precise estimate of transplant outcome.

Early relapse post autologous transplant is a stronger predictor of survival compared with pretreatment patient factors in the novel agent era: analysis of the Singapore Multiple Myeloma Working Group.

The clinical outcome of multiple myeloma is heterogeneous. Both the depth of response to induction and transplant as well as early relapse within a year are correlated with survival, but it is unclear which factor is most relevant in Southeast Asian patients with multiple myeloma. We retrospectively analyzed outcomes of 215 patients who were treated with upfront autologous transplant in Singapore between 2000 and 2014. In patients who received novel agent (NA)-based induction, achieving only partial response (PR) post-induction was associated with poorer OS (HR 1.95, P=0.047) and PFS (HR 2.9, P<0.001), while achieving only PR post-transplant was strongly correlated with both OS (HR 3.3, P=0.001) and PFS (HR 7.6, P<0.001), compared with patients who achieved very good partial response (VGPR) or better. Early relapse was detected in 18% of all patients, although nearly half had initially achieved VGPR or better post-transplant. Early relapse after NA-based induction led to significantly shorter OS (median 22 months vs not reached, P<0.001), and was strongly associated with OS (HR 13.7, P<0.001). The impact of suboptimal post-transplant response and early relapse on survival may be more important than pretransplant factors, such as International Staging System or cytogenetics, and should be considered in risk stratification systems to rationalize therapy.

Single center retrospective analysis of BU-based conditioning regimens in allogeneic transplantation.

We performed a single institution retrospective analysis of 114 patients treated with BU-based pretransplant conditioning regimens. Oral BU was administered to 76 patients (total dose 16 mg/kg or 8 mg/kg) and i.v. BU to 38 others (total dose 12.8 mg/kg or 6.4 mg/kg). Either CY (n=74) or fludarabine (n=40) was given in combination with BU. Median age was 35 years in the oral BU group and 48.5 years with i.v. BU (P<0.001). OS and PFS rates at 3-years post HSCT were not different in patients who received either i.v. or oral BU (OS: 41.3 vs 44.0% (P=0.981); PFS: 52.7 vs 54.7% (P=0.526), respectively). The i.v. BU, however, was associated with a significantly shorter time to engraftment (13.5 days vs 16 days, respectively; P<0.001). There were no significant differences in survival or 100-day mortality for patients who received either CY or fludarabine, in combination with BU. After adjustment for confounders, multivariate analysis showed that age of transplant (P=0.002), donor type (sibling or unrelated; P=0.003), GVHD (P<0.05) and route of administration (P=0.023) were significant risk factors for OS. The i.v. BU used in an older age group yielded equivalent survival compared with oral BU used in a younger population.

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.

The anti-tumour activity of allogeneic cytokine-induced killer cells in patients who relapse after allogeneic transplant for haematological malignancies.

We performed a Phase I/II clinical trial to study the feasibility, toxicity and efficacy of allogeneic cytokine-induced killer (CIK) cell expansion, and treatment for patients with haematological malignancies who relapsed after allogeneic haemopoietic SCT (allo-HSCT). Allogeneic CIK cells were successfully generated for a total of 24 patients, including those from patients' own leukapheresis products in 5 patients who had no access to further donor cells. The median CD3(+) T-cell expansion was 9.33 (1.3-38.97) fold, and CD3(+)CD56(+) natural killer (NK)-like T-cell expansion was 27.77 (2.59-438.93) fold. A total of 55 infusions were done for 16 patients who had either failed or progressed after initial response to various individualized chemotherapy regimens and donor lymphocyte infusion (DLI), at doses ranging from 10 to 200 million CD3(+) cells/kg. Response attributable to CIK cell infusion was observed in five patients. These included two with ALL, two with Hodgkin's disease (HD) and one with AML, and two of whom had a response sustained for more than 2 years. Acute GVHD occurred in three and was easily treatable. This study provides some evidence suggestive of the efficacy of allogeneic CIK cells even after failure of DLI in some cases.

Impact of Microcystis aeruginosa on membrane fouling in a biologically treated effluent.

Microcystis aeruginosa was cultured in biologically treated municipal effluent to simulate blue-green algal bloom conditions in a treatment lagoon. The effect of algae in the early, mid and late phases of growth on membrane fouling, chemical coagulation (alum or aluminium chlorohydrate (ACH)) and hydraulic cleaning on the microfiltration of this effluent was investigated. The effect of M. aeruginosa in the early phase was negligible and gave a similar flux profile and permeate volume to that of effluent alone. The increase in M. aeruginosa concentration for the mid and late phases caused a significant reduction in permeate volume compared with the early phase. Full flux recovery was achieved with an alum dose of 1 mg Al3+ L(-1) (early phase) and 10 mg Al3+ L(-1) (mid phase), demonstrating that membrane fouling was hydraulically reversible. For the late phase, the highest flux recovery was 89%, which was achieved with an alum dose of 5 mg Al3+ L(-1). Higher alum dosages resulted in a reduction in flux recovery. The use of 1.5 pm pre-filtration after alum treatment showed little improvement in water quality but led to a drastic reduction in flux recovery, which was attributed to diminishing the protective layer on the membrane surface, thus enabling internal fouling. The performance of ACH was comparable to alum at low dissolved organic carbon (DOC) and cell concentration, but was not as effective as alum at high DOC and cell concentration due to the formation of more compact ACH flocs, which resulted in a higher cake layer specific resistance, leading to the deterioration of performance.

Reducing the effect of cyanobacteria in the microfiltration of secondary effluent.

Cyanobacterial blooms in the lagoons of sewage treatment plants can severely impact the performance of membrane plants treating the effluent. This paper investigates the impact of Microcystis aeruginosa in a secondary effluent on the microfiltration filterability and cleaning of the membrane. Alum coagulation and dissolved air flotation (DAF) were investigated to remove the algae and so enhance the volume of effluent processed, and their influence on reversible and irreversible fouling. Degree of fouling due to the algal components was found to be in decreasing order of algal cells, algal organic matter and extracellular organic matter. Alum coagulation with 5 mg L⁻¹ as Al³(+) led to a substantial increase in permeate volume, an increase in dissolved organic carbon removal, and a foulant layer which protected the membrane from internal fouling but which was hydraulically removable resulting in full flux recovery. Pre-treatment by DAF or 1.5 µm filtration following alum coagulation enhanced the flux rate and permeate volume but exposed the membrane to internal irreversible fouling.

An abnormal nonhyperdiploid karyotype is a significant adverse prognostic factor for multiple myeloma in the bortezomib era.

Multiple myeloma is clinically heterogeneous and risk stratification is vital for prognostication and informing treatment decisions. As bortezomib is able to overcome several high-risk features of myeloma, the validity of conventional risk-stratification and prognostication systems needs to be reevaluated. We study the survival data of 261 previously untreated myeloma patients managed at our institution, where bortezomib became available from 2004 for the treatment of relapse disease. Patient and disease characteristics, and survival data were evaluated overall, and with respect to bortezomib exposure. Overall, the international staging system (ISS), metaphase karyotyping and interphase fluorescence in situ hybridization (FISH) were discerning of survival outcomes, where the median for the entire cohort was 5.2 years. However, when stratified by bortezomib exposure, only metaphase karyotyping was still discriminating of long-term prognosis. The presence of an abnormal nonhyperdiploid karyotype overrides all other clinical and laboratory parameters in predicting for a worse outcome on multivariate analysis (median survival 2.6 years, P = 0.001), suggesting that bortezomib used at relapse is better able to overcome adverse risk related to high tumor burden (as measured by the ISS) than adverse cytogenetics on conventional karyotyping. Metaphase karyotyping provides additional prognostic information on tumor kinetics where the presence of a normal diploid karyotype in the absence of any high-risk FISH markers correlated with superior survival and could act as a surrogate for lower plasma cell proliferation.

Attainment of at least a very good partial response after induction treatment is an important surrogate of longer survival for multiple myeloma.

The importance of achieving a very good partial response or better (≥VGPR) after induction treatment of myeloma has traditionally only been discussed in the context of high-dose therapy with auto-SCT (HDT/auto-SCT). Of late, the advent of novel agents for induction treatment has resulted in improved CR and VGPR rates, which are comparable with those observed with HDT/auto-SCT. We show that in an unselected group of 179 myeloma patients with diverse baseline characteristics, and treated with different modern induction regimens within a single institution, the attainment of ≥VGPR with or without HDT/auto-ASCT represents a major surrogate marker of better clinical outcomes. On the basis of a 1-year landmark survival analysis, patients achieving ≥VGPR enjoy a significantly longer PFS, which translated to a longer OS. Superseding the adverse effects of advanced age, high International Staging System (ISS) stage, adverse cytogenetics and independent of the transplant status, the attainment of ≥VGPR emerged as the single most significant predictor of long-term survival on multivariate analysis.

Effect of missing killer-immunoglobulin-like receptor ligand in recipients undergoing HLA full matched, non-T-depleted sibling donor transplantation: a single institution experience of 151 Asian patients.

This retrospective analysis studied the impact of natural killer (NK) alloreactivity based on the missing ligand model, for a cohort of recipients undergoing haemopoietic stem cell transplant without T-cell depletion from HLA full-matched sibling donors. All patients received a uniform myeloablative conditioning regimen and prophylaxis for GVHD. A total of 151 patients were studied, including 62 patients with AML or myelodysplastic syndrome, 42 patients with ALL and 47 patients with CML. We found that 81% of patients had at least one missing KIR-ligand (KIR-L), and HLA-C1 allogroup homozygosity is present in 70% of patients. From multivariate analysis, we observed that the only consistently significant factor that was associated with superior survival was disease stage. Missing KIR-L, whether considering HLA-Bw and HLA-C alleles, without or with HLA-A ligands or narrowing to only HLA-C alleles alone to classify the number of missing KIR-L, did not have any impact on OS or relapse-free survival. This negative finding implies that as the KIR-L composition of recipient is not important in this matched non-T-depleted setting, further immunotherapeutic measures involving adoptive NK cell infusions have to be explored to exploit the benefit of NK alloreactivity for such transplants.

Characterization of hemopoietic engraftment kinetics and development of secondary cytopenia in AML post auto-SCT and its correlation with survival outcome.

We performed a single center retrospective analysis of 84 autologous hemopoietic stem cell transplants done for AML to characterize the pattern of hemopoietic engraftment, post-transplant cytopenia and their impact on survival outcome. Following autologous transplant and engraftment, 30 patients (35.7%) had a transient secondary decline in their plt counts, which was not associated with graft rejection, relapse or infection. The median time to onset of thrombocytopenia was 59 days post transplant, with spontaneous recovery after a median period of 41 days. A secondary decline in ANC also occurred in eight patients. Patients with secondary plt decline had a significantly earlier primary plt engraftment (median 15 days) and a trend towards earlier neutrophil engraftment compared with patients who maintained steady plt counts (median 21 days). There was a trend towards a lower incidence of secondary plt decline in patients who received BM stem cells compared with those who received PBSC. No cause was evident for the occurrence of a secondary cytopenia, and it did not adversely affect survival. We conclude that secondary cytopenia is a common and harmless occurrence after autologous transplant especially from PBSC graft.

Use of the cytomegalovirus pp65 antigenemia assay for preemptive therapy in allogeneic hematopoietic stem cell transplantation: a real-world review.

Despite advances in surveillance strategies and antivirals, cytomegalovirus (CMV) infection continues to pose problems to patients receiving hematopoietic stem cell transplants (HSCTs). The bone marrow transplant (BMT) unit at the Singapore General Hospital embraced the preemptive strategy in late 2003. Although several studies have demonstrated its usefulness, we conducted this review to document CMV-related events at our institution. Forty-six patients underwent CMV surveillance using the CMV pp65 antigenemia (CMV Ag) assay from January 2004 to December 2005. Twenty-seven patients had CMV infection, and 19 remained antigenemia-negative. No differences were found between the 2 groups for the following potential risk factors for CMV infection: age, total number of co-morbidities, duration of neutropenia after conditioning, baseline creatinine, type of conditioning regimen (conventional vs. reduced intensity), type of transplant (matched sibling vs. others), recipient CMV status, donor CMV status, and use of total body irradiation. Two patients received alemtuzumab; both developed CMV Ag. Twelve episodes of CMV infection occurred after the 100th post-HSCT day. Two patients developed CMV disease. One of them could be considered a failure of the preemptive strategy, as she had CMV gastritis diagnosed on the same day that she became pp65-positive. The other developed CMV disease despite prompt institution of ganciclovir, although she had multiple post-HSCT complications requiring enhanced immunosuppression, as well as relapsed disease. One-year disease-free survival was 55.5% in those with CMV infection and 52.3% in those without infection. Survival was not affected by CMV infection.

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.

Therapeutic leukapheresis in hyperleukocytic leukaemias--the experience of a tertiary institution in Singapore.

INTRODUCTION: Hyperleukocytic leukaemias are associated with early mortality due to respiratory or neurological complications. They result from endothelial damage secondary to leukostasis. Leukapheresis, which aims to lower the white blood cell (WBC) count, has been used in certain patients to reduce the threat from leukostasis. However, there are very few published clinical investigations on the most appropriate use of leukapheresis in hyperleukocytosis. MATERIALS AND METHODS: We performed a retrospective analysis of 14 patients with hyperleukocytic leukaemia who presented to our institution and underwent therapeutic leukapheresis. We compare their clinical and biological characteristics and investigate the impact of leukapheresis on early mortality and long-term prognosis. RESULTS: The median presenting WBC count was 439 x 10(3)/mm(3). Although patients with acute myeloid leukaemia (AML) had the lowest median presenting WBC counts, they constituted the largest group of patients with symptomatic hyperleukocytosis. Leukapheresis was highly effective, with the mean absolute and percentage reduction in WBC after each cycle being 126 x 10(3)/mm(3) and 31.9% respectively. Four patients with AML died within 2 weeks of presentation despite prompt and effective leukapheresis. CONCLUSION: The interaction between the leukaemic cells and the vascular environment, a mechanism that none of the current therapies directly address, is probably more important in causing leukostasis than the absolute cell count itself.