International, open-label, noncomparative, clinical trial of micafungin alone and in combination for treatment of newly diagnosed and refractory candidemia

Candida spp. are the fourth leading cause of bloodstream infections, and non-albicans species are increasing in importance. Micafungin is a new echinocandin antifungal agent with excellent in vitro activity against Candida spp. Pediatric, neonatal, and adult patients with new or refractory candidemia were enrolled into this open-label, noncomparative, international study. The initial dose of micafungin was 50 mg/d (1 mg/kg for patients <40 kg) for infections due to C. albicans and 100 mg/d (2 mg/kg for patients <40 kg) for infections due to other species. Dose escalation was allowed. Maximum length of therapy was 42 days. A total of 126 patients were evaluable (received at least five doses of micafungin). Success (complete or partial response) was seen in 83.3% patients overall. Success rates for treatment of infections caused by the most common Candida spp. were as follows: C. albicans 85.1%, C. glabrata 93.8%, C. parapsilosis 86.4%, and C. tropicalis 83.3%. Serious adverse events related to micafungin were uncommon. Micafungin shows promise as a safe and effective agent for the treatment of newly diagnosed and refractory cases of candidemia. Large-scale, randomized, controlled trials are warranted.

Is it appropriate to offer allogeneic hematopoietic stem cell transplantation to patients with primary refractory acute myeloid leukemia?

Although continued advances have been made in the treatment of acute myeloid leukemia (AML), approximately 20-30% of patients will never achieve a remission. For these patients with primary refractory AML, the only curative option remains an allogeneic stem cell transplant. Allogeneic transplantation provides the ability to administer myeloablative doses of chemotherapy or chemoradiotherapy, as well as the advantage of a possible graft-versus-leukemia effect. Difficulty in interpreting the literature is due to selection bias, in particular, the varying definitions of primary refractory disease with respect to the morphological criteria and the number of induction regimen required before being defined as being refractory. Regardless, it is a procedure with high treatment-related mortality and risk of relapse. Most studies demonstrate an event-free survival of 10-20% at 5 years. Predictive factors of outcome include blast cell count in the marrow, karyotype, the number of prior regimen, age, performance status and availability of a related donor. These prognostic factors should be considered prior to offering allogeneic transplantation for primary refractory AML. Those patients with many favorable prognostic factors and an HLA-matched related donor available would be the best candidate for the procedure. Those with many poor prognostic factors and only an unrelated donor available may be better served by being offered palliation or being enrolled in investigational studies.

Myeloablative allografting for chronic lymphocytic leukemia: evidence for a potent graft-versus-leukemia effect associated with graft-versus-host disease

In all, 30 patients with CLL proceeded to myeloablative allogeneic BMT using related (n=20, 67%) or unrelated (n=10) donors, at the Princess Margaret Hospital (Toronto) (n=20) or the Leukemia/BMT Program of BC (Vancouver) (n=10), from 1989 to 2001. Median (range) interval from diagnosis to BMT was 4.8 (0.3-13) years, median number of prior therapies was three and median age 48 years. The preparative regimen included total body irradiation in 15 (50%). In all, 14 of 30 patients (47%) are alive, with median (range) follow up of 4.3 (2.4-10.5) years. All are in complete remission, two following therapy for post-BMT progression. Actuarial overall (OS) and event-free survival (EFS) at 5 years is 39% (OS 48% for related donor and 20% for unrelated donor BMT); cumulative incidence of nonrelapse mortality (NRM) and relapse is 47 and 19%, respectively. Both acute (RR=0.008, P=0.01) and chronic (RR=0.006, P=0.02) Graft-versus-host disease (GVHD) were associated with markedly decreased risk of relapse. Patients receiving grafts from unrelated donors had increased NRM (RR=3.6, P=0.02) and decreased OS (RR of death=3.4, P=0.002). Allogeneic BMT has resulted in long-term EFS in approximately 40% of patients with CLL. There is evidence for a strong graft-versus-leukemia effect associated with acute and chronic GVHD, resulting in near complete protection from relapse.

Response to imatinib in patients who relapse after allogeneic stem cell transplantation for chronic myeloid leukemia

We studied 128 patients with chronic myeloid leukemia (CML) relapsing after allogeneic stem cell transplantation (SCT). Disease at the time of treatment with Imatinib was in chronic phase (CP) in 51 patients, accelerated phase (AP) in 31 and blastic crisis (BC) in 46. Of the 51 patients in CP, 14 were in cytogenetic and two in molecular relapses. The median interval between relapse and Imatinib therapy was 5 months (0-65). A total of 50 patients had failed treatment with donor lymphocyte infusions prior to Imatinib. The overall hemato-logical response rate was 84% (98% for patients relapsing in CP). The complete cytogenetic response (CCR) was 58% for patients in CP, 48% for AP and 22% for patients in BC. Complete molecular responses were obtained in 25 patients (26%), of whom 21 were in CP or AP. With a median follow-up of 9 months, the estimated 2-year survival for CP, AP and BC patients was 100, 86 and 12%, respectively. Out of 79 evaluable patients, 45 (57%) achieved full donor and 11 (14%) mixed chimerism after Imatinib. We conclude that Imatinib has significant activity against CML in relapse after allogeneic SCT. Durable cytogenetic and molecular remissions are obtainable in patients in CP.

Stem cell transplantation for myelofibrosis: a report from two Canadian centers

We describe the course of 25 patients with myelofibrosis (MF) due to agnogenic myeloid metaplasia (n=19) or essential thrombocytosis (n=6) who underwent allogeneic stem cell transplantation (SCT) at one of two Canadian centers. The median age at transplantation was 48.7 (IQR 45.9-50.4) years and transplantation was carried out at a median of 10.7 (IQR 5.67-26.5) months after diagnosis. Granulocyte engraftment (absolute neutrophil count >0.5 x 109/l) occurred at a median of 20 days after transplantation for splenectomized patients, compared with 27.5 days for nonsplenectomized individuals (P=0.03). Increased risk of grade II-IV acute graft-versus-host disease (P=0.04) was noted in patients transplanted after splenectomy. Patients with MF received 0.264+/-0.189 U of packed red blood cells per day over the first 180 days after transplantation, and remained dependent on red blood cell transfusions for a median of 123 (IQR 48-205) days. Complete remission of MF was documented in 33% of evaluable patients. The 1 year cumulative nonrelapse mortality was 48.3%. Median survival for this group of patients was 393 (IQR 109-1014+) days, with a projected 2-year overall survival of 41%. We conclude that allogeneic SCT offers a reasonable chance for prolonged survival in patients with advanced MF, but this occurs at the cost of considerable toxicity and nonrelapse mortality.

Why aren't we performing more allografts for aggressive non-Hodgkin's lymphoma?

Allogeneic stem cell transplantation has an under-appreciated role in the management of intermediate-grade non-Hodgkin's lymphoma. It provides several advantages over autologous stem cell transplantation including provision of a lymphoma-free graft, reduced rates of secondary myelodysplastic syndrome and leukemia, and a potentially curative graft-versus-lymphoma effect. When applied to chemosensitive patients, the lower relapse rates and reasonable long-term outcomes make allogeneic transplantation a promising therapy to pursue. Patient populations, such as those with bone marrow involvement or very high-risk disease, can be identified as having suboptimal outcomes after autotransplantation and may benefit from such an approach. While the exact role of allogeneic stem cell transplantation remains to be determined, broad recommendations can be suggested for the management of patients with intermediate-grade lymphoma. New approaches to allogeneic transplantation, including the use of matched-unrelated donors and reduced-intensity conditioning regimens, may expand the applicability of this potentially curative modality.

The effects of long-term cadmium exposure on the growth and survival of juvenile bull trout (Salvelinus confluentus)

Bull trout (Salvelinus confluentus) have been listed recently as threatened in the United States under the federal Endangered Species Act. This species currently resides, or historically resided, in several waterways that either are impacted or are under threat of impact from metals mining activities. We conducted a 55-day sub-chronic (i.e. sublethal) cadmium (Cd) exposure in water at 30 mg l(-1) (as CaCO(3)) hardness, pH 7.5, and 8 degrees C. Exposures were conducted using six replicate exposure tanks for each of the six treatments (five Cd concentrations and one control). Measured Cd concentrations were <0.013 (control), 0.052, 0.089, 0.197, 0.383, and 0.786 microg Cd l(-1). Exposure to 0.786 microg Cd l(-1) caused increased mortality (37%) and reduced growth (28% reduction in weight change) in fish exposed for 55 days. All Cd exposure concentrations caused significant whole body accumulation of Cd compared with controls. Our results indicate that even though fish are significantly accumulating Cd in each non-control treatment, growth reductions in bull trout occurred only at Cd concentrations that also caused significant mortality. The Cd concentration that reduced growth and survival in this long-term exposure (0.786 microg Cd l(-1)) is greater than the recently-revised US federal aquatic life criteria (ALC) value for the corresponding hardness concentration (ALC=0.62 microg Cd l(-1) for acute effects and 0.11 microg Cd l(-1) for chronic effects).

Relationship between exposure duration, tissue residues, growth, and mortality in rainbow trout (Oncorhynchus mykiss) juveniles sub-chronically exposed to copper

We conducted a 56-day sub-chronic test on the effects of Cu on rainbow trout (Oncorhynchus mykiss) fry at a nominal water hardness of 100 mg l(-1) (as CaCO(3)). Response measures were growth, whole body Cu concentrations, and mortality. Significant mortality was observed in fish exposed to 54.1 microg Cu l(-1) (47.8%) and 35.7 microg Cu l(-1) (11.7%). Growth was dose-dependent over the range of Cu treatments (0-54 microg Cu l(-1)), and was modeled as a function of Cu exposure concentration and exposure duration. Calculated inhibition concentrations (based on change in wet weight through a 56-day Cu exposure) were IC(50)=54.0 microg Cu l(-1), IC(20)=21.6 microg Cu l(-1), IC(10)=10.8 microg Cu l(-1), and IC(01)=1.1 microg Cu l(-1). Measured whole body Cu was also dose-dependent, and growth of trout fry was readily modeled as a function of tissue Cu and exposure duration. This model was virtually identical to a model previously developed for rainbow trout exposed to Cu at a hardness of 25 mg l(-1). Following the 56-day exposure period, we performed a 96-h acute challenge to Cu and Cd to evaluate the effects of Cu acclimation on acute Cu and Cd toxicity. Sensitivity to Cu was dependent on the 'acclimation dose'; trout previously held in control aquaria (i.e. not acclimated to Cu) suffered over 80% mortality, whereas trout previously exposed to 35.7 microg Cu l(-1) for 56 day suffered 20% mortality. These fish also showed somewhat reduced sensitivity to Cd, suggesting acclimation to Cu can enhance tolerance to other metals. Finally, the relationship between growth response and hardness (derived from several studies) appeared to have a different slope than the hardness relationship previously observed for lethality responses.

A randomised trial comparing cytomegalovirus antigenemia assay vs screening bronchoscopy for the early detection and prevention of disease in allogeneic bone marrow and peripheral blood stem cell transplant recipients

Preemptive antiviral therapy is often employed for CMV prevention following allogeneic BMT. Two common strategies are a screening bronchoscopy for CMV post-BMT or regular CMV antigenemia testing with ganciclovir administration for a positive result. In a randomised trial, we prospectively compared the efficacy of these two preemptive strategies. Consecutive patients were randomised to either a bronchoscopy for CMV on day 35 post BMT or weekly CMV antigenemia testing. If the bronchoscopy was positive for CMV, patients received preemptive ganciclovir for 8-10 weeks. If the antigenemia was positive for CMV, patients received a minimum of 2 weeks of preemptive ganciclovir. The primary endpoint was the development of active CMV disease. One hundred and eighteen allogeneic BMT patients were enrolled (60 in the antigenemia arm and 58 in the bronchoscopy arm). The two groups were comparable with respect to baseline demographic data, underlying disease, conditioning regimen, and immunosuppression. Active CMV disease developed in 7/58 (12.1%) patients in the bronchoscopy arm vs 1/60 patients (1.7%) in the CMV antigenemia arm (P = 0.022). Based on the screening test, 13.8% of patients received preemptive ganciclovir in the bronchoscopy arm vs 48.3% of patients in the antigenemia arm (P < 0.001). There was no significant difference in the rate of graft-versus-host disease, bacteremia, invasive fungal infections or mortality between the two groups. Preemptive therapy based on regular CMV antigenemia monitoring is superior to screening bronchoscopy for the prevention of CMV disease after allogeneic BMT.

Primary chromosomal rearrangements of leukemia are frequently accompanied by extensive submicroscopic deletions and may lead to altered prognosis

BCR/ABL fluorescent in situ hybridization study of chronic myeloid leukemia (CML) and Philadelphia(+) (Ph(+)) acute lymphoid leukemia (ALL) indicated that approximately 9% of patients exhibited an atypical hybridization pattern consistent with a submicroscopic deletion of the 5' region of ABL and the 3' region of the BCR genes on the 9q(+) chromosome. The CML patients with deletions had a shorter survival time and a high relapse rate following bone marrow transplant. Since deletions are associated with both Ph(+) CML and ALL, it seemed probable that other leukemia-associated genomic rearrangements may also have submicroscopic deletions. This hypothesis was confirmed by the detection of deletions of the 3' regions of the CBFB and the MLL genes in AML M4 patients with inv(16) and in patients with ALL and AML associated with MLL gene translocations, respectively. In contrast, analysis of the AML M3 group of patients and AML M2 showed that similar large deletions were not frequently associated with the t(15;17) or t(8;21) translocations. Analysis of sequence data from each of the breakpoint regions suggested that large submicroscopic deletions occur in regions with a high overall density of Alu sequence repeats. These findings are the first to show that the process of deletion formation is not disease specific in leukemia and also implicate that the presence of repetitive DNA in the vicinity of breakpoint regions may facilitate the generation of submicroscopic deletions. Such deletions could lead to the loss of one or more genes, and the associated haploinsufficiency may result in the observed differences in clinical behavior. (Blood. 2001;97:3581-3588)

Bone marrow mobilized with granulocyte colony-stimulating factor in related allogeneic transplant recipients: a study of 29 patients

We studied whether a short course of granulocyte colony-stimulating factor (G-CSF) administered to normal donors immediately before bone marrow (BM) harvest would shorten time to neutrophil and platelet engraftment in matched related allogeneic BM recipients. Twenty-nine normal donors received 4 consecutive daily subcutaneous injections of G-CSF (median dose, 12.1 microg/kg per day; range, 9.6-15.7 microg/kg per day) immediately before BM harvest. Donors tolerated G-CSF well, with only mild myalgias and arthralgias, and BM was easy to aspirate. The BM harvest contained a median of 5.3 x 10(8) white blood cells (WBCs)/kg (range, 3.1-11.1 x 10(8) WBCs/kg) and 2.5 x 10(6) CD34+ cells per kg (range, 1.5-7.3 x 10(6) CD34+ cells per kg). Median times to neutrophil (18 days [range, 11-30 days] versus 22 days [range, 16-36 days]; P = .05) and platelet (22 days [range, 15-55 days] versus 27 days [range, 18-46 days]; P = .04) engraftment were statistically shorter than those of historical control subjects whose donors had not received G-CSF before BM harvest. However, secondary engraftment-dependent outcomes including red blood cell and platelet transfusions, febrile days, days on antibiotics, days from transplant to hospital discharge, and days in hospital during the first 60 days after transplant were not statistically different from historical control subjects. We conclude that G-CSF administered to normal donors immediately before harvest facilitates BM aspiration, increases the WBC content of the harvest, and hastens neutrophil and platelet engraftment compared with historical control subjects.

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Subretinal abscess due to Nocardia farcinica infection

PURPOSE

Nocardia infection of the eye is uncommon. A case of choroidal abscess due to Nocardia farcinica infection is presented, and the literature is reviewed.

METHODS

A 41-year-old immunocompromised man with chronic myeloid leukemia developed a unilateral choroidal abscess. N. farcinica was isolated from a simultaneous subcutaneous abscess and both infections responded to systemic sulfonamide therapy.

RESULTS

Three weeks after discontinuation of the sulfonamides, the choroidal abscess recurred with involvement of the vitreous. The infection was brought under control after reinstitution of the same drug.

CONCLUSIONS

Nocardiosis is a multisystem disease that has high mortality and ocular morbidity rates. The eyes of immunocompromised patients should be examined frequently as early detection and administration of the proper antibiotics may reduce the risk of this life-threatening infection.

Management of allogeneic bone marrow transplant recipients at risk for cytomegalovirus disease using a surveillance bronchoscopy and prolonged pre-emptive ganciclovir therapy

BACKGROUND

Patients undergoing allogeneic bone marrow transplant (BMT) are considered to be at increased risk of cytomegalovirus (CMV) disease if they and/or their donor are CMV seropositive pre-transplant. Although several pre-emptive strategies have been shown to be effective in preventing early CMV disease, the ability of pre-emptive strategies using prolonged ganciclovir therapy to reduce the incidence of late-onset CMV infection, disease and mortality has not been fully evaluated.

OBJECTIVE

To assess the efficacy of 18 weeks of pre-emptive ganciclovir therapy in preventing late-onset (> 100 days post-transplant) CMV disease when administered to asymptomatic BMT patients found to have CMV in bronchoalveolar lavage (BAL) fluid obtained during a surveillance bronchoscopy approximately 35 days post-transplant. To determine whether or not survival of BMT recipients is influenced by pre-transplant donor and recipient CMV serostatus in the context of this pre-emptive ganciclovir strategy.

STUDY DESIGN

Consecutive patients undergoing allogeneic BMT were assessed for their risk of developing CMV disease based on their pre-transplant CMV serostatus and that of their donor. Patients who were CMV seropositive and/or received marrow from a CMV seropositive donor underwent a surveillance bronchoscopy and BAL approximately 35 days post-transplant. Patients with positive BAL fluid for CMV received pre-emptive ganciclovir therapy for 18 weeks at decreasing dose levels. Patients considered to be at low risk for the development of CMV disease (donor and recipient CMV seronegative) were followed without intervention.

RESULTS

Of 98 consecutive patients, 55 were considered to be at risk for CMV disease and underwent a surveillance bronchoscopy. Sixteen (29%) patients had a positive BAL fluid for CMV and were started on pre-emptive ganciclovir therapy. Two patients progressed and died with CMV-related pneumonia. One additional patient developed CMV-related enteritis on day 42 post-transplant and recovered with continuing ganciclovir treatment. Of the 39 patients with a negative BAL fluid for CMV, one developed a fatal CMV pneumonia 150 days post-transplant and two additional patients developed gastrointestinal CMV disease 28 and 57 days post-BMT, respectively. None of the patients in the low risk group developed CMV disease.

CONCLUSIONS

The strategy utilizing a surveillance bronchoscopy for CMV and initiating prolonged (18 weeks) pre-emptive ganciclovir therapy for patients with a positive BAL fluid for CMV resulted in a low incidence of CMV-related post-transplant complications. After a minimum follow-up of 16 months, late CMV reactivations (occurring > 100 days post-transplant) were not observed in the group of individuals pre-emptively treated with ganciclovir. This observation suggests that prolonged therapy with a reduced dose of ganciclovir may be important in the prevention of CMV reactivation. The CMV serostatus of donors and recipients prior to BMT did not correlate with survival.

Phase I trial of sequential topotecan followed by etoposide in adults with myeloid leukemia: a National Cancer Institute of Canada Clinical Trials Group Study

Prolonged exposure to a topoisomerase I inhibitor may increase expression of topoisomerase II, making cells more susceptible inhibitors of that enzyme. This study was undertaken to establish the maximum tolerated dose (MTD) of a topotecan/topoisomerase II inhibitor sequential combination that may be active in acute leukemia, and to evaluate the effects of in vivo exposure to topotecan on topoisomerase II levels in leukemic blast cells as measured by image cytometry. Patients who were eligible for this phase I study had relapsed or refractory acute myeloid leukemia (< or = 2 prior regimens) or CML blast crisis (0 or 1 prior regimen). Topotecan was given as a 5 day continuous i.v. infusion and was to be escalated through three levels (1.5, 1.75 and 2.0 mg/m2 day), followed by etoposide at two dose levels (100 and 150 mg/m2) i.v. bolus days 6, 7 and 8. Topoisomerase IIalpha levels in leukemic blasts from bone marrow were measured by image cytometry prior to starting treatment, on day 5 of topotecan infusion and on day 28; and daily during topotecan in peripheral blood blasts. Dose-limiting toxicity was seen in two of six patients at the first dose level (topotecan 1.5 mg/m2/day, etoposide 100 mg/m2/day; > or = grade 3 mucositis in both cases). This cohort was expanded to 10 patients; no further non-hematologic dose-limiting toxicity was observed, but given the extent of toxicity seen, further dose escalation was judged not to be feasible. Topo IIalpha levels increased in peripheral blood blasts during the first 72 h of topotecan infusion and returned to near baseline by day 5, whereas levels appeared to decrease in bone marrow blasts by day 5 compared to pretreatment. One complete hematologic and cytogenetic remission in a patient with CML blast crisis was observed in the 10 patients evaluable for response. The sequential administration of topotecan 1.5 mg/m2/day continuous infusion for 5 days followed by etoposide 100 mg/m2/day x 3 is the recommended phase II dose for this schedule. Topotecan increases topo IIalpha expression in vivo in leukemia cells, but levels of the enzyme are cell cycle dependent. Pharmacodynamic evaluation of the sequential or combination administration of novel antileukemic agents may help improve treatment strategies in acute leukemia.

Elevated serum cytokines are associated with cytomegalovirus infection and disease in bone marrow transplant recipients

To assess the relationship between serum cytokines and cytomegalovirus (CMV) reactivation, 75 allogeneic bone marrow transplant patients underwent weekly measurements of interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-alpha, CMV blood cultures, and antigenemia tests. Of the patients, 44 (58.7%) developed CMV infection, and 19 (25.3%) developed clinical CMV disease. The mean maximum levels of all three cytokines were significantly increased in patients with CMV infection compared with levels in those without. Maximum levels of IL-6 were significantly higher in patients with active CMV disease than in those who did not develop CMV disease (281.2+/-85.5 vs. 95.7+/-15.0 pg/mL; P=.034). Levels of IL-8 and TNF-alpha were also elevated in patients who developed active disease. In a multivariate logistic regression model, IL-6 levels were independently associated with CMV disease (odds ratio=1.70 per 100-pg/mL increase in IL-6; P=.009). Cytokines may play an important role in the pathogenesis of CMV after bone marrow transplantation and may be a useful predictor for CMV.

The clinical utility of CMV surveillance cultures and antigenemia following bone marrow transplantation

At our institution, the cytomegalovirus (CMV) prophylaxis protocol for allogeneic bone marrow transplant (BMT) recipients who are CMV-seropositive or receive marrow from a CMV-seropositive donor consists of a surveillance bronchoscopy approximately 35 days posttransplant. Patients with a positive surveillance bronchoscopy for CMV receive pre-emptive ganciclovir. In order to determine the utility of other screening methods for CMV, we prospectively performed weekly CMV antigenemia, and blood, urine and throat cultures from time of engraftment to day 120 post-BMT in 126 consecutive patients. Pre-emptive ganciclovir was given to 11/81 patients (13.6%) because of a positive surveillance bronchoscopy for CMV. Results of CMV blood, urine and throat cultures and the antigenemia assay done prior to or at the time of the surveillance bronchoscopy were analyzed for their ability to predict the bronchoscopy result. The antigenemia test had the highest positive and negative predictive values (72% and 96%, respectively). The ability of these tests to predict CMV disease was evaluated in the 70 patients with a negative surveillance bronchoscopy who did not receive pre-emptive ganciclovir. Of 19 cases of active CMV disease, CMV antigenemia was positive in 15 patients (79%) a mean of 34 days preceding symptoms. Blood cultures were positive in 14/19 patients (74%) a mean of 31 days before onset of disease. CMV antigenemia is useful for predicting the surveillance bronchoscopy result, and also predicts the development of CMV disease in the majority of patients missed by the surveillance bronchoscopy.