Younger patients with chronic myeloid leukemia do well in spite of poor prognostic indicators: results from the randomized CML study IV

Since the advent of tyrosine kinase inhibitors, the impact of age on outcome of chronic myeloid leukemia (CML) patients has changed. We therefore analyzed patients from the randomized CML study IV to investigate disease manifestations and outcome in different age groups. One thousand five hundred twenty-four patients with BCR-ABL-positive chronic phase CML were divided into four age groups: (1) 16–29 years, n = 120; (2) 30–44 years, n = 383; (3) 45–59 years, n = 495; and (4) ≥60 years, n = 526. Group 1 (adolescents and young adults (AYAs)) presented with more aggressive disease features (larger spleen size, more frequent symptoms of organomegaly, higher white blood count, higher percentage of peripheral blasts and lower hemoglobin levels) than the other age groups. In addition, a higher rate of patients with BCR-ABL transcript levels >10 % on the international scale (IS) at 3 months was observed. After a median observation time of 67.5 months, no inferior survival and no differences in cytogenetic and molecular remissions or progression rates were observed. We conclude that AYAs show more aggressive features and poor prognostic indicators possibly indicating differences in disease biology. This, however, does not affect outcome.

Regression of eosinophil counts after diagnosis of chronic graft-versus-host disease as a potential marker for improved clinical outcome

Eosinophilia after allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been associated with the development of acute and chronic graft-versus-host disease (cGVHD). However, a limited number of studies have investigated the course of eosinophil counts in relation to the onset of cGVHD. In this study, the course of relative eosinophil counts (RECs) was retrospectively analyzed in 64 patients who developed cGVHD following allogeneic HSCT in relation to overall survival (OS), relapse rate and clinical course of cGVHD. At onset of cGVHD, eosinophilia was observed in 45% of the patients and developed one week prior to cGVHD diagnosis. Furthermore, a trend towards improved OS in patients with eosinophilia was observed. Beneficial effects were most evident in patients who exhibited decreasing eosinophil counts one week after diagnosis of cGVHD. By contrast, an increase in or stable eosinophil counts one week after diagnosis were associated with significantly impaired OS and a significantly higher rate of later aggravation of cGVHD. Findings of this study suggested that the course of eosinophil counts may provide a useful parameter in the assessment of cGVHD development and activity allowing the potential identification of patient subpopulations with a good outcome and reduced cGVHD-related mortality.

Isolated late metastasis from testicular seminoma presenting as a parotid gland mass: case report and review of the literature

Parotid metastases from non-head-and-neck cancers are rare and may represent a diagnostic and therapeutic challenge. A late metastasis to the parotid gland from a seminoma is an unusual manifestation of disease. A 45-year-old man with a history of testicular seminoma 5 years earlier presented with a rapidly progressing parotid mass. Ultrasonography and computed tomography showed a space-occupying lesion at the angle of the right jaw. The mass was infiltrating into the parotid gland and into the parapharyngeal space. A primary parotid neoplasm was suspected, and panendoscopy combined with open biopsy was performed. Histology examination confirmed a seminoma metastatic to the parotid gland, and comparison with the primary tumour showed identical histology. The patient received chemotherapy for recurrent seminoma in accordance with the pei (cisplatin, etoposide, ifosfamide) protocol. After 4 courses of chemotherapy, salvage radical parotidectomy with removal of all suspicious residual tumour tissue was performed. This case illustrates the difficulties that may be encountered in the differential diagnosis of parotid gland masses and underlines the necessity for a detailed clinical history and for strong interdisciplinary collaboration between oncologists and pathologists to correctly diagnose cases with such unusual presentations.

High-Dose Cytarabine Consolidation With or Without Additional Amsacrine and Mitoxantrone in Acute Myeloid Leukemia: Results of the Prospective Randomized AML2003 Trial

Purpose

To assess the treatment outcome benefit of multiagent consolidation in young adults with acute myeloid leukemia (AML) in a prospective, randomized, multicenter trial.

Patients and Methods

Between December 2003 and November 2009, 1,179 patients (median age, 48 years; range, 16 to 60 years) with untreated AML were randomly assigned at diagnosis to receive either standard high-dose cytarabine consolidation with three cycles of 18 g/m2 (3× HD-AraC) or multiagent consolidation with two cycles of mitoxantrone (30 mg/m2) plus cytarabine (12 g/m2) and one cycle of amsacrine (500 mg/m2) plus cytarabine (10 g/m2; MAC/MAMAC/MAC). Allogeneic and autologous hematopoietic stem-cell transplantations were performed in a risk-adapted and priority-based manner.

Results

After double induction therapy using a 3 + 7 regimen including standard-dose cytarabine and daunorubicin, complete remission was achieved in 65% of patients. In the primary efficacy population of patients evaluable for consolidation outcomes, consolidation with either 3× HD-AraC or MAC/MAMC/MAC did not result in any significant difference in 3-year overall (69% v 64%; P = .18) or disease-free survival (46% v 48%; P = .99) according to the intention-to-treat analysis. Furthermore, MAC/MAMAC/MAC led to additional GI and hepatic toxicity and a higher rate of infection and bleeding, resulting in significantly shorter 3-year overall survival in the per-protocol analysis compared with 3× HD-AraC (63% v 72%; P = .04).

Conclusion

In younger adults with AML, multiagent consolidation using mitoxantrone and amsacrine in combination with high-dose cytarabine does not improve treatment outcome and confers additional toxicity.

Rationing cancer care: a survey among the members of the german society of hematology and oncology

Rising costs of cancer care and the growing burden of cancer in a world of finite resources seem to make rationing in oncology inevitable. Information is currently lacking about oncologists' strategies in responding to resource constraints and the prevalence of withholding costly treatments. An online survey was offered via e-mail to physician members of the German Society of Hematology and Oncology. Those actively practicing were asked to complete an online questionnaire asking how limited resources were currently affecting their clinical practice. Two-thirds of 345 participating oncologists reported withholding costly treatments in at least some instances. Regarding their rationale, 70% stated that evidence for costly intervention was not convincing enough, and 59% said that they rationed approved treatments because of an unfavorable cost/benefit calculation. Only 29% reported being explicit about their rationing decision if the patient did not know or inquire about the respective intervention. Withholding expensive procedures from individual patients was widespread among the respondents. Oncologists withheld treatments not only if they perceived the scientific evidence to be questionable but also if they perceived reimbursement prospects or the cost/benefit ratio to be unfavorable, a behavior that could be called rationing. Currently this mostly refers to costly procedures with limited additional benefits. Although this result may be interpreted as indicating that oncologists assume responsibility for spending the resources in a justified way, more transparency and an open discussion on cost-effectiveness and the just allocation of costly treatments is needed.

Effect of dose-optimized imatinib (IM) 800 mg on deep molecular responses (CMR 4.5) and prediction of survival: Results from the randomized CML-study IV

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Background: Since complete molecular remission (CMR 4.5) defines a subgroup of patients who may stay in remission even after discontinuation of treatment, we analysed whether CMR 4.5 is reached faster with dose optimized IM 800 mg and whether the achievement of CMR 4.5 at specified points in time results in better survival than the achievement of less deep remissions. Methods: Confirmed CMR 4 and CMR 4.5 are defined as ≤ 0.01% BCR-ABL IS or ≥ 4 log reduction and ≤ 0.0032% BCR-ABL IS or ≥ 4.5 log reduction, respectively, from standardized baseline as determined by real-time PCR in 2 independent analyses. Details on CML-Study IV have been published (Hehlmann et al., JCO 2011). Cumulative incidences were estimated under consideration of competing risks. Landmark analyses were performed to evaluate the prognostic impact of different remissions at 4 years on survival. Results: Of 1551 randomized patients with newly diagnosed chronic phase CML 1525 were evaluable. Median age was 52 years, 88% were EUTOS low risk, 12% high risk. 113 patients were transplanted (73 in first chronic phase), 246 received 2nd generation TKI. 152 patients have died. After a median observation time of 67.5 months, 6-year OS was 88.2%.CMR 4.5 was reached after a median of about 76.1 months with IM 800 and 107.3 months with IM 400. EUTOS low-risk patients reached all remissions faster than high-risk patients. Independent of treatment approach CMR 4.5 at 4 years predicted OS significantly better than complete cytogenetic remission (p=0.043), but not significantly better than major molecular remission (MMR) or CMR4. After a median observation of 3.9 years 1 of 626 patients with CMR 4 has progressed. Only six of the 394 patients with CMR 4.5 have died after a median observation time of 3.0 years, no patient has progressed. An additional finding was that achieving MMR at 3 and at 6 months predicts faster achievement of CMR 4.5. Conclusions: We conclude that dose optimized IM 800 induces CMR 4.5 faster than IM 400 and that CMR 4.5 at 4 years is associated with a survival advantage. Dose optimized IM 800 may provide an improved therapeutic basis for treatment discontinuation in patients with CML. Clinical trial information: NCT00055874.

Comparison of automated differential blood cell counts from Abbott Sapphire, Siemens Advia 120, Beckman Coulter DxH 800, and Sysmex XE-2100 in normal and pathologic samples

Reliable automated blood cell characterization and quantification remain challenging in pathologic samples, whereas slide reviews due to unnecessary flagging should be avoided. We compared 4 modern hematology analyzers-Abbott Sapphire, Siemens Advia 120, Sysmex XE-2100, and Beckman Coulter DxH 800-regarding complete blood cell count (CBC), leukocyte differential count, and flagging efficacy in a total of 202 samples from hematology patients and normal controls. Manual differential count was used as reference. The analyzers exhibited very good correlation for CBC parameters. Neutrophils and eosinophils also showed very good correlations, whereas lymphocytes and monocytes correlated fairly. The Advia 120 displayed notably lower measurements for both parameters, which is attributable to classification of some events as large unstained cells. Basophil counts were unreliable with all analyzers. Flagging for blasts and immature granulocytes showed moderate sensitivity and specificity. Operators must not rely on blast flagging alone to detect leukemic samples with any analyzer.

Primary prophylaxis of bacterial infections and Pneumocystis jirovecii pneumonia in patients with hematological malignancies and solid tumors : guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

Bacterial infections are the most common cause for treatment-related mortality in patients with neutropenia after chemotherapy. Here, we discuss the use of antibacterial prophylaxis against bacteria and Pneumocystis pneumonia (PCP) in neutropenic cancer patients and offer guidance towards the choice of drug. A literature search was performed to screen all articles published between September 2000 and January 2012 on antibiotic prophylaxis in neutropenic cancer patients. The authors assembled original reports and meta-analysis from the literature and drew conclusions, which were discussed and approved in a consensus conference of the Infectious Disease Working Party of the German Society of Hematology and Oncology (AGIHO). Antibacterial prophylaxis has led to a reduction of febrile events and infections. A significant reduction of overall mortality could only be shown in a meta-analysis. Fluoroquinolones are preferred for antibacterial and trimethoprim–sulfamethoxazole for PCP prophylaxis. Due to serious concerns about an increase of resistant pathogens, only patients at high risk of severe infections should be considered for antibiotic prophylaxis. Risk factors of individual patients and local resistance patterns must be taken into account. Risk factors, choice of drug for antibacterial and PCP prophylaxis and concerns regarding the use of prophylactic antibiotics are discussed in the review.

Prognosis of patients with primary central nervous system lymphoma after high-dose chemotherapy followed by autologous stem cell transplantation

High-dose chemotherapy followed by autologous stem cell transplantation has been shown to be feasible and highly effective in newly diagnosed primary central nervous system lymphoma. In this retrospective multicenter study, we investigated prognosis and baseline risk factors in patients with primary central nervous system lymphoma who underwent this treatment approach. We retrospectively analyzed 105 immunocompetent patients with primary central nervous system lymphoma who underwent high-dose chemotherapy followed by autologous stem cell transplantation with or without whole brain radiotherapy as first-line consolidation treated at 12 German centers between 1997 and 2011. We estimated survival rates and investigated the impact of age, performance status, serum lactate dehydrogenase level, and deep brain involvement on overall and progression-free survival. Patients were additionally categorized into three prognostic groups according to the Memorial Sloan Kettering Cancer Center prognostic model. After a median follow up of 47 months, median progression-free survival and overall survival was reached after 85 and 121 months; 2- and 5-year survival rates were 82% and 79%, respectively. The Memorial Sloan Kettering Cancer Center prognostic model did not predict survival. Only age revealed some evidence of prognostic relevance. Overall response rate was 95%; of those patients with progressive disease before high-dose chemotherapy, 7 of 20 achieved ongoing complete remission after therapy without whole brain radiation therapy. Transplantation-associated mortality was 2.8%. High-dose chemotherapy followed by autologous stem cell transplantation is a highly effective and safe treatment modality for selected primary central nervous system lymphoma patients. Superiority compared to standard chemotherapy still warrants further investigation.

The prognostic significance of early molecular and cytogenetic response for long-term progression-free and overall survival in imatinib-treated chronic myeloid leukemia (CML)

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Background: In the face of competing first line treatment options for CML early prediction of prognosis on imatinib is desirable to assure favorable survival or otherwise consider the use of an alternative therapy. We sought to evaluate the prognostic impact of early response landmarks. Methods: A total of 1,303 newly diagnosed imatinib-treated patients (pts) from the randomized CML Study IV were investigated to correlate molecular and cytogenetic response at 3 and 6 months with progression-free and overall survival (PFS, OS). Median follow-up was 4.7 years (range 0-9). The BCR-ABL expression was determined by quantitative RT-PCR and standardized according to the international scale (BCR-ABLIS). The proportion of Philadelphia-chromosome positive metaphases (Ph+) was determined by conventional metaphase analysis. To confirm the prognostic significance of early molecular response, an independent validation sample of 174 pts treated with imatinib within the IRIS trial was analyzed. Results: The persistence of >10% BCR-ABLIS at 3 months separated a high-risk group (28% of pts; 5-year OS: 87%) from a group with 1-10% BCR-ABLIS (41% of pts; 5-year OS: 94%; p=0.012), and from a group with <1% BCR-ABLIS (31% of pts; 5-year OS: 97%; p=0.004). By cytogenetics high-risk patients could be identified by the persistence of >35% Ph+ (27% of pts; 5-year OS: 87%) as compared to ≤35% Ph+ (73% of pts; 5-year OS: 95%; p=0.036). At 6 months the >1% BCR-ABLIS group (37% of pts; 5-year OS: 89%) showed inferior survival compared to ≤1% (63% of pts; 5-year OS: 97%; p<0.001); survival of the >0% Ph+ group (34% of pts; 5-year OS: 91%) was inferior to 0% Ph+ (66% of pts; 5-year OS: 97%; p=0.015). Regarding the IRIS pts 3 month BCR-ABLIS >10% (25% of pts; 8-year OS: 81%) was associated with inferior survival compared to ≤10% (75% of pts; 8-year OS: 93%; p=0.011). Conclusions: Failure to achieve the response landmarks of 10% BCR-ABLIS or 35% Ph+ at 3 months of imatinib treatment and 1% BCR-ABLIS or 0% Ph+ at 6 months identifies high-risk patients which might benefit from an early change of therapy.

Abstract 4622: A novel CD33/CD3-bispecific BiTE antibody can effectively recruit autologous T cells from AML-patients for in vitro cell lysis of CD33+ blasts

Bispecific T cell-engaging (BiTE®) antibodies are single-chain antibody constructs which combine dual specifity against CD3 on T cells and against a tumor-associated antigen. Phase 1 and 2 clinical trials with the CD19/CD3-bispecific BiTE antibody blinatumomab have shown very high response rates in patients suffering from non-Hodgkin's lymphoma and acute lymphoblastic leukemia. Here, we report on the potential of a novel BiTE antibody targeting CD33 in redirecting autologous T cells for in vitro lysis of blasts from acute myeloid leukemia (AML) patients. Initial antibody titration experiments showed that CD33 BiTE concentrations at low picomolar ranges mediate effective lysis of leukemic cell lines. We next analysed primary samples from AML patients, which were co-cultured with mononuclear cells (MNC) from healthy donors in presence or absence of specific BiTE antibodies at an E:T ratio of 1:1. After 48h of incubation in the presence of 1ng/ml CD33 BiTE we observed a decrease of both CD33+ AML blasts as well as CD33+ monocytes when compared to samples with control BiTE or without BiTE. 1ng/ml CD33 BiTE specifically induced strong upregulation of activation markers CD25 and CD69 on the vast majority of all CD4+ and CD8+ T cells. We furthermore investigated whether T cells from AML patients were able to mediate lysis of CD33+ leukemia cells by CD33 BiTE. T cells purified from peripheral blood or bone marrow of newly diagnosed AML patients were tested for BiTE mediated lysis of U-937 target cells. Redirected T cells from AML patients were capable of eliminating leukemic cells in the presence of CD33 BiTE as effectively as T cells from healthy controls. In consequence of this we studied blast lysis and T cell behaviour in a completely autologous setting using cryo-conserved samples from AML patients. Despite strong activation of T cells only moderate lysis of myeloid cells was observed after 48h, possibly due to low E:T ratios in these samples. Therefore, to allow autologous T cell expansion, cells were cultured for up to 144h. After this prolonged incubation, CD33 BiTE-mediated redirected lysis of AML blasts and myeloid cells was observed in most but those patient samples that had a very low initial effector-to-target (E:T) cell ratio. To adress this problem, we stimulated autologous T cells in a first step by incubating AML samples in presence of 1ng/ml CD33 BiTE for 7 days. After purification of the expanded T cells we performed autologous cultures with high initial E:T ratio (1:1). This led to fast, effective and almost complete lysis of CD33+ target cells. Taken together, autologous T cells from AML patients are effectively engaged and activated by the novel CD33 BiTE and redirected for the elimination of myeloblasts at low picomolar concentrations in vitro and may thereby constitute a promising novel therapeutic option for the treatment of patients with CD33+ acute myeloid leukemia.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4622. doi:1538-7445.AM2012-4622

Early molecular and cytogenetic response is predictive for long-term progression-free and overall survival in chronic myeloid leukemia (CML)

In the face of competing first-line treatment options for CML, early prediction of prognosis on imatinib is desirable to assure favorable survival or otherwise consider the use of a second-generation tyrosine kinase inhibitor (TKI). A total of 1303 newly diagnosed imatinib-treated patients (pts) were investigated to correlate molecular and cytogenetic response at 3 and 6 months with progression-free and overall survival (PFS, OS). The persistence of BCR-ABL transcript levels >10% according to the international scale (BCR-ABL(IS)) at 3 months separated a high-risk group (28% of pts; 5-year OS: 87%) from a group with >1-10% BCR-ABL(IS) (41% of pts; 5-year OS: 94%; P=0.012) and from a group with ≤1% BCR-ABL(IS) (31% of pts; 5-year OS: 97%; P=0.004). Cytogenetics identified high-risk pts by >35% Philadelphia chromosome-positive metaphases (Ph+, 27% of pts; 5-year OS: 87%) compared with ≤35% Ph+ (73% of pts; 5-year OS: 95%; P=0.036). At 6 months, >1% BCR-ABL(IS) (37% of pts; 5-year OS: 89%) was associated with inferior survival compared with ≤1% (63% of pts; 5-year OS: 97%; P<0.001) and correspondingly >0% Ph+ (34% of pts; 5-year OS: 91%) compared with 0% Ph+ (66% of pts; 5-year OS: 97%; P=0.015). Treatment optimization is recommended for pts missing these landmarks.

Survey and analysis of the efficacy and prescription pattern of sorafenib in patients with acute myeloid leukemia

Sorafenib is a multi-kinase inhibitor with activity against several intracellular kinases which may play a role in the pathogenesis of acute myeloid leukemia (AML). In vitro data and results from early clinical trials suggest that sorafenib might be an effective drug for the treatment of AML. However, clinical data are still sparse, and there are only a few reported cases of monotherapy. The aim of the present research was to collect clinical data on efficacy and safety in a systematic way by conducting a survey on clinical experience with sorafenib. Thirty institutions were asked to document all patients treated with sorafenib diagnosed with AML. Of all 29 evaluable patients, six (21%) responded to sorafenib containing treatment by achieving a complete remission (CR, n = 2) or complete remission with incomplete platelet recovery (CRi, n = 4). In 23 patients receiving sorafenib as monotherapy, the CRi rate amounted to 13% and no CRs were documented. Of the 18 FLT-ITD positive patients with sorafenib monotherapy, two patients achieved a CRi (11%). In five FLT3-ITD negative cases, one CRi was documented (20%). Our results suggest the potential ability of the drug to induce remissions in refractory or relapsed AML even when given as monotherapy.

Eight Cycles of Escalated-Dose BEACOPP Compared With Four Cycles of Escalated-Dose BEACOPP Followed by Four Cycles of Baseline-Dose BEACOPP With or Without Radiotherapy in Patients With Advanced-Stage Hodgkin's Lymphoma: Final Analysis of the HD12 Trial of the German Hodgkin Study Group

Purpose

Eight cycles of BEACOPPescalated (escalated dose of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone) followed by radiotherapy (RT) to initial bulk or residual tumor mass is the German Hodgkin Study Group standard of care for advanced-stage Hodgkin's lymphoma (HL). However, treatment-related toxicity is a concern, and the role of RT in this setting is unclear. The HD12 study thus aimed to reduce toxicity while maintaining efficacy.

Patients and Methods

In this prospectively randomized multicenter trial, eight cycles of BEACOPPescalated was compared with four cycles of BEACOPPescalated followed by four cycles of the baseline dose of BEACOPP (BEACOPPbaseline; 4 + 4), and RT with no RT in the case of initial bulk or residual disease. The study was designed to exclude a difference in 5-year freedom from treatment failure (FFTF) rate of 6%.

Results

Between January 1999 and January 2003, 1,670 patients age 16 to 65 years were enrolled onto the HD12 study. At 5 years, FFTF was 86.4% in the BEACOPPescalated arm and 84.8% in the 4 + 4 arm (difference, −1.6%; 95% CI, −5.2% to 1.9%), and overall survival was 92% versus 90.3% (difference, −1.7%; 95% CI, −4.6% to 1.1%). Deaths related to acute toxicity of chemotherapy were observed in 2.9% of patients (BEACOPPescalated, n = 19; 4 + 4, n = 27). FFTF was inferior without RT (90.4% v 87%; difference, −3.4%; 95% CI, −6.6% to −0.1%), particularly in patients who had residual disease after chemotherapy (difference, −5.8%; 95% CI, −10.7% to −1.0%), but not in patients with bulk in complete response after chemotherapy (difference, −1.1%; 95% CI, −6.2% to 4%).

Conclusion

The reduction of BEACOPP to the 4 + 4 regimen did not substantially reduce severe toxicity but might decrease efficacy. Our results do not support the omission of consolidation RT for patients with residual disease. Alternative strategies for improving the risk-to-benefit ratio for patients with advanced HL are needed.

[Hemolytic anemias in adults]

The erythrocyte lifespan in haemolytic anemia is shortened while erythropoesis is increased. Important labaratory findings are increased reticulocytes, LDH, indirect bilirubin and a decreased haptoglobin level. The most important diagnostic tool for further work up of hemolytic anemia is the direct antiglobulin test (DAT, Coombs test) to differentiate autoimmune hemolytic anemia (AIHA) from other causes. Another important group are fragmentation syndroms (hemolytic uremic syndrome and thrombotic thrombocytopenic purpura). In these forms of haemolytic anemia fragmented red blood cells can be found in the blood smear together with thrombocytopenia. A severe problem in paroxysmal nocturnal hematuria is the incidence of thrombosis. The following review describes the most important forms of hemolytic anemia in the adult and the diagnostic and therapeutic strategies.

Tolerability-adapted imatinib 800 mg/d versus 400 mg/d versus 400 mg/d plus interferon-α in newly diagnosed chronic myeloid leukemia

PURPOSE

Treatment of chronic-phase (CP) chronic myeloid leukemia (CML) with imatinib 400 mg/d can be unsatisfactory. Optimization of treatment is warranted.

PATIENTS AND METHODS

In all, 1,014 newly diagnosed CP-CML patients were randomly assigned to imatinib 800 mg/d (n = 338), imatinib 400 mg/d (n = 325), or imatinib 400 mg/d plus interferon alfa (IFN-α; n = 351). Dose adaptation to avoid higher-grade toxicity was recommended. First primary end point was major molecular remission (MMR) at 12 months.

RESULTS

A higher rate of MMR at 12 months occurred with tolerability-adapted imatinib 800 mg/d than with imatinib 400 mg/d (59% [95% CI, 53% to 65%] v 44% [95% CI, 37% to 50%]; P < .001) or imatinib 400 mg/d plus IFN-α (59% v 46% [95% CI, 40% to 52%]; P = .002). Median dose in the 800-mg/d arm was 628 mg/d with a maximum dose of 737 mg/d during months 4 to 6 and a maintenance dose of 600 mg/d. All three treatment approaches were well tolerated with similar grade 3 and 4 adverse events. Independent of treatment approach, MMR at 12 months showed better progression-free survival (99% v 94%; P = .0023) and overall survival (99% v 93%; P = .0011) at 3 years when compared with > 1% on the international scale or no MMR but showed no difference in 0.1% to < 1% on the international scale, which closely correlates with complete cytogenetic remission.

CONCLUSION

Treatment of early-phase CML with imatinib can be optimized. Early high-dose therapy followed by rapid adaptation to good tolerability increases the rate of MMR at 12 months. Achievement of MMR by month 12 is directly associated with improved survival.

Active DNA demethylation in human postmitotic cells correlates with activating histone modifications, but not transcription levels

Background

In mammals, the dynamics of DNA methylation, in particular the regulated, active removal of cytosine methylation, has remained a mystery, partly due to the lack of appropriate model systems to study DNA demethylation. Previous work has largely focused on proliferating cell types that are mitotically arrested using pharmacological inhibitors to distinguish between active and passive mechanisms of DNA demethylation.

Results

We explored this epigenetic phenomenon in a natural setting of post-mitotic cells: the differentiation of human peripheral blood monocytes into macrophages or dendritic cells, which proceeds without cell division. Using a global, comparative CpG methylation profiling approach, we identified many novel examples of active DNA demethylation and characterized accompanying transcriptional and epigenetic events at these sites during monocytic differentiation. We show that active DNA demethylation is not restricted to proximal promoters and that the time-course of demethylation varies for individual CpGs. Irrespective of their location, the removal of methylated cytosines always coincided with the appearance of activating histone marks.

Conclusions

Demethylation events are highly reproducible in monocyte-derived dendritic cells from different individuals. Our data suggest that active DNA demethylation is a precisely targeted event that parallels or follows the modification of histones, but is not necessarily coupled to alterations in transcriptional activity.

Primary prophylaxis of invasive fungal infections in patients with hematologic malignancies. Recommendations of the Infectious Diseases Working Party of the German Society for Haematology and Oncology

There is no widely accepted standard for antifungal prophylaxis in patients with hematologic malignancies. The Infectious Diseases Working Party of the German Society for Haematology and Oncology assigned a committee of hematologists and infectious disease specialists to develop recommendations. Literature data bases were systematically searched for clinical trials on antifungal prophylaxis. The studies identified were shared within the committee. Data were extracted by two of the authors (OAC and MSi). The consensus process was conducted by email communication. Finally, a review committee discussed the proposed recommendations. After consensus was established the recommendations were finalized. A total of 86 trials were identified including 16,922 patients. Only a few trials yielded significant differences in efficacy. Fluconazole 400 mg/d improved the incidence rates of invasive fungal infections and attributable mortality in allogeneic stem cell recipients. Posaconazole 600 mg/d reduced the incidence of IFI and attributable mortality in allogeneic stem cell recipients with severe graft versus host disease, and in patients with acute myelogenous leukemia or myelodysplastic syndrome additionally reduced overall mortality. Aerosolized liposomal amphotericin B reduced the incidence rate of invasive pulmonary aspergillosis. Posaconazole 600 mg/d is recommended in patients with acute myelogenous leukemia/myelodysplastic syndrome or undergoing allogeneic stem cell recipients with graft versus host disease for the prevention of invasive fungal infections and attributable mortality (Level A I). Fluconazole 400 mg/d is recommended in allogeneic stem cell recipients until development of graft versus host disease only (Level A I). Aerosolized liposomal amphotericin B is recommended during prolonged neutropenia (Level B II).

CCAAT enhancer-binding protein beta regulates constitutive gene expression during late stages of monocyte to macrophage differentiation

Human monocyte to macrophage differentiation is accompanied by pronounced phenotypical changes and generally proceeds in the absence of proliferation. The molecular events governing this process are poorly understood. Here, we studied the regulation of the macrophage-specific chitotriosidase (CHIT1) gene promoter to gain insights into the mechanisms of transcriptional control during the differentiation of human blood monocytes into macrophages. We used transient transfections to define a cell type-specific minimal promoter that was mainly dependent on a proximal C/EBP motif that bound multiple C/EBP factors in gel shift assays. In depth analysis of occupied promoter elements using in vivo footprinting and chromatin immunoprecipitation analyses demonstrated the differentiation-associated recruitment of C/EBPbeta and PU.1 at the proximal promoter in parallel with CHIT1 mRNA induction. Notably, the induction of C/EBPbeta promoter binding strongly correlated with increased nuclear levels of Thr-235-phosphorylated C/EBPbeta protein during the differentiation process, whereas C/EBPbeta mRNA and total protein expression remained relatively stable. Our data suggest an important constitutive gene regulatory function for C/EBPbeta in differentiated macrophages but not in human blood monocytes.

Ifosfamide, epirubicin, and etoposide (IEV) mobilize peripheral blood stem cells more efficiently than cyclophosphamide/etoposide

High-dose chemotherapy with autologous stem cell support is an effective treatment in advanced multiple myeloma. In this study, we compare chemotherapy with ifosfamide, epirubicin, and etoposide (IEV) or cyclophosphamide and etoposide (CE) in 47 patients with multiple myeloma with regard to stem cell mobilization, toxicity, and tumor response. The proportion of patients reaching the threshold of >6 x 10(6) CD34+ cells/kg body weight was significantly higher in the IEV group (97% vs 71%), and more CD34+ cells (10 x 10(6) vs 3.5 x 10(6) cells/kg; p = 0.002) could be collected by the first leukapheresis associated with less leukaphereses needed. Non-hematopoietic side effects were mild with nausea being more frequent after IEV treatment (30% vs 7%). Grade 3/4 neutropenia (thrombocytopenia) occurred in 89 and 100% (55 and 44%) of the patients. There was one treatment-related death due to septic shock in the IEV group. Grade 3/4 anemia was more frequent in the IEV group (19% vs 0%). Forty-two percent (IEV) and 50% (CE) received inpatient treatment for neutropenic fever. In 20 and 7% of the patients, a partial response was observed after IEV and CE. However, the overall response rate (complete response and partial tumor response) after mobilization and tandem high-dose chemotherapy was 75% after IEV and 78% after CE and, thus, independent of the mobilization. In summary, both treatment protocols can readily be used for the mobilization of peripheral blood stem cells with comparable major toxicities and similar tumor response rates. However, the efficiency of the stem cell mobilization was significantly higher after IEV treatment.

Liposomal amphotericin B as initial therapy for invasive mold infection: a randomized trial comparing a high-loading dose regimen with standard dosing (AmBiLoad trial)

BACKGROUND

Treatment of invasive mold infection in immunocompromised patients remains challenging. Voriconazole has been shown to have efficacy and survival benefits over amphotericin B deoxycholate, but its utility is limited by drug interactions. Liposomal amphotericin B achieves maximum plasma levels at a dosage of 10 mg/kg per day, but clinical efficacy data for higher doses are lacking.

METHODS

In a double-blind trial, patients with proven or probable invasive mold infection were randomized to receive liposomal amphotericin B at either 3 or 10 mg/kg per day for 14 days, followed by 3 mg/kg per day. The primary end point was favorable (i.e., complete or partial) response at the end of study drug treatment. Survival and safety outcomes were also evaluated.

RESULTS

Of 201 patients with confirmed invasive mold infection, 107 received the 3-mg/kg daily dose, and 94 received the 10-mg/kg daily dose. Invasive aspergillosis accounted for 97% of cases. Hematological malignancies were present in 93% of patients, and 73% of patients were neutropenic at baseline. A favorable response was achieved in 50% and 46% of patients in the 3- and 10-mg/kg groups, respectively (difference, 4%; 95% confidence interval, -10% to 18%; P>.05); the respective survival rates at 12 weeks were 72% and 59% (difference, 13%; 95% confidence interval, -0.2% to 26%; P>.05). Significantly higher rates of nephrotoxicity and hypokalemia were seen in the high-dose group.

CONCLUSIONS

In highly immunocompromised patients, the effectiveness of 3 mg/kg of liposomal amphotericin B per day as first-line therapy for invasive aspergillosis is demonstrated, with a response rate of 50% and a 12-week survival rate of 72%. The regimen of 10 mg/kg per day demonstrated no additional benefit and higher rates of nephrotoxicity.

Inhibitory effect of tumor cell-derived lactic acid on human T cells

A characteristic feature of tumors is high production of lactic acid due to enhanced glycolysis. Here, we show a positive correlation between lactate serum levels and tumor burden in cancer patients and examine the influence of lactic acid on immune functions in vitro. Lactic acid suppressed the proliferation and cytokine production of human cytotoxic T lymphocytes (CTLs) up to 95% and led to a 50% decrease in cytotoxic activity. A 24-hour recovery period in lactic acid-free medium restored CTL function. CTLs infiltrating lactic acid-producing multicellular tumor spheroids showed a reduced cytokine production. Pretreatment of tumor spheroids with an inhibitor of lactic acid production prevented this effect. Activated T cells themselves use glycolysis and rely on the efficient secretion of lactic acid, as its intracellular accumulation disturbs their metabolism. Export by monocarboxylate transporter-1 (MCT-1) depends on a gradient between cytoplasmic and extracellular lactic acid concentrations and consequently, blockade of MCT-1 resulted in impaired CTL function. We conclude that high lactic acid concentrations in the tumor environment block lactic acid export in T cells, thereby disturbing their metabolism and function. These findings suggest that targeting this metabolic pathway in tumors is a promising strategy to enhance tumor immunogenicity.

Monocyte-Derived Human Macrophages Mediate Anergy in Allogeneic T Cells and Induce Regulatory T Cells

Activation of alloreactive T cells by APCs such as dendritic cells (DC) has been implicated as crucial step in transplant rejection. In contrast, it has been proposed that macrophages (Mphi) maintain tolerance toward alloantigens. It was therefore the aim of this study to further analyze the T cell-stimulatory capacity of mature DC and Mphi in vitro using the model of allogeneic MLR. There was a strong proliferative response in T cells cocultured with DC, which was further increased upon restimulation in a secondary MLR. In contrast, T cells did not proliferate in cocultures with Mphi despite costimulation with anti-CD28 and IL-2. Cytokine analysis revealed considerable levels of IL-10 in cocultures of T cells with Mphi, whereas high amounts of IL-2 and IFN-gamma were present in cocultures with DC. There was only minimal T cell proliferation in a secondary MLR when T cells were rescued from primary MLR with Mphi and restimulated with DC of the same donor, or DC of an unrelated donor (third party), whereas a strong primary proliferative response was observed in resting T cells, demonstrating induction of T cell anergy by Mphi. Functional analysis of T cells rescued from cocultures with Mphi demonstrated that anergy was at least partly mediated by IL-10-producing regulatory T cells induced by Mphi. These results demonstrate that Mphi drive the differentiation of regulatory T cells and mediate anergy in allogeneic T cells, supporting the concept that Mphi maintain peripheral tolerance in vivo.

Ex Vivo-activated Human Macrophages Kill Chronic Lymphocytic Leukemia Cells in the Presence of Rituximab: Mechanism of Antibody-dependent Cellular Cytotoxicity and Impact of Human Serum

Antibody-dependent cellular cytotoxicity (ADCC) is one of the mechanisms of tumor killing during antibody (Ab) immunotherapy, and a role for myeloid cells as effectors has been observed in several models. We are developing immunotherapy approaches based on administration of large numbers of ex vivo interferon-gamma-activated macrophages to cancer patients. With a quantitative assay measuring killing of nonproliferating tumor cells, we evaluated whether, in physiologic conditions, these macrophages synergize with the anti-CD20 Ab rituximab for killing primary B-cell chronic lymphocytic leukemia (B-CLL) cells. ADCC reached levels of 70% to 80% at effector to target ratios as low as 1:1. Macrophage recruitment by Ab-opsonized tumor cells did not result in enhanced cytokine secretion, suggesting that the cytokine shower observed in rituximab-treated patients is not caused by macrophage activation, and that cytokines have no role in CLL killing. We observed that uptake of tumor material by macrophages was not directly correlated to tumor killing. Nonetheless, experiments in the presence of cytochalasin D showed that ADCC occurred mainly by phagocytosis. Tumor killing was largely mediated by Fc gammaRI and inhibited by increasing concentration of serum. Importantly, complement deposition on B-CLL cells did not seem to enhance macrophage ADCC in this model, as complement-depleted and complement-repleted human plasmas exerted comparable inhibition.

Transcription factor Tfec contributes to the IL-4-inducible expression of a small group of genes in mouse macrophages including the granulocyte colony-stimulating factor receptor

Expression of the mouse transcription factor EC (Tfec) is restricted to the myeloid compartment, suggesting a function for Tfec in the development or function of these cells. However, mice lacking Tfec develop normally, indicating a redundant role for Tfec in myeloid cell development. We now report that Tfec is specifically induced in bone marrow-derived macrophages upon stimulation with the Th2 cytokines, IL-4 and IL-13, or LPS. LPS induced a rapid and transient up-regulation of Tfec mRNA expression and promoter activity, which was dependent on a functional NF-kappaB site. IL-4, however, induced a rapid, but long-lasting, increase in Tfec mRNA, which, in contrast to LPS stimulation, also resulted in detectable levels of Tfec protein. IL-4-induced transcription of Tfec was absent in macrophages lacking Stat6, and its promoter depended on two functional Stat6-binding sites. A global comparison of IL-4-induced genes in both wild-type and Tfec mutant macrophages revealed a surprisingly mild phenotype with only a few genes affected by Tfec deficiency. These included the G-CSFR (Csf3r) gene that was strongly up-regulated by IL-4 in wild-type macrophages and, to a lesser extent, in Tfec mutant macrophages. Our study also provides a general definition of the transcriptome in alternatively activated mouse macrophages and identifies a large number of novel genes characterizing this cell type.

Treatment of colon and lung cancer patients with ex vivo heat shock protein 70-peptide-activated, autologous natural killer cells: a clinical phase i trial

PURPOSE

The 14 amino acid sequence (aa(450-463)) TKDNNLLGRFELSG (TKD) of heat shock protein 70 (Hsp70) was identified as a tumor-selective recognition structure for natural killer (NK) cells. Incubation of peripheral blood lymphocyte cells with TKD plus low-dose interleukin 2 (IL-2) enhances the cytolytic activity of NK cells against Hsp70 membrane-positive tumors, in vitro and in vivo. These data encouraged us to test tolerability, feasibility, and safety of TKD-activated NK cells in a clinical Phase I trial.

EXPERIMENTAL DESIGN

Patients with metastatic colorectal cancer (n = 11) and non-small cell lung cancer (n = 1) who had failed standard therapies were enrolled. After ex vivo stimulation of autologous peripheral blood lymphocytes with Hsp70-peptide TKD (2 microg/ml) plus low-dose IL-2 (100 units/ml), TKD was removed by extensive washing, and activated cells were reinfused i.v. The procedure was repeated for up to six cycles, applying a dose escalation schedule in 4 patients.

RESULTS

The percentage of activated NK cells in the reinfused leukapheresis products ranged between 8 and 20% of total lymphocytes, corresponding to total NK cell counts of 0.1 up to 1.5 x 10(9). Apart from restless feeling in 1 patient and itching in 2 patients, no negative side effects were observed. Concomitant with an enhanced CD94 cell surface density, the cytolytic activity of NK cells against Hsp70 membrane-positive colon carcinoma cells was enhanced after TKD/IL-2 stimulation in 10 of 12 patients. Concerning tumor response, 1 patient was in stable disease during therapy by formal staging criteria and another patient showed stable disease in one metastases and progression in another.

CONCLUSIONS

Reinfusion of Hsp70-activated autologous NK cells is safe. Immunological results warrant additional studies in patients with lower tumor burden.

Elimination of activated but not resting primary human CD4 and CD8 T cells by Fas ligand (FasL/CD95L)-expressing Killer-dendritic cells

Dendritic cells (DC) genetically engineered to express high levels of Fas ligand (FasL/CD95L) have been demonstrated to delete T cells in an antigen specific manner in several different animal models in vivo. However, the immunomodulatory capacity of primary human FasL-expressing Killer-DC has not been determined. Therefore, human Killer-DC were generated from mature monocyte-derived DC using the inducible CRE/LoxP adenoviral vector system, and the immunoregulatory capacity of these cells was analyzed in cocultures with primary human T cells in vitro. Combined transductions of DC by AdloxPFasL and AxCANCre resulted in FasL expression in > 70% of DC without affecting the mature phenotype. Proliferation of activated primary human T cells was inhibited up to 80% in cocultures with FasL-expressing DC but not EGFP-transduced DC, which was due to induction of apoptosis in activated but not resting CD4+ and CD8+ T cells. Apoptosis induced by Killer-DC could be blocked by an anti-FasL-antibody in a dose dependent fashion. The present results demonstrate that FasL-expressing Killer-DC eliminate activated but not resting primary human CD4+ and CD8+ T cells by induction of Fas-mediated apoptosis supporting the concept to apply Killer-DC as a novel strategy for the treatment of T cell-dependent autoimmune disease and allograft rejection in humans.

Hybrid Cell Vaccination in Metastatic Melanoma

Hybrid cell vaccination with cell fusion products (CFPs) of autologous tumor cells and mature allogenic MHC II bearing dendritic cells has been described to induce cytotoxic T lymphocyte (CTL)-mediated immune responses. The aim of this study was to assess safety, antitumor activity, and immune responses of a CFP-vaccine in patients with disseminated malignant melanoma. In a phase I/II study, we treated 11 patients by monthly intracutaneous or subcutaneous application of a CFP vaccine generated by electrofusion of autologous melanoma cells with mature allogenic dendritic cells. In addition, patients received subcutaneous low-dose interleukin-2 injections for 6 days after each vaccination. No serious adverse effects were observed. Ten patients showed progressive disease and one patient had a short-lasting stable disease. None of the patients developed a positive delayed-type hypersensitivity reaction against irradiated autologous melanoma cells. In 2 patients, who were monitored in more detail, we found no evidence of induction of a specific antimelanoma T-cell response by analyzing the proliferation, cytokine secretion, and cytotoxicity of their T cells toward autologous melanoma cells. No unequivocal beneficial effects of the used CFP vaccine could be demonstrated.

Pioglitazone and rofecoxib combined with angiostatically scheduled trofosfamide in the treatment of far-advanced melanoma and soft tissue sarcoma

BACKGROUND

Combined treatment approaches targeting tumor cells as well as stromal cells may control chemorefractory malignancies. In the current study, the authors sought to test one such combined approach in the treatment of chemorefractory melanoma and soft tissue sarcoma.

METHODS

A Phase II trial was initiated to analyze the activity of a continuously administered molecularly targeted treatment regimen (daily pioglitazone [45 mg administered orally] and rofecoxib [25 mg administered orally]) combined with sequentially added angiostatic chemotherapy for patients with previously treated metastatic melanoma (n = 19) or soft tissue sarcoma (n = 21). Angiostatic chemotherapy consisted of trofosfamide (50 mg) administered orally 3 times daily beginning on the 15th day after the start of molecularly targeted therapy.

RESULTS

Forty patients were evaluable for response and toxicity. Major side effects (World Health Organization Grade 3 or 4) were not observed. Objective responses and disease stabilization lasting longer than 6 months were noted in 11% and 11%, respectively, of all patients with melanoma and in 19% and 14%, respectively, of all patients with soft tissue sarcoma. Complete remission was noted in one patient with melanoma and in three patients with sarcoma. Both normal C-reactive protein (CRP) levels and CRP levels that decreased by > 30% during the 14-day biomodulator pretreatment period were found to be predictive of prolonged progression-free survival.

CONCLUSIONS

To our knowledge, the current study is the first to demonstrate that a novel, completely orally administered combined biomodulator/metronomic chemotherapy regimen may be active and well tolerated in patients with chemorefractory malignancies.

Transcriptional regulation of CHI3L1, a marker gene for late stages of macrophage differentiation

The protein product of the CHI3L1 gene, human cartilage 39-kDa glycoprotein (HC-gp39), is a tissue-restricted, chitin-binding lectin and member of glycosyl hydrolase family 18. In contrast to many other monocyte/macrophage markers, its expression is absent in monocytes and strongly induced during late stages of human macrophage differentiation. To gain insights into the molecular mechanisms underlying its cell type-restricted and maturation-associated expression in macrophages, we initiated a detailed study of the proximal HC-gp39 promoter. Deletion analysis of reporter constructs in macrophage-like THP-1 cells localized a region directing high levels of macrophage-specific reporter gene expression to approximately 300 bp adjacent to the major transcriptional start site. The promoter sequence contained consensus binding sites for several known factors, and specific binding of nuclear PU.1, Sp1, Sp3, USF, AML-1, and C/EBP proteins was detectable in gel shift assays. In vivo footprinting assays with dimethyl sulfate demonstrate that the protection of corresponding sequences was enhanced in macrophages compared with monocytes. Mutational analysis of transcription factor binding sites indicated a predominant role for a single Sp1 binding site in regulating HC-gp39 promoter activity. In addition, gel shift assays using nuclear extracts of monocytes and macrophages demonstrated that the binding of nuclear Sp1, but not Sp3, markedly increases during macrophage differentiation. Our results further highlight the important role of Sp1 in macrophage gene regulation.

Dynamics of BCR-ABL mRNA expression in first-line therapy of chronic myelogenous leukemia patients with imatinib or interferon α/ara-C

We sought to determine dynamics of BCR-ABL mRNA expression levels in 139 patients with chronic myelogenous leukemia (CML) in early chronic phase, randomized to receive imatinib (n=69) or interferon (IFN)/Ara-C (n=70). The response was sequentially monitored by cytogenetics from bone marrow metaphases (n=803) and qualitative and quantitative RT-PCR from peripheral blood samples (n=1117). Complete cytogenetic response (CCR) was achieved in 60 (imatinib, 87%) vs 10 patients (IFN/Ara-C, 14%) after a median observation time of 24 months. Within the first year after CCR, best median ratio BCR-ABL/ABL was 0.087%, (imatinib, n=48) vs 0.27% (IFN/Ara-C, n=9, P=0.025). BCR-ABL was undetectable in 25 cases by real-time PCR, but in only four patients by nested PCR. Median best response in patients with relapse after CCR was 0.24% (n=3) as compared to 0.029% in patients with continuous remission (n=52, P=0.029). We conclude that (i) treatment with imatinib in newly diagnosed CML patients is associated with a rapid decrease of BCR-ABL transcript levels; (ii) nested PCR may reveal residual BCR-ABL transcripts in samples that are negative by real-time PCR; (iii) BCR-ABL transcript levels parallel cytogenetic response, and (iv) imatinib is superior to IFN/Ara-C in terms of the speed and degree of molecular responses, but residual disease is rarely eliminated.

The JAM-assay: optimized conditions to determine death-receptor-mediated apoptosis

Apoptosis induced by interaction of members of the TNF-/TNF-receptor superfamily has been considered as a major mechanism of cell-mediated cytotoxicity. For functional analysis, the 51Cr release assay has been widely used, which requires loss of membrane integrity in the apoptotic target cell. However, loss of membrane integrity is a late event during apoptosis and therefore only late apoptotic cells will be detected by this method. In contrast, the JAM-assay first described by Polly Matzinger has been demonstrated to be more sensitive than the 51Cr release assay, since this method is dependent on DNA-fragmentation which precedes loss of membrane integrity in most apoptotic cells. The JAM-assay is easier to perform, less expansive, and safer than the current standard (51)Cr release assay. Therefore, this article will focus on optimized conditions of the JAM-assay to detect and quantitate Fas (CD95/Apo-1)-induced apoptosis as an example of death-receptor-mediated cytotoxicity.

Blood leukocyte subsets and cytokine profile after autologous peripheral blood stem cell transplantation

High-dose chemotherapy with autologous peripheral blood stem cell transplantation (PBSCT) includes the risk of infectious complications due to neutropenia and therapy-induced immune deviation. In order to understand early immune recovery in this situation, we analyzed the distribution of cell subsets by flow cytometry and we measured cytokine production in a whole blood assay stimulated with lipopolysaccharide (LPS) in order to induce monocyte (MO) activation in 43 patients with solid tumors or lymphoma treated with two cycles of high-dose chemotherapy and PBSCT. Blood was collected at the following time points: before start of mobilization chemotherapy, before and after high-dose chemotherapy, and 10 and 30 days after PBSCT. In the lymphocyte compartment, we found a depletion of B cells and naive T cells and a transitory reduction of natural killer (NK) cells, whereas MO and neutrophils recovered rapidly. However, during early recovery, HLA-DR expression on MO and the percentage of CD16(+) MO was considerably reduced. Production of proinflammatory cytokines interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-alpha upon LPS stimulation was severely impaired directly after chemotherapy and unexpectedly remained low during early recovery of myeloid cells, whereas production of IL-1RA was enhanced, indicating a shift of immune competent cells to an anti-inflammatory or anergic state early after PBSCT.

Species-specific regulation of Toll-like receptor 3 genes in men and mice

Toll-like receptor 3 (TLR3) belongs to a family of evolutionary conserved innate immune recognition molecules and recognizes double-stranded RNA, a molecular pattern associated with viral infections. Earlier studies suggested a differential expression pattern in men and mice; the molecular basis for this observation, however, was unknown. Here we demonstrate that species-specific differences in tissue expression and responses to lipopolysaccaride (LPS) coincide with the presence of different, evolutionary non-conserved promoter sequences in both species. Despite the overall unrelatedness of TLR3 promoter sequences, mRNA expression of both TLR3 orthologues was induced by interferons, particularly by interferon (IFN)-beta. The basal and IFN-beta-induced activation of promoters from both species largely depended on similar interferon regulatory factor (IRF) elements, which constitutively bound IRF-2 and recruited IRF-1 after stimulation. In murine macrophages, IFN-beta-induced TLR3 up-regulation required IFNAR1, STAT1, and in part IRF-1, but not the Janus kinase (Jak) family member Tyk2. We also show that LPS specifically up-regulates TLR3 expression in murine cells through the induction of autocrine/paracrine IFN-beta. In humans, however, IFN-beta-induced up-regulation of TLR3 was blocked by pretreatment with LPS, despite the efficient induction of IRF-1. Our findings reveal a mechanistic basis for the observed differences as well as similarities in TLR3 expression in men and mice. The IFN-beta-TLR3 link further suggests a role of TLR3 in innate and adaptive immune responses to viral infections. It will be interesting and important to clarify whether the observed differences in the transcriptional regulation of TLR3 influence innate immune responses in a species-specific manner.

Mature but not immature Fas ligand (CD95L)-transduced human monocyte-derived dendritic cells are protected from Fas-mediated apoptosis and can be used as killer APC

Several in vitro and animal studies have been performed to modulate the interaction of APCs and T cells by Fas (CD95/Apo-1) signaling to delete activated T cells in an Ag-specific manner. However, due to the difficulties in vector generation and low transduction frequencies, similar studies with primary human APC are still lacking. To evaluate whether Fas ligand (FasL/CD95L) expressing killer APC could be generated from primary human APC, monocyte-derived dendritic cells (DC) were transduced using the inducible Cre/Loxp adenovirus vector system. Combined transduction of DC by AdLoxpFasL and AxCANCre, but not single transduction with these vectors, resulted in dose- and time-dependent expression of FasL in >70% of mature DC (mDC), whereas <20% of immature DC (iDC) expressed FasL. In addition, transduction by AdLoxpFasL and AxCANCre induced apoptosis in >80% of iDC, whereas FasL-expressing mDC were protected from FasL/Fas (CD95/Apo-1)-mediated apoptosis despite coexpression of Fas. FasL-expressing mDC eliminated Fas(+) Jurkat T cells as well as activated primary T cells by apoptosis, whereas nonactivated primary T cells were not deleted. Induction of apoptosis in Fas(+) target cells required expression of FasL in DC and cell-to-cell contact between effector and target cell, and was not dependent on soluble FasL. Induction of apoptosis in Fas(+) target cells required expression of FasL in DC, cell-to-cell contact between effector and target cell, and was not dependent on soluble FasL. The present results demonstrate that FasL-expressing killer APC can be generated from human monocyte-derived mDC using adenoviral gene transfer. Our results support the strategy to use killer APCs as immunomodulatory cells for the treatment of autoimmune disease and allograft rejection.

[The "classical" macrophage marker CD68 is strongly expressed in primary human fibroblasts]

AIM

Monoclonal antibodies against the human homologue of mouse macrosialin, CD68, are generally commercialized as markers for human monocytes and macrophages. Indeed, CD68 is considered as a selective marker for human myeloid cells, although several previous immunohistochemical studies indicate that some antibody clones also react with other hematopoietic and non-hematopoietic cell types. The aim of our study was to verify these observations and to evaluate the reliability of CD68 as a macrophage marker.

METHODS

We investigated protein and RNA expression of CD68 in various fibroblast types and carcinoma cell lines as compared to monocytes and macrophages using immunohistochemistry, flow cytometry, and specific RT-PCR. Different monoclonal antibody clones against CD68 were applied including KP-1 and EBM11.

RESULTS

As expected, the intensity of immunohistochemical and flow cytometric CD68 staining was dependent on both the antibody clone and the fixation procedure. However, fibroblasts isolated from normal skin, normal breast, breast tumor tissue, and osteoarthritis synovia clearly expressed CD68 protein at levels comparable to macrophages. The specificity of CD68 expression in fibroblasts was verified by RT-PCR which also showed some tumor cell types to express CD68 mRNA.

CONCLUSION

Our findings clearly demonstrate that the expression of CD68 is not restricted to the macrophage lineage. This is highly relevant for experimental and diagnostic purposes, since anti CD68 antibodies cannot be accepted without reservations for the discrimination of myeloid cells and fibroblasts even in paraffin sections after formalin fixation.

Characterization of cells prepared by dendritic cell-tumor cell fusion

Dendritic cells (DCs) are professional antigen-presenting cells currently being discussed as a potent tool for antitumor vaccination strategies. The approach consisting of the in vitro generation of DC-tumor cell hybrids may be advantageous for individualized vaccines since there is no need for the determination of MHC-restricted tumor-associated antigens recognized by T cells. As recent vaccination studies gave varying results, we tested the impact of the fusion treatment on the cells used. Polyethylene glycol-induced fusion, as well as electrofusion, proved to be suitable for generating hybrid cells although at a low frequency. Of note, both methods also gave rise to DCs having phagocytosed apoptotic tumor cells. The expression of surface molecules relevant for specific T cell stimulation was not altered by the fusion procedure and the DCs were still functionally active as demonstrated by the secretion of IL-12 and the uptake of antigen. The cells were able to induce a tumor-specific T cell response in vitro and therefore deserve further investigation as potent tools for immunotherapy trials.

The treatment of patients with disseminated malignant melanoma by vaccination with autologous cell hybrids of tumor cells and dendritic cells

Malignant melanoma has been shown to be susceptible to T cell-mediated immunity and, therefore, is a candidate for vaccination approaches. Clinical trials using dendritic cells (DC) loaded with peptides corresponding to tumor antigens are ongoing in several institutions, and some promising results have already been published. However, every single peptide-based vaccine can only be used in a patient with a given single HLA type, and this strategy is not appropriate for patients with rare HLA types or with tumors without defined antigens. A clinical pilot study in patients with disseminated melanoma refractory to standard therapy was initiated using a different approach. The authors generated autologous monocyte-derived DC and fused these DC with gamma-irradiated primary autologous tumor cells by incubation in polyethylene glycol. In previous experiments, the authors had shown that these fused cell products are potent inducers of a T-cell response in a mixed lymphocyte tumor cell culture. Seventeen patients were immunized with the cell product by s.c. injection in monthly intervals without any serious side effects. Of these patients, one had a partial response with decrease in size of all evaluable tumor manifestations. In one patient, some of the metastases were regressing despite an overall progressive disease, and one patient achieved disease stabilization for six months. In the responding patient, in parallel to tumor regression, circumscript hair depigmentation occurred. These data show, that a hybrid vaccine of DC and tumor cells can be safely applied and can induce tumor regressions, however, the clinical efficacy of the approach in its present form is insufficient.

Analysis of the immune response against tetanus toxoid: enumeration of specific T helper cells by the Elispot assay

Tetanus toxoid (TT) is an antigen known to induce strong T cell specific immune responses in humans after vaccination. Here we have used the Elispot assay to assess the number of TT-specific Interferon-gamma (IFN-gamma) secreting T cells present in individuals and monitored the number of TT specific T cells present in the donors for more than two years. In each of the 22 healthy volunteers tested, TT-specific T cells could be detected. Six out of 7 repetitively tested donors showed a remarkably constant number of TT-specific IFN-gamma secreting T cells over several months, whereas one donor demonstrated a transient increase during a flu-like infection. Three healthy donors received TT booster-immunizations and showed significant increases in the number of TT-specific IFN-gamma secreting T cells which reached peak levels by 4 weeks after vaccination. Depletion of either CD4+ T cells, CD8+ T cells or CD16+/CD56+ T cells by immunomagnetic separation demonstrated that TT-specific IFN-gamma secretion is mediated exclusively by CD4+ T cells. In addition, HLA class-I and -II blocking studies showed that IFN-gamma production is performed by HLA class-II restricted cells. Our data show that the Elispot assay can be reliably used to assess the number of TT-specific CD4+ IFN-gamma producing cells (i.e. probably T helper cells) and therefore maybe also useful for the assessment of reactions to other helper antigens.

Genomic organization of the human gene HEP27: alternative promoter usage in HepG2 cells and monocyte-derived dendritic cells

We used representational difference analysis to discover new genes with specific expression in dendritic cells. Among other genes, we identified HEP27, encoding a member of the short chain alcohol dehydrogenase/reductase family to be upregulated during monocyte to dendritic cell differentiation. Originally cloned from hepatocellular carcinoma cells (HepG2), HEP27 was exclusively expressed in monocyte-derived dendritic cells within the hematopoietic system. The presence of different transcripts in monocyte-derived dendritic cells, HepG2 cells, and various tissues could be traced back to alternative splicing and alternative promoter usage. We describe here the complete genomic organization of HEP27, including two alternative promoter regions: a hepatocyte-specific promoter which was induced by the histone deacetylase inhibitor sodium butyrate in several other cell types, and a second upstream promoter which was specifically active in monocyte-derived dendritic cells. Its exclusive usage in monocyte-derived dendritic cells makes the alternative HEP27 promoter an interesting target to study dendritic-cell-specific gene regulation.

Adoptive therapy with monocyte-derived macrophages in the setting of high-dose chemotherapy and peripheral blood stem cell transplantation

In an attempt to ameliorate chemotherapy-induced side-effects after transplantation of autologous peripheral blood stem cells (PBSCT), we tested the reinfusion of autologous macrophages (MAC) that are known to be potent antimicrobial effector cells and cytokine producers. Ten patients were treated with two sequential cycles of high-dose chemotherapy followed by PBSCT. Before the second cycle of PBSCT, mononuclear cells were harvested, cultured for 8 d in order to induce MAC maturation and reinfused 3 d after PBSCT without clinical problems. However, MAC infusions did not substantially alleviate the toxicity of autologous PBSCT.

Structure of the human carboxypeptidase M gene. Identification of a proximal GC-rich promoter and a unique distal promoter that consists of repetitive elements

The human carboxypeptidase M (CPM) gene was found to encompass about 112.6 kb of genomic sequence, containing 11 exons of which eight (exons 2-9) are common to all transcripts and contain the entire coding region. We have cloned several alternative variants of CPM transcripts that result from differential promoter usage and alternative splicing. Although CPM belongs to the same metallocarboxypeptidase subfamily as CPE, their intron/exon structures differ significantly. Multiple transcription start sites were found in the CPM gene that cluster in two regions separated by about 30 kb and are flanked by two unique functional promoters. One ('proximal') is immediately upstream of the coding region and contains GC-rich sequences and a typical TATA box whereas the other ('distal') consists almost entirely of repetitive elements. Luciferase reporter assays with constructs of the promoter regions showed they were both quite active in several cell lines. However, the proximal promoter was much stronger than the distal one in two of the human cell lines tested (HepG2 and HEK293) whereas both promoters were highly and equally active in the human monocytic cell line THP-1, which has high constitutive expression of CPM.

Activation of lymphocytes inhibits human monocyte to macrophage differentiation

Tissue macrophages (MAC) differentiate from circulating blood monocytes (MO) during a maturation step that is of crucial importance for their functional competence. In vitro a similar process of maturation can be observed, if MO are cultured in the presence of serum. In the work presented here, we show that activated lymphocytes can interfere with MAC differentiation. Resting lymphocytes have only marginal influence upon MO to MAC transition in vitro. However, if cells are activated by the lectins PWM or ConA or by double-stranded RNA (polyinosinic-polycytidylic acid, pI:C), normal MAC maturation is suppressed: MO stay small and do not acquire MAC maturation-associated surface molecules like carboxypeptidase M (CPM, determined by antibody MAX.1) or CD84 (determined by antibody MAX.3). This phenomenon can be induced by small numbers of lymphocytes and can be transmitted by soluble factors in cultures stimulated with ConA or PWM. IFN-gamma is present in these conditioned media and partially suppresses MAC maturation but cannot fully substitute for the conditioned media. On the contrary, in pI:C stimulated cultures, suppression of MAC differentiation is dependent on cell-cell contact. In conclusion, activated lymphocytes are able to suppress the terminal differentiation of MAC by several pathways depending on the mode of lymphocyte stimulation.

Decreased T cell stimulatory capacity of monocyte-derived human macrophages following herpes simplex virus type 1 infection

Macrophages play a central role in establishing a specific immune response by acting as professional antigen presenting cells (APC) for T cells leading to a vigorous immune response. In order to analyze if Herpes simplex Virus (HSV) type 1 infection might affect the macrophage APC-function, monocyte-derived human macrophages were infected with HSV-1 strain F in vitro. Cocultures with allogeneic T cells revealed a strongly impaired stimulatory capacity of HSV-infected macrophages compared to uninfected controls which was not owing to a productive viral infection in macrophages. An increased expression of Fas ligand (FasL/CD95L) was detected in HSV-infected macrophages by FACS analysis. Although the majority of the macrophages expressed high levels of Fas (CD95/Apo-1), the HSV-induced upregulation of FasL did not result in an increased autocrine apoptosis of macrophages which might be related to endogenous expression of the apoptosis inhibitor FLICE inhibitory protein (FLIP). However, substantial apoptosis occurred in peripheral T cells as well as Fas-sensitive Jurkat T cells when cocultured with HSV-infected macrophages. These findings suggest that the paracrine killing of activated T cells by FasL expressing APC might be a novel strategy of immune evasion by HSV.