Functional response of leukaemic blasts to stromal cell-derived factor-1 correlates with preferential expression of the chemokine receptor CXCR4 in acute myelomonocytic and lymphoblastic leukaemia

The chemokine stromal cell-derived factor-1 (SDF-1) that is released by bone marrow (BM) stromal cells and contributes to stem cell homing may also play a role in the trafficking of leukaemic cells. We analysed SDF-1-induced intracellular calcium fluxes in leukaemic blasts from the peripheral blood of patients with newly diagnosed acute myeloid leukaemia (AML) and lymphoblastic leukaemia (B-lineage ALL), determined the effect of BM stromal cell-conditioned medium on in vitro transendothelial migration (TM) and measured expression of the SDF-1 receptor, CXCR4, by flow cytometry. AML FAB M1/2 blasts did not show calcium fluxes and TM was not stimulated. In myelomonocytic AML (M4/5), however, SDF-1 induced significant calcium fluxes and TM was increased twofold by the conditioned medium. M3 and M4 blasts with eosinophilia (M4eo) showed intermediate activity and M6 blasts showed no functional activity. In ALL, strong calcium fluxes and increased TM (2.5-fold) were observed. Accordingly, expression of CXCR4 was low in undifferentiated (M0) AML, myeloid (M1/2) AML and erythroid (M6) AML, but high [mean fluorescence (MF) > 50] in promyelocytic (M3) AML, myelomonocytic (M4/5) AML and B-lineage ALL. We conclude that, in AML, SDF-1 is preferentially active in myelomonocytic blasts as a result of differentiation-related expression of CXCR4. Functional activity of SDF-1 and high expression of CXCR4 in B-lineage ALL is in accordance with the previously described activity of SDF-1 in early B cells. SDF-1 may contribute to leukaemic marrow infiltration, as suggested by increased CXCR4 expression and migratory response in BM-derived blasts compared with circulating cells.

Identification of prognostic subgroups among patients with metastatic 'IGCCCG poor-prognosis' germ-cell cancer: an explorative analysis using cart modeling

OBJECTIVES

The IGCCCG classification has identified three prognostic groups of patients with metastatic germ-cell tumors. 'Poor prognosis' is based on primary tumor localization, the presence of visceral metastases, and/or high tumor-marker levels. The overall survival rate of these patients is about 45%-55%. The present analysis attempts to identify subsets of patients with a more or less favorable outcome among the 'poor-prognosis' group.

PATIENTS AND METHODS

We retrospectively explored prognostic subgroups in 332 patients with 'IGCCCG' poor-risk GCT using the classification-and-regression-tree model (CART). The following variables were included: primary tumor localization, presence of visceral or lung metastases, presence of an abdominal tumor, number of metastatic sites, serum levels of beta-HCG, AFP and LDH. All patients had been treated with cisplatin-etoposide-based chemotherapy within controlled clinical trials between 1984 and 1997.

RESULTS

PATIENT CHARACTERISTICS

gonadal/retroperitoneal (G/R) primary tumor 260 patients (78%), mediastinal primary tumor 72 patients (22%), visceral metastases 205 patients (62%) including 33 patients with CNS metastases, lung metastases 247 patients (74%), abdominal tumor 241 patients (72%), elevated AFP, beta-HCG or LDH levels 235 (71%), 253 (76%) and 275 (83%) of patients, respectively. Patients with primary mediastinal disease plus lung metastases exhibited the worst two-year PFS (28%), whereas patients with a primary G/R tumor and without visceral metastases showed the highest chance of two-year PFS (75%). The latter group of patients without visceral metastases and with a primary G/R tumor also had the most favourable two-year OS (84%). In contrast, patients with a primary mediastinal tumor and visceral metastases displayed the worst two-year OS (49%).

CONCLUSIONS

Different prognostic subsets of patients can be identified among the group of 'poor-prognosis' GCT patients. The CART analysis model results in a hierarchy of prognostic factors which may allow to more precisely estimate the individual patient's prognosis. Identifying subgroups of 'very poor-prognosis' among 'poor-prognosis' patients may allow to test for new treatment strategies in selected subgroups.

Topotecan - A novel topoisomerase I inhibitor: pharmacology and clinical experience

Topotecan, a water-soluble analogue of camptothecin, is a newly available cytotoxic agent which acts as an inhibitor of topoisomerase I, an enzyme necessary for DNA replication. Topotecan is a semisynthetic product derived from camptothecin, which was discovered during a National Cancer Institute cytotoxic drug screening program almost 30 years ago. It acts by forming a stable covalent complex with the DNA/topoisomerase I aggregate, the so-called 'cleavable complex'. This process leads to breaks in the DNA strand resulting in apoptosis and cell death. Topotecan possesses a serum half-life of approximately 3 h, a high volume of distribution with high tissue uptake and a low protein binding. The chemical structure is based on a lactone ring. Topotecan undergoes reversible hydrolysis from its biologically active lactone form to the open ring inactive carboxylate form. It is also able to penetrate the intact blood-brain barrier. Since most of the agent is excreted by the kidneys, dose adjustment is necessary when renal function is impaired. In contrast, pharmacokinetic behavior is unchanged in patients with limited hepatic function. The principal toxicity of topotecan when administered at standard doses is neutropenia, but thrombocytopenia and anemia occur as well, while the nonhematological toxicities are usually mild. Alopecia is frequently observed and some patients may suffer from pronounced fatigue. Most clinical data available are based on the following schedule: 1.5 mg/m2 topotecan given as a 30-min infusion, days 1-5. There are currently only minimal data available regarding a dose-antitumor activity relationship. Other topotecan administration schedules are currently being investigated. Preclinical data suggest that continuous-infusion schedules may be a better application form in terms of both, toxicity and antitumor activity. However, clinical trials could not confirm these results to date. Results of phase II studies suggest considerable antitumor activity of single agent topotecan in small cell lung cancer and ovarian cancer patients. A randomized phase III trial of topotecan versus paclitaxel in ovarian cancer patients pretreated with cisplatin/cyclophosphamide has demonstrated that topotecan is as effective as paclitaxel in the second-line treatment of these patients. Activity of topotecan was also observed in non-small-cell lung cancer, refractory leukemias/myelodysplastic syndromes and in childhood sarcomas. Due to its unique mechanism of action and lack of cross-resistance, cisplatin, etoposide, cytarabine and paclitaxel are potential interacting partners for combination chemotherapy regimens. However, the best combination regimen as well as the optimal combination schedule have yet to be conclusively determined. The potential of topotecan in a variety of solid tumors, as well as its use in combination regimens for ovarian and small cell lung cancer is currently being investigated.

Tumor necrosis factor alpha and CD40 ligand antagonize the inhibitory effects of interleukin 10 on T-cell stimulatory capacity of dendritic cells

Interleukin (IL)-10 secretion by tumor cells was demonstrated to be one of the mechanisms by which tumor cells can escape immunological recognition and destruction. In dendritic cells (DCs), which are currently used for vaccination therapies for malignant diseases, IL-10 inhibits IL-12 production and induces a state of antigen-specific anergy in CD4- and CD8-positive T cells. We therefore analyzed the effects of different activation stimuli including lipopolysaccharide (LPS), tumor necrosis factor (TNF)-alpha, and CD40 ligation on IL-10 mediated inhibition of DC development and stimulatory capacity. In our study, the addition of IL-10 to the cultures containing granulocyte/macrophage-colony stimulating factor and IL-4 with or without LPS completely inhibited the generation of DCs from peripheral blood monocytes. These cells remained CD14 positive and expressed high levels of IL-10 receptor (IL-10R), suggesting that IL-10 mediates its effects by up-regulating the IL-10R. In contrast, the simultaneous incubation of monocytes with IL-10 and TNF-alpha or soluble CD40 ligand (sCD40L) resulted in the generation of CD83-positive DCs, induction of nuclear localized RelB, and inhibition of IL-10R up-regulation. DCs grown in the presence of IL-10 and TNF-alpha or sCD40L elicited efficient CTL responses against viral and tumor-associated peptide antigens, which, however, were reduced as compared with DC cultures generated without IL-10. IL-10 decreased the production of IL-6 and the expression of IL-12 in the presence of TNF-alpha or sCD40L, but it had no effect on IL-15, IL-18, and TNF-alpha secretion. Our results show that TNF-alpha or CD40 ligation can antagonize the IL-10-mediated inhibition on DC function, suggesting that depending on activation stimuli, the presence of IL-10 does not necessarily result in T-cell anergy.

Phase II study of bendamustine in patients with relapsed or cisplatin-refractory germ cell cancer

Despite generally high cure rates in patients with metastatic germ cell cancer, patients with incomplete response to first-line cisplatin-based chemotherapy or with relapsed disease following high-dose salvage therapy exhibit a very poor prognosis. We investigated the efficacy and toxicity of bendamustine, a bifunctional alkylating benzimidol derivative with only partial cross-resistance to other alkylating agents such as ifosfamide or cyclophosphamide. Nineteen patients with cisplatin-refractory germ cell tumors (GCT) or relapse after high-dose chemotherapy plus autologous stem cell support were treated with bendamustine at a dose of 120 mg/m2 on 2 consecutive days at 3 week intervals. Patients had received a median of 9 (range 4-20) platinum-containing treatment cycles prior to bendamustine and 13 patients (68%) had previously received carboplatin/etoposide-based high-dose chemotherapy. One patient achieved a partial remission of only 6 weeks duration. No other responses were seen. Toxicity was low with one patient developing WHO grade 3 thrombocytopenia as the only WHO grade 3/4 toxicity observed. Hematologic toxicity was similar in patients pretreated with and without high-dose chemotherapy plus autologous stem cell support. We conclude that bendamustine has little or no clinically relevant activity in patients with cisplatin-refractory GCT or relapsed disease after high-dose chemotherapy.

[The MR characterization of the composition of the hematopoietic bone marrow. The findings in generalized neoplasms and the monitoring of therapy]

PURPOSE

Methodological work was performed in the field of magnetic resonance imaging (MRI) and spectroscopy (MRS) in order to develop suitable tools for non-invasive characterization of hematopoietic bone marrow. The methods were applied for the assessment of normal values in healthy persons and to examine patients with generalized hematological diseases or to monitor effects of therapies influencing the composition of bone marrow.

METHODS

Besides standard techniques of MRI as T1- or T2-weighted methods, chemical shift techniques for selective visualization of water or lipid components were applied. The method of magnetization transfer (MT) contrast was used with the intention to differentiate between multiple water containing tissue compartments (intra- vs. extracellular space). A further approach was the determination of the magnetic field distribution within spongy bone marrow. Besides investigations in healthy volunteers, prospective clinical studies were carried out in patients suffering from acute leukemia during their initial treatment and in patients who underwent high-dose therapy with following peripheral blood stem cell transplantation (PBSCT).

RESULTS

Especially MR techniques for selective imaging of water of fat signals and proton spectroscopy yielded a high sensitivity to primarily pathological or therapeutically induced changes of hematopoietic bone marrow. Application of MT allowed an improved differentiation of the tissue compartments under PBSCT, which might result in temporary edema. Storage of hemosiderin in bone marrow after blood transfusions and simultaneous hematopoietic insufficiency could be revealed by methods sensitive to magnetic field inhomogeneities.

CONCLUSIONS

Methods of MRI and MRS allow to non-invasively characterize hematopoietic bone marrow in the course of hematological diseases and during therapy. Marked changes in the composition of hematological bone marrow are detectable for extensive marrow areas. The prognostic relevance of the findings has to be evaluated in future follow-up studies.

A randomized trial comparing the nephrotoxicity of cisplatin/ifosfamide-based combination chemotherapy with or without amifostine in patients with solid tumors

This study evaluates the degree of kidney damage during cisplatin/ifosfamide-based combination chemotherapy and its possible prevention by amifostine. Thirty-one patients with solid tumors stratified according to pretreatment were randomized to receive VIP- or TIP-chemotherapy with or without amifostine (910 mg/m2) given as a short infusion prior to cisplatin. Chemotherapy consisted of cisplatin (50 mg/m2), ifosfamide (4 g/m2) and either etoposide (500 mg/m2) (= VIP) or paclitaxel (175 mg/m2) (= TIP) repeated at 3 weekly intervals. For all patients the glomerular filtration rate (GFR) measured by creatinine-clearance, serum creatinine, electrolytes and differential urinary protein/enzyme excretion were determined prior to, during and after each cycle. A total of 62 cycles of chemotherapy were evaluable. In the amifostine-group GFR was fully maintained after application of two cycles of chemotherapy, whereas in the control group a > 30%-reduction of median GFR (108 to 80 ml/min) was observed (p < 0.001). Patients receiving amifostine had a lower degree of high molecular weight proteins excretion indicating less glomerular damage. In both groups significant increases of tubular marker profiles peaking at day 3 after chemotherapy were observed with a nearly complete reversibility of these changes prior to the next chemotherapy cycle. The number of patients with low magnesium serum levels during treatment was 17% after amifostine application versus 69% in control patients. The results seem to indicate that treatment with amifostine can preserve GFR after application of two cisplatin/ifosfamide-based chemotherapy cycles. This may be advantageous if repetitive cycles of chemotherapy or subsequent administration of high dose chemotherapy is planned.

Clinical applications of CD34(+) peripheral blood progenitor cells (PBPC)

Recently, a number of devices have been developed for the positive selection of CD34(+) peripheral blood progenitor cells (PBPC) for clinical use in autologous or allogeneic transplantation. The rationale for CD34(+) selection is based on clinical studies showing a two- to five-log reduction of contaminating tumor cells in patients with breast cancer, multiple myeloma and low-grade lymphoma. In addition, a three- to five-log reduction of T cells can be obtained by CD34(+) selection in both autologous grafts for patients with autoimmune disease resistant to conventional therapy and allogeneic grafts to reduce the incidence and severity of acute graft-versus-host disease. Transplantation of positively selected autologous CD34(+) PBPC results in a rapid and stable neutrophil and platelet engraftment in patients who received an infused dose of at least 2.0 x 10(6) CD34(+) cells/kg. Results from randomized trials suggest that time to engraftment is not different compared to unmanipulated PBPC autografts. However, close monitoring for infectious complications (e.g., cytomegalovirus disease) is required. Allogeneic CD34(+) PBPC have also been successfully transplanted and, using novel technologies, megadoses of purified CD34(+) PBPC can be obtained and used to overcome histocompatibility differences betweeen allogeneic donor and patient resulting in stable engraftment, even in a haploidentical setting. Additional randomized phase III trials are required to determine whether tumor cell purging or lymphocyte depletion by CD34(+) cell selection will have a significant impact on progression-free and overall survival in both autologous and allogeneic transplantation.

A phase II study of paclitaxel, weekly, 24-hour continous infusion 5-fluorouracil, folinic acid and cisplatin in patients with advanced gastric cancer

To evaluate the toxicity and efficacy of combination chemotherapy with paclitaxel, cisplatin and 24 h continuous infusion of 5-FU/folinic acid in patients (pts) with unresectable, locally advanced or metastatic gastric adenocarcinoma. Forty-five chemotherapy-naive pts (28 male and 17 female) with a median age of 60 years (range 35-74) were enrolled. 5-FU 2 g/m2 was given weekly over 24 h i.v. preceded by folinic acid 500 mg/m2 as a 2 h infusion. Paclitaxel 175 mg/m2 was administered as a 3 h-infusion on days 1 and 22 and cisplatin 50 mg/m2 as 1 h infusion on days 8 and 29. Six weeks of therapy (days 1, 8, 15, 22, 29, 36) followed by 2 weeks rest were considered one cycle. A median of 3 cycles (range 1-4) were administered to 45 pts assessable for response, survival and toxicity. Five pts (11%) obtained a CR and 18 pts (40%) a PR (ORR 51%; 95% CI: 35.8-66.3%). Responses were achieved in the liver, lymph nodes, lungs and at the site of the primary tumour. Nine pts (20%) had stable disease. Thirteen pts (29%) were considered to have failed treatment, 8 pts (18%) due to progressive disease and 5 pts (11%) who did not receive one complete cycle of therapy due to acute non-haematologic toxicity. The median progression-free and overall survival times were 9 months (range 1-36+) and 14 months (range 2-36+), respectively. Neutropenia WHO III(o)/IV(o) occurred in 7 pts (15%) with only 1 pt having grade IV. Additional non-haematologic WHO III(o)/IV(o) toxicities included nausea/vomiting in 5 (11%), alopecia in 22 (49%), and diarrhoea in 1 patient each (2%). Dose reductions or treatment delays were necessary in 8 pts (17%), mainly due to neutropenia. All pts were treated on an outpatient basis. The combination of paclitaxel, cisplatin and continuously infused 5-FU/folinic acid appears to be a highly active regimen for the treatment of pts with advanced gastric cancer. While the overall acceptable toxicity allows its use in the palliative setting, it may also be an attractive option to be tested for neoadjuvant or adjuvant treatment.

Expression and secretion of vascular endothelial growth factor-A by cytokine-stimulated hematopoietic progenitor cells. Possible role in the hematopoietic microenvironment

In the hematopoietic microenvironment, bone marrow endothelial cells may play an important role in trafficking and maintenance of progenitor and stem cells due to adhesive interactions and paracrine secretion of hematopoietic growth factors. However, it is unknown whether progenitors in turn modulate endothelial proliferation and function. We analyzed mRNA expression (Northern blot) and release of vascular endothelial growth factor-A (VEGF-A), which specifically acts on endothelial cells, by cytokine-stimulated peripheral blood-derived CD34+ hematopoietic progenitor cells. While unstimulated CD34+ cells expressed VEGF-A mRNA weakly without cytokine release in vitro, incubation for 24 hours with a single cytokine (e.g., kit ligand [KL]) resulted in increased VEGF-A mRNA expression and significant secretion of VEGF-A into the supernatant. The amount of VEGF released was substantially augmented by incubation with a combination of cytokines (e.g., KL, IL-3, GM-CSF, G-CSF), or by exposure to hematopoietic cytokines for a longer time period. In addition, we show that VEGF induced the release of hematopoietic growth factors (GM-CSF) by bone marrow endothelial cells and that in vitro stromal cell-derived factor-1 (SDF-1) driven transendothelial progenitor cell migration was increased by the presence of VEGF, which might be due to pore formation (increased endothelial fenestration). In vivo, release of VEGF by progenitor cells may result in a paracrine loop supporting proliferation of both endothelium and progenitors and may facilitate transendothelial migration during cytokine-induced progenitor cell mobilization.

The relative risk of second nongerminal malignancies in patients with extragonadal germ cell tumors

BACKGROUND

Apart from a recognized association between extragonadal mediastinal germ cell tumors (GCT) and the occurrence of hematologic malignancies, the risk of developing second nongerminal solid tumors after the diagnosis or treatment of extragonadal GCT is unknown.

METHODS

Six hundred thirty-five consecutive patients with extragonadal GCT treated at 11 centers in the U.S. and Europe during the era of cisplatin-based chemotherapy (1975-1996) were included into a large database. These patients were evaluated for the occurrence of second malignancies.

RESULTS

No treatment-related leukemia was observed in 611 patients treated with chemotherapy. In 7 patients, second solid tumors were observed, resulting in a frequency of 1.86% (95% confidence interval [95% CI], 1.79-1.93%) after a median follow-up of 55 months (95% CI, 50-60 months) (annual incidence, 0.30% [95% CI, 0.14-0.59]). Four solid tumors (57%) developed in patients with primary mediastinal and 3 tumors (43%) developed in patients with retroperitoneal GCT. Three patients (43%) had a nonseminomatous and 4 patients (57%) had a seminomatous histology. Six patients had been treated with chemotherapy and one patient with radiotherapy. Six of 7 solid tumors (86%) had developed within 5 years and 7 of 7 solid tumors within 10 years of diagnosis. The median time period to the occurrence of neoplasia was 47 months (range, 9-145 months). Four cutaneous tumors were observed (melanoma, two patients; basal cell carcinoma, one patient; and squamous cell carcinoma, one patient); the other three tumors were angiosarcoma, nonsmall cell lung carcinoma, and colorectal carcinoma. The overall risk for developing a second tumor was not increased compared with an age-matched general population with a standard incidence ratio (SIR) of 1.49 (95% CI, 0.60-3.06). An elevated risk for skin tumors was observed in all extragonadal GCT patients (SIR, 4.00 [95% CI, 1. 09-10.24]), as well as in the subgroup of patients treated with chemotherapy (SIR, 5.33 [95% CI, 1.45-13.65]).

CONCLUSIONS

This analysis excludes an increased biologic risk of developing second solid malignancies in patients with extragonadal GCT except for the previously reported association between primary mediastinal nonseminoma and hematologic disorders. The overall risk of developing second malignancies in extragonadal GCT patients appears to be comparable to that in patients with primary testicular carcinoma. The incremental occurrence of skin malignancies in patients treated with chemotherapy should be investigated further.

Early detection of aspergillus infection after allogeneic stem cell transplantation by polymerase chain reaction screening

Invasive aspergillosis (IA) has become a major cause of mortality in patients after allogeneic stem cell transplantation. To assess the potential of prospective polymerase chain reaction (PCR) screening for early diagnosis of IA, 84 recipients of an allogeneic stem cell transplant were analyzed with the investigators blinded to clinical and microbiologic data. Of 1193 blood samples analyzed, 169 (14.2%) were positive by PCR. In patients with newly diagnosed IA (n=7), PCR positivity preceded the first clinical signs by a median of 2 days (range, 1-23 days) and preceded clinical diagnosis of IA by a median of 9 days (range, 2-34 days). Pretransplantation IA (relative risk [RR], 2.37), acute graft-versus-host disease (RR, 2.75), and corticosteroid treatment (RR, 6.5) were associated with PCR positivity. The PCR assay revealed a sensitivity of 100% (95% confidence interval [CI], 48%-100%) and a specificity of 65% (95% CI, 53%-75%). None of the PCR-negative patients developed IA during the study period. Thus, prospective PCR screening allows for identification of patients at high risk for subsequent onset of IA.

First-line high-dose chemotherapy +/- radiation therapy in patients with metastatic germ-cell cancer and brain metastases

PURPOSE

To examine the feasibility and efficacy of first-line high-dose chemotherapy (HD-CTX) in patients with advanced metastatic germ-cell tumors (GCT) and brain metastases.

PATIENTS AND METHODS

Twenty-two patients with brain metastases at initial diagnosis were identified within a cohort of two hundred thirty-one consecutive patients with advanced metastatic disease, entered on a German multicenter trial between January 1993 and July 1998. All patients received first-line HD-CTX with cisplatin-etoposide-ifosfamide (HD-VIP) followed by autologous stem-cell transplantation. Brain irradiation (BRT) with 30-50 Gy +/- 10 Gy boost was applied in patients with symptomatic CNS disease or as consolidation in case of residual CNS lesions after HD-CTX.

RESULTS

A median number of 4 HD-CTX cycles (range 2-5) were applied to the 22 patients. Ten patients received HD-CTX alone and twelve patients were treated with HD-CTX plus BRT. Median duration of WHO grade 4 granulocytopenia and thrombocytopenia was seven and five days after each cycle, respectively. Non-hematologic toxicity consisted mainly of mucositis/enteritis (WHO grade 3-4 32%). Two early deaths occurred in twenty-two patients (one CNS-bleeding/one sepsis). Fourteen of twenty patients achieved a CR/PRm- status. Twenty patients (91%) responded in the brain (55% CR/36% PR). Two-year progression-free and overall survival rates were 72% and 81%, respectively. These survival rates are substantially higher compared to the available data in the literature.

CONCLUSIONS

High-dose chemotherapy with autologous stem-cell support +/- BRT appears to be feasible without increased therapy-related mortality in patients with advanced metastatic GCT and brain metastases. The results achieved emphasize the high chemosensitivity of CNS metastases from GCT and suggest a potential role for dose intensification. The dose of BRT in addition to HD-CTX may be tailored to the presence of clinical symptoms and the response of CNS metastases to chemotherapy.

Successful transplantation of highly selected CD34+ peripheral blood stem cells in a HLA-sensitized patient treated with immunoadsorption onto protein A

BACKGROUND

Haploidentical bone marrow transplantation with preexisting anti-HLA antibodies is associated with a high risk of graft failure.

METHODS

A 27-year-old female patient with chronic myeloid leukemia and evidence of several osseous chloromas had no suitable matched bone marrow donor, and fluorescence cytometric cross-match (FCXM) revealed antibodies against donor-specific HLA-molecules. Immunoadsorption onto staphylococcal protein A was applied to remove these antibodies, and peripheral stem cell transplantation was performed from her haploidentical sister after a negative FCXM was documented after immunoadsorption and conditioning treatment.

RESULTS

FCXM for donor lymphocytes and stem cells remained negative throughout the posttransplant period, and engraftment of donor cells was documented on day +69.

CONCLUSION

Immunoadsorption onto protein A should be considered in stem cell transplantation even from an haploidentical donor where anti-HLA antibodies and a positive FCXM are documented.

Effective ex vivo generation of granulopoietic postprogenitor cells from mobilized peripheral blood CD34(+) cells

OBJECTIVE

Neutropenia following high-dose chemotherapy and peripheral blood progenitor cell (PBPC) transplantation might be abrogated by an additional transplantation of ex vivo generated granulopoietic postprogenitor cells (GPPC). Therefore, the ex vivo expansion of CD34(+) PBPC was systematically studied aiming for optimum GPPC production.

MATERIALS AND METHODS

CD34(+) PBPC were cultured in serum-free medium comparing different (n = 32) combinations of stem cell factor (S), interleukin 1 (1), interleukin 3 (IL-3) (3), interleukin-6 (6), erythropoietin (E), granulocyte colony-stimulating factor (G), granulate-macrophage colony-stimulating factor (GM), daniplestim (D, a novel IL-3 receptor agonist), and Flt3 ligand (FL) under various culture conditions. Ex vivo generated cells were assessed by flow cytometry, morphology, and progenitor cell assays.

RESULTS

Addition of G +/- GM but not GM alone to cultures stimulated with S163E effectively induced the generation of GPPC. GPPC production was maximum after 12 to 14 days. Best expansion rates were observed when cells were cultured at 1.5x10(4)/mL in 21% O(2). Modifications of culture conditions were either less or equally effective (i.e., modification of starting cell concentrations, low oxygen, addition of serum albumin or autologous plasma, repetitive feeding). Comparison of different cytokine combinations revealed that the optimum GPPC expansion cocktail consisted of S6GD+FL (day 12: 130-fold cellular expansion, 32% myeloblasts/promyelocytes, 49.4% myelocytes/metamyelocytes, 12.4% bands/segmented), which furthermore expanded CD34(+) cells (3.4-fold) and clonogenic progenitors (13.4-fold).

CONCLUSION

Using the S6DG+FL expansion cocktail, GPPC could be effectively produced ex vivo starting from positively selected CD34 PBPC, possibly enabling amelioration or even abrogation of posttransplant neutropenia.

Risk factors for treatment failures in patients receiving PCR-based preemptive therapy for CMV infection

PCR-based preemptive therapy with ganciclovir has been shown to reduce the incidence of CMV disease after BMT. Failures of this treatment strategy are CMV disease and secondary non-viral infections. Eighty-six consecutive patients at high risk for CMV disease who received PCR-based preemptive therapy with ganciclovir were assessed for treatment failures and possible risk factors. Ganciclovir was initiated in 57 of 86 patients (66%). Only 28 of 86 (32%) patients received 4 or more weeks of ganciclovir. Recurrence of CMV infection after successful treatment was more frequent among recipients of a BMT from an unrelated compared to a sibling donor (P = 0.004). Three (3.5%) patients developed non-fatal early onset CMV disease and seven of 68 (10.3 %) late onset CMV disease (>100 days post transplant). Risk factors for late onset CMV disease were cGVHD (P = 0.0017) and duration of prior antiviral therapy >4 weeks (P = 0. 0073). The incidence of secondary non-viral infections was 28% with the duration of antiviral treatment being a significant risk factor for secondary bacterial (P = 0.0045) and invasive fungal infections (P = 0.006). Thus, PCR-based preemptive treatment with ganciclovir reduces early onset CMV disease, but the duration of antiviral therapy prior to day +100 is a significant risk factor for late onset CMV disease as well as secondary non-viral infections.

Phase II study of continuous 120-hour-infusion of mitomycin C as salvage chemotherapy in patients with progressive or rapidly recurrent gastrointestinal adenocarcinoma

The aim of the study was to evaluate the therapeutic activity and safety of continuously infused (c.i.) mitomycin C in patients with metastatic gastrointestinal adenocarcinomas recurring after or progressing during chemotherapy. The patients were treated with mitomycin C 20 mg/m2 intravenously over a time period of 120 hours, followed by a 3-week rest. Seventy-eight patients were entered into the study. All the patients were assessable for toxicity and 72 for response evaluation, having completed at least one full course of chemotherapy. Among 52 colorectal cancer patients one single objective response (2%) was observed. Disease stabilisation was achieved in 11 patients (23%). Median survival time was 4.7 months (CI95%, 1.9 to 8.6). In 20 evaluable patients with gastric cancer, one complete and 5 partial remissions were observed [ORR: 30% (CI95%, 9.1-50.9%)]. The median response duration was 2.1 months (range, 2 to 6), and the median survival time 3.6 months (CI95%, 2.1 to 6.0). WHO degree III/IV mucositis, diarrhea and fever/infection each occurred in 6% of the patients. Thrombo- and leukocytopenia (WHO degree III/IV) occurred in 19% and 6% of the patients, respectively. Mitomycin C has some single-agent activity in advanced gastric cancer but no substantial efficacy was seen as in heavily pretreated colorectal carcinoma.

Effective ex vivo generation of megakaryocytic cells from mobilized peripheral blood CD34(+) cells with stem cell factor and promegapoietin

OBJECTIVE

The additional transplantation of ex vivo-generated megakaryocytic cells might enable the clinician to ameliorate or abrogate high-dose chemotherapy-induced thrombocytopenia. Therefore, the ex vivo expansion of CD34(+) PBPC was systematically studied aiming for an optimum production of megakaryocytic cells.

MATERIALS AND METHODS

CD34(+) PBPC were cultured in serum-free medium comparing different (n = 23) combinations of stem cell factor (SCF) (S), IL-1beta (1), IL-3 (3), IL-6 (6), erythropoietin (EPO) (E), thrombopoietin (TPO) (T) and promegapoietin (PMP, a novel chimeric IL-3/TPO receptor agonist). Ex vivo-generated cells were assessed by flow cytometry, morphology, and progenitor cell assays.

RESULTS

Addition of TPO to cultures stimulated with S163E, a potent progenitor cell expansion cocktail previously described by our group, effectively induced the generation of CD61(+) cells (day 12: 31.4 +/- 7.9%). The addition of PMP tended to be more effective than TPO +/- IL-3. Whereas EPO was not required to maximize TPO- or PMP-induced megakaryocytic cell production, the use of IL-6 and IL-1beta augmented cellular expansion as well as CD61(+) cell production rates in the majority of cytokine combinations studied. Thus, the most effective CD61(+) cell expansion cocktail consisted of S163 + PMP which resulted in 65.9 +/- 3.0% CD61(+) at day 12 and an overall production of 40.7 +/- 4.5 CD61(+) cells per seeded CD34(+) PBPC. However, the basic 2-factor combination S + PMP also allowed for an effective CD61(+) cell production (day 12 CD61(+) cell production: 15.1 +/- 1.6). Moreover, maximum amplification of CFU-Meg was observed after 7 days using this two-factor cocktail (12.9 +/- 2.6-fold). The majority of CD61(+) cells generated in TPO- or PMP-based medium were low-ploidy 4N and 8N cells, and ex vivo-generated CD61(+), CD41(+), and CD42b(+) cells were mainly double positive for FACS-measured intracellular von Willebrand Factor (vWF) (76.7 +/- 3.3%, 58.8 +/- 4.4%, and 82.7 +/- 2.5%, respectively).

CONCLUSIONS

Taken together, this study demonstrates that megakaryocytic cells can be effectively produced ex vivo with as little as two-factors (SCF + PMP), an approach that might be favorably employed in a clinical expansion trial aiming to ameliorate high-dose chemotherapy-induced thrombocytopenia.

Regression of human metastatic renal cell carcinoma after vaccination with tumor cell-dendritic cell hybrids

Reports of spontaneous regressions of metastases and the demonstration of tumor-reactive cytotoxic T lymphocytes indicate the importance of the host's immune system in controlling the devastating course of metastatic renal cell carcinoma. Recent research indicates that immunization with hybrids of tumor and antigen presenting cells results in protective immunity and rejection of established tumors in various rodent models. Here, we present a hybrid cell vaccination study of 17 patients. Using electrofusion techniques, we generated hybrids of autologous tumor and allogeneic dendritic cells that presented antigens expressed by the tumor in concert with the co-stimulating capabilities of dendritic cells. After vaccination, and with a mean follow-up time of 13 months, four patients completely rejected all metastatic tumor lesions, one presented a 'mixed response', and two had a tumor mass reduction of greater 50%. We also demonstrate induction of HLA-A2-restricted cytotoxic T cells reactive with the Muc1 tumor-associated antigen and recruitment of CD8+ lymphocytes into tumor challenge sites. Our data indicate that hybrid cell vaccination is a safe and effective therapy for renal cell carcinoma and may provide a broadly applicable strategy for other malignancies with unknown antigens.

Thyroid toxicity of treatment for Hodgkin's disease

Thyroid disease, especially hypothyroidism, is one of the more frequently encountered late endocrine sequelae of treatment for Hodgkin's disease. We analyzed the thyroid function of 177 patients (92 male and 85 female) who had been treated for Hodgkin's disease between 1970 and 1995; their median age was 38 years (range 18-74) and their median time after therapy was 6 years (range 1-20). Thirty-five (20%) patients were treated with chemotherapy alone (mainly COPP/ABVD), 44 (25%) with radiotherapy (RTX) alone, and 98 (55%) received combined modality treatment according to the protocols of the German Hodgkin's Disease Study Group. All patients had been without evidence of disease for at least 1 year. They were evaluated between 1994 and 1997 for thyroid disease by clinical examination, thyroid function tests, and ultrasound imaging if indicated. Overall, 48 patients (27%) were found to have subclinical (36 patients, 20%) or overt (12 patients, 7%) hypothyroidism. No patient in the group treated with chemotherapy alone developed hypothyroidism, in contrast to 15 of 44 (34%) patients treated with radiotherapy alone and 33 of 98 (34%) patients treated with the combined modality approach who did. All patients with hypothyroidism had received some form of supradiaphragmatic radiation except one patient who underwent infradiaphragmatic RTX but with preceding hemithyroidectomy for staging purposes. After an average follow-up of 6 years, 27% of patients treated for Hodgkin's disease with either radiotherapy alone or a combination of radiotherapy and chemotherapy developed hypothyroidism. Supradiaphragmatic radiation, but not the use of chemotherapy alone, is associated with an increased risk for hypothyroidism. Evaluation of thyroid function after therapy is important, and appropriate substitution medication should be initiated.

Assessment of keratoconjunctivitis sicca in patients with fibromyalgia: results of a prospective study

Patients with fibromyalgia (FM) often describe the presence of dry eyes and other ocular symptoms. It has been claimed that a subgroup of patients with FM might have features suggestive of primary Sjögren syndrome. In others, such a relationship could not be found. The purpose of the present study was to investigate the association and prevalence of keratoconjunctivitis sicca (KCS) in patients with FM. Among 285 patients with FM, 40 patients reporting sicca symptoms were screened with Schirmer's I test, break-up time and Rose-Bengal score. KCS was diagnosed when two of the selected three tests gave pathological results. A detailed ophthalmological examination was also performed. In 15 patients the diagnosis of KCS could be confirmed. Eighteen of 40 patients had been taking low-dose antidepressants and 7 of them had objective signs of KCS. Eight of 40 patients had signs of chronic blepharitis and 4 of them had KCS. Fourteen patients showed unremarkable test results. Chronic blepharitis and the use of tricyclic antidepressants may play a role in developing KCS. It seems that the rate of KCS does not increase in patients with FM and they probably have objective ocular findings comparable with the normal population.

Magnetic resonance imaging guided corticosteroid injection of the sacroiliac joints in patients with therapy resistant spondyloarthropathy: a pilot study

OBJECTIVE

To evaluate magnetic resonance imaging (MRI) guided corticosteroid injections of inflamed sacroiliac (SI) joints in patients with spondyloarthropathy with therapy resistant sacroiliitis.

METHODS

We performed 16 injections in 9 patients on an outpatient basis (6 men, 3 women, mean age at onset 24.7 +/- 7.5 yrs). All patients had MRI guided injection of 40 mg triamcinolone acetonide into SI joints using an open 0.2 Tesla unit. Before and 3 months after corticosteroid injection they underwent an MRI examination with a closed 1.5 Tesla unit.

RESULTS

Seven of 9 patients reported subjective improvement that lasted at least a mean of 10.8 +/- 5.6 months. Subchondral bone marrow edema on fat suppressed images resolved in 8 patients after corticosteroid injection.

CONCLUSION

MRI guided corticosteroid injection of SI joints appears to be an effective and safe procedure without exposure to radiation. It is a useful therapeutic modality, especially in young patients with severe isolated sacroiliitis.

Hematologic disorders associated with primary mediastinal nonseminomatous germ cell tumors

BACKGROUND

The association between primary germ cell tumors of the mediastinum (the space between the lung pleura that contains the heart and other chest viscera) and hematologic malignancies has been described by retrospective analysis of patients treated at individual clinical centers. To better characterize the risk of hematologic disorders in patients with extragonadal germ cell tumors and to describe the clinical and biologic features of the disorders, we studied an unselected population in a large, international, multicenter database.

METHODS

Six hundred thirty-five patients treated at 11 centers in the United States and Europe from 1975 through 1996 were evaluated retrospectively.

RESULTS

A hematologic disorder was observed in 17 patients with germ cell tumors. All cases developed among the 287 patients with primary mediastinal nonseminomatous germ cell tumors, giving an incidence rate in this group of 2.0% (95% confidence interval [CI] = 1.1%-3.1%) per year over a median follow-up time of 3 years. The risk of developing hematologic disorders was statistically significantly increased in patients with primary mediastinal nonseminomatous germ cell tumors in comparison with the age-matched general population (standardized incidence ratio = 250; 95% CI = 140-405). The median time to onset of hematologic neoplasia was 6 months (range, 0-47 months), and the median survival after diagnosis of the hematologic disorder was 5 months (range, 0-16 months) (two-sided P<.0001, comparing survival from the time of diagnosis of the germ cell tumor of patients with and without hematologic disorders).

CONCLUSION

In our study, approximately one in 17 patients with primary mediastinal nonseminomatous germ cell tumors was affected by a hematologic disorder, whereas no cases were seen among 334 patients with other extragonadal germ cell tumors. The hematologic disorder had a statistically significant impact on prognosis, with none of the 17 reported patients surviving for more than 2 years.