A phase I-II study of rituximab, ifosfamide, mitoxantrone and etoposide (R-IME) for B cell non-Hodgkin's lymphoma prior to and after high-dose chemotherapy and autologous stem cell transplantation (HDC-ASCT).

This phase I-II study describes the safety of rituximab, ifosfamide, mitoxantrone and etoposide (R-IME) as an induction regimen prior to high-dose chemotherapy and autologous stem cell transplantation (HDC-ASCT), and rituximab given post-HDC-ASCT for B cell non-Hodgkins's lymphoma. This study also measured the effect on disease burden and stem cell contamination. Patients with relapsed, refractory or poor risk B cell lymphomas were eligible. Patients were treated with two cycles of R-IME; all non-progressing patients under-went a third cycle and peripheral blood stem cell (PBSC) collection. Patients underwent HDC-ASCT and those patients in remission after HDC-ASCT were treated with four additional doses of rituximab. Tumor cell contamination was measured at baseline and in the PBSC. Serial immunoglobulin levels were measured. Patients were followed for time to treatment failure (TTF) and overall survival (OS). Thirty-two patients were enrolled. Thirty patients had at least stable disease after two cycles of R-IME. Twenty-nine underwent stem cell collection. The response rate to R-IME induction was 77% (20/26) with 35% (9/26) complete response(CR). Stem cell mobilization was successful in 93% (27/29) of patients. The response rate to R-IME induction and HDC-ASCT was 95% with a confirmed CR of 68%. Median follow-up was 28 months; the median TTFand OS have not been reached. There was a significant decline in stem cell tumor cell contamination and a significant decline in IgG without an increase in infections. Forty-three per cent of patients had transient neutropenia after post-transplant rituximab. R-IME is an effective cytoreductive and mobilization regimen. There appears to be a reduction in the number of lymphoma cells in the stem cell product and the toxicity is manageable.

Rituximab and ifosfamide, mitoxantrone, etoposide (RIME) with Neupogen support for B-cell non-Hodgkin's lymphoma prior to high-dose chemotherapy with autologous haematopoietic transplant.

A phase I/II study was performed to analyse the ability of ifosfamide-based chemotherapy with rituximab to produce a turmour-free graft as well as the safety of retuximab prior to stem cell harvest and post high-dose chemotherapy. Twenty-two patients with B-cell non-Hodgkin's lymphoma were enrolled either having aggressive large-cell disease in relapse or at high/high-intermediate risk of relapse, or refractory lymphoma or mantle cell lymphoma, or indolent lymphoma. Chemotherapy consisted of ifosfamide 2 g/m2, days 1-3 with mesna, etoposide 100 mg/m2, days 1-3, and mitoxantrone 8 mg/m2 day 1, with figrastim. Rituximab was given at 375 mg/m2 for 4 doses. An encouraging overall response rate of 90%, including 11 CRs was achieved. CD34+ cells were successfully mobilized in 18 or 19 patients analysed so far with a median number of 3.4 x 10(6) cells/kg. The combination of ifosfamide-based chemotherapy with rituximab significantly reduced the number of contaminating B-cells in the stem cell product and so far there has only been a single relapse post high-dose chemotherapy with autologous haematopoietic transplant. The RIME regimen was generally well tolerated with minimal non-haematological toxicity and most of the treatment was done completely on an outpatient basis. Haematological toxicity was manageable with filgrastim, there were some infectious complications.

Unexpected citrate toxicity and severe hypocalcemia during apheresis.

BACKGROUND: The citrate anticoagulant used during apheresis procedures is considered a safe medication because it is rapidly metabolized by the donor. However, acute, life-threatening hypocalcemia is possible if the infusion rate of citrate is increased. CASE REPORT: A 54-year-old woman with metastatic breast cancer, but otherwise in good health, had just begun a fifth collection of hematopoietic peripheral blood progenitor cells by leukapheresis. The instrument's self-loading apheresis kit was primed uneventfully. Seven minutes into the procedure, the patient developed signs and symptoms suggesting severe hypocalcemia, including muscle spasms, chest pain, and hypotension. The citrate bag was discovered to have emptied, and a section of the anticoagulant tubing was protruding outside of the rotary pump. The patient's ionized calcium level was 0.64 mmol per L (normal range, 1.18-1.38 mmol/L). In subsequent experiments where the anticoagulant tubing was either improperly loaded at the outset or partially pulled out of the rotary pump, no instrument alarms sounded. CONCLUSION: Citrate toxicity and life-threatening hypocalcemia can occur if the anticoagulant line of an apheresis instrument is not properly housed in its rotary pump or becomes disengaged during the procedure. Instrument manufacturers are encouraged to consider designs that allow the direct measurement of the volume of citrate delivered. In the interim, periodic visual and tactile confirmation of tubing placement during apheresis procedures is prudent.

Liquid nitrogen freezers: a potential source of microbial contamination of hematopoietic stem cell components.

BACKGROUND: The recent report of hepatitis B transmission between hematopoietic progenitor and putative stem cell (HPC) components stored in liquid nitrogen led to the questioning of whether evidence existed for similar contamination by bacterial or fungal elements. STUDY DESIGN AND METHODS: Microbial contamination rates were reviewed for 704 HPC components from 255 patients over an 18-month period. Five liquid nitrogen freezers were surveyed for microbial contamination. The literature was reviewed to ascertain the published experience of other laboratories with HPC component contamination first documented on thawing. RESULTS: Seven (1.2%) of 583 thawed components were found to be contaminated with a variety of environmental or waterborne organisms, despite a meticulous protocol to prevent contamination during thawing. All of these components had been sterile on cryopreservation. Literature review revealed a similar incidence of post-thaw contamination from other centers. Microbial survey of liquid nitrogen freezers revealed low-level contamination in four of five. The organisms represented were similar to those cultured from thawed HPC components. One freezer was heavily contaminated by Aspergillus species. CONCLUSION: Liquid nitrogen freezers are not sterile, and both the liquid and vapor phases are potential sources of microbial contamination of HPC components. While low-level contamination by environmental organisms may be common, the occurrence of heavy contamination by potential pathogens such as Aspergillus species suggests that monitoring of liquid nitrogen sterility may be indicated. Strategies to assess and prevent microbial transmission from liquid nitrogen to HPC components need further development.

Preapheresis peripheral blood CD34+ mononuclear cell counts as predictors of progenitor cell yield.

BACKGROUND: Peripheral blood progenitor cells, harvested by apheresis after mobilization, provide rapid hematologic recovery after high-dose chemotherapy. However, because harvesting these cells is expensive and time-consuming, there has been much interest in optimizing collection protocols. An investigation was made to determine whether, in this clinical setting, peripheral blood progenitor cell yields may be predicted from preapheresis progenitor cell counts, allowing the length of each procedure to be "fine tuned" to achieve specific target goals. STUDY DESIGN AND METHODS: Preapheresis peripheral blood CD34+ cell and total colony-forming cell counts were assessed before 78 peripheral blood progenitor cell collections from 13 consecutive patients were performed. Preapheresis counts were correlated with actual progenitor cell yields. Factors affecting this correlation were analyzed. RESULTS: With the use of linear regression analysis preapheresis progenitor cell counts were found to correlate significantly but weakly with actual yields per kg of body weight per liter of blood processed (CD34+ cells: r = 0.43; colony-forming cells: r = 0.56). Further analysis revealed two possible causes: 1) circulating progenitor cell concentrations fluctuate widely during harvest, which implies that preapheresis counts are not representative of actual concentrations during apheresis, and 2) the efficiency with which apheresis machines extract mononuclear cells varies greatly between procedures. CONCLUSION: Preapheresis CD34+ and colony-forming cell counts correlated poorly with subsequent yields in this clinical setting, which suggests that it is not practical to use such counts to predict with certainty the length of apheresis needed to achieve a target yield.

The collection and evaluation of peripheral blood progenitor cells sufficient for repetitive cycles of high-dose chemotherapy support.

BACKGROUND: The development of an optimized peripheral blood progenitor cell (PBPC) harvest protocol to provide support for repetitive chemotherapy cycles is described. STUDY DESIGN AND METHODS: PBPCs mobilized by cyclophosphamide plus granulocyte-colony-stimulating factor (G-CSF) were studied in 163 leukapheresis harvests from 26 lymphoma patients. Harvested cells were transfused with two chemotherapy cycles and with an autologous bone marrow transplant. Progenitor cell content was examined in the context of hematopoietic engraftment. RESULTS: Mobilization allowed the harvest of large numbers of PBPCs. Peak harvests tended to occur after the recovering white cell count exceeded 10 x 10(9) per L. CD34+ lymphomononuclear cell (MNC) and colony-forming units-granulocyte-macrophage (CFU-GM) counts correlated poorly, but both measures peaked within 24 hours of each other in 21 of 26 patients, which demonstrated PBPC mobilization. Engraftment of platelets (> 50 x 10(9)/L) and granulocytes (> 500 x 10(6)/L) was achieved in a median of 20.5 and 16 days, respectively. A minimum number of progenitors necessary to ensure engraftment could be derived. CONCLUSION: Cyclophosphamide and G-CSF allowed the harvest of sufficient PBPCs to support multiple rounds of chemotherapy. Harvest should commence when the recovery white cell count exceeds 10 x 10(9) per L. PBPC harvest CD34+MNC counts are as useful as CFU-GM results in the assessment of PBPC content, and they may allow harvest protocols to be tailored to individual patients.

Mycobacteremia and granulomatous hepatitis following initial intravesical bacillus Calmette-Guerin instillation for bladder carcinoma.

We describe the first case of mycobacteremia and granulomatous hepatitis occurring after the initial intravesical instillation of bacillus Calmette-Guerin (BCG) for bladder cancer. Eight days after BCG instillation, a liver biopsy revealed well-defined granulomas and acid-fast bacilli. A blood culture drawn 8 h after BCG instillation grew Mycobacterium bovis. We summarize the reported complications of BCG intravesical immunotherapy, the associated risk factors, and discuss options for treatment. Although rare, mycobacteremia and granulomatous hepatitis are important systemic side effects of intravesical instillation of BCG for bladder cancer, and should be considered in any patient who presents with persistent fever and abnormal liver function tests after instillation of BCG.

Transglutaminase activity and embryonal carcinoma cell differentiation.

Murine embryonal carcinoma (EC) cells induced to differentiate by retinoic acid (RA) modulate transglutaminase (TGase) activity shortly after exposure to the inducer. Compounds that inhibit TGase enzyme activity in vitro can successfully block RA induced EC cell differentiation in culture. These observations suggest that TGase may play a role in mediating RA induced EC cell differentiation.

alpha-Difluoromethylornithine induces differentiation of a human embryonal carcinoma cell line in vitro.

Human embryonal carcinoma cells could serve as a useful model system for analysis of early human development. A limited number of human embryonal carcinoma cell lines have been generated from in vivo tumors. We report here that alpha-difluoromethylornithine, a specific enzyme-activated inhibitor of ornithine decarboxylase activity, can induce differentiation in human embryonal carcinoma cells. The differentiated phenotype could be distinguished from undifferentiated cells by altered cellular morphology, biochemical and cell surface antigenic properties. These results suggest that alterations in the intracellular levels of polyamines may play a role in human embryonal carcinoma cell differentiation, and possibly human embryogenesis.