Richard K. Shadduck

Ex vivo expansion of human umbilical cord blood and peripheral blood CD34+ hematopoietic stem cells

The proliferation and expansion of human hematopoietic stem cells (HSC) in ex vivo culture was examined with the goal of generating a suitable clinical protocol for expanding HSC for patient transplantation.HSC were derived from umbilical cord blood (UCB) and adult patient peripheral blood stem cell collections. HSC were stimulated to proliferate ex vivo by a combination of two growth factors, flt-3 ligand (FL) and thrombopoietin/c-mpl ligand (TPO/ML), and assessed for expansion by flow cytometry.Ex vivo expansion cultures of UCB were maintained for prolonged periods (up to 16 weeks), and sufficient HSC were generated for adult transplantation. In contrast to UCB, FL + TPO/ML did not significantly increase CD34(+) peripheral blood stem cell (PBSC) numbers.UCB-HSC can be expanded in culture to numbers theoretically adequate for safe, rapid engraftment of adult patients. Additional studies are needed to establish the functional activity of expanded UCB-HSC.

Treatment of acute myelogenous leukemia with outpatient azacitidine

Patients older than 55 years of age with acute myelogenous leukemia (AML) are less likely to achieve complete remission and more likely to experience toxicity with conventional induction chemotherapy than younger patients. Azacitidine administered in the outpatient setting is well tolerated and can induce complete hematological remission in patients with myelodysplastic syndromes (MDS). At higher doses, azacitidine has activity in AML.

Treatment of myelodysplastic syndromes with 5-azacytidine.

Patients with myelodysplastic syndromes (MDS) who were anemic and/or thrombocytopenic were treated with 5-azacytidine (5-AZA) at a dose of 75 mg/m(2) per day SQ x 7 days. This cycle was repeated every 28 days. Forty-eight patients who received at least one cycle of 5-AZA were evaluable for response. Hematological toxicity was mild and consisted of thrombocytopenia and leukopenia. Extramedullary toxicity was uncommon and consisted of pneumonia, arthralgia, diarrhea, and injection site irritation. Eighteen of the 46 transfusion dependent patients became transfusion independent (39%). Median duration of response was 7 months with three patients continuing beyond 2 years. French Anglo British (FAB) classification and the International Scoring System (ISS) did not predict response to 5-AZA. However, a decrease in the white blood cells (WBC) during the initial cycle of 5-AZA correlated with a higher response rate.

Prevention of Legionella Infections in a Bone Marrow Transplant Unit: Multifaceted Approach to Decontamination of a Water System

OBJECTIVEnTo evaluate measures intended to reduce Legionella infections in patients undergoing bone marrow transplantation (BMT).nnnDESIGNnOngoing clinical and microbiological surveillance for Legionella colonization or infection was undertaken. All neutropenic patients with pulmonary infiltrates and fever unresponsive to broad-spectrum antibiotics were tested for Legionella organisms.nnnSETTINGnA 505-bed medical-surgical hospital with a designated BMT unit.nnnPATIENTSnTwo hundred twenty-five patients underwent BMT; 201 were treated on a new BMT unit. The incidence of Legionella infections was compared to that seen in an estimated 150 neutropenic patients treated on other units.nnnINTERVENTIONnA combined approach to decontamination of a hospital water supply was assessed. This included heating, particulate filtration, ultraviolet sterilization, and monthly pulse hyperchlorination of water supplied to the BMT unit. The incidence of Legionella infections was assessed on the BMT unit and compared with the frequency elsewhere in the hospital.nnnRESULTSnThere were only three cases of Legionella pneumonia among 201 patients undergoing transplantation on a new BMT unit. In contrast, 33 cases of Legionella infections were detected from approximately 150 patients treated on general medical floors.nnnCONCLUSIONnA multifaceted approach to decontamination of a hospital water system led to a marked reduction in Legionella infections.

Acute Myeloblastic Leukemia and Hypercalcemia

Abstract We studied a patient with acute myeloblastic leukemia, hypercalcemia, hypophosphatemia and inappropriately elevated serum parathyroid hormone levels to define the mechanism of the hypercalcemia. On six occasions during two years, hypercalcemia occurred in conjunction with relapses of leukemia. Each time, serum calcium decreased to normal levels in parallel with reduction of the leukemic mass. During two periods of hypercalcemia, immunoreactive parathyroid hormone values were abnormally high. In addition, hormone was detected in vitro after short-term incubation of the leukemic cells (after 24 hours, the patients cells produced 129 pg of PTH per milliliter, whereas myeloblasts from a normocalcemic patient with leukemia produced only 33 pg). In freezethawing experiments, 39 pg of parathyroid hormone was released from 1 X 108 of the patients myeloblasts; no hormone was released from the normocalcemic cells. These findings suggest that the hypercalcemia resulted from ectopic parathyroid hormone pro...

Pentoxifylline and ciprofloxacin in patients with myelodysplastic syndrome. A phase II trial.

Tumor necrosis factor (TNF) inhibits hematopoietic cell proliferation. The combination of pentoxifylline (PTX) and ciprofloxacin (Cipro) has been previously shown to reduce circulating serum levels of TNF. In this Phase II trial 14 patients with advanced myelodysplastic syndrome were treated with PTX (2,000 mg/day) and Cipro (1,000 mg/day) in order to determine tolerability and effect on peripheral blood cell counts, progenitor cell responsiveness to cytokines and circulating serum levels of interleukin-6 (IL6) and TNF. Toxicity attributed to PTX and Cipro were limited to nausea in 4 patients. Peripheral blood cell counts, platelet transfusion requirements and red blood cell transfusion requirements did not change during administration of PTX and Cipro (daily for 28 days). Marrow progenitor cells of patients entered into trial were less responsive to stimulation with cytokines in vitro at baseline and during the trial compared to normal volunteers. Eight patients had elevated IL6 levels before treatment with PTX and Cipro these levels did not change during therapy. Five patients had elevated TNF levels at baseline. There was a suggestion of decreased TNF levels during treatment with PTX and Cipro (P = .09). In conclusion, PTX and Cipro was well tolerated but no evidence of efficacy was observed.

Factors affecting purification of CD34(+) peripheral blood stem cells using the Baxter Isolex 300i.

A total of 201 patients with breast cancer, ovarian cancer, or hematological malignancies underwent mobilization of peripheral blood stem cells (PBSC) using chemotherapy and granulocyte-colony stimulating factor (G-CSF). Stem cell products were collected using the Baxter CS3000 pheresis machine. The Baxter Isolex 300i was used to perform 240 CD34(+) cell separations on the apheresis products. Factors affecting yield and purity of the CD34(+) cells were analyzed. Overall yield was 55% and overall purity was 91.7%. T cell contamination was limited to 0.43% of total cells. Variables including red blood cells (RBC) concentration, platelet concentration, CD34(+) cell concentration, total WBCs selected, and time until processing had little effect on yields and purities. Installation of version 2.5 of the software in the Isolex 300i showed a modest improvement in yield and purity. Patients were reinfused with the cryopreserved CD34(+) selected cells following high-dose chemotherapy. No infusion-related side effects were noted. Analysis of engraftment data using the CD34(+)-selected cells revealed an increased risk of delayed or failed platelet engraftment when <5.0 x 10(6) CD34(+) cells per kilogram were transplanted. The Baxter Isolex 300i provides reproducible CD34(+) cell purification over a wide range of starting conditions. To provide prompt engraftment, >5.0 x 10(6) CD34(+) cells per kilogram should be infused for transplantation.

Disposition of total and unbound etoposide following high-dose therapy

Total and unbound etoposide pharmacokinetics were studied in 16 adult patients (median age, 34 years; range, 18–61 years) undergoing autologous bone marrow transplantation for advanced lymphoma after receiving high-dose etoposide (35–60 mg/kg) as a single intravenous infusion. Pretreatment values for mean serum albumin and total bilirubin were 3.0±0.4 g/dl and 0.5±0.4 mg/dl, respectively. Etoposide plasma concentrations and protein binding (% unbound) were determined by high-performance liquid chromatography (HPLC) and equilibrium dialysis, respectively. Pharmacokinetic parameters for unbound and total etoposide were calculated by nonlinear regression analysis using a two-compartment model. Te mean (±SD) parameters for total etoposide included: clearance (CL), 31.8±17.7 ml min−1 m−2; volume of distribution (Vss), 11.5±5.9 l/m2, and terminal half-life (t1/2 β), 7.2±3.7 h. Mean unbound CL was 209.6±62.7 ml min−1 m−2 and %unbound was 16%±5%. The mean etoposide %unbound was inversely related to serum albumin (r2=0.45,P=0.0043). The mean %unbound at the end of the etoposide infusion was higher than that at the lowest measured concentration (21% vs 13%, respectively;P=0.017), suggesting that concentration-dependent binding may occur after high etoposide doses. The median total CL was higher in patients with serum albumin concentrations of ≤3.0 g/dl than in those with levels of >3.0 g/dl (34.6 vs 23.5 ml min−1 m−2,P=0.05). Total CL was directly related to %unbound (r2=0.61,P=0.0004). Unbound CL was unrelated to either serum albumin or %unbound. These results demonstrate that hypoalbuminemia is independently associated with an increased etoposide %unbound and rapid total CL after the administration of high-dose etoposide. Unbound CL in hypoalbuminemic patients is unchanged in the presence of normal total bilirubin values.

Intravenous iron replacement for persistent iron deficiency anemia after Roux-en-Y gastric bypass

BACKGROUNDnIron deficiency is a major postoperative complication of Roux-en-Y gastric bypass surgery. Oral replacement can fail to correct the deficiency. Thus, recourse to parenteral iron administration might be necessary. Our objective was to evaluate the effectiveness and safety of a standardized 2 g intravenous iron dextran infusion in the treatment of iron deficiency after Roux-en-Y gastric bypass surgery. The setting was a university-affiliated community hospital in the United States.nnnMETHODSnWe reviewed the medical records of 23 patients at our institution who had received 2 g of iron dextran intravenously for recalcitrant iron deficiency after Roux-en-Y gastric bypass surgery. We obtained the demographic data and the complete blood count and serum iron studies obtained before treatment and at outpatient visits after infusion.nnnRESULTSnBefore treatment, all 23 patients were iron deficient (average ferritin 6 ng/mL) and anemic (average hemoglobin 9.4 g/dL). By 3 months, the average ferritin and hemoglobin had increased to 269 ng/mL and 12.3 g/dL, respectively. The hemoglobin levels remained stable throughout the follow-up period. The iron stores were adequately replaced in most patients. Four patients required a repeat infusion by 1 year, because the ferritin levels had decreased to <15 ng/mL. The probability of remaining in an iron replete state was 84.6% (95% confidence interval 78-91.2%). One patient required warm compresses for superficial phlebitis. No other significant adverse events were reported.nnnCONCLUSIONnIntravenous administration of 2 g of iron dextran corrects the anemia and repletes the iron stores for ≥1 year in most patients. This therapy is safe, tolerable, efficient, and effective.

Protective effects of BB-10010 treatment on chemotherapy-induced neutropenia in mice.

Chemotherapy-induced neutropenia is a major dose-limiting factor in the management of cancer patients. Most chemotherapeutic agents are active against proliferating cells, interfering with DNA replication and/or mitosis. A number of chemokines, notably macrophage inflammatory protein-1 alpha [MIP-1alpha], have been reported to induce cell-cycle arrest in immature hematopoietic progenitors, raising the possibility that chemokines, such as MIP-1alpha, could be used to reduce or even eliminate the hematologic toxicity of cycle-active chemotherapy. We tested the effectiveness of BB-10010 [a genetically engineered analog of human MIP-1alpha] in vivo against three different cytotoxic drugs [cyclophosphamide (Cy), 5-fluorouracil (5-FU) and cytosine arabinoside (Ara-C)] commonly used in cancer therapy. BB-10010 treatment reduced the toxicity of all three agents, though the precise mode of protection varied with the cytotoxic drug used. BB-10010 reduced the neutropenic interval in Cy-treated mice without affecting the neutropenic nadir, whereas the absolute neutrophil counts [ANC] of both 5-FU and Ara-C treated mice were significantly higher throughout the neutropenic interval for mice receiving BB-10010 prior to chemotherapy. These findings indicate that the ability to manipulate the cell cycle of hematopoietic progenitors with chemokines, such as BB-10010/MIP-1alpha and other negative regulators, may be exploited to reduce chemotherapy-induced neutropenia; furthermore, the fact that BB-10010 is effective against several different cytotoxic agents is cause for guarded optimism that this approach may be generally applicable, and, once optimized for patient use, may prove to be of significant clinical benefit.