Successful treatment of subcutaneously disseminated aspergillosis with caspofungin acetate in an allogeneic peripheral blood stem cell transplantation patient.

We present a patient with acute myeloid leukaemia who developed subcutaneously disseminated aspergillosis after allogeneic peripheral stem cell transplantation (PSCT). Disseminated aspergillosis after stem cell transplantation has a high mortality despite treatment with amphotericin B or one of the azoles. Aspergillosis in our patient was refractory to amphotericin B and itraconazole but was successfully treated with caspofungin acetate.

Extensive early apoptosis in frozen-thawed CD34-positive stem cells decreases threshold doses for haematological recovery after autologous peripheral blood progenitor cell transplantation.

Stem cell doses necessary for engraftment after myelo-ablative therapy as defined for fresh transplants vary largely. Loss of CD34+ cell quality after cryopreservation might contribute to this variation. With a new early apoptosis assay including the vital stain Syto16, together with the permeability marker 7-AAD, CD34+ cell viability in leucapheresis samples of 49 lymphoma patients receiving a BEAM regimen was analysed. After freeze-thawing large numbers of non-viable, early apoptotic cells appeared, leading to only 42% viability compared to 72% using 7-AAD only. Based on this Syto16 staining in the frozen-thawed grafts, threshold numbers for adequate haematological recovery of 2.8-3.0 x 10(6) CD34+ cells/kg body weight determined for fresh grafts, now decreased to 1.2-1.3 x 10(6) CD34+ cells/kg. In whole blood transplantation of lymphoma patients (n = 45) receiving a BEAM-like regimen, low doses of CD34+ cells were sufficient for recovery (0.3-0.4 x 10(6)CD34+ cells/kg). In contrast to freeze-thawing of leucapheresis material, a high viability of CD34+ cells was preserved during storage for 3 days at 4 degrees C, leaving threshold doses for recovery unchanged. In conclusion, the Syto16 assay reveals the presence of many more non-functional stem cells in frozen-thawed transplants than presumed thus far. This led to a factor 2.3-fold adjustment downward of viable CD34+ threshold doses for haematological recovery.

[Diagnostic image (117). A man with frequent blood transfusion and blister on his fingers. A form of porpheria cutanea tarda caused by excess iron]. / Diagnose in beeld (117). Een man met regelmatige bloedtransfusie en blaren aan de vingers. Verworven vorm van porphyria cutanea tarda door ijzerstapeling.

A 70-year-old man with primary myelofibrosis was treated with hydroxycarbamide and blood transfusions. He developed porphyria cutanea tarda.

Storage of unprocessed G-CSF-mobilized whole blood in a modified Leibovitz's L15 medium preserves clonogenic capacity for at least 7 days.

Autologous stem cell transplantation using unprocessed, G-CSF-mobilized whole blood (WB) is a simple, cost-reducing procedure and supports high-dose chemotherapy regimens not exceeding 72 h. Thereafter, clonogenic capacity rapidly decreases if routine anticoagulants are used for storage. In order to increase clinical applicability, we investigated the requirements for optimal preservation of unprocessed WB for 7 days. During storage at 22 degrees C in CPDA-1, a decrease in pH was noted, which was at least partially responsible for the low recovery of clonogenic cells. Subsequently, WB cells were stored in various cell culture media (RPMI 1640, alpha-MEM, X-VIVO15, CellGro SCGM and Leibovitz's L15 medium) containing either serum, serum-free substitutes or no additives. Leibovitz's L15 showed significantly better CFU-GM recoveries than the other media. Using a calcium-free modification of L15 medium (added 3:10 to WB), 94 +/- 24% of CD34(+) cells, 41 +/- 14% of BFU-E, 56 +/- 17% CFU-GM and 90 +/- 14% of LTC-IC were preserved during storage for 7 days at 22 degrees C. Storage at 4 degrees C was also feasible, but showed less optimal recoveries of 52 +/- 29% (CD34), 32 +/- 10% (BFU-E), 13 +/- 7% (CFU-GM) and 58 +/- 9% (LTC-IC). The expression of CD38, Thy-1, c-kit, AC133, L-selectin and CXCR4 on CD34-positive cells remained unchanged. In conclusion, a modified Leibovitz's L15 medium better meets the metabolic requirements of a high-density cell culture and allows safe storage of G-CSF mobilized WB for at least 7 days. The results encourage further exploration of WB transplants stored for 7 days for clinical use.

High-dose melphalan with G-CSF-stimulated whole blood rescue followed by stem cell harvesting and busulphan/cyclophosphamide with autologous stem cell transplantation in multiple myeloma.

In 90 consecutive patients with multiple myeloma, we investigated the feasibility of administering a tandem high-dose therapy regimen, using whole blood for rescue after the first and leucapheresis harvested between the two high doses, for rescue after the second high dose. After 5 days of G-CSF 1 litre of whole blood (WB) was obtained, left undisturbed at 4 degrees C and reinfused 24 h after HDM (140 mg/m(2)). Patients not in progression after 3-6 months were again mobilised, leucapheresed and treated with busulphan 16 mg/kg and cyclophosphamide 120 mg/kg (Bu/Cy) and reinfusion. In 90 patients, WB contained a mean (range) of 0.57 (0.02-3.22) x 10(6)/kg CD34(+) cells. Recovery after HDM was in 13 days for granulocytes and in 18 days for platelets, with 11 patients not recovering within 3 months. There were three toxic deaths. Sixty-six patients qualified for harvesting after HDM. In the first 11, marrow was harvested. The subsequent 55 patients were mobilised and in 45 the preset minimum of 1.5 x 10(6) CD34(+) cells was obtained. Forty-nine patients actually received Bu/Cy. Recovery after Bu/Cy and marrow reinfusion was in 35 days for granulocytes and 20 days for platelets, with two of five patients not recovering after 3 months. After Bu/Cy and leucapheresis reinfusion, recovery was in 17 days for granulocytes and in 34 days for platelets. Nine patients did not recover within 3 months. There were four toxic deaths. The median overall survival from diagnosis for patients receiving HDM was 49 months and for patients also receiving Bu/Cy, 84 months. We conclude that WB rescue after HDM followed by leucapheresis and a second transplant is feasible in the majority of patients. Better mobilisation techniques are required to increase the number of patients who can receive the second transplant.

A single-step colony-forming unit assay for unseparated mobilized peripheral blood, cord blood, and bone marrow.

The colony-forming unit (CFU) assay is exposed to a lot of variation, part of which is introduced by several enrichment strategies that are routinely performed before assessment of clonogenic capacity in mobilized peripheral blood (PB), bone marrow (BM), or cord blood (CB). We investigated the possibility to perform a single-step CFU assay by direct plating of PB, BM, or CB into CFU culture medium to obtain more reproducible results than after a standard Ficoll or lysis procedure. Direct plating implies the presence of red blood cells (RBC), white blood cells (WBC), and plasma in the CFU assay, which could possibly influence the outcome of the assay. Of all components, only the RBC was found to negatively influence CFU-GM growth if a concentration of > 0.02 x 10(9)/ml was present in the CFU culture medium. Subsequently, depending on the RBC concentration PB, BM, and CB samples were prediluted in triplicate or quadruplicate and plated into CFU medium. Lysis and/or Ficoll procedures were also performed in triplicate or quadruplicate on the same samples, and the mean colony number and coefficient of variation (CV) of the three techniques were compared. Significantly smaller CV values were found using the direct plating technique (all assays, mean 7.5%, range 1.6-15.6%) than after Ficoll separation (mean 18.0%, range 2.2-62.5%). Intermediate results were obtained with the lysis method (mean CV 11.6%, range 3.3-29%). In most samples, and especially in those with a very low number of clonogenic cells per milliliter, more colonies were detected with the direct plating method than with either the lysis or Ficoll method. In conclusion, the single-step direct plating method significantly enhances reproducibility of the CFU assay for PB, BM, and CB samples in comparison with standard techniques by circumvention of loss of colony formation and by decreasing variability. Furthermore, the direct plating technique is a timesaving assay.

Fluconazole versus itraconazole for the prevention of fungal infections in haemato-oncology.

AIMS: To compare the efficacy of and tolerance to oral fluconazole and intraconazole in preventing fungal infection in neutropenic patients with haematological malignancies. PATIENTS: 213 consecutive, afebrile adult patients treated with or without autologous stem cell transplantation for haematological malignancies. METHODS: A randomised, double blind, single centre study. Patients were randomly assigned to receive fluconazole 50 mg or itraconazole 100 mg, both twice daily in identical capsules. An intention to treat analysis was performed on 202 patients, 101 in each group. RESULTS: Microbiologically documented systemic fungal infections occurred in four patients in each group. Clinical fungal infection was thought to be present in seven recipients of fluconazole and four of itraconazole. In all 202 patients, 29 proceeded to intravenous amphotericin (amphotericin B), 16 in the fluconazole group and 13 in the itraconazole group. Superficial fungal infection was seen only in three non-compliant patients in the fluconazole group. All these infections were oral. No major differences were noted in the isolates of fungi in mouth washes and fecal samples. Overall mortality was 8.9% (18 deaths; seven in the fluconazole group, 11 in the itraconazole group). Mortality from microbiologically and clinically documented fungal infection was 4.5% (nine deaths; three in the fluconazole group, six in the itraconazole group). Median time to suspected or proven fungal infection was 16 days in both groups. None of these comparisons reached statistical significance (p < 0.05). No major clinical toxicity was noted and compliance was excellent. CONCLUSIONS: In neutropenic patients treated for haematological malignancies with or without autologous stem cell transplantation, fluconazole and itraconazole in low doses result in a similar low frequency of fungal disease. Fluconazole may be the preferable drug because of the smaller number of capsules and lack of need for timing relative to meals.

Peripheral blood stem cell transplantation as an alternative to autologous marrow transplantation in the treatment of acute myeloid leukemia?

The clinical use of autologous marrow transplantation in acute myeloid leukemia (AML) has been hampered by the inability to collect adequate numbers of cells after remission induction chemotherapy and the notably delayed hematopoietic regeneration following autograft reinfusion. Here we present a study in which the feasibility of mobilizing stem cells was investigated in newly diagnosed AML. Among 96 AML patients, 76 patients (79%) entered complete remission. Mobilization was undertaken with low dose and high dose schedules of G-CSF in 63 patients, and 54 patients (87%) were leukapheresed. A median of 2.0 x 10(6) CD34+ cells/kg (range 0.1-72.0) was obtained in a median of three leukaphereses following a low dose G-CSF schedule (150 microg/m2) during an average of 20 days. Higher dose regimens of G-CSF (450 microg/m2 and 600 microg/m2) given during an average of 11 days resulted in 28 patients in a yield of 3.6 x 10(6) CD34+ cells/kg (range 0-60.3) also obtained following three leukaphereses. The low dose and high dose schedules of G-CSF permitted the collection of 2 x 10(6) CD34-positive cells in 46% and 79% of cases respectively (P = 0.01). Twenty-eight patients were transplanted with a peripheral blood stem cell (PBSC) graft and hemopoietic repopulation was compared with the results of a previous study with autologous bone marrow. Recovery of granulocytes (>0.5 x 10(9)/l, 17 vs 37 days) and platelets (>20 x 10(9)/l; 26 vs 96 days) was significantly faster after peripheral stem cell transplantation compared to autologous bone marrow transplantation. These results demonstrate the feasibility of PBSCT in the majority of cases with AML and the potential advantage of this approach with respect to hemopoietic recovery.

New strategies in hematopoietic stem cell transplantation: G-CSF-mobilized unprocessed whole blood.

Transplantation of mobilized peripheral blood stem cells (PBSC) for rescue of bone marrow function after high-dose chemo-/radiotherapy is widely used in hematologic malignancies and solid tumors. Mobilization of stem cells to the peripheral blood can be achieved by cytokine treatment of the patients. The main advantage of autologous PBSC transplantation over bone marrow transplantation is the faster recovery of neutrophil and platelet counts. The threshold number of PBSC required for adequate rescue of bone marrow is thought to be about 2 x 10(6) CD34+ cells/kg, if the stem cells are collected by leukapheresis and subsequently cryopreserved. We show that this critical number could be further reduced to as few as 0.2 x 10(6) cells/kg. In 30 patients with multiple myeloma and 25 patients with bad risk lymphoma 1 liter of granulocyte colony-stimulating factor (G-CSF)-mobilized unprocessed whole blood (stored at 4 degrees C for 1-3 days) was used for transplantation. Compared to a historical control group, a significant reduction in the duration of neutropenia, thrombocytopenia and the length of hospital stay was documented. Furthermore, the effect of stem cell support was reflected by a lower need for platelet and red cell transfusions and a reduced antibiotic use. Considering the data as a whole, a cost saving of about 50% was achieved. To date, this easy to perform method of transplantation is only feasible following high-dose therapies that are completed within 72 h, since longer storage of unprocessed blood is accompanied by a substantial loss of progenitor cell function. Ongoing investigations include attempts to prolong storage times for whole blood.

Cell cycle dependency of 67gallium uptake and cytotoxicity in human cell lines of hematological malignancies.

67Gallium (67Ga) is a radionuclide which accumulates in hematological malignancies and is used for diagnostic imaging. We investigated in this in vitro study the cell cycle dependency of cellular uptake and cytotoxicity of 67Ga. Cell cycle synchronization of cells was achieved by counterflow centrifugal elutriation and the use of cytostatic drugs. The human lymphoma cell lines U-937 and U-715 were used and in elutriation experiments we also used the leukemic cell line HL-60. The transferrin receptor (CD71) expression, 67Ga uptake and cell proliferation inhibition were the parameters measured. We also studied cytotoxicity in various schedules for combination of 67Ga and drugs and the residual proliferative capacity was measured. The CD71 expression in the three cell lines increased from 106-177% on S phase cells and from 118-233% on G2M cells, as compared to the G0/G1 cell fraction. The 67Ga uptake varied from 108-127% for S cells and 128-139% for G2M cells. The drugs chosen induced cell cycle phase accumulation in S and/or G2M phase during preincubation. 67Ga preincubation induced accumulation in the G2M phase. Almost all combinations of 67Ga and drugs resulted in a non-interactive effect, except for methotrexate which resulted in an antagonistic effect. No preferential effect of any of the incubation schemes was seen. CD71 expression and 67Ga uptake were increased in S and G2M cells. Combination of 67Ga with drugs which arrest cells in these cell cycle phases did not result in a change in cytotoxicity. However, these results implicate that 67Ga and the cytostatic drugs tested except for methotrexate might be used together or sequentially in therapy.

High-dose melphalan with re-infusion of unprocessed, G-CSF-primed whole blood is effective and non-toxic therapy in multiple myeloma.

In order to shorten the pancytopenic period following high-dose melphalan 140 mg/m2 (HDM) treatment of multiple myeloma patients, we studied the effects of re-infusing granulocyte colony stimulating factor (G-CSF) [Filgrastim, Neupogen]-primed unprocessed whole blood. 30 patients with multiple myeloma were treated with HDM. One litre of blood after 5 or 6 days stimulation with G-CSF (10 micrograms/kg) was drawn, kept unprocessed for 1 day and re-infused 24 h after chemotherapy. Time to granulocyte recovery (> 0.5 x 10(9)/1) and platelet recovery (> 20 x 10(9)/1) were assessed as well as length of hospital stay, number of transfusions and antibiotic use. These 30 patients were compared with 20 historical control patients who were similarly treated but without stem cell support. The response rate was 75% (21/28) including a complete remission (CR) rate of 29% (8/28). Two early deaths due to Aspergillus pneumonia were observed. The median overall survival after HDM has not been reached after a median follow-up of 14 months. 10 patients showed progression at a median of 7 months. Currently, 23 patients are alive with a median follow-up time of 14 months. Haematological recovery was significantly faster in the study group as compared to the historical control group. The neutrophil count reached 0.5 x 10(9)/1 at a median of 14 days after infusion of 1 litre of unprocessed whole blood compared with 38 days in the historical control group. A platelet count of 20 x 10(9)/1 was reached at a median of 26 days compared with 36 days in the historical control group. Length of hospital stay decreased from a median of 43 to 18.5 days. The number of days with antibiotics was reduced from a median of 21 to 6 days. HDM is effective therapy for multiple myeloma. Toxicity of the regimen is considerably reduced by the use of G-CSF-stimulated unprocessed whole blood, an easy to perform and cheap technique to mobilise and collect stem cells.

G-CSF (filgrastim)-stimulated whole blood kept unprocessed at 4 degrees C does support a BEAM-like regimen in bad-risk lymphoma.

The purpose of this study was to demonstrate the reconstitutive potential of granulocyte colony-stimulating factor (G-CSF) (filgrastim; Neupogen-primed unprocessed whole blood after myelotoxic therapy in bad-risk lymphoma. Nine patients with resistant lymphoma were treated with BAM: a BEAM regimen modified to a 72 h course consisting of BCNU 300 mg/m2 i.v. (day 1), Ara-C 3000 mg/m2 i.v. q 12 h (day 2) and melphalan 140 mg/m2 i.v. (day 3). After 5 days stimulation with G-CSF (10 micrograms/kg) 1l of blood was drawn, kept unprocessed for 3 days and reinfused 24 h after completion of chemotherapy. Back-up peripheral stem cells were available for all patients. The neutrophil count reached 0.5 x 10(9)/l at a median of 16 days (range 11-25) and a platelet count of 10 x 10(9)/l was reached at a median of 20 days (range 11-NR (not reached)). The median length of hospital stay was short in these patients with a median of 19 days (range 17-33). In three patients platelet transfusion independence did not occur before day 28. Those patients received their back-up stem cells. Antibiotics had to be used in two patients. The median number of reinfused CD34+ cells was 0.28 x 10(6)/kg (range 0.01-0.59). When more than 0.2 x 10(6)/kg CD34+ cells were reinfused the time to recovery was comparable to that observed after 'classical PBSCT'. In conclusion, the use of G-CSF-stimulated unprocessed whole blood is easy to perform and a cheap technique to mobilize and collect stem cells that can serve as a stem cell source after severe myelotoxic therapy in bad-risk malignant lymphoma.

High-dose gallium-67 therapy in patients with relapsed acute leukaemia: a feasibility study.

Gallium-67 (67Ga) accumulates in malignant tissues via the transferrin receptor without need for a monoclonal antibody and emits cytotoxic low-energy electrons. In this study we investigated the feasibility, pharmacokinetics, toxicity and preliminary efficiency of high-dose 67Ga injected intravenously (i.v.) in patients with acute leukaemia not responding to conventional therapy. Twelve doses of 36-105 mCi of Gallium67 citrate were administered as a push injection to eight patients with resistant leukaemia in a pilot study. All five patients with acute myeloid leukaemia (AML) and three patients with acute lymphoblastic leukaemia (ALL) had resistant disease or resistant relapse. No (sub)acute toxicity was observed. Independent of the administered dose, whole-blood radioactivity levels 10 min after administration measured only 1.25 +/- 1.39 microCi ml-1, indicating a large volume of distribution. Urine excretion in the first 24 h ranged from 18% to 51.5% (median 29.5%) of the administered dose. Cellular uptake of 67Ga was less than in previous in vitro studies. Whole-body radiation dose was estimated to be 0.25 +/- 0.03 cGy mCi-1. Red marrow dose was estimated to be between 0.18 +/- 0.02 and 0.97 +/- 0.12 cGy mCi-1. One definite response was observed in an ALL patient with disappearance of skin lesions, normalisation of the enlarged spleen and profound leucopenia. Three other patients showed transient reductions in white blood cell counts without disappearance of blasts from the peripheral blood. We conclude that high-dose i.v. 67Ga can be safely administered but that the uptake of 67Ga in blast cells must increase to make 67Ga therapeutically useful in patients with relapsed leukaemia.

Radiotoxicity of 67-gallium on myeloid leukemic blasts.

Promising clinical results are obtained with radiolabeled antibodies in leukemia patients. 67Gallium (67Ga) is a radionuclide that accumulates in many malignant tissues without need for a monoclonal antibody. For this reason, the use of 67Ga as a therapeutic agent is appealing. In the present we study, we report data about the radiotoxicity of 67Ga on peripheral blast cells of 23 patients with acute myelogenous leukemia (AML) in vitro. Isolated blast cells were incubated for 4 days with 0.74 MBq/ml (20 microCi/ml), 1.48 MBq/ml (40 microCi/ml) or 2.96 MBq/ml (80 microCi/ml) 67Ga. Compared with non-irradiated control cells proliferation during incubation was almost abolished. Clonogenic survival was measured by a colony forming unit assay (CFU-assay). In 13 of the 23 patients (56%) sufficient colony growth was observed for evaluation. The mean clonogenic survival of blasts after incubation with 0.74 MBq/ml and 2.96 MBq/ml 67Ga was 22.5, 11.3 and 3.5%, respectively. In some cases colony growth was completely abolished after incubation with only 0.74 MBq/ml 67Ga. No correlation was found between cellular 67Ga-uptake, (micro)dosimetry and transferrin receptor density (CD-71) via which 67Ga enters the cell. In vitro the blasts received a dose of > 10 Gy in 9 of the 2.96 MBq/ml, in 3 of the 1.48 MBq/ml and in 2 of the 0.74 MBq/ml incubations. In one patient, even a radiation dose > 40 Gy was reached. Low dose rate irradiation is known to arrest cells in G2/M-phase of the cell cycle, but no such arrest was observed during incubation with 67Ga. Thus, 67Ga induces clonogenic cell death in leukemic blasts. Cellular uptake of 67Ga in vitro varies between patients and can be very high in some patients. The easy availability, low costs and absence of immunological problems warrant further investigation of the therapeutic potential of 67Ga in refractory or relapsed AML patients.

Biological effectiveness of 67-gallium decay in HL60 cells compared with external low dose rate gamma irradiation: effects on proliferation, G2 arrest, and clonogenic capacity.

PURPOSE: Estimation of the relative biological effectiveness of electron emissions of 67Gallium for cell growth delay and inactivation. METHODS AND MATERIALS: Human myeloid HL60 cells were incubated in vitro with 0.74 MBq/mL, 1.48 MBq/mL, or 2.96 MBq/mL of 67Gallium for 4 days. Proliferation (vital cell counts and colorimetric tetrazolium assay), clonogenic survival, and cell-cycle effects were compared with responses of HL60 cells externally irradiated with 0.78, 10.37, and 13.22 Gy by an external 67Gallium source. Dosimetric calculations were performed by Monte Carlo simulations (10,000 events). RESULTS: Proliferation of cells was equally inhibited after 67Gallium incubation with 1.48 and 2.96 MBq/mL compared with 10.37 and 13.22 Gy external irradiation. Irradiation with 10.37 and 13.22 Gy caused a 81% and 89% reduction of Colony Forming Units, compared with 34%, 66%, and 80% reduction after 67Gallium incubation with 0.74, 1.48, and 2.96 MBq/mL, respectively. Peak values for G2/M accumulation were reached on day 4 for the cells externally irradiated with 10.37 and 13.22 Gy (47.5% and 56.7%) and on day 5 after 67Gallium incubation with 0.74 MBq/mL, 1.48 MBq/mL, and 2.96 MBq/mL (26.7%, 43.4%, and 58.2%). CONCLUSIONS: 67Gallium incubation exerts a significant cytotoxic effect on human HL60 cells, which, on the basis of dosimetric studies, may be mainly ascribed to conversion electrons (80 KeV) and 8 KeV Auger electrons. Low energy (< 1 keV) Auger electrons do not contribute significantly. The relative biological effectiveness of 67Gallium compared with external low dose rate gamma irradiation is about 1.0 for clonogenic survival and approximately 1.8 and 1.5 for proliferation inhibition and G2 arrest, respectively. For in vivo therapy, this might implicate that higher doses of 67Gallium than 131Iodine or 90Yttrium are necessary for the same biological effect.

Peripheral blood progenitors mobilised by G-CSF (filgrastim) and reinfused as unprocessed autologous whole blood shorten the pancytopenic period following high-dose melphalan in multiple myeloma.

Growth factor granulocyte colony-stimulating factor (G-CSF; filgrastim) is effective at progenitor release into the peripheral blood. After high-dose chemotherapy haematopoietic reconstitution occurs after reinfusion of these peripheral blood progenitor cells (PBPC). However, the collection by leukapheresis and further processing of PBPC are very time consuming and expensive. We have studied the transplantation potential of a small volume of unprocessed autologous whole blood after G-CSF mobilisation. Six patients with plasma cell disorders received G-CSF 10 micrograms/kg sc during 6 days. Subsequently 11 of whole blood was collected by phlebotomy, kept unprocessed at room temperature and reinfused 24 h after high-dose melphalan 140 mg/m2. CFU-GM content was 845 per ml blood (median, range 320-3472) and CD34+ cells rose to a median percentage of 0.9 (range 0.4-2.0). Haematological recovery was significantly faster in the study group compared with the control group of 20 patients who received the same dose of melphalan without reinfusion of PBPC. The neutrophil count reached 0.5 x 10(9)/l at a median of 12.5 days after infusion of PBPC vs 38 days in the control group (p = 0.0003). The platelet count reached 20 x 10(9)/l after a median of 23.5 days vs 38 days (p = 0.0218). The shortened recovery was reflected by less transfusions, less antibiotic use and shortening of hospital stay (19 days vs 43 days, p = 0.0003). We conclude that this easy technique of mobilisation and collection of PBPC is very effective for hastening haematologic recovery after high-dose chemotherapy.