Survey on the usage of therapeutic erythrocytapheresis in transfusion services in Italy for the treatment of polycythemia vera, secondary erythrocytosis and hemochromatosis.

INTRODUCTION: Erythrocytapheresis, an apheresis treatment which selectively removes red blood cells, is an alternative to therapeutic phlebotomy, over which it has several advantages. Actually there is a high degree of variability in the use of this treatment. This prompted SIdEM (Italian Society of Hemapheresis and Cell Manipulation) to conduct a survey on the use of erythrocytapheresis in the Italian Transfusion Services. The purpose is to monitor this activity in the treatment of Polycythemia Vera (pv), secondary erythrocytosis and hemochromatosis. MATERIALS AND METHODS: A data collection file was sent to the SIdEM regional delegates who, in turn, involved the Transfusion Centers in the areas they cover. The data collected were processed on a Microsoft Excel spreadsheet. RESULTS: 75 centers from 14 Italian regions responded to the Survey: 36 centers (48 %) use erythrocytapheresis (35 centers perform therapeutic apheresis and 1 center only donor apheresis), 39 centers (52 %) do not (15 centers perform therapeutic apheresis, 18 centers only donor apheresis and 6 centers do not perform either therapeutic apheresis or donor apheresis). Although most centers have a substantially uniform attitude concerning the indications for which erythrocytapheresis is used, the survey shows that there are still differences more evident in the treatment of secondary erythrocytosis than in the treatment of pv or hemochromatosis. CONCLUSIONS: This survey has been useful to document the current Italian reality and to raise awareness about the need for improvement in optimizing and standardizing the use of a therapy with a great potential to exploit properly.

Prognostic factors and outcome of Epstein-Barr virus DNAemia in high-risk recipients of allogeneic stem cell transplantation treated with preemptive rituximab.

AIMS AND METHODS: This study assessed incidence, predictive factors, and outcome of Epstein-Barr virus (EBV) DNAemia in 100 recipients of allogeneic hematopoietic stem cell transplant. A total of 68 patients received anti-thymocyte globulin before unrelated grafts. RESULTS: Cumulative incidence of high-load EBV DNAemia defined by levels >10,000 copies/mL was 14% at 12 months. In multivariate analysis, a CD4+ T-lymphocyte count >50 µL at day +30 was the only factor significantly associated with a reduced risk of high-load EBV DNAemia. Thirteen of 16 patients with high viral loads were preemptively treated with rituximab and achieved EBV DNA negativity. Three patients had already developed post-transplant lymphoproliferative disorder (PTLD) at the time of detection of high EBV DNA loads, and they obtained complete response after rituximab infusions and chemotherapy. Patients with high EBV DNA load had a significantly higher transplant-related mortality (TRM) compared with patients with negative or low viral load (54% vs. 16%, P = 0.009) and a trend to lower overall survival (55% vs. 29%, P = 0.060). CONCLUSION: We conclude that CD4+ cell count at day +30 is a predictive factor for EBV DNAemia and may help identify patients requiring closer monitoring. Although only 3% of patients progressed to PTLD and were all successfully managed, EBV reactivation was associated with higher TRM, mainly because of infections.

Infections caused by filamentous fungi in patients with hematologic malignancies. A report of 391 cases by GIMEMA Infection Program.

BACKGROUND AND OBJECTIVES: To evaluate the clinical characteristics of patients with hematologic malignancies developing a filamentous fungi infection (FFI) and to define the prognostic factors for their outcome. DESIGN AND METHODS: A retrospective study, conducted on patients admitted to 14 Hematology divisions of tertiary care or university hospitals, participating in the GIMEMA Infection Program, over a ten-year period (1988-1997). The study included patients with hematological malignancies and a histologically and/or microbiologically proven or probable FFI. RESULTS: We included 391 patients (male/female: 262/129, median age 49 years) with hematologic malignancies (225 acute myeloid leukemia, 67 acute lymphocytic leukemia, 30 chronic myeloid leukemia, 22 non-Hodgkin's lymphoma, 12 myelodysplastic syndrome, 10 aplastic anemia, 7 Hodgkin's disease, 8 chronic lymphocytic leukemia, 5 multiple myeloma, and 5 hairy cell leukemia) who developed a proven FFI. Eighty percent of the patients had been neutropenic for an average of 14 days before the infection, and 71% had an absolute neutrophil count lower than 0.5 x 10(9)/L at the time of FFI diagnosis. The primary sites of infection were: lungs (85%), nose and paranasal sinus (10%), and other sites (5%). The diagnosis was made while still alive in 310 patients (79%), and at autopsy in the remaining 81 patients (21%). Chest X-ray was diagnostic in 77% of patients with pulmonary FFI, while computed tomography (CT) scan of the thorax was positive in 95% of cases. A significant diagnostic advantage for CT scan was observed in 145 patients who had both a chest X-ray and CT scan. Aspergillus was identified as the cause of FFI in 296 patients, Mucorales in 45 patients, Fusarium in 6 patients and other filamentous fungi species in 4 patients, while in a further 40 patients no agent was identifiable. The overall mortality rate three months after the diagnosis of FFI was 74%, and fungal infection had been the cause of death in 51% of patients. INTERPRETATION AND CONCLUSIONS: Our retrospective study shows that FFI still remains a life-threatening complication in neutropenic patients. Despite appropriate treatment, half of the patients die due to this complication. The use of glucocorticoids and recovery from neutropenia are the most important prognostic factors. Mucorales infections are associated with a significantly poorer prognosis than those due to Aspergillus spp.

Autologous bone marrow transplantation in non-Hodgkin's lymphoma patients: effect of a brief course of G-CSF on harvest and recovery.

This study compares harvest and hematological recovery data of 100 lymphoma patients who underwent BM harvest either after a short course of G-CSF (16 microg/kg for 3 days) (n = 57) or in steady-state conditions (n = 43). G-CSF allowed the attainment of a significantly higher median number of total nucleated cells x 10(8)/kg (4.4, range 1.4-17, vs 2.1, range 0.6-4.2; P < 0.0001), mononuclear cells x 10(8)/kg (0.55, range 0.20-1.4, vs 0.41, range 0.15-0.76, P < 0.0001) and CFU-GM/ml (310, range 10-5500, vs 80, range 10-3800, P = 0.008), with lower volumes of blood collected (17.5 ml/kg, range 8-31 vs 21.0, range 15-30, P = 0.0001). Hematological recovery was faster in patients who received pre-treated BM (median time to PMN >0.5 x 10(9)/l and to platelets >20 x 10(9)/l was 12, range 10-14, and 13, range 10-18, days, respectively) than in those autotransplanted with steady-state BM (median time to PMN >0.5 x 10(9)/l and to platelets >20 x 10(9)/l 13, range 10-18 and 14, range 10-20 days, respectively, P = 0.004 and P = 0.01). Transfusional requirement was significantly different and patients of the G-CSF group needed shorter hospitalization (17 days, range 12-24, vs 20 days, range 14-32; P = 0.02). These data suggest that treating patients with G-CSF before BM harvest improves the quality of the harvest and accelerates engraftment and hematological recovery.

Autologous stem cell transplantation for aggressive non-Hodgkin's lymphomas in first complete or partial remission: a retrospective analysis of the outcome of 52 patients according to the age-adjusted International Prognostic Index.

The aim of the study was to retrospectively evaluate the outcome of patients with aggressive non-Hodgkin's lymphoma (NHL), undergoing autologous stem cell transplantation (ASCT) in first complete (CR) or partial (PR) remission, according to the age-adjusted International Prognostic Index (IPI). Fifty-two consecutive patients, aged less than 60 years, with intermediate- or high-grade NHL, and at least one of the following adverse risk factors: bulky disease, B symptoms or Ann Arbor stage III-IV, and at least a PR after CHT (and radiotherapy (RT) on residual mediastinal mass when required), underwent ASCT conditioned with BAVC. Sixty-five percent (33/52) of the patients achieved CR after CHT; 69% (36/52) after CHT + RT; 90% (47/52) after CHT +/- RT + ASCT. One death during conditioning and three major toxic events after ASCT were recorded. Overall survival (OS) is 98% at 37 months (16-88); disease-free survival (DFS) is 100% at 27 months (7-82). Comparing the observed results with those expected if patients were treated only with CHT, the sequential treatment including ASCT conferred an advantage in terms of CR rate of 14, 23 and 54%, respectively, in the low-intermediate (LI), high-intermediate (HI) and high (H)-risk groups, respectively. The 2-year OS advantage is 10, 21, 31 and 63%, respectively, and the 2-year DFS advantage is 12, 26, 38 and 39%, respectively. Even more striking is the 5-year projected advantage in the number of patients alive without disease, even when considering only the low (L) (P < 0.0001) and the LI (P < 0.0001) risk groups. For patients in the higher (HI + H) risk groups, ASCT should be included in the initial plan of treatment as consolidation of first CR or PR, but the differences seen in this study suggest a formal comparison in a randomized study also for patients in the LI risk group.

Autologous stem cell transplantation for multiple myeloma: a single centre experience.

Thirty-two patients with multiple myeloma (MM) were autografted in our Centre over a 3-year period. Twenty-three patients had a newly diagnosed MM submitted to one induction regimen and 9 had a refractory or relapsing disease treated with at least two different chemotherapy lines: 15 out of 32 patients were sensitive to conventional treatment. In 2 patients BM was harvested while in the majority PBSC were collected after administration of 7 g/m2 Cyclophosphamide plus G-CSF (in 25 patients) or G-CSF alone at the dose of 16 microg/Kg/daily for 5-7 days (in 5 patients). Conditioning regimen was busulfan 16 mg/Kg plus melphalan 120 mg/m2. One patient died of cerebral hemorrhage after reinfusion of PBSC. Out of 31 evaluable patients, 24 (77%) had a response which was complete in 6 patients (19%) and partial in 18 patients (58%), 5 cases (17%) had no response, and 2 (6%) showed myeloma progression. There was a statistical difference in the outcome between newly diagnosed and pretreated patients (p = 0.003). At a median follow-up of 9 months (range 5-37), two patients had died for progression and 3 out of the 29 alive, relapsed after 17, 18 and 36 months respectively. Although median overall survival was not reached, there was a significant survival benefit for autografted patients in comparison with a matched control group conventionally treated in our Centre before 1994 (p = 0.02).

Randomized trial of autologous filgrastim-primed bone marrow transplantation versus filgrastim-mobilized peripheral blood stem cell transplantation in lymphoma patients.

Although a large amount of data is available on the effects of filgrastim (granulocyte colony-stimulating factor [G-CSF]) on the mobilization of stem cells in the circulation, data concerning its effects on bone marrow (BM) harvesting is scarce and controversial. We have designed a randomized trial comparing filgrastim-mobilized peripheral blood stem cell (PBSC) transplantation with filgrastim-primed autologous bone marrow transplantation (ABMT). Fifty-five patients affected by non-Hodgkin's (n = 38) or Hodgkin's (n = 17) lymphoma, selected for autologous transplantation over a 12-month period in a single institution, were randomized 2:1 to undergo BM or PB harvest/collection after priming for 3 days with filgrastim, 16 microg/kg body weight daily subcutaneously. BM priming with G-CSF allowed the harvest of a significantly higher number of mononuclear cells (MNC) (0.53 x 10(8)/kg, range, 0.32 to 1.40), as compared with a historical control of unprimed BM harvests (0.43 x 10(8) MNC/kg, range, 0.15 to 0.72, P = .001). After high-dose ablative therapy, median time to neutrophil recovery above 0.5 x 10(9)/L was 12 days for BM and 11 days for PB (P = .219); median time to platelet recovery above 20 x 10(9)/L was 13 days for BM and 11 days for PB (P = .242). The same number of red blood cells, platelet transfusions, and posttransplant G-CSF doses were required in the two groups of patients. Less patients (50% v 70%) became febrile in the group transplanted with mobilized PB, but days of fever/patient and days on antibiotics were overlapping. The median time spent in the hospital after reinfusion was 16.5 and 15.5 days after primed BM and primed PB, respectively (P = .134). These data suggest that in patients with lymphoma submitted to autologous transplantation, the reinfusion of filgrastim-primed BM or filgrastim-mobilized PB leads to similar results, with an advantage of only 1 day in the neutrophil recovery and 1 day on the time spent in the hospital in favor of primed PB. Either option can be chosen on the basis of the availability of a surgery room or cell separator facilities and considering the patients' characteristics and wishes.

Treatment intensification of malignant lymphomas with autologous bone marrow transplantation and granulocyte colony stimulating factor.

Treatment intensification with autologous bone marrow transplantation (ABMT) was administered to 37 cases of Hodgkin's and non-Hodgkin's lymphoma (HL and NHL) who were in complete or partial remission (CR or PR) after chemotherapy (MOPP/ABVD or F-MACHOP respectively) and to 12 cases of HL and NHL who were in relapse. ABMT treatment was BAVC for NHL and BEAM for HL. Marrow cells were harvested from the marrow and cryopreserved. The number of mononuclear marrow cells that was reinfused ranged between 0.19 and 0.80 x 108/Kg b.w. (median 0.39). All the patients were treated with granulocyte colony stimulating factor (G-CSF, Filgrastim) at a dose of 5 mg/Kg b.w. from day +4 until the absolute neutrophil count exceeded 1 x109/L for 3 consecutive days. Engraftment was observed in all cases, and no transplant-related deaths occurred. The patients with NHL and HL received a median of 12 (range 2-19) and 14.5 (range 9-27) doses of G-CSF respectively. Median time to 20 x 109/L platelet count was 14 to 17 days. Median time to an absolute neutrophil count 0.5x109/L was 13 days. A febrile episode during the period of post-transplant aplasia was documented in 35 patients (71%). Fever was associated with Gram+ bacteraemia in 31% of the cases and with Gram- bacteraemia in 11% of cases. Herpes Simplex infection was documented in two cases. No fungal infections were recorded. Median hospitalisation time from reinfusion ranged between 19.5 days (NHL) and 23 days (HL). Thirty-four of 37 cases (92%) who were transplanted in CR or in PR are currently alive and in continuous CR with a median follow-up time of 37 months after ABMT. Three of 12 cases (25%) who were transplanted in relapse are alive and in CR. Our data point out that ABMT followed by G-CSF is a safe and a very effective procedure for high risk malignant lymphomas, when ABMT is planned and is performed not as a rescue procedure but when it is integrated in the treatment strategy from the very beginning.

Sequential intensive treatment with the F-MACHOP regimen (+/- radiotherapy) and autologous stem cell transplantation for primary systemic CD30 (Ki-1)--positive anaplastic large cell lymphoma in adults.

Most of the adult patients with primary systemic CD30 (Ki-1)-positive anaplastic large cell lymphoma (ALCL) reported in the literature have been treated with combination chemotherapy (CHT), with only an occasional patient being autotransplanted, mostly after relapse. Here we report a series of 19 patients treated at our Institution with a sequential intensive therapeutic program including CHT (the F-MACHOP regimen given for 6 cycles), radiotherapy (RT), and autologous stem cell transplantation (ASCT) after conditioning with the BAVC regimen. Eleven of 19 (58%) patients achieved a complete remission (CR) after CHT; 3 after RT and 4 after ASCT (1 patient is still not evaluable for response to ASCT). The actuarial overall survival is 100% at a median of 49 months from diagnosis and the actuarial disease free survival is 100% at a median of 41 months from the time CR was reached. These data suggest that ALCL can be successfully managed with a sequential intensive treatment that prevents early relapses and projects these patients as long-term survivors.

Localization of aspergillosis to the central nervous system among patients with acute leukemia: report of 14 cases. Gruppo Italiano Malattie Ematologiche dell'Adulto Infection Program.

We retrospectively studied a consecutive series of 100 patients with acute leukemia and aspergillosis to evaluate the clinical findings and risk factors for colonization of the central nervous system (CNS) by Aspergillus species. The diagnosis of CNS aspergillosis was made in 14 patients on the basis of the following criteria: neurological signs of CNS involvement (13 of 14 patients); cerebral CT scan findings (9 of 12); microbiological findings (6 of 12); and histological findings at autopsy (11 of 11). The majority of patients had severe neurological complications (i.e., hemiparesis or seizures), due mainly to brain abscesses or mycetomas. Autopsies were performed on 11 of 14 patients and provided evidence that CNS localization was secondary to invasive aspergillosis; in each case, the most likely primary focus of infection was the lung. Although all patients had received oral antimycotic prophylaxis and had received timely empirical antifungal treatment, they all died within a median time of 5 days from the onset of neurological symptoms. Analysis of the characteristics of patients with invasive aspergillosis did not reveal any difference between those with CNS localization and those without CNS localization.

Primary systemic CD30 (Ki-1)-positive anaplastic large cell lymphoma of the adult: sequential intensive treatment with the F-MACHOP regimen (+/- radiotherapy) and autologous bone marrow transplantation.

Few series of adult patients with primary systemic CD30 (Ki-1)-positive anaplastic large cell lymphoma (ALCL) are reported in the literature; most of them have been treated with combination chemotherapy (CHT), with only an occasional patient being autotransplanted, mainly after relapsing. The remission rate ranges from 60% to 90%, but relapses are frequent (up to 60%) and precocious (mainly in the first 24 months). The aim of our study was to analyze the outcome of a series of adult patients affected by primary systemic ALCL that were treated at our institution with a sequential intensive therapeutic program including CHT, radiotherapy (RT), and autologous bone marrow transplantation (ABMT). Sixteen consecutive, unselected patients with ALCL were identified. All of them were treated with the 5-fluorouracil, methotrexate, cytosine arabinoside, cyclophosphamide, doxorubicin, vincristine, and prednisone (F-MACHOP) regimen; 9 of 16 (56.2%) reached a complete remission (CR). In six cases with residual mediastinal disease, involved-field RT was performed, allowing three additional patients to become free of disease. All 16 were then autotransplanted with bone marrow stem cells after conditioning with the cytosine arabinoside, etoposide, cyclophasphamide, and carmustine (BAVC) regimen. A present, 16 of 16 patients are alive and in CR. The actuarial overall survival is 100% at a median of 45.5 months, and the actuarial disease-free survival is 100% at a median of 33.5 months. These data suggest that ALCL can be successfully managed with a sequential intensive treatment (CHT +/- RT + ABMT) that prevents early relapses and projects these patients as long-term survivors.

Effect of marrow processing on hematopoietic cell recovery in bone marrow harvests: focus on filtration.

Bone marrow processing requires a first step of filtration to remove small clots, bone fragments, fat cells and fibrin followed by centrifugation to separate mononuclear cells (MNC). These procedures cause a significant loss of cells potentially including hematopoietic stem cells (HSC). We therefore analyzed the cell recovery and phenotype of various fractions (whole marrow; filtered marrow; MNC collected after centrifugation; bone marrow fragments trapped by filtration) of bone marrow harvests (BMH) from patients with different hematological malignancies undergoing autologous bone marrow transplantation. Analysis of 25 BMH showed that the mean percentage of WBC and MNC recovered after filtration was respectively 92.28 +/- 7.42% and 92.3 +/- 9.05% of the original BMH while after centrifugation the percentage was 20.23 +/- 6.47% and 75.7 +/- 12.81%. The percentage of cells present in the tissue fragments trapped in the filters obtained from five BMH was only 3.93 +/- 1.25% (WBC) and 5.65 +/- 2.2% (MNC) of those originally present in the harvest. Phenotypic analysis performed on the same samples showed that there is no selective loss of MNC or CD34+ cells in the filtration process. Our data indicate that processing of BMH, in particular filtration of tissue fragments, does not affect the recovery of HSC.

Autologous bone marrow transplantation in non-Hodgkin's lymphomas: prediction of mononuclear cell yield in bone marrow harvests.

We retrospectively analyzed the factors influencing the mononuclear cell (MNC) yield on bone marrow (BM) harvests in a cohort of 15 non-Hodgkin's lymphoma patients undergoing autologous bone marrow transplantation. All the patients were treated with the F-MACHOP regimen and four of them also received radiotherapy on bulky disease. Before harvesting, the patients underwent complete peripheral blood (PB) count, BM biopsy and aspirate. WBC and MNC/microL were determined on the pre-harvest PB and BM aspirate samples using an automated counter. The following variables were examined in univariate and multivariate regression analysis for possible influence on the MNC yield in the harvests: age, sex, number of cycles of CT, previous radiotherapy, state of the disease at the time of harvest, interval between the end of therapy and BM harvest, cellularity of the BM biopsy, absolute WBC and MNC counts in the PB before harvesting, absolute WBC and MNC counts in the BM aspirate performed before harvesting. The amount of marrow harvested was constant for all patients: 21.2 +/- 0.24 microL/kg B.W. Among the factors analyzed, two correlated strongly with the MNC yield/kg B.W. in the harvests: the MNC count in pre-harvest PB (r = 0.823; p = 0.0001) and the MNC count in pre-harvest BM aspirate (r = 0.802; p = 0.0003). A regression equation was generated that allows calculation of the MNC/kg yield prior to harvesting.

Incidence and diagnosis of EDTA-dependent pseudothrombocytopenia in a consecutive outpatient population referred for isolated thrombocytopenia.

Among 111 patients referred to our outpatient clinic for isolated thrombocytopenia during a 24-month period, 17 (15.3%) cases of EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) were identified. EDTA-PTCP represented the second most frequent cause of thrombocytopenia in this population. The diagnosis was confirmed by the following findings: (a) normal platelet numbers immediately after blood withdrawal; (b) progressive fall of platelet counts and evident platelet clumping over time, only in EDTA-anticoagulated blood. A simple, inexpensive and quick diagnostic method was devised, that consists in evaluating the platelet number in a blood sample anticoagulated with EDTA immediately after blood withdrawal and 4 h later.

CD34+ cell selection: focus on immunomagnetic beads and chymopapain.

The aim of the present study was to develop immunoadsorption techniques for purifying CD34+ cells from the peripheral blood (PB) and the bone marrow (BM). First, we compared two methods for isolating CD34+ cells from patients with acute non-lymphocytic leukemia. Twenty-two samples (17 PB, 5 BM) were obtained from 19 patients, were density cut and, after incubation with My10 antibody, were separated by panning or by immunomagnetic beads. Beads allowed a significantly better separation, either in terms of purification of CD34+ cells (85.5% +/- 11.1% vs 55.7 +/- 23.8%, p = 0.003) or in terms of depletion of CD34+ cells from the negative fractions (3.9 +/- 7.6 vs 30.9 +/- 25.1%, p = 0.008). In a second study, 2 BMs from healthy subjects and 1 BM and 2 PBs from chronic myeloid leukemia patients were separated using immunomagnetic beads. The results confirmed the previous study the overall frequency of CD34+ cells in the isolated positive fractions was 85.0 +/- 10.6% (with a recovery of 64.0 +/- 5.7%), while it was only 2.7 +/- 6.6% in the negative fractions. In particular the purity in the two normal BMs was respectively 86 and 97%. According to these results, the great majority of clonogenic cells was separated in the CD34+ fractions. Chymopapain, that was used to detach the beads from the cells, was shown to be non-toxic to the clonogenic cells. Positive selection of CD34+ cells with immunomagnetic beads and chymopapain is a useful method for isolating almost pure progenitors from the PB and the BM for experimental use and is under investigation for clinical applications.

The expression of the multidrug resistance related glycoprotein in adult acute lymphoblastic leukemia.

BACKGROUND: More than 50% of adults with acute lymphoblastic leukemia (ALL) actually die with resistant leukemia. The multidrug resistance (MDR) related P170 glycoprotein may be involved in treatment failure. METHODS: P170 content of leukemic cells was assayed by immunocytochemistry with the MRK-16 monoclonal antibody in 41 consecutive cases of adult ALL (27 at onset and 14 at relapse). RESULTS: Positive cells were found in 11/14 cases at relapse and in 18/27 cases at onset. All cases with a high WBC, FAB L3, B-mature phenotype, and t(9; 22) were positive. In the 27 patients who were studied at onset and were treated with the same protocol, the overall failure rate was 44% in negative cases and 83% in positive cases. CONCLUSION: P170 overexpression may contribute to drug resistance and to chemotherapy failure in adult ALL.

Infections in patients with acute non-lymphocytic leukemia nursed with central or peripheral venous access.

AIMS AND BACKGROUND: Infections are a major problem in patients undergoing induction chemotherapy for acute leukemia. Granulocytopenia is the single most important risk factor, but the pattern of infecting organisms can change according to nursing facilities or bacterial and fungal prophylaxis. METHODS: We reviewed the patterns and types of infections in 30 patients with acute non-lymphocytic leukemia. Eighty-nine periods of neutropenia following chemotherapy were evaluated: in 60 courses patients had central and in 29 had peripheral venous access. RESULTS: Almost all patients (97%) became febrile after the 1st course of therapy, but one-third remained apyretic after the fourth course (P = 0.002). In this series, the incidence of gram-positive, gram-negative and mycotic isolations were respectively 76%, 18% and 6%. The need for antimicrobic treatment varied in relation to the course of chemotherapy. CONCLUSIONS: We conclude that in acute non-lymphocytic leukemia the first neutropenic period following the onset of disease is the most critical regarding infectious problems. Both quinolonic prophylaxis and central venous access could be responsible for the microbiologic findings.

[Gaucher's disease: study of a family from Friuli]. / La malattia di Gaucher: studio di un gruppo familiare del Friuli.

Gaucher's disease is the most frequent of lysosomal storage diseases. In a family study two affected sisters of a type I patient were identified. Two of them underwent splenectomy, so reaching hematological normalization.

Expression of multidrug resistance gene (MDR-1) in human normal leukocytes.

BACKGROUND: The mdr-1 gene, which codes for a 170-kd transmembrane glycoprotein (P170), is frequently overexpressed in multidrug resistant (MDR) tumor cell lines and in spontaneous tumors, including leukemia and lymphoma. However, it is also constitutively expressed as a normal gene in normal tissues. METHODS: We used human mdr-1 cDNA and three anti-P170 monoclonal antibodies (MoAbs: MRK-16, C-219 and JSB-1) to investigate the normal peripheral blood leukocyte content of mdr-1 specific mRNA and of P170 through immunocytochemistry and flow cytometry. RESULTS: We did not find any increase in mdr-1-specific mRNA, while small amounts of P170 were easily detectable in about two thirds of the lymphocytes and monocytes and in about one third of the granulocytes. The level of P170 expression in leukocytes was similar to that found in non-MDR tumor cell lines. CONCLUSIONS: mdr-1 is constitutively expressed in human normal leukocytes at levels that cannot significantly affect drug resistance. Accordingly, low-level mdr-1 expression in leukemic cells should not be considered a label of pleiotropic drug resistance.

CD34-positive cell selection by immunomagnetic beads and chymopapain.

BACKGROUND: Pluripotent hemopoietic stem cells, progenitors of all hemolymphopoietic lineages, and clonogenic cells from many patients with acute nonlymphocytic leukemia (ANLL) and chronic myeloid leukemia (CML) express the CD34 antigen on their surface. Isolation of these cell populations is of primary experimental and clinical importance. METHODS: Six bone marrow (BM) and 10 peripheral blood (PB) samples were obtained from 2 normal individuals, 3 patients with CML and 9 with ANLL. The CD34+ cell fraction was isolated using MY10 antibody, sheep anti-mouse immunomagnetic beads and the enzyme chymopapain. Indirect immunofluorescence and semisolid culture were employed to evaluate the percentage of CD34+ cells and that of clonogenic cells in each cell fraction. RESULTS: The frequency of CD34+ cells in the original unseparated populations was (mean +/- SE) 24.3 +/- 7.3%, and reached 85.0 +/- 2.7% in the isolated CD34-positive fractions; in the negative fractions it was only 2.7 +/- 1.7%. According to these results, the great majority of clonogenic cells was separated in the CD34-positive fractions and depleted in those CD34-negative. Moreover, chymopapain was shown to be non-toxic to the clonogenic cells. CONCLUSIONS: Positive immunoselection using My10 Ab, immunomagnetic beads and chymopapain is a method for isolating almost pure progenitors from the BM and PB of normal individuals and patients with myeloid leukemias.