Interleukin-10 (IL-10) has been found to inhibit lipopolysaccharide (LPS)-induced tissue factor expression by monocytes in vitro. To determine the effects of IL-10 on LPS-induced activation of the hemostatic mechanisms in vivo, we performed a placebo-controlled, cross-over study of human endotoxemia. Two groups of eight volunteers were challenged with LPS (4 ng/kg) on two occasions: once in conjunction with placebo, and once with recombinant human IL-10 (rhIL-10; 25 microg/kg). In group 1, placebo or rhIL-10 was given 2 minutes before LPS challenge, group 2 received placebo or rhIL-10 1 hour after LPS administration. Pretreatment with rhIL-10 reduced both LPS-induced activation of the fibrinolytic system (plasma concentrations of tissue type plasminogen activator, plasmin-alpha2-antiplasmin complexes, and D-dimer), and inhibition of fibrinolysis (plasma levels of plasminogen activator inhibitor 1), whereas posttreatment only inhibited the latter response. Both IL-10 pre- and posttreatment attenuated activation of the coagulation system (plasma levels of prothrombin fragment F1 + 2 and thrombin-antithrombin complexes). These results indicate that rhIL-10, besides its well-described inhibitory effects on cytokine release, potently modulates the fibrinolytic system and inhibits the coagulant responses during endotoxemia.

We report the results of intravenous anti-D (WinRho, WinRho SD) therapy in 261 non-splenectomized patients treated at the New York Hospital-Cornell Medical Center over the period from 1987 to 1994. Children (n = 124) and adult patients (n = 137) with classic immune thrombocytopenic purpura (ITP; n = 156) or human immunodeficiency virus (HIV) related thrombocytopenia (n = 105) and acute (n = 75) or chronic (n = 186) disease at the time of the initial anti-D treatment were studied. In addition, 11 previously splenectomized patients were treated as a separate group. Our objectives were to evaluate the following. (1) Efficacy of anti-D: The response after the initial infusion was analyzed according to clinical parameters, such as patient's age, HIV status, gender, disease duration, pretreatment platelet count, and hemoglobin value, as well as treatment-related factors, including the dose of anti-D, the solvent detergent treatment of the preparation, and the type of administration. (2) Use of anti-D as maintenance therapy: The duration of response after the initial infusion and the results of subsequent treatments were evaluated. (3) Safety/toxicity of anti-D: Postinfusion reactions and hemoglobin decrease after treatment were studied. Anti-D is a safe treatment providing a hemostatic platelet increase in greater than 70% of the Rh+ non-splenectomized patients. The group with the best results is HIV- children, but all patient groups respond and the effect lasts more than 21 days in 50% of the responders. Duration of response is not influenced by HIV status; furthermore, HIV+ patients show no adverse effects on hemoglobin decrease or HIV disease progression. Patients with chronic ITP after splenectomy have minimal or no response to intravenous anti-D.

Despite myelosuppression, polycythemic (PV) patients greater than 65 years of age have a high risk of vascular complications, and the leukemic risk exceeds 15% after 12 years. Is the addition of low-dose maintenance treatment with hydroxyurea (HU) after radiophosphorus (32P) myelosuppression able to decrease these complications? Since the end of 1979, 461 patients were randomized to receive (or not) low-dose HU (5 to 10 mg/kg/d), after the first 32P-induced remission, and were observed until death or June 1996. Maintenance treatment very significantly prolonged the duration of 32P-induced remissions and reduced the annual mean dose received to one-third. However, despite this maintenance, 25% of the patients had an excessive platelet count and the rate of serious vascular complications was not decreased, except in the most severe cases with short-term relapse of polycythemia. Furthermore, the leukemia rate was significantly increased beyond 8 years and a significant excess of carcinomas was also observed. The continuous use of HU did not decrease the risk of progression to myelofibrosis (incidence of 20% after 15 years). Life expectancy was shorter (a median of 9.3 years v 10.9 years with 32P alone), except in the most severe cases (initial 32P-induced remission lasting <2 years) in which maintenance treatment moderately prolonged the survival by reducing the vascular risk. In most cases of PV, in which the duration of the first 32P-induced remission exceeded 2 years, the introduction of HU maintenance did not reduce the vascular risk. Although it considerably decreased the mean dose of 32P received, HU maintenance therapy significantly increased the leukemia and cancer risks and reduced the mean life expectancy by 15%. However, in cases with more rapid recurrence, the introduction of maintenance treatment reduced the vascular risks and moderately prolonged survival. The use of HU as a maintenance therapy is therefore only justified in this situation.

The relative efficacy and toxicity of the chemotherapeutic agents thioguanine (6TG) and etoposide (VP16) were assessed by a randomized comparison of the DAT (daunorubicin, cytarabine, thioguanine) versus ADE (daunorubicin, cytarabine, etoposide) regimens in the Medical Research Council's 10th acute myeloid leukaemia trial (MRC AML 10), which was open to patient entry from May 1988 to April 1995. In this, the largest reported trial of AML therapy to date, 1,857 eligible patients, mostly less than 56 years old, were randomized: 929 (including 143 children under 15 years old) were allocated to DAT and 928 (143 children) to ADE. The two groups were well matched for presentation features. The complete remission (CR) rate was 81% with DAT and 83% with ADE (P = .3). The percentages of remitters achieving remission after 1, 2, or more than 2 courses were 70%, 22%, and 8% for DAT and 74%, 21%, and 5% for ADE. The percentages failing to achieve a CR due to resistant disease were 11% with DAT versus 9% with ADE (P = .07). There was a slightly higher death rate in CR during consolidation chemotherapy with ADE (9%) than with DAT (6%) (P = .06). Patients receiving DAT took slightly but significantly longer to recover from neutropenia and thrombocytopenia but the median number of days in hospital were similar in each group. ADE patients experienced slightly more severe nonhematologic toxicity. There was also no significant difference between the groups in the longer-term measures of efficacy: disease-free survival at 6 years from CR was 42% (+/-4) for DAT and 43% (+/-4) for ADE (P = .8); relapse rate at 6 years was 50% (+/-4) for DAT and 49% (+/-5) for ADE (P = .6); survival at 6 years was 40% (+/-4) for both DAT and ADE (P = .9). Subgroup analysis failed to show any benefit for etoposide in patients with monocytic or myelomonocytic disease, or in any other diagnostic subgroup. In conclusion, DAT and ADE both achieve high remission rates and good long-term survival, and are equally effective chemotherapy regimens for the treatment of AML patients aged up to 55 years.

Clofazimine (Lamprene) is an antimycobacterial drug that has antiinflammatory activity in a number of chronic autoimmune skin disorders. We report 22 patients treated with clofazimine for chronic graft-versus-host disease (cGVHD). The initial dose was 300 mg orally in a single daily dose for 90 days. After 90 days, the dose was lowered to 100 mg orally each day and the medication continued indefinitely as tolerated. Treatment courses lasted 7 to 835 days and were generally well tolerated. Gastrointestinal side effects occurred in eight of 22 patients (36%) and hyperpigmentation was noted in 12 of 22 patients (55%), which resolved upon decrease or discontinuation of the drug. Over 50% of patients with skin involvement, flexion contractures, or oral manifestations achieved complete or partial responses. Seven of 22 patients (32%) were able to reduce other immunosuppressive medications. Thus, clofazimine is safe and has encouraging efficacy in cGVHD, particularly if sclerodermatous skin, joint contractures, or oral manifestations are present. The mechanism by which clofazimine induces a response is unknown, but might be secondary to suppression of alloreactive T-cell function in cGVHD target organs. Clofazimine deserves further study for the treatment of cGVHD.

Among high-grade malignant non-Hodgkin's lymphomas the updated Kiel classification identifies three major B-cell entities: centroblastic (CB), B-immunoblastic (B-IB), and B-large cell anaplastic (Ki-1+) (now termed anaplastic large cell [CD30+], [B-ALC]). The clinical prognostic relevance of this distinction was evaluated in a randomized prospective treatment trial (COP-BLAM/IMVP-16 regimen randomly combined +/- radiotherapy in complete responders) conducted in adult (age 15 to 75) patients with Ann Arbor stage II-IV disease (n = 219) diagnosed by optimal histomorphology (Giemsa staining) and by immunohistochemistry. Overall survival was significantly better in CB lymphoma as compared to B-IB (P = .0002) or B-ALC (P = .046). Relapse-free survival was worse for B-IB (P = .0003) as compared to CB lymphomas. The prognostic differences between CB and B-IB were confirmed by multivariate analyses including the risk factors of the International Index. Overall survival was significantly determined by performance status (P = .0003), serum-LDH (P = .036), and B-IB histology subtype (P = .036). Relapse-free survival was influenced by age (P = .007) and histological subtype (P = .007). Thus, the diagnosis of the CB and B-IB lymphomas by the histological criteria of the Kiel classification was identified as an independent prognostic factor in diffuse large B-cell lymphomas.

Administration of the immunosuppressive drug cyclosporine after autologous bone marrow transplantation induces a systemic autoimmune syndrome resembling graft-versus-host disease (GVHD). This syndrome termed autologous GVHD has significant antitumor activity. Associated with autologous GVHD is the development of T lymphocytes that recognize major histocompatibility complex (MHC) class II determinants, including self. The present studies attempted to characterize and define the molecular specificity of the effector T lymphocytes in autologous GVHD induced in patients with metastatic breast cancer. The results suggest that the effector cells associated with human autologous GVHD are CD8+ T lymphocytes expressing the alpha/beta T-cell receptor. Additional studies show that the effector T cells recognize MHC class II antigens in association with a peptide from the invariant chain (CLIP). Pretreatment of autologous lymphoblast target cells with anti-CLIP antibody completely blocked lysis mediated by autologous GVHD effector T cells. On the other hand, force loading this peptide markedly enhanced the susceptibility of the target cells to recognition by the autoreactive T cells. The recognition of the MHC class II CLIP complex may account for the novel specificity of the effector T cells associated with human autologous GVHD. Moreover, identification of the target peptide may allow for the development of novel immunotherapeutic strategies to enhance the antitumor efficacy of autologous GVHD.

Fifteen patients with refractory Hodgkin's disease were treated in a phase I/II trial with the natural killer (NK)-cell-activating bispecific monoclonal antibody HRS-3/A9, which is directed against the Fc(gamma)-receptor III (CD16 antigen) and the Hodgkin's-associated CD30 antigen, respectively. Median counts of NK cells and of all lymphocyte subsets were considerably decreased in the patients before therapy. HRS-3/A9 was administered 4 times every 3 to 4 days, starting with 1 mg/m2. The treatment was well tolerated, and the maximum tolerated dose was not reached at 64 mg/m2, the highest dose administered because of the limited amounts of HRS-3/A9 available. Side effects were rare and consisted of fever, pain in involved lymph nodes, and a maculopapulous rash. A total of 9 patients developed human antimouse Ig antibodies, and 4 patients developed an allergic reaction after attempted retreatment. A total of 1 complete and 1 partial remission (lasting 6 and 3 months, respectively) [corrected], 3 minor responses (1 to 11+ months), and 1 mixed response were achieved. There was no clear-cut dose-side effect or dose-response correlation. Our results encourage further clinical trials with this novel immunotherapeutic approach and emphasize the necessity to reduce the immunogenicity of the murine bispecific antibodies.

Cholecystectomy is the most common surgical procedure performed in sickle cell anemia (SCA) patients. We investigated the effects of transfusion and surgical method on perioperative outcome. A total of 364 patients underwent cholecystectomy: group 1 (randomized to aggressive transfusion) 110 patients; group 2 (randomized to conservative transfusion) 120 patients; group 3 (nonrandomized nontransfusion) 37 patients; and group 4 (nonrandomized transfusion) 97 patients. Patients were similar except group 3 patients were more likely to be female, over 20 years old, smokers, and more healthy by American Society of Anesthesiologists (ASA) physical status score. Total complication rate was 39%: sickle cell events 19%; intraoperative or recovery room events 11%; transfusion complications 10%; postoperative surgical events 4%; and death 1%. Group 3 patients had the highest incidence of sickle cell events (32%). Open cholecystectomies were performed in 58% and laparoscopic in 42%. Laparoscopic patients were younger and more healthy by ASA score. Laparoscopic patients had longer anesthesia time (3.2 v 2.9 hours), but shorter hospitalization time (6.4 days v 9.8). Complications were similar between these two groups. We conclude that SCA patients undergoing cholecystectomy have a high perioperative morbidity, and the incidence of sickle cell events may be higher in patients not preoperatively transfused. We recommend a conservative preoperative transfusion regimen, and we encourage the use of the laparoscopic technique for SCA patients undergoing elective cholecystectomy.

TEL gene rearrangement is the most common genetic lesion in pediatric acute lymphoblastic leukemia (ALL), occurring in about 25% of B-lineage cases. We previously showed that, among patients treated on St Jude protocols, TEL rearrangement independently conferred an excellent prognosis. To extend these results to patients treated with antimetabolite-based therapy, we performed Southern blot analysis to determine the TEL gene status of 104 cases of B-lineage ALL treated on Pediatric Oncology Group 8602, matched on age, gender, and leukocyte count. There were 52 failures among the 77 patients with germline TEL, compared with only 8 failures among 27 patients in the rearranged group. Based on a two-sided logistic regression analysis, stratified for age (subdivided at 10 years), leukocyte count (subdivided at 50,000), and gender, the estimated odds of failing by 4 years in the germline TEL group is 5.4 times that of the rearranged TEL group, with 95% confidence from 1.9 to 15.6, two-sided P = .0009. Thus, the presence of a rearranged TEL gene is also associated with an improved survival among patients treated with antimetabolite-based therapy. Our results indicate that all newly diagnosed ALL patients should be screened for TEL gene rearrangements and suggest that these patients are candidates for less intensive therapy.

Hydroxyurea (HU) can increase fetal hemoglobin (HbF) in sickle cell anemia (HbSS). To identify determinants of the HbF response, we studied 150 HU-treated patients grouped by quartiles of change in HbF from baseline to 2 years. Half of the HU-assigned patients had long-term increments in HbF. In the top two quartiles, HbF increased to 18.1% and 8.8%. These patients had the highest baseline neutrophil and reticulocyte counts, and largest treatment-associated decrements in these counts. In the lower two quartiles, 2-year HbF levels (4.2% and 3.9%) and blood counts changed little from baseline. In the highest HbF response quartile, myelosuppression developed in less than 6 months, compliance was best, and final doses of HU were 15 to 22.5 mg/kg. All four quartiles had substantial increases of F cells in the first year. This was maintained for 2 years only in the top three quartiles. Leukocyte and reticulocyte counts decreased initially in all quartiles, but drifted back toward baseline levels in the lowest HbF response quartile. Initial HbF level and phenotype of the F-cell production (FCP) locus were not associated with HbF response, but absence of a Central African Republic (CAR) haplotype was. Bone marrow ability to withstand HU treatment may be important for sustained HbF increases during HU treatment of HbSS.

One hundred nineteen patients with relapsed or refractory Hodgkin's disease (HD) received high-dose therapy followed by autologous hematopoietic progenitor cell transplantation. Three preparatory regimens, selected on the basis of prior therapy and pulmonary status, were employed. Twenty-six patients without a history of prior chest or pelvic irradiation were treated with fractionated total body irradiation, etoposide (VP) 60 mg/kg and cyclophosphamide (Cy) 100 mg/kg. Seventy-four patients received BCNU 15 mg/kg with identical doses of VP and Cy. A group of 19 patients with a limited diffusing capacity or history of pneumonitis received a novel high-dose regimen consisting of CCNU 15 mg/kg, VP 60 mg/kg and Cy 100 mg/kg. Twenty-nine patients (24%) had failed induction therapy and 35 (29%) had progressive HD within 1 year of initial chemotherapy. At 4 years actuarial survival was 52%, event-free survival was 48% and freedom from progression (FFP) was 62%. No significant differences were seen in survival data with the three preparatory regimens. Six patients died within 100 days of transplantation and 5 died at a later date of transplant-related complications. Secondary malignancies have developed in 6 patients, including myelodysplasia/leukemia in four patients and solid tumors in two patients. Regression analysis identified systemic symptoms at relapse, disseminated pulmonary or bone marrow disease at relapse and more than minimal disease at the time of transplantation as significant prognostic factors for overall and event-free survival and FFP. Patients with none of these factors enjoyed an 85% FFP at 4 years compared with 41% for patients with one or more unfavorable prognostic factors (P = .0001). Our results confirm the efficacy of high-dose therapy and autografting in recurrent or refractory HD. Although longer follow-up is necessary to address ultimate cure rates and toxicity, our data indicate that a desire to reduce late effects should drive future research efforts in favorable patients whereas new initiatives are needed for those with less favorable prognoses.

Virtually no progress has been made during more than 2 decades of clinical trials for multiple myeloma (MM) involving standard therapy (ST). Recent studies suggest that dose intensification requiring hematopoietic stem cell support results in higher complete response (CR) rates and extended disease control. "Total Therapy" (TT) consisting of noncross-resistant induction regimens, followed by a double autotransplant (AT) procedure, was administered to 123 untreated patients with symptomatic MM. Upon hematologic recovery, interferon (IFN) maintenance (3 million units [MU]/m2 subcutaneously thrice weekly) was given until disease recurrence/progression. Results were compared with the outcome of untreated patients receiving ST according to Southwest Oncology Group (SWOG) trials. One hundred sixteen pair mates were selected from both TT and among 1,123 patients to match for the major prognostic features. TT induced CR in 40% of all 123 patients (intent-to-treat). By 12 months, 7% had died, including 4% from treatment-related complications. With a median follow-up of 31 months, median durations of event-free survival (EFS) and overall survival (OS) are 49 and 62+ months, respectively. Abnormalities of chromosomes 11q and 13 were associated with inferior outcome, whereas CR within 6 months after induction was a favorable prognostic feature for both EFS and OS. In comparison to ST, TT induced higher PR rates (85% v 52%, P < .0001) (CR rates not available on SWOG trials) and extended EFS (49 v 22 months, P = .0001) and OS (62+ v 48 months, P = .01). Compared to ST, dose intensification with double AT markedly augments tumor cytoreduction, effecting not only higher CR rates but also significantly extending EFS and OS in previously untreated patients with MM.

This study evaluated the effect of filgrastim (granulocyte colony-stimulating factor [G-CSF]) on the duration of granulocytopenia and thrombocytopenia after intensive consolidation therapy with diaziquone (AZO) and mitroxantrone for patients less than 60 years of age with acute myeloid leukemia (AML) in complete remission. Patients less than 60 years of age with AML who achieved complete remission (CR) with daunorubicin and cytarabine induction therapy, were scheduled to receive three sequential courses of high-dose cytarabine, cyclophosphamide/etoposide, AZQ, and mitroxantrone in a pilot study to determine their tolerance of these three sequential consolidation regimens. The initial patients treated with AZQ and mitroxantrone experienced prolonged bone marrow suppression and, therefore, subsequent cohorts were treated with G-CSF, 5 micrograms/kg, beginning the day after completion of the third cycle of chemotherapy. There was a marked decrease in the duration of granulocytopenia less than 500/microL in two groups of patients receiving two different dose levels of AZQ and the same dose of mitoxantrone compared with patients not receiving the G-CSF. There was also a decrease in the need for hospitalization, as well as the duration of hospitalization. There was a trend towards shortening of the duration of thromobocytopenia, as well. The duration of complete remission and overall survival was similar in patients who received or did not receive G-CSF. G-CSF markedly shortened the duration of granulocytopenia in patients with AML receiving intensive postremission consolidation with AZQ and mitoxantrone. There was no adverse effect on CR duration or survival.

In an attempt to restore immune competence to 12 human immunodeficiency virus-1 (HIV-1)-infected patients, lymphocytes from their HIV-1-uninfected identical twin siblings were cultured in medium supplemented with 5% fetal calf serum (FCS), anti-CD3 antibody, and interleukin-2 (100 IU/mL) for 10 days and then infused into the patients. After multiple infusions, at 6- to 8-week intervals, half of the patients developed arthus-like reactions within 4 to 12 hours of infusion consisting of fever > 39 degrees C, hypotension, rigors, arthralgias, myalgias, headache, and/or malaise. Preinfusion and postinfusion serum samples were evaluated for the presence of antibodies to FCS using double immunodiffusion. All preinfusion serum samples were negative by this method while 8 of the 12 patients developed antibodies to a single component of FCS after two or more infusions of lymphocytes cultured in FCS-supplemented medium. Prick skin testing to standardized beef extract was negative in all patients. There was a correlation between initial CD4 level and the development of antibodies to FCS (median initial CD4 count in FCS antibody positive patients = 362.0/microL v median initial CD4 count of nonresponders = 135.0/microL). There was no correlation with response to recall antigens in delayed-type hypersensitivity testing. We conclude that selected patients were sensitized to a single component of FCS carried on donor lymphocytes, despite thorough washing of the cells before infusion. The development of antibodies to FCS indicates that immune complex formation could have occurred after the cell infusions, resulting in the arthus-like reactions. These observations suggest that the therapeutic use of human lymphocytes cultured in FCS may expose the recipient to immunogenic substances with possible clinical sequelae.

In a double-blind, randomized, placebo-controlled trial, we evaluated the ability of epoetin beta (recombinant human erythropoietin) to avoid allogeneic blood transfusions (ABT) and the associated risks in patients undergoing primary elective open-heart surgery and in whom autologous blood donation (ABD) was contraindicated. Seventy-six patients overall were enrolled onto the trial and were randomly assigned to the two treatment groups, 5 x 500 U/kg body weight (BW) epoetin beta or placebo intravenously over 14 days preoperatively. All patients received 300 mg Fe2+ orally per day during the treatment period. Preoperatively, the mean hemoglobin increase was 1.50 g/dL greater in epoetin beta patients than in placebo patients (95% confidence interval, 1.10 to 1.90 g/dL), allowing a rapid return to the baseline value by the seventh postoperative day in most epoetin beta patients. The mean volume of blood collected by intraoperative isovolemic hemodilution was 562 mL (red blood cell mass, 274 mL) in the epoetin beta group and 218 mL (red blood cell mass, 94 mL) in the placebo group, respectively. Only four patients (11%) in the epoetin beta group received an ABT, compared with 19 (53%) in the placebo group (P = .0003). Epoetin beta was most useful in patients with a perioperative blood loss greater than 750 mL, in those with a baseline hematocrit value less than 0.42, and in those aged > or = 60 years. The iron supplementation proved adequate despite the fact that a significant decrease in ferritin (median, 48.1%) and transferrin saturation (median, 40.5%) was observed in epoetin beta patients preoperatively. No influence of epoetin beta therapy on blood pressure, laboratory safety variables, or the frequency of specific adverse events was observed. Intravenous epoetin beta treatment of 5 x 500 U/kg BW in combination with 300 mg Fe2+ orally per day administered over 14 days preoperatively is an adequate therapy for increasing mean hemoglobin levels by approximately 1.50 g/dL and reducing the allogeneic blood requirement in patients undergoing elective open-heart surgery and in whom ABD is contraindicated.

The anti-CD25 immunotoxin (IT), RFT5-SMPT-dgA, was used in a phase I dose escalation trial in patients with refractory Hodgkin's lymphoma. The IT was constructed by linking the monoclonal antibody RFT5 via a sterically hindered disulfide linker to deglycosylated ricin-A. All patients in this trial were heavily pretreated with a mean of 5 (range, 2 to 8) different prior therapies, including autologous bone marrow transplantation in 8 of 15. The mean age was 29 years (range, 19 to 34 years). Thirteen of 15 patients had advanced disease (stage IV) with massive tumor burdens and 6 of 15 had B symptoms. The IT was administered intravenously over 4 hours on days 1, 3, 5, and 7 for total doses per cycle of 5, 10, 15, or 20 mg/m2. Patients received one to four cycles of treatment. The peak serum concentration of intact IT varied from 0.2 to 9.7 micrograms/mL. The serum half life (T1/2) of the IT ranged from 4.0 to 10.5 hours (mean, 6.1 hours). Side effects were related to vascular leak syndrome (VLS), ie, decreases in serum albumin, edema, weight gain, hypotension, tachycardia, myalgia, and weakness. Two patients had a National Cancer Institute (NCI) grade 2 allergic reaction with generalized urticaria and mild bronchospasm. At 15 mg/m2, 1 patient experienced a grade 3 myalgia. All 3 patients receiving 20 mg/m2 experienced NCI grade 3 toxicities (edema, nausea, dyspnea or tachycardia) and 1 patient had NCI grade 4 myalgia. Thus, the maximal tolerated dose was 15 mg/m2. Seven of 15 patients made human antiricin antibodies (> or = 1.0 microgram/mL) and 6 of 15 developed human antimouse antibodies (> or = 1.0 microgram/mL). Clinical response included 2 partial remissions, 1 minor response, 3 stable diseases, and 9 progressive diseases. As has been predicted from the preclinical tests, these data seem to indicate clinical efficacy of this new IT in heavily pretreated Hodgkin's patients, thus warranting further clinical investigation.

The clinical application of gene transfer is hindered by the availability of the multipotential stem cells and the difficulty in obtaining efficient retroviral transduction. To assess potential means by which gene transfer into human hemopoietic stem cells might be enhanced, the retroviral transduction efficiency of human bone marrow cells (BM) or peripheral blood progenitor cells (PBPC) was compared at multiple time points after in vivo administration of granulocyte colony-stimulating factor (G-CSF). This was further compared with the transduction efficiency of cells mobilized with G-CSF plus stem cell factor (SCF) in a cohort of patients randomized to receive either one or two growth factors and with normal BM function. Using the LNL6 retrovirus, retroviral transduction efficiencies of up to 19% were observed for both PBPC and BM (n = 26 patients). There was at least a 100-fold increase in PBPC with G-CSF alone and a further 30-fold increase in the total number of progenitor cells available for retroviral transduction using the combination of SCF plus G-CSF. However, pretreatment of patients with G-CSF with or without SCF did not enhance the retroviral infectability of growth factor-mobilized progenitor cells. The effect of the growth factor, Flk-2/Flt3 ligand (FL), was also examined with respect to retroviral transduction efficiency of human progenitor cells. FL plus IL-3 in vitro increased the retroviral transduction efficiency up to eightfold compared with results observed using other combinations of cytokines tested (P < .001). These findings have clinical implications both for increasing the number of target cells for in vivo gene-marking/gene-therapy studies and improving the efficiency of gene transfer.

Thirty adults with leukemia or lymphoma undergoing marrow transplantation from HLA-compatible unrelated donors received tacrolimus (FK506), a new immunosuppressive macrolide lactone, and minidose methotrexate to prevent acute graft-versus-host disease (GVHD). The group had a median age of 36 years (range 21 to 49 years). Twenty-four patients had advanced disease, and 11 were resistant to conventional therapy. Tacrolimus was administered at 0.03 mg/kg/d intravenously (i.v.) by continuous infusion from day -2, converted to oral at four times the i.v. dose following engraftment, and continued through day 180 posttransplant. Methotrexate 5 mg/m2 was given i.v. on days 1, 3, 6, and 11. All patients engrafted. Grades 2-4 GVHD occurred in 34% (95% CI, 17% to 52%), and grades 3-4 GVHD in 17% (95% CI, 3% to 31%). Mild renal toxicity was common before day 100; 63% of patients had a doubling of creatinine, and 52% had a peak creatinine greater than 2 mg/dL, but only one patient was dialyzed. The median last i.v. dose of tacrolimus was 53% of the scheduled dose, and the median oral dose on day 100 was 41% of that scheduled. Overall survival at 1 year was 47% (95% CI, 27% to 66%). We conclude that tacrolimus can be combined safely with minidose methotrexate, and the combination has substantial activity in preventing acute GVHD after unrelated donor marrow transplantation.