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Biomedical subjects

W G Ho

Publications and source records attributed to W G Ho.

At least 19 recordsLinked to original sources

Randomized, double-blind, multicenter trial comparing clinafloxacin with imipenem as empirical monotherapy for febrile granulocytopenic patients.

In a double-blind, multicenter trial, 541 febrile granulocytopenic patients were randomized to receive either intravenous (iv) clinafloxacin (200 mg every 12 h) or i.v. imipenem (500 mg every 6 h) as empirical monotherapy. More baseline pathogens were susceptible to clinafloxacin (259 [99%] of 262 organisms) than to imipenem (253 [95%] of 265; P=.03). Initial favorable clinical response rates for clinafloxacin (88 [32%] of 272 patients) and imipenem (89 [33%] of 269) were similar. After addition of other antimicrobial agents, overall response rates were 259 (95%) of 272 for clinafloxacin and 251 (93%) of 269 for imipenem. During the study, only 13 clinafloxacin (5%) and 18 imipenem (7%) recipients died. Both drugs were generally well tolerated. Drug-related skin rash occurred more often with clinafloxacin (11% vs. 6%; P=.07), whereas nausea (2% vs. 5%; P=.16), Clostridium-difficile-associated diarrhea (3% vs. 8%; P=.02), and seizures (0% vs. 2%; P=.06) occurred more often with imipenem. These results suggest that clinafloxacin and imipenem have similar efficacy as empirical monotherapy in febrile granulocytopenic patients.

Adolescent↗

A multicenter, randomized, double-blind comparison of different doses of intravenous immunoglobulin for prevention of graft-versus-host disease and infection after allogeneic bone marrow transplantation.

Intravenous immunoglobulin is approved for use in allogeneic bone marrow transplant recipients for prevention of graft-versus-host disease (GVHD) and infections, but the minimally effective dose has not been established. In this multicenter, randomized, double-blind trial, patients undergoing allogeneic marrow transplantation were randomized to receive 100 mg/kg, 250 mg/kg, or 500 mg/kg doses of intravenous immunoglobulin. Each dose was given weekly for 90 days and then monthly until 1 year after transplant. Six hundred and eighteen patients were evaluated. Acute GVHD (grades 2-4) occurred in 39% of the patients (80 of 206) in the 100 mg/kg group, 42% of the patients (88 of 208) in the 250 mg/kg group, and in 35% of the patients (72 of 204) in the 500 mg/kg group (P = 0.344). Among patients with unrelated marrow donors, a higher dose of intravenous immunoglobulin (500 mg/kg) was associated with less acute GVHD (P = 0.07). The incidences of chronic GVHD, infection and interstitial pneumonia were similar for all three doses of intravenous immunoglobulin. The dose of intravenous immunoglobulin also had no effect on the types of infection, relapse of hematological malignancy or survival. Except for more frequent chills (P = 0.007) and headaches (P = 0.015) in patients given the 500 mg/kg or 250 mg/kg dose of immunoglobulin, adverse events were similar for all three doses. These results suggest that 100 mg/kg, 250 mg/kg, and 500 mg/kg doses of intravenous immunoglobulin are associated with similar incidences of GVHD and infections in most allogeneic marrow transplants. These results should be considered when designing cost-effective strategies for the use of intravenous immunoglobulin in allogeneic marrow transplants receiving other current regimens for prophylaxis of GVHD and infection.

Adolescent↗

Long-term outcome of aplastic anemia in adults treated with antithymocyte globulin: comparison with bone marrow transplantation.

The outcome of 155 adult aplastic anemia (AA) patients treated with antithymocyte globulin (ATG, Upjohn, Kalamazoo, MI) at University of California, Los Angeles from 1977 to 1988 was evaluated. The median survival of the 146 patients who did not undergo bone marrow transplantation was 5.6 years, with 49% +/- 4% surviving more than 6 years. The most important predictor of survival was positive response to ATG (P < 0.001), which was observed in 48% of patients. Among pretreatment variables, disease severity was the best predictor of survival. Patients with moderate AA (MAA) had significantly better survival than those with severe (SAA) or very severe (VSAA) disease (P = 0.04). The 6-year actuarial survival rates of the three groups were 71% +/- 9%, 48% +/- 7% and 38% +/- 7%, respectively. Cox regression analysis found disease severity to be the only pretreatment variable significantly associated with survival (P = .02). Patient age, sex, disease etiology, concurrent treatment with androgens, or duration of ATG therapy were not associated with differences in survival or response to ATG. Late clonal hematologic complications (ie, myelodysplasia, acute myelogenous leukemia) were observed in 5 of the 77 patients followed for more than 2 years after ATG treatment. In addition, one case of non-Hodgkin's lymphoma and three solid tumors occurred in the ATG-treated patients. The survival of 56 ATG-treated patients with SAA or VSAA between the ages of 16 and 43 did not differ significantly from that of 55 adult AA patients who underwent bone marrow transplant (BMT) during the same time period (P = 0.6). However, 6-year survival rates improved from 43% for patients transplanted before 1984, to 72% for those who underwent BMT between 1984 and 1989. In contrast, there was no difference in the survival rates of patients treated with ATG during these two time periods (46% v 45%, respectively). The results suggest a superior long-term outcome for adult patients with SAA treated with BMT rather than with ATG alone, using current protocols.

Adolescent↗

Fluconazole prophylaxis of fungal infections in patients with acute leukemia. Results of a randomized placebo-controlled, double-blind, multicenter trial.

OBJECTIVE: To evaluate the efficacy and safety of fluconazole for prevention of fungal infections. DESIGN: A randomized, placebo-controlled, double-blind, multicenter trial. PATIENTS: Adults (257) undergoing chemotherapy for acute leukemia. INTERVENTION: Patients were randomly assigned to receive either fluconazole (400 mg orally once daily or 200 mg intravenously every 12 hours) or placebo. The study drug was started at initiation of chemotherapy and continued until recovery of neutrophil count, development of proven or suspected invasive fungal infection, or the occurrence of a drug-related toxicity. MEASUREMENTS: Fungal colonization, proven superficial or invasive fungal infection, empiric antifungal therapy with amphotericin B, drug-related side effects, and mortality. MAIN RESULTS: Fluconazole decreased fungal colonization (83 of 122 [68%] placebo patients compared with 34 of 119 [29%] fluconazole patients colonized at end of prophylaxis, P < 0.001) and proven fungal infections (27 of 132 [21%] placebo patients compared with 11 of 123 [9%] fluconazole patients infected, P = 0.02). Superficial fungal infections occurred in 20 of 132 (15%) placebo patients but in only 7 of 123 (6%) fluconazole patients (P = 0.01), whereas invasive fungal infections developed in 10 of 132 (8%) placebo patients and in 5 of 123 (4%) fluconazole patients (P = 0.3). Fluconazole was especially effective in eliminating colonization and infection by Candida species other than Candida krusei (66 of 122 [64%] placebo patients colonized at end of prophylaxis compared with 11 of 119 [9%] fluconazole patients, P < 0.001; 22 of 132 [17%] placebo patients infected compared with 7 of 123 [6%] fluconazole patients, P = 0.005). Aspergillus infections were infrequent in both fluconazole (3 cases) and placebo groups (3 cases). The use of amphotericin B, the incidence of drug-related side effects, and overall mortality were similar in both study groups. CONCLUSION: Prophylactic fluconazole prevents colonization and superficial infections by Candida species other than Candida krusei in patients undergoing chemotherapy for acute leukemia and is well tolerated. Fluconazole could not be clearly shown to be effective for preventing invasive fungal infections, reducing the use of amphotericin B, or decreasing the number of deaths.

Acute Disease↗

Ganciclovir prophylaxis of cytomegalovirus infection and disease in allogeneic bone marrow transplant recipients. Results of a placebo-controlled, double-blind trial.

OBJECTIVE: To evaluate the efficacy and safety of ganciclovir for prevention of cytomegalovirus (CMV) infection and disease. DESIGN: A randomized, placebo-controlled, double-blind trial. SETTING: University-affiliated bone marrow transplant center. PATIENTS: Cytomegalovirus-seropositive allogeneic bone marrow transplant recipients. INTERVENTIONS: Random assignment to receive either a placebo or ganciclovir at a dose of 2.5 mg/kg body weight every 8 hours for 1 week before transplant and then at a dose of 6 mg/kg once per day, Monday through Friday, after transplant when the post-transplant neutrophil count reached 1.0 x 10(9)/L. MEASUREMENTS: Cytomegalovirus infection (positive culture, seroconversion, positive histologic findings), CMV disease (pneumonia, gastroenteritis, the wasting syndrome), and study-drug toxicity. RESULTS: Cytomegalovirus infection developed in 25 of 45 placebo patients (56%) but in only 8 of 40 ganciclovir patients (20%) (P < 0.001). Cytomegalovirus disease may also have occurred less often in the ganciclovir patients (4 of 40 patients [10%] versus 11 of 45 patients [24%]; P = 0.09). The probability of CMV disease occurring within the first 120 days after transplantation was 0.29 among the placebo patients but only 0.12 among ganciclovir patients (P = 0.06). Reversible neutropenia was the only appreciable toxicity related to ganciclovir and required interruption of the study drug after transplant in 25 of 43 ganciclovir patients (58%) and in 13 of 47 placebo patients (28%) (P = 0.005). Overall survival was similar in both the placebo patients (29 of 45 [64%]) and ganciclovir patients (28 of 40 [70%]; P > 0.2). CONCLUSIONS: Prophylactic ganciclovir, started before transplant and continued after recovery of the post-transplant neutrophil count, reduces the incidence and severity of CMV infection in CMV-sero-positive bone marrow transplant recipients but is frequently associated with neutropenia.

Adolescent↗

Intravenous immunoglobulin and CMV-seronegative blood products for prevention of CMV infection and disease in bone marrow transplant recipients.

The efficacy of i.v. immunoglobulin plus CMV-seronegative blood products or CMV-seronegative blood products alone for prevention of CMV infection, symptomatic CMV disease, other infections and GVHD after BMT was evaluated in a randomized, controlled trial. Fifty-one CMV-seronegative allogeneic BMTs with a CMV-seronegative or CMV-seropositive marrow donor were randomly assigned to receive either i.v. immunoglobulin (1.0 g/kg once weekly for 120 days after transplant) plus CMV-seronegative blood products or CMV-seronegative blood products alone. CMV infection occurred in 2 of 25 patients (7%) receiving i.v. immunoglobulin plus CMV-seronegative blood and in 2 of 23 patients (9%) receiving CMV-seronegative blood alone. All CMV infections were asymptomatic and characterized by viral excretion with or without CMV seroconversion. There were no cases of CMV-related interstitial pneumonia. Grade > or = II GVHD was less frequent in patients given i.v. immunoglobulin (5 of 25 patients (20%) vs. 11 of 23 patients (48%), p = 0.04). The number of bacterial and fungal infections was similar in both groups. Fewer non-CMV viral infections (9 of 27 patients (33%) vs. 15 of 24 patients (63%), p = 0.03) and fewer deaths associated with infection (1 of 27 patients (4%) vs. 5 of 24 patients (21%), p = 0.07) occurred in recipients of immunoglobulin. Neither survival nor risk of leukemia relapse was changed by the immunoglobulin. The high doses of i.v. immunoglobulin were well tolerated. These results suggest that CMV-seronegative blood products alone prevent most CMV infections and CMV disease in CMV-seronegative allogeneic BMT recipients, even when the marrow donor is CMV-seropositive.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Hemolysis of transfused group O red blood cells in minor ABO-incompatible unrelated-donor bone marrow transplants in patients receiving cyclosporine without posttransplant methotrexate.

Hemolysis most commonly occurs following bone marrow transplant when there is "minor" ABO blood group incompatibility between donor and recipient. The hemolysis has been attributed to destruction of the patient's incompatible erythrocytes by donor-derived anti-A and/or anti-B antibody produced from "passenger" immunocompetent donor lymphocytes. Extraordinary transfusion requirements of group O erythrocytes in a series of patients receiving unrelated minor ABO-incompatible marrow grafts led us to investigate whether this mechanism could account for the extent of hemolysis observed. In seven consecutive minor ABO-incompatible unrelated-donor bone marrow transplant recipients receiving cyclosporine without posttransplant methotrexate, we observed excessive hemolysis. For cases in this index group, a strongly reactive donor-derived ABO blood group antibody was identified coincident with development of hemolysis. Transfusion requirements in the first three patients (26 U of group O erythrocytes each) greatly exceeded the recipient's volume of incompatible erythrocytes, indicating that lysis of transfused group O erythrocytes was also occurring. Pretransplant erythrocyte exchange transfusion with group O erythrocytes performed in the four subsequent patients decreased the severity of hemolysis, but did not prevent it. Among minor ABO-incompatible marrow graft recipients, an analysis of variance demonstrated effects on transfusion requirements due to donor-recipient relationship being unrelated (P less than .002) and the use of posttransplant methotrexate (P = .0001), and there was interaction between these two factors (P less than .001). Bone marrow transplants from unrelated donors resulted in an exaggerated immune response to ABO blood group antigens, which was associated with hemolysis of transfused group O erythrocytes, as well as the patient's ABO-incompatible erythrocytes. This serious complication may be prevented by posttransplant immunosuppression with methotrexate.

ABO Blood-Group System↗

Bone marrow transplantation versus high-dose cytarabine-based consolidation chemotherapy for acute myelogenous leukemia in first remission.

PURPOSE: Despite substantial progress in the treatment of acute myeloid leukemia (AML), fewer than 25% of patients survive free of leukemia for more than 5 years without allogeneic bone marrow transplantation (BMT). In this study we analyzed the results of one or more cycles of high-dose cytarabine-based consolidation chemotherapy as compared with allogeneic BMT in first remission. PATIENTS AND METHODS: The results in 28 adult patients, aged 16 to 45 years, who underwent a closely HLA-matched BMT for AML in first remission were compared with those in 54 consecutive, age-matched, adult patients treated with one or more cycles of high-dose, cytarabine-based consolidation chemotherapy. RESULTS: After a median follow-up of 4 years, the actuarial risk of leukemic relapse was considerably lower in the transplant group than in the group treated with consolidation chemotherapy (32% +/- 26% v 60% +/- 14%; P = .05). Treatment-related mortality, however, was much higher in the group treated with BMT (32% v 6%, P = .002). The actuarial disease-free survival at 5 years was not significantly different for the two groups (45% +/- 24% v 38% +/- 14%). CONCLUSIONS: Our results show that BMT in first remission AML did not offer a disease-free survival advantage over intensive postremission consolidation chemotherapy. Larger studies are needed to identify patients who might benefit most from BMT.

Actuarial Analysis↗

Beta-lactam antibiotic therapy in febrile granulocytopenic patients. A randomized trial comparing cefoperazone plus piperacillin, ceftazidime plus piperacillin, and imipenem alone.

OBJECTIVE: To compare the efficacy, toxicity, and cost-effectiveness of double beta-lactam therapy with monotherapy. DESIGN: A randomized, controlled trial. PATIENTS: Febrile, granulocytopenic patients (429). INTERVENTIONS: Patients were randomly assigned to receive iv cefoperazone (3 g every 12 hours) plus piperacillin (75 mg/kg body weight every 6 hours), ceftazidime (2 g every 8 hours) plus piperacillin (75 mg/kg every 6 hours), or imipenem alone (1.0 g or 0.5 g every 6 hours). Patients also received prophylactic vitamin K. MEASUREMENTS: Clinical improvement, eradication of the infecting organism, and toxicity in 403 evaluable patients with one or more infections. MAIN RESULTS: Cefoperazone and ceftazidime, when given in combination with piperacillin, were equally effective (response rates of 75% (104 of 138 patients) and 74% (101 of 137 patients), respectively). Monotherapy with imipenem had a response rate of 82% (111 of 136 patients) and was as effective as double beta-lactam therapy. Overall antibiotic-related toxicity was minimal, although seizures were associated with high doses of imipenem. Seizures occurred in 3 of 29 patients (10.3%) who were receiving 4 g/d of imipenem, in 3 of 136 patients (2.2%) who were receiving cefoperazone plus piperacillin, in 0 of the 132 patients who were receiving ceftazidime plus piperacillin, and in 1 of 106 patients (0.9%) who were receiving 2 g/d of imipenem (P less than 0.005). The 2-g daily dose of imipenem was as effective as the 4-g daily dose. Diarrhea was more frequent in patients receiving cefoperazone, whereas nausea occurred more often with imipenem. No antibiotic-related hemorrhage or nephrotoxicity was observed. Superinfections caused by beta-lactam-resistant, gram-negative bacilli were uncommon but occurred more frequently with double beta-lactam therapy than with imipenem monotherapy (11 of 268 patients compared with 1 of 135 patients; P = 0.06). Xanthomonas maltophilia superinfections occurred only in patients receiving imipenem (3 of 135 patients compared with 0 of 268 patients; P = 0.03). Imipenem monotherapy was the least expensive therapy. CONCLUSIONS: Cefoperazone and ceftazidime were equally effective when used in combination antibiotic therapy with piperacillin. Twice-daily cefoperazone is less expensive than ceftazidime given three times daily. Monotherapy with imipenem, at a daily dose of 2 g, is as efficacious as double beta-lactam therapy and costs less than combination therapy.

Adolescent↗

Ofloxacin versus vancomycin/polymyxin for prevention of infections in granulocytopenic patients.

INTRODUCTION: The efficacy and safety of oral ofloxacin were compared with those of vancomycin/polymyxin for prophylaxis of bacterial infections in granulocytopenic patients undergoing chemotherapy for hematologic malignancy. PATIENTS AND METHODS: Antimicrobial prophylaxis was begun at the time of initiation of chemotherapy. Thirty patients received ofloxacin tablets (300 mg orally every 12 hours) plus a nystatin suspension. Thirty-two patients received vancomycin capsules (500 mg orally every eight hours) and polymyxin capsules (100 mg orally every eight hours) plus a nystatin suspension. RESULTS: In the group of patients receiving ofloxacin, there were a lower number of acquired gram-negative bacillary organisms per patient (0.13 versus 1.37, p less than 0.00005), fewer patients with documented infection (11 of 30 versus 21 of 32, p = 0.04), and fewer cases of gram-negative septicemia (zero of 30 versus five of 32, p = 0.05). Ofloxacin was also better tolerated (24 of 30 versus 10 of 32 patients highly compliant, p = 0.01) and associated with fewer gastrointestinal side effects (one of 30 versus nine of 32 patients with gastrointestinal side effects, p = 0.01) than vancomycin/polymyxin. However, except for a reduction of Staphylococcus aureus colonization and infection by ofloxacin, neither ofloxacin nor vancomycin/polymyxin was effective in eliminating colonization or infection with viridans group streptococci, coagulase-negative staphylococci, or other gram-positive organisms. Only three isolates of ofloxacin-resistant gram-negative bacteria (Pseudomonas fluorescens, Pseudomonas putida, and Enterobacter aerogenes) were isolated from surveillance cultures, but none caused infection. CONCLUSION: These results suggest that oral ofloxacin is a more tolerable and efficacious alternative to vancomycin/polymyxin for prevention of serious gram-negative bacillary infections in granulocytopenic patients. More effective prophylaxis of gram-positive infections, however, is still needed.

Adolescent↗

Bone marrow transplantation using unrelated donors for patients with advanced leukemia or bone marrow failure.

Thirty-four patients received bone marrow transplants from unrelated donors. Donors and recipients were phenotypically matched for 6 of 6 HLA-A, B, and DR antigens in 27 cases and at 5 of 6 antigens in 7 cases. Twenty-three patients had leukemia, six had myelodysplasia, and five had aplastic anemia. Twenty-four patients had durable engraftment. Five died of sepsis prior to engraftment. Five patients failed to engraft; 2 of these patients had autologous bone marrow recovery. Seventeen patients developed grade greater than or equal to II acute graft-versus-host disease for an actuarial probability of 67 +/- 20%. The severity of acute graft-versus-host disease and its mortality appeared increased for recipients matched for 5 of 6 HLA-A, B, and DR antigens. Of the 34 patients, 13 (38%) are alive; actuarial survival beyond 6 months is 44 +/- 17%. None of the 25 leukemia and myelodysplasia patients achieving engraftment have relapsed. For leukemia and myelodysplasia recipients of 6 of 6 HLA-matched grafts, actuarial survival at 6 months was 55 +/- 21% compared with 14 +/- 26% for recipients matched for 5 of 6 HLA loci (P = 0.19). Infection and acute graft-versus-host disease were the primary causes of death in the engrafted patients. Survival for aplastic anemia patients was 20%. Late deaths due to pneumonia and bronchiolitis obliterans occurred after one year in 2 patients. Closely matched unrelated donor bone marrow transplants are associated with a higher incidence of graft failure and graft-versus-host disease than typically reported for transplants from HLA-identical siblings, but these preliminary data suggest a lower rate of relapse.

Acute Disease↗

Bone marrow transplantation for severe aplastic anemia. Effect of a preparative regimen of cyclophosphamide-low-dose total-lymphoid irradiation and posttransplant cyclosporine-methotrexate therapy.

Twenty-nine patients with severe aplastic anemia were entered into a study of pre- and posttransplant immunosuppressive therapy for bone marrow transplantation. Four of twenty-five previously transfused recipients prepared with cyclophosphamide 200 mg/kg and total-lymphoid irradiation 3 Gy experienced graft failure, indicating that this regimen was inadequate to ensure sustained engraftment. Posttransplant treatment with cyclosporine and methotrexate resulted in an actuarial incidence for grade greater than or equal to 2 graft-versus-host disease of 22 +/- 16%. Actuarial survival was 78 +/- 15%. These data indicate that more effective treatment is necessary to prevent graft failure, but since many patients can be successfully retransplanted, overall survival is comparable to other recent studies.

Adolescent↗

Efficacy of intensive chemotherapy for acute myelogenous leukemia associated with a preleukemic syndrome.

One hundred ninety-six patients with acute myelogenous leukemia (AML) were treated with intensive induction chemotherapy using similar daunorubicin/cytarabine/thioguanine regimens. Treatment results of 44 patients who had a documented preleukemic syndrome or cytopenia present for more than 2 months before developing over AML were compared with 152 patients with de novo AML. Eighteen (41%) patients with preleukemia evolving into AML achieved complete remission compared with 111 (73%) patients with de novo AML (P less than .01). Patients with preleukemia-AML had a significantly longer period to recovery of granulocytes. Multivariate analysis indicated that presence of a previous preleukemic syndrome and advancing age were independent poor prognostic indicators for achieving remission. For patients who achieved remission, disease-free survival and overall survival were also inferior for patients with previous preleukemia; disease-free survival was 17 +/- 17% at 3 years compared with 29 +/- 10% in patients with de novo AML (P = .02). These data indicate that intensive chemotherapy has limited efficacy in patients with AML following a preleukemic syndrome. Durable remissions may be achieved in some patients.

Age Factors↗

Current approaches to management of infections in bone marrow transplants.

Infections continue to be common complications of bone marrow transplantation, but recent advances have improved their outcome. Oral chemoprophylaxis with the fluoroquinolones has reduced gram-negative infections during periods of granulocytopenia, while new triazole drugs show promise for improving antifungal prophylaxis. Similarly, recombinant hematopoietic growth factors may reduce infections by shortening the period of post-transplant granulocytopenia. The efficacy of double beta-lactam antibiotic therapy or monotherapy with imipenem has obviated the need to use aminoglycosides in the empiric treatment of febrile patients receiving cyclosporine or other nephrotoxic agents. Treatment of post-transplant interstitial pneumonia associated with cytomegalovirus (CMV) remains problematic, but recent results using the combination of ganciclovir plus intravenous immune globulin have been favorable. In CMV-seronegative patients, CMV infections and pneumonia can be prevented or modified by using CMV-seronegative blood products and intravenous immune globulin. Intravenous immune globulin also has the additional benefits of modifying graft versus host disease and preventing late bacterial infections after marrow engraftment. In CMV-seropositive patients, prophylactic ganciclovir may prevent CMV reactivation and pneumonia and is the subject of an ongoing controlled clinical trial.

Bone Marrow Transplantation↗

Use of recombinant granulocyte-macrophage colony stimulating factor in the Brazil radiation accident.

8 patients with bone marrow failure after a caesium-137 radiation accident were treated with recombinant human granulocyte-macrophage colony stimulating factor (rHuGM-CSF). The 7 who were evaluable had prompt increases in granulocytes and bone marrow cellularity. 2 patients died of radiation toxicity and haemorrhage and 2 of bacterial sepsis acquired before the start of rHuGM-CSF treatment. 4 patients survive, including 2 who were treated early and never became infected. This therapeutic approach to radiation-induced granulocytopenia may therefore be useful after radiation and nuclear accidents.

Accidents↗