High-dose cytarabine (ara-c) may overcome cytarabine resistance in leukemic blasts. It has been used as a successful salvage and in postremission therapy but not as initial induction treatment. Patients aged 15 to 60 years, presenting with newly diagnosed acute myeloid leukemia (AML) were randomized to receive either high-dose cytarabine, 3 g/m2 12 hourly on days 1, 3, 5, and 7 for 8 doses, daunorubicin 50 mg/m2 days 1 to 3, etoposide 75 mg/m2 days 1 to 7, (HIDAC-3–7) or standard dose cytarabine 100 mg/m2 continuous intravenous infusion for 7 days with daunorubicin and etoposide at the same dose and schedule as above (7–3–7). Patients could receive a second or third induction course if complete remission (CR) was not achieved. All patients received the same postinduction consolidation therapy (5–2–5) for 2 courses. Eligible patients had no prior chemotherapy or myelodysplastic disease. Patients have been followed for a median of 4.5 years. Of 301 patients treated, complete response (CR) was achieved in 71% with HIDAC- 3–7 and 74% with 7–3–7. For patients in CR, the estimated median remission duration was 45 months with HIDAC-3–7 and 12 months with 7–3– 7 (P = .0005 univariate analysis, P = .0004 multivariate analysis). The estimated percentage of patients relapse free 5 years after achieving a CR was 49% on HIDAC-3–7 and 24% on 7–3–7. Patients in CR tended to survive longer with HIDAC-3–7 but there were no overall survival differences between the two arms. HIDAC-3–7 was associated with significantly more toxicity in induction with more leukopenia, thrombocytopenia, nausea, and vomiting and eye toxicity (all P < .001) but a similar incidence of severe central nervous system and cerebellar toxicity compared to 7–3–7. The consolidation treatment was the same in both arms but caused significantly more leukopenia and thrombocytopenia in patients previously treated with HIDAC-3–7 induction (P < .0001). We conclude that a dose-effect exists for cytarabine in AML and that HIDAC- 3–7 prolongs remission duration and disease-free survival and is tolerable when used as initial induction therapy in patients with de novo AML.

The 20-hour posttransfusion platelet count determines transfusion policy for patients requiring platelet support, and yet factors influencing the 20-hour count have been poorly defined. The clinical factors influencing both the 1- and 20-hour corrected count increment (CCI), were studied in 623 human leukocyte antigen (HLA)-unmatched platelet transfusions in 108 patients. The 1- and 20-hour CCIs were highly correlated (r = 0.67, p less than 0.001). On average, the 20-hour CCI was 64 percent of the 1-hour CCI. Multiple linear regression analyses identified splenectomy, bone marrow transplantation, disseminated intravascular coagulation, administration of amphotericin B, palpable spleen, and HLA antibody grade as the major factors influencing the 20-hour posttransfusion CCI. Platelet-specific antibodies, number of concurrent antibiotics, clinical bleeding, and temperature did not significantly influence the 20-hour posttransfusion CCI. The 1-hour CCI was the only significant factor influencing the 20-hour CCI in a regression model containing the 1-hour CCI and the above factors. Thus, the same clinical factors exert a major influence on the CCI at both 1 and 20 hours after platelet transfusion, with no evidence that any factor has more influence at 20 hours after transfusion than at 1 hour.

To determine the relative importance of clinical factors on the efficacy of platelet transfusions, 941 pooled platelet transfusions from HLA-unmatched donors were studied prospectively in 133 patients with bone marrow failure. Multiple linear regression analyses identified the major factors influencing one-hour-corrected increments (CI) as prior splenectomy, bone marrow transplantation, disseminated intravascular coagulation, concurrent intravenous amphotericin B, splenomegaly, and HLA antibody grade. The relative impact of these factors on CI has been quantitated by using a formula developed from these data. A linear relationship was demonstrated between increasing percentage of HLA antibody grade and decreasing CI. A number of other factors were less important in the linear regression model than the aforementioned major factors. These included platelet-specific antibodies, concurrent antibacterial antibiotics, clinical bleeding grade, and temperature. Factors that did not influence CI included the number of prior platelet transfusions, prior granulocyte transfusions, prior red cell transfusions, infection, age, blood group, diagnosis, sex, pretransfusion platelet count, prior pregnancies, and concurrent antineoplastic drugs. This study identified major clinical factors that significantly influenced CI and were major causes of refractoriness to pooled platelet transfusions.

Aspergillus colonization is a common phenomenon in adult cystic fibrosis (CF) patients. The clinical significance of Aspergillus for the pathogenesis of CF lung disease remains unclear and factors predisposing to such colonization are still completely unknown. We investigated the prevalence of Aspergillus colonization in 104 adult CF patients who attended our outpatient clinic in 1997. With respect to demographic and clinical data, and antibiotic therapy received, we further examined which factors were associated with Aspergillus colonization in these patients. Repeated investigations of CF sputum samples revealed Aspergillus species in 43/104 (41.3%; 95% confidence interval 30.2-52.5%) of the patients. We found no significant relationship between Aspergillus colonization and age (P > 0.4), gender (P = 0.4), colonization with pseudomonas species (P > 0.6), lower lung function values (P > 0.9), or worse chest radiography (P > 0.1). Surprisingly, the prevalence of Aspergillus colonization was higher in CF patients receiving prophylactic antibiotic therapy (oral antibiotics: P = 0.05; inhalative antibiotics: P = 0.035; both antibiotics: P = 0.048). Prophylactic antibiotics are widely used to eradicate or decrease chronic bronchopulmonary infection in CF. Our results indicate that long-term antibiotic therapy may predispose CF patients to Aspergillus colonization.