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Biomedical subjects

E A Engels

Publications and source records attributed to E A Engels.

6 recordsLinked to original sources
PubMed1999

Plasma HIV viral load in patients with hemophilia and late-stage HIV disease: a measure of current immune suppression. Multicenter Hemophilia Cohort Study.

BACKGROUND: For patients infected with HIV, plasma HIV viral load in early disease predicts long-term prognosis. However, the implications of viral load measurements late in HIV disease are uncertain. OBJECTIVE: To evaluate the relation between plasma HIV viral load and subsequent risk for disease progression in patients with late-stage HIV disease. DESIGN: Retrospective cohort study. SETTING: 16 treatment centers for patients with hemophilia. PATIENTS: 389 patients with hemophilia and late-stage HIV disease (CD4 count < 200 cells/mm3). MEASUREMENTS: Plasma HIV viral load was measured at baseline. Patients were followed for AIDS-related illnesses (primary outcome) and, specifically, Pneumocystis carinii pneumonia (secondary outcome). RESULTS: HIV viral load strongly predicted AIDS-related illness. For patients with viral loads less than 4.00 log10 copies/mL, the 1-year actuarial risk was 0% and the 5-year risk was 25%. For patients with viral loads of at least 6.00 log10 copies/mL, the 1-year actuarial risk was 42% and the 5-year risk was 78%. A linear relation existed between viral load and risk for AIDS-related illness (hazard ratio, 2.37 per 1og10 copies/mL; P < 0.001). In addition, viral load most strongly predicted risk for illness immediately after viral load testing; this predictive relation attenuated over time (P = 0.002). These findings changed little after adjustment for CD4 cell counts that were updated during follow-up. In the first year after viral load was measured, it predicted occurrence of P. carinii pneumonia (hazard ratio, 4.69 per 1og10 copies/mL; P < 0.001). CONCLUSIONS: In patients with hemophilia and late-stage HIV disease, viral load predicts disease progression independently of CD4 cell counts. Because viral load most strongly predicts progression immediately after load is measured, it seems to reflect the current level of immunosuppression.

AIDS-Related Opportunistic Infections↗
PubMed1999

Early infection in bone marrow transplantation: quantitative study of clinical factors that affect risk.

Infections remain common life-threatening complications of bone marrow transplantation. To examine clinical factors that affect infection risk, we retrospectively studied patients who received bone marrow transplants (53 autologous and 51 allogeneic). Over a median of 27 hospital days, 44 patients developed documented infections. Both autologous transplantation and hematopoietic growth factor use were associated with less prolonged neutropenia and decreased occurrence of infection (P < or = .05). In a survival regression model, variables independently associated with infection risk were the log10 of the neutrophil count (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.32-0.75), ciprofloxacin prophylaxis (HR, 0.42; 95% CI, 0.19-0.95), empirical intravenous antibiotic use (HR, 0.09; 95% CI, 0.03-0.32), and an interaction between neutrophil count and intravenous antibiotic use (HR, 1.86; 95% CI, 1.06-3.29). In this model, infection risk increases steeply at low neutrophil counts for patients receiving no antibiotic therapy. Ciprofloxacin prophylaxis and particularly intravenous antibiotic therapy provide substantial protection at low neutrophil counts. These results can be used to model management strategies for transplant recipients.

Adult↗
PubMed1998

Typhoid fever vaccines: a meta-analysis of studies on efficacy and toxicity.

OBJECTIVE: To estimate the efficacy and toxicity of typhoid fever vaccines. DESIGN: Meta-analysis of randomised efficacy trials and both randomised and non-randomised toxicity studies of the parenteral whole cell, oral Ty21a, and parenteral Vi vaccines. SUBJECTS: 1,866,951 subjects in 17 efficacy trials; 11,204 subjects in 20 toxicity studies. MAIN OUTCOME MEASURES: Pooled estimates of three year cumulative efficacy, year specific efficacy, and incidence of adverse events. RESULTS: Three year cumulative efficacy was 73% (95% confidence interval 65% to 80%) for two doses of whole cell vaccines (based on seven trials); 51% (35% to 63%) for three doses of Ty21a vaccine (four trials); and 55% (30% to 71%) for one dose of Vi vaccine (one trial). For whole cell and Ty21a vaccines, regimens of fewer doses were less effective. Efficacy was shown to be significant for five years for whole cell vaccines, four years for Ty21a vaccine, and two years for Vi vaccine. Neither the age of vaccine recipient nor the incidence of typhoid fever in the control group (varying from 6 to 810 cases per 100,000 person years) affected the efficacy of the whole cell or Ty21a vaccines. After vaccination, fever occurred in 15.7% (11.5% to 21.2%) of whole cell vaccine recipients, 2.0% (0.7% to 5.3%) of Ty21a vaccine recipients, and 1.1% (0.1% to 12.3%) of Vi vaccine recipients. CONCLUSIONS: Whole cell vaccines are more effective than the Ty21a and Vi vaccines but are more frequently associated with adverse events. Whether the added efficacy of the whole cell vaccines outweighs their toxicity will depend on the setting in which vaccination is used.

Administration, Oral↗
PubMed1998

Efficacy of quinolone prophylaxis in neutropenic cancer patients: a meta-analysis.

PURPOSE: To perform a meta-analysis to estimate the efficacy of quinolone antibiotics in preventing infections, fevers, and deaths among cancer patients neutropenic following chemotherapy. METHODS: We searched MEDLINE to identify randomized trials of quinolone prophylaxis, controlled either with no prophylaxis or trimethoprim/sulfamethoxazole (TMS) prophylaxis. We pooled relative risks for outcomes using a random-effects model. RESULTS: Eighteen trials with 1,408 subjects were included. Compared with no prophylaxis, quinolones significantly reduced the incidence of gram-negative bacterial infections (relative risk, 0.21; 95% confidence interval [CI], 0.12 to 0.37), microbiologically documented infections (0.65; 0.50 to 0.85), total infections (0.54; 0.31 to 0.95), and fevers (0.85; 0.73 to 0.99). Quinolone prophylaxis did not alter the incidence of gram-positive bacterial, fungal, or clinically documented infections, or infection-related deaths. Results were similar for trials that used TMS as the control regimen. Among those who received quinolones, the incidence of infections due to quinolone-resistant organisms was 3.0% (95% CI, 1.7% to 5.2%) for gram-negative species and 9.4% (95% CI, 5.3% to 16.3%) for gram-positive species. Based on limited data, the incidence of quinolone-resistant infections was not higher among quinolone recipients than controls. With fever as outcome, blinded trials found quinolones less efficacious than did unblinded trials. CONCLUSION: Quinolone prophylaxis substantially reduces the incidence of various infection-related outcomes, but not deaths, in these patients. Although this reduction in infections may translate into a decrease in morbidity, the reduction in fevers (and by extension, use of empiric antibiotics) appears small, and blinded trials provided less evidence for benefit than unblinded trials. Quinolone-resistant infections are uncommon, but continued vigilance is warranted.

Anti-Infective Agents↗