Pulmonary nocardiosis: computed tomography features at diagnosis.

PURPOSE: To review the computed tomography (CT) imaging features of pulmonary nocardiosis (PN) at the time of initial presentation. MATERIALS AND METHODS: All patients from 1991 to 2008 with PN were identified (n=105). Patients without CT scan available at initial presentation were excluded (n=52). For the remaining 53 patients, standardized radiographic features were recorded. The patients were grouped by predisposing condition. Analysis includes descriptive summary statistics as well as associations among radiographic findings, associated findings, and host characteristics. Parametric and nonparametric statistical methods were used. RESULTS: Median age of the patients was 52 years (range, 6 to 82 y). Some form of immunosuppression was present in 83% of the cases. Preexisting structural abnormalities of the lung were uncommon (bronchiectasis, 7; chronic obstructive pulmonary disease, 3). Twenty (38%) patients had interstitial opacities. Airspace disease was seen in 34 (64%) cases. Thirty (57%) cases revealed discrete nodules, 25 patients had 1 to 6 nodules (mean, 2), and 5 patients had fewer than 6 nodules, with the mean size of the largest nodule being 1.67 cm. Masses were seen in 11 patients (21%), 9 of whom had concomitant nodules. Cavitary lesions, including nodules, masses, or airspace disease, occurred in 40% of the cohort. Mediastinal lymphadenopathy was present in 8 (15%) patients. Fifteen patients (28%) had pleural effusions; the effusions were unilateral in 10 patients. Analysis of radiographic associations with patient groups found discrete nodules to be more often associated with immunosuppression compared with the nonimmunosuppressed group (66% vs. 11%; P=0.0067). CONCLUSION: The CT presentation of PN is heterogeneous. Airspace disease appeared most frequently (in 64% of the cases), and nodules were present in 57% of the cases. Nocardiosis should be considered in the differential diagnosis of immunosuppressed patients with new nodules or masses.

Can preemptive cytomegalovirus monitoring be as effective as universal prophylaxis when implemented as the standard of care in patients at moderate risk?

BACKGROUND: Cytomegalovirus (CMV) is a significant cause of morbidity, mortality, and cost in solid organ transplant recipients. This study was conducted to measure both the clinical efficacy and the pharmacoeconomic impact of implementing, as standard of care, an abbreviated preemptive monitoring strategy compared with universal prophylaxis in a large teaching hospital. METHODS: This prospective observational study included only recipients at moderate risk for CMV infection, specifically recipients who were CMV seropositive before transplant. Recipients transplanted between February 2006 and December 2006 received prophylactic valganciclovir for 90 days after transplant, and those transplanted between January 2007 and December 2007 were enrolled in a preemptive monitoring strategy that included no anti-CMV prophylaxis but instead used serial CMV polymerase chain reactions in weeks 4, 6, 8, 10, 12, 16, 20, and 24 to monitor the development of CMV DNAemia. Costs were analyzed from a societal perspective. RESULTS: A total of 130 patients were included in this study. Baseline and transplant demographics are well matched between groups. CMV syndrome occurred in three patients in each group, and one patient in the preemptive group developed CMV disease. Thirty-seven percent of patients in the preemptive group developed CMV DNAemia, 68% of these patients received antiviral therapy. Personnel and laboratory monitoring costs were significantly higher in the preemptive group, whereas medication cost was significantly higher in the prophylaxis group. CONCLUSIONS: Although outcomes and the overall cost of (1) universal prophylaxis and (2) preemptive monitoring are similar, universal prophylaxis places the cost burden on the patient whereas preemptive monitoring shifts the cost burden to the healthcare system.

Steady-state pharmacokinetics of lamivudine in human immunodeficiency virus-infected patients with end-stage renal disease receiving chronic dialysis.

The steady-state pharmacokinetics of lamivudine were evaluated in 11 subjects with human immunodeficiency virus infection and end-stage renal disease, 9 of whom were receiving hemodialysis and 2 of whom were receiving chronic ambulatory peritoneal dialysis (CAPD). All subjects received 150 mg of lamivudine daily for at least 2 weeks prior to sampling for determination of the pharmacokinetics of lamivudine over a 24-h period on 2 consecutive days. On the first day, subjects received 150 mg of oral lamivudine and underwent dialysis (hemodialysis or CAPD). On the second day, subjects received another 150 mg of oral lamivudine but dialysis was not performed. For the subjects undergoing hemodialysis, the geometric mean predose serum lamivudine concentration was 1.14 microg/ml (95% confidence interval [CI], 0.83 to 1.58 microg/ml), the geometric mean maximum concentration in serum (C(max)) was 3.77 microg/ml (95% CI, 3.01 to 4.71 microg/ml), and the geometric mean area under the serum concentration-time curve from time zero to 24 h (AUC(0-24)) was 49.8 microg. h/ml (95% CI 39.1 to 63.6 microg. h/ml). Hemodialysis removed approximately 28 mg of lamivudine but had no significant effect on C(max) or AUC(0-24). In the absence of hemodialysis, the geometric mean lamivudine terminal elimination half-life was 17.2 h (95% CI, 10.5 to 28.1 h), whereas the geometric mean intradialysis half-life of lamivudine was 5.3 h (95% CI, 3.4 to 8.2 h). The pharmacokinetics of lamivudine in subjects undergoing CAPD were similar to those in subjects undergoing hemodialysis. CAPD removed 24 mg of lamivudine over a 24-h period but had no effect on C(max) or AUC(0-24). Pharmacokinetic modeling suggests that a lamivudine dose of 25 mg daily in hemodialysis subjects would provide serum exposure similar to that provided by a dose of 150 mg twice daily in patients with normal renal function.