ABSTRACT
PURPOSE: Fidaxomicin use in real-world clinical practice, especially for severe Clostridium difficile infection (CDI), is mainly based on single-center observational studies. The purpose of this pharmacoepidemiology study was to assess outcomes of patients given fidaxomicin based on episode number and use of concomitant antibiotics. METHODS: Fidaxomicin use over time across included hospitals in the United States was assessed using a large inpatient drug utilization database. A multicenter retrospective chart review was also conducted of hospitalized patients with CDI that received fidaxomicin between 2011 and 2013. Fidaxomicin utilization and clinical outcomes were stratified by use of fidaxomicin for first or second episode (early episodes) versus greater than or equal to episodes (later episodes). RESULTS: The overall fidaxomicin use rate was 2.16 % which increased from 0.22 % in the last two quarters of 2011 to 3.16 % in the first two quarters of 2013. A total of 102 hospitalized patients that received fidaxomicin from 11 hospitals were identified in the multicenter study. Sixty-nine patients received fidaxomicin for early (68 % with severe CDI) and 33 received for later episodes. The majority of patients received other CDI therapy including 61 patients (88 %) for early episodes and 27 (82 %) for later episodes. Concomitant non-CDI antibiotics were received by 48 patients (47 %). Rates of clinical outcomes were similar regardless of CDI episode. CONCLUSION: This study demonstrated a slow but steady increase in fidaxomicin utilization over time; most of which was combined with other systemic antibiotics. Antimicrobial stewardship teams should provide guidance on appropriate use of fidaxomicin to optimize therapy and assess the need to continue other antibiotics during CDI treatment.
ABSTRACT
OBJECTIVE: The premature atherosclerosis seen in patients with systemic lupus erythematosus (SLE) is not explained by traditional risk factors. SLE disease activity, such as renal involvement and presence of autoantibodies, is associated with elevated serum levels of type I interferon (IFN-I), a family of cytokines with potent antiviral and antiproliferative effects. This study was undertaken to test the hypothesis that elevated IFN-I levels could lead to endothelial dysfunction, a surrogate for cardiovascular disease, by causing a reduction in the number of endothelial progenitor cells (EPCs), bone marrow-derived cells that participate in endothelial repair. METHODS: EPCs were enumerated in the peripheral blood of SLE patients (n = 70) and healthy controls (n = 31), using a colony-forming assay. Serum IFN-I levels were quantified by real-time polymerase chain reaction measurement of the expression of the IFN-I-inducible gene MX1. Endothelial function was determined by peripheral arterial plethysmography. RESULTS: SLE patients had markedly reduced levels of EPC colony-forming units compared with controls (median 5.7/ml peripheral blood [interquartile range 1.9-12.8] versus 28.5/ml peripheral blood [14.7-47.3]; P < 0.0001), and the depletion of EPCs was more dramatic in patients with elevated levels of IFN-I. Stepwise multiple regression analysis showed that MX1 expression and serum levels of C-reactive protein were independently associated with the reduction of EPCs. Importantly, high IFN-I levels were associated with impaired endothelial function in patients with SLE. CONCLUSION: These data support the novel hypothesis that depletion of EPCs caused by excessive IFN-I may be linked to endothelial dysfunction and increased cardiovascular risk in SLE.
