High-Resolution Melting Assay for Genotyping Variants of the CYP2C19 Enzyme and Predicting Voriconazole Effectiveness.

Voriconazole is a triazole antifungal agent recommended as primary treatment for invasive aspergillosis, as well as some other mold infections. However, it presents some pharmacokinetic singularities that lead to a great variability intra- and interindividually, nonlinear pharmacokinetics, and a narrow therapeutic range. Most experts have recommended tracing the levels of voriconazole in patients when receiving treatment. This azole is metabolized through the hepatic enzyme complex cytochrome P450 (CYPP450), with the isoenzyme CYP2C19 being principally involved. Allelic variations (polymorphisms) of the gene that encodes this enzyme are known to contribute to variability in voriconazole exposure. Three different allelic variants, CYP2C19*17, CYP2C19*2, and CYP2C19*3, could explain most of the phenotypes related to the voriconazole metabolism and some of its pharmacokinetic singularities. We designed a rapid molecular method based on high-resolution melting to characterize these polymorphisms in a total of 142 samples, avoiding sequencing. Three PCRs were designed with similar cycling conditions to run simultaneously. The results showed that our method represents a fast, accurate, and inexpensive means to study these variants related to voriconazole metabolism. In clinical practice, this could offer a useful tool to individually optimize therapy and reduce expenses in patients with fungal infections.

Galactomannan in bronchoalveolar lavage fluid for diagnosis of invasive aspergillosis in non-hematological patients.

BACKGROUND: The role of galactomannan (GM) in serum or bronchoalveolar lavage fluid (BALF) for the diagnosis of invasive pulmonary aspergillosis (IPA) has been extensively evaluated in hematological patients, however its performance in non-hematological patients is not well established. METHODS: We performed a multicenter retrospective study in 3 university hospitals in Madrid, Spain between 2010 and 2014. The study population comprised patients with chronic obstructive pulmonary disease (COPD) and patients with immunosuppressive conditions in whom IPA was suspected and for whom BALF GM was available. Patients with hematological disorders were excluded. RESULTS: A total of 188 patients (35 with COPD and 153 with immunosuppressive conditions) were analyzed, and 31 cases of IPA (proven or probable) were identified. The global sensitivity of BALF GM (optical density index [ODI] ≥ 1.0) was 77.4%; sensitivity was higher in patients with immunosuppressive conditions than in patients with COPD (81.8% vs 66.7%; p: 0.38). In COPD patients, the best performance was obtained for BALF GM (ODI ≥ 0.5), although sensitivity (88.9%) was similar to that of BALF fungal culture (88.9%). The sensitivity of GM in serum was very poor in both populations (36.4% and 11.6%, respectively). CONCLUSIONS: In the present series, the diagnostic performance of BALF GM was good for IPA in non-hematological patients, especially in patients with immunosuppressive conditions.

Emerging trends in candidemia: a higher incidence but a similar outcome.

The clinical presentation and outcome of candidemia has changed in recent years. We compared two 5-year periods (2000-2004 and 2005-2009) in a single institution. We recorded 419 candidemia episodes during the study period (124 in the first period and 295 in the second period). We observed a significant increase in the number of cases per 1000 admissions per year, from 0.57 in 2000 to 1.52 in 2009 (χ(2) LT <0.001). Candida albicans was the most frequently isolated species (42.2%), followed by Candida parapsilosis (34.4%) and Candida glabrata (12.9%). In the second period, episodes were associated with higher comorbidity and were more commonly nosocomial, with a more frequent catheter-related source and an increased rate of C. glabrata infection. No significant differences were observed in susceptibility by species during the study period. According to multivariate analysis, the independent factors associated with higher mortality were shock, age >50 years, elevated comorbidity score (Charlson index >6), and source of candidemia other than catheter. In contrast to the increase in comorbid conditions observed in recent years, mortality remained similar during both periods (~37% during the first month). This finding could be attributed to a significant increase in catheter-related candidemia and better outcome, as well as to a potential improvement in the management of antifungal therapy in recent years.