Kazuhiko Hashinaga

Inhibitory effect of statins on inflammatory cytokine production from human bronchial epithelial cells.

Statins are 3‐hydroxy‐3‐methylglutaryl‐co‐enzyme A reductase inhibitors of cholesterol biosynthesis, and have been reported to exert pleiotropic effects on cellular signalling and cellular functions involved in inflammation. Recent reports have demonstrated that previous statin therapy reduced the risk of pneumonia or increased survival in patients with community‐acquired pneumonia. However, the precise mechanisms responsible for these effects are unclear. In the present study, we examined the effects of statins on cytokine production from lipopolysaccharide (LPS)‐stimulated human bronchial epithelial cells (BEAS‐2B). Interleukin (IL)‐6 and IL‐8 mRNA expression and protein secretion in LPS‐stimulated cells were inhibited significantly by the lipophilic statin pitavastatin and the hydrophilic statin pravastatin. As these inhibitory effects of statin were negated by adding mevalonate, the anti‐inflammatory effects of statins appear to be exerted via the mevalonic cascade. In addition, the activation levels of Ras homologue gene family A (RhoA) in BEAS‐2B cells cultured with pitavastatin were significantly lower than those without the statin. These results suggest that statins have anti‐inflammatory effects by reducing cytokine production through inhibition of the mevalonic cascade followed by RhoA activation in the lung.

Association of sustained high plasma trough concentration of voriconazole with the incidence of hepatotoxicity

BACKGROUND Therapeutic drug monitoring (TDM) of voriconazole is important to optimize efficacy and to minimize toxicity and intolerance. In this study, we evaluated the effect of sustained high plasma trough concentration of voriconazole on the incidence of hepatotoxicity in hospitalized Japanese patients. METHODS Thirty-nine patients were divided into 3 groups according to trough concentrations in two consecutive TDMs: <4 μg/ml in the first TDM (group A, n=25), >4 μg/ml in the first and <4 μg/ml in the second TDM (group B, n=8), and >4 μg/ml in both first and second TDMs (group C, n=6). RESULTS Incidences of hepatotoxicity in groups A, B and C were 16.0, 25.0 and 83.3%, and significant differences were observed between groups A and C and groups B and C. Multiple logistic regression analysis identified the classification into groups A, B and C as an independent variable of hepatotoxicity. CONCLUSIONS These results suggest that sustained high trough concentration of voriconazole may increase the risk of hepatotoxicity, and decreasing trough concentration to <4 μg/ml by dose adjustment after the initial TDM may reduce the incidence of hepatotoxicity in patients treated with voriconazole.

Inhibitory effects of pitavastatin on fibrogenic mediator production by human lung fibroblasts

AIMS Idiopathic pulmonary fibrosis continues to be a devastating clinical disorder for which there are few therapeutic options, and the pathogenesis of this disease remains largely unknown. Statins are inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in cholesterol biosynthesis, and they have been reported to exert pleiotropic effects on the cellular signaling involved in tissue inflammation and in organ fibrosis/remodeling. We examined the preventive effects of statins on fibrogenic mediator expression and production in normal human lung fibroblasts (NHLF). MAIN METHODS NHLF were pretreated with 100nM pitavastatin or medium alone (control), and were then stimulated with transforming growth factor-β1 (TGF-β1). mRNA expression and protein secretion of several mediators from cells were analyzed by real-time polymerase chain reaction, enzyme-linked immunosorbent assay or multiplex assay. KEY FINDINGS TGF-β1-induced expression or production of mediators, such as collagen-1, vascular endothelial growth factor and chemokine C-X-C motif ligand 8, in NHLF pretreated with pitavastatin was significantly suppressed with inhibition of Smad-3 phosphorylation, as compared to untreated controls. In addition, the inhibitory effects of pitavastatin were negated by addition of mevalonate. SIGNIFICANCE Pitavastatin appeared to inhibit TGF-β1-induced fibrogenic mediator production from lung fibroblasts via the mevalonic cascade. Although further evaluation of the signaling pathways for these phenomena is necessary, our results suggest the potential benefits of pitavastatin.

Sensitive and selective quantification of total and free itraconazole and hydroxyitraconazole in human plasma using ultra-performance liquid chromatography coupled to tandem mass spectrometry

OBJECTIVES Protein-free (unbound) drug concentrations have been reported to be better biomarker of pharmacodynamics compared with total drug concentrations. In this study, we developed and validated an assay for the quantification of total and free itraconazole and hydroxyitraconazole, a main metabolite with antifungal activity, in human plasma using ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). DESIGN & METHODS Plasma sample was ultra-filtrated for the measurement of free itraconazole and hydroxyitraconazole concentrations. The samples were prepared by solid phase extraction, and then subject to UPLC-MS/MS quantification. RESULTS The assay fulfilled the requirements of the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) guidelines for assay validation, with a lower limit of quantification of 10ng/mL for total itraconazole and hydroxyitraconazole, and 0.1 and 0.5ng/mL for free itraconazole and hydroxyitraconazole, respectively. Recovery rates of total itraconazole and hydroxyitraconazole from whole plasma ranged from 53.3% to 64.0%, and recovery rates of free itraconazole and hydroxyitraconazole from ultrafiltrated plasma ranged from 81.6% to 98.7%. Matrix effect varied between 79.1% and 109.4% for total itraconazole and hydroxyitraconazole, and between 81.3% and 99.7% for free itraconazole and hydroxyitraconazole. The assay was successfully applied to therapeutic drug monitoring of itraconazole in three patients with chronic progressive pulmonary aspergillosis or invasive pulmonary aspergillosis. Plasma free hydroxyitraconazole concentrations were 8.1-, 23.3-, and 51.1-fold higher than plasma free itraconazole concentrations in the three patients. CONCLUSIONS A method for sensitive and selective quantification of plasma total and free itraconazole and hydroxyitraconazole concentrations was developed using UPLC-MS/MS. Free hydroxyitraconazole concentration may be most important in therapeutic drug monitoring of itraconazole.