Atsuko Iwata

Clinical features of healthcare-associated pneumonia (HCAP) in a Japanese community hospital: Comparisons among nursing home-acquired pneumonia (NHAP), HCAP other than NHAP, and community-acquired pneumonia

Background and objective:  More than 100 000 Japanese die of pneumonia every year. The number of people residing in nursing homes is increasing with the ageing of the population. In 2005, the American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) published important guidelines for the management of healthcare‐associated pneumonia (HCAP). In Japan, however, the optimum strategy for management of HCAP is still unclear. The purpose of this study was to clarify the clinical features of patients with HCAP.

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.

High serum levels of thrombospondin-1 in patients with idiopathic interstitial pneumonia.

Thrombospondin-1 (TSP-1), a multifunctional matricellular glycoprotein, can activate transforming growth factor-beta, an important profibrotic cytokine involved in various fibrotic diseases. TSP-1 is expressed in the lung tissue of animal models of bleomycin-induced pulmonary fibrosis and in patients with some interstitial lung diseases. The present study investigated the serum and bronchoalveolar lavage fluid (BALF) levels of TSP-1 in the idiopathic interstitial pneumonias (IIPs) and the relationship between these levels and other clinical factors. The TSP-1 in the serum and BALF were measured in 45 patients with pathologically diagnosed IIPs [22 with usual interstitial pneumonia (UIP), 23 patients with non-specific interstitial pneumonia (NSIP)], as well as in 28 patients with pulmonary sarcoidosis and 15 healthy volunteers using a competitive enzyme immunoassay. The expression and localization of TSP-1 in the lungs were analyzed by immunohistochemical staining. The serum TSP-1 levels were significantly higher in patients with IIPs than in either those with sarcoidosis or the controls. These levels correlated well with those of an angiogenic cytokine vascular endothelial growth factor while correlating inversely with the %VC. Positive immunostaining of TSP-1 was predominantly observed in the regenerated alveolar epithelium and alveolar macrophages in the lung. Our findings suggest that the circulating TSP-1 levels are associated with the presence of interstitial pneumonia, but further studies are required before we can definitively conclude that TSP-1 plays a role in the pathogenesis of these diseases.

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.

Hemophagocytic lymphohistiocytosis in a human immunodeficiency virus-positive homosexual high school student.

The spread of human immunodeficiency virus (HIV) infection has exploded over the past two decades and such infections in young people are no longer uncommon. However, the major infection route of pediatric patients remains vertical transmission, and sexual, especially homosexual transmission, is highly unusual. We herein describe the case of a 17-year-old boy who developed hemophagocytic lymphohistiocytosis (HLH). Although HLH was remitted soon with dexamethasone therapy, an HIV infection caused by homosexual transmission was detected.