Ayumu Takahashi

Osteopontin is involved in migration of eosinophils in asthma

Background Osteopontin (OPN) is an extracellular matrix protein with a wide range of functions, and is involved in various inflammatory diseases. However, the role of OPN in eosinophilic airway inflammation is unclear.

Genetic variants in the mannose receptor gene ( MRC1 ) are associated with asthma in two independent populations

Mannose receptor is a member of the C-type lectin receptor family involved in pathogen molecular pattern recognition and thought to be critical in shaping host immune responses and maintaining homeostasis. The aim of this study was to investigate potential associations of genetic variants in the MRC1 gene with asthma in two independent populations. Seven single-nucleotide polymorphisms (SNPs; rs2477637, rs2253120, rs2477631, rs2477664, rs692527, rs1926736, and rs691005) in the MRC1 gene locus were genotyped and evaluated regarding association with asthma in 870 unrelated Japanese subjects (446 asthmatics, 424 controls). The same markers were validated in 176 unrelated African–American subjects (86 asthmatics, 90 controls). Suggestive evidence of association between five SNPs (rs2477637, rs2253120, rs2477664, rs692527, and rs1926736) and asthma was observed in the analysis of the Japanese population independent of sex, age, smoking status, and atopic status. SNPs rs692527 and rs691005 showed significant association with asthma in the African–American population. Haplotypes containing two linked SNPs (rs692527 and rs1926736) were significantly associated with asthma in both Japanese and African–American populations. Our results suggest that sequence variations in the MRC1 gene are associated with the development of asthma in two independent and ethnically diverse populations.

Genetic variants in mannose receptor gene (MRC1) confer susceptibility to increased risk of sarcoidosis.

BackgroundMannose receptor (MR) is a member of the C-type lectin receptor family involved in pathogen molecular-pattern recognition and thought to be critical in shaping host immune response. The aim of this study was to investigate potential associations of genetic variants in the MRC1 gene with sarcoidosis.MethodsNine single nucleotide polymorphisms (SNPs), encompassing the MRC1 gene, were genotyped in a total of 605 Japanese consisting of 181 sarcoidosis patients and 424 healthy controls.ResultsSuggestive evidence of association between rs691005 SNP and risk of sarcoidosis was observed independent of sex and age in a recessive model (P = 0.001).ConclusionsThese results suggest that MRC1 is an important candidate gene for sarcoidosis. This is the first study to imply that genetic variants in MRC1, a major member of the C-type lectin, contribute to the development of sarcoidosis.

A functional polymorphism (-603A → G) in the tissue factor gene promoter is associated with adult-onset asthma.

Tissue factor (TF) is important for initiation of coagulation and for the increased thrombin activity observed at sites of inflammation. Thrombin activity is induced by allergen challenge in asthmatic airways and is involved in the pathogenesis of asthma. A −603A → G polymorphism (rs1361600) in the promoter region of the TF gene has been associated with serum TF levels and with the development of cardiovascular diseases. The aim of this study was to determine whether the functional −603A → G polymorphism has genetic influences on the development of asthma. Case–control analysis was performed of the association between six common single-nucleotide polymorphisms (SNPs), including the −603A → G polymorphism, at the TF gene, and the development of asthma, using two unrelated Japanese populations. In the primary population (n=826), the GG genotype at the −603A → G polymorphism was associated with adult-onset asthma (onset at ⩾21 years of age) (odds ratio (OR) 2.886, P=0.0231). A second population showed a similar tendency (n=1654, OR 1.602, P=0.064). Transcriptional activity of promoters with −603A → G genotypes were examined using luciferase promoter assays. The −603G allele was associated with higher promoter activity (P<0.05). The association between the functional polymorphism (−603A → G) in the TF gene promoter and adult-onset asthma indicates that TF is a candidate gene contributing to asthma susceptibility.

Regulatory role of DC-derived osteopontin in systemic allergen sensitization

Osteopontin (OPN) is a secreted phosphoglycoprotein with a wide range of functions, and is involved in various pathophysiological conditions. However, the role of OPN in IgE and Th2‐associated allergic responses remains incompletely defined. The aim of this study was to elucidate the role of OPN in systemic allergen sensitization in mice. When compared with OPN+/+ mice, significantly increased levels of OVA‐induced IgE were found in OPN−/− mice. OPN−/− DC demonstrated an increased capacity to enhance Th2 cytokine production in CD4+ T cells from sensitized OPN+/+ mice. Furthermore, significantly reduced levels of IL‐12p70 expression were seen in LPS‐stimulated OPN−/− DC as compared with the WT DC, and the reduction was reversible by the addition of recombinant OPN (rOPN). rOPN was able to suppress OVA‐induced IL‐13 production in the cultures of CD4 and OPN−/− DC, but this inhibitory activity was neutralized by the addition of anti‐IL‐12 Ab. In addition, administration of rOPN in vivo suppressed OVA‐specific IgE production; however, this suppressive effect was abrogated in IL‐12‐deficient mice. These results indicate that DC‐derived OPN plays a regulatory role in the development of systemic allergen sensitization, which is mediated, at least in part, through the production of endogenous IL‐12.

Necrotizing Sarcoid Granulomatosis Presenting with Elevated Serum Soluble Interleukin-2 Receptor Levels

A 52-year-old woman presented with a one-week history of low-grade fever and dyspnea. A CT scan showed multiple pulmonary nodules with cavitation, as well as bilateral pleural thickenings with effusions. A specimen resected by video-assisted thoracoscopic surgery showed multiple confluent granulomas with central necrosis and granulomatous vasculitis. These findings were consistent with necrotizing sarcoid granulomatosis. An elevated serum soluble interleukin-2 receptor level became normal following clinical and radiological improvement. This indicates that the serum soluble interleukin-2 receptor can be a useful marker for the clinical management of necrotizing sarcoid granulomatosis.

Genetic Impact of a Butyrophilin-like 2 (BTNL2) Gene Variation on Specific IgE Responsiveness to Dermatophagoides farinae (Der f) in Japanese

BACKGROUND Dermatophagoides farinae (Der f) is one of the most frequently implicated allergens in several allergic diseases. Several genome-wide screens have identified a linkage between chromosome 6p21 and mite-specific IgE responsiveness. Butyrophilin-like 2 (BTNL2) is a member of the immunoglobulin superfamily and, on the basis of its homology to B7-1, has been implicated as a costimulatory molecule involved in T-cell activation. BTNL2 resides in the HLA region on chromosome 6p21, and significant associations between BTNL2 gene polymorphisms and several inflammatory diseases have been reported. OBJECTIVE The aim of this study was to examine whether BTNL2 gene polymorphisms are associated with specific IgE responses to Der f. METHODS Three single nucleotide polymorphisms (SNPs), including 2 coding SNPs and 1 intron SNP, were studied. One of the coding SNPs was the rs2076530 A > G, which has a functional consequence. A total of 863 unrelated Japanese subjects (447 positive and 416 negative for IgE to Der f) were recruited for a case-control study. RESULTS Controlling for gender, age, smoking, and the presence of asthma, multiple logistic regression analyses showed that homozygosity of the rs2076530 A allele, which has been reported to be a risk allele for sarcoidosis, was associated with a risk of sensitization towards Der f (Odds ratio; 1.55, p = 0.0060). CONCLUSIONS Although an association which may be due to the linkage disequilibrium with other genes in 6p21 needs to be ruled out, the present findings suggest that the BTNL2 gene might be one of the candidate genes that is responsible for the pathogenesis of Der f-specific IgE responsiveness.

The ATS/ERS/JRS/ALAT statement “IPF by HRCT” could predict acute exacerbation of interstitial lung disease in non-small cell lung cancer

Introduction Patients with non-small cell lung cancer (NSCLC) and interstitial lung disease (ILD) are at high risk of acute exacerbation of ILD (AE-ILD) when treated with systemic chemotherapy. Standard treatment for NSCLC complicated by ILD has not been established. Purpose and methods To examine whether the type of ILD categorized by the official ATS/ERS/JRS/ALAT statement as “idiopathic pulmonary fibrosis (IPF) by high-resolution computed tomography (HRCT)” could predict chemotherapy-induced AE-ILD in NSCLC patients with ILD, we retrospectively reviewed all patients with NSCLC complicated by ILD who had received chemotherapy at our institute from January 2007 until December 2013. Patients’ characteristics, pathology and clinical staging of lung cancer, chemotherapy, type of ILD and AE-ILD during chemotherapy were evaluated. ILD was classified according to the statement as follows: usual interstitial pneumonia (UIP), possible UIP, and inconsistent with a UIP pattern. Results A total of 46 patients had pre-existing ILD and received chemotherapy. The mean age was 73 years (range 46-83 years). Fifteen (32.6%) of 46 patients with ILD developed chemotherapy-induced AE-ILD, which was seen more frequently in patients with ILD with a UIP pattern or possible UIP pattern than in patients with a pattern inconsistent with UIP (80% versus 9.7%, p<0.001). Multivariate analyses including age, sex, performance status and radiographic patterns of ILD showed that the presence of a UIP or possible UIP pattern was an independent risk factor for chemotherapy-induced AE-ILD. Conclusions ILD with a UIP pattern or possible UIP pattern by the classification could be a risk factor for AE-ILD in NSCLC patients with ILD.

The role of atopy in the clinical course of pulmonary sarcoidosis in the Japanese population

Sarcoidosis is a multisystem disorder characterized by a T-helper 1 (Th1)-mediated immune response. Conversely, atopy is characterized by the presence of a specific immunoglobulin E (IgE) E response in association with a Th2-type immune response. Several epidemiological studies have shown that atopic status influences disease activity and clinical course for several Th1-mediated diseases. The aim of this study was to evaluate associations between atopic status and clinical findings of sarcoidosis. We further evaluated the impact of atopic status on the clinical course of pulmonary sarcoidosis. We defined atopy as a positive specific IgE response to at least one common inhaled allergen (multiple antigen simultaneous test scores, lumicount of >1.01). Subjects comprised 134 patients given a diagnosis of sarcoidosis between 2000 and 2006, divided into atopic and nonatopic groups. Several clinical findings were compared between the two groups. Furthermore, 100 subjects observed 2 years after diagnosis were divided into resolving and persistent clinical course groups according to chest radiography and associations with atopic status were evaluated. Atopy was more prevalent among men than women (p = 0.009) and subjects with atopy were younger (p = 0.002) and showed less frequent lung parenchymal lesions (stages II and III; p = 0.018) compared with subjects without atopy. The prevalence of atopy was higher in the resolving clinical course group than in the persistent clinical course group (p = 0.002) and this association was independent of sex, age, presence of lung parenchymal lesions, and presence of extrapulmonary lesions (p = 0.037). Classification of sarcoidosis based on atopic status might be useful for predicting the clinical course of pulmonary sarcoidosis.

Interstitial Lung Disease after Pleurodesis for Malignant Pleural Effusion

Objective Pleurodesis is an effective therapy for malignant pleural effusion (MPE). While interstitial lung disease (ILD) has been regarded as a serious complication of pleurodesis, its clinicopathological characteristics have not been fully understood. This study was conducted to elucidate the incidence of ILD and the risk factors for ILD in patients who underwent pleurodesis to control MPE. Methods The medical records of patients who underwent pleurodesis in Aichi Medical University between March 2008 and February 2013, the period before the approval of talc in Japan, were retrospectively analyzed. Results A total of 84 patients underwent pleurodesis, all using OK-432. ILD occurred in 13 patients (15.5%). The development of ILD after pleurodesis was significantly associated with old age (odds ratio [OR]: 4.82, 95% confidence interval [CI]: 1.22-19.08) and epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment (OR: 5.97, CI: 1.7-20.9). A multivariate analysis revealed that >67 years of age (p=0.01) and EGFR-TKI treatment (p=0.02) were significantly associated with the development of pleurodesis-related ILD. Among the patients who received both pleurodesis and EGFR-TKIs (n=23), 8 patients developed ILD. All of these patients were receiving EGFR-TKI therapy at the time of pleurodesis or within 30 days after pleurodesis. In contrast, no cases of ILD were observed among the patients who stopped EGFR-TKIs before pleurodesis or started EGFR-TKIs at more than 30 days after pleurodesis. Conclusion ILD seemed to be a frequent complication of pleurodesis in patients using OK-432, especially elderly patients and those who underwent pleurodesis while receiving EGFR-TKI therapy or who started EGFR-TKI therapy within 30 days after pleurodesis.