IL4Rα and ADAM33 as genetic markers in asthma exacerbations and type-2 inflammatory endotype.

BACKGROUND: Genetic markers of susceptibility to asthma exacerbations in adults remain unclear. OBJECTIVE: To identify genetic markers of asthma exacerbations, particularly in patients with type-2 inflammatory endotype. METHODS: In this observational study of patients enrolled in the Kinki Hokuriku Airway disease Conference multicenter study, frequency of exacerbations requiring systemic corticosteroids during 2 years after enrolment and associated risk factors was determined. For genetic marker analysis, interleukin-4 receptor α (IL4RA) rs8832 and a disintegrin and metalloprotease 33 (ADAM33) S_2 (rs528557), T_1 (rs2280091), T_2 (rs2280090), and V_4 (rs2787094) variants were included. Elevated serum periostin levels at enrolment (≥95 ng/mL, defined as type-2 inflammatory endotype) were considered in the analysis. RESULTS: Among 217 patients who were successfully followed up for 2 years after enrolment, 60 patients showed at least one asthma exacerbation during the 2 years. Airflow limitation (%FEV1 <80%) and recent exacerbations but not genetic variants were identified as risk markers of exacerbations. A total of 27 patients showed type-2 inflammatory endotype (serum periostin ≥95 ng/mL at enrolment) and subsequent exacerbations; risk factors in these patients were airflow limitation (odds ratio, 6.51; 95% confidence interval (CI): 2.37-18.6; P=.0003), GG genotype of IL4RA rs8832 (odds ratio, 4.01; 95% CI: 1.47-11.0; P=.007), and A allele of ADAM33 T_2 (odds ratio, 2.81; 95% CI: 1.05-7.67; P=.04) by multivariate analysis. In addition, GG genotype of IL4RA rs8832 was associated with type-2 endotype, whereas A allele of ADAM33 T_2 was associated with mixed type of eosinophilic/type-2 and neutrophilic inflammations. CONCLUSIONS AND CLINICAL RELEVANCE: IL4RA and ADAM33 variants may be risk markers of asthma exacerbations in type-2 inflammatory endotype. Precise endotyping may facilitate the identification of genetic risk markers of asthma exacerbations.

Recent advance in investigation of gene polymorphisms in Japanese patients with aspirin-exacerbated respiratory disease.

Aspirin-exacerbated respiratory disease (AERD) is a complex clinical syndrome characterised by severe asthmatic attack upon treatment with aspirin and/or non-steroidal anti-inflammatory drugs (NSAIDs). Genetic predisposition has been considered as a crucial determinant and candidate genes have concentrated especially on cysteinyl leukotrienes (LTs)-related genes as the inhibitory action of aspirin and NSAIDs on cyclooxygenase activity may cause overproduction of cysteinyl LTs. However, conflicting results have been reported, in parallel with replication studies in different ethnic groups. Thus, future areas of investigations need to focus on comprehensive approaches towards the discovery of other genetic biomarkers. Unfortunately, few papers have been reported about gene polymorphisms in Japanese patients with AERD. Here, we described on our recent genetic investigations on B2ADR, IL-13, IL-17A, CYP2C19, TBXA2R, CRTH2 and HSP70. This review indicates potential genetic biomarkers contributing to the early diagnosis of AERD, which may include CYP2C19 and HSP70 gene polymorphisms, and future validation studies in independent population are required to provide reassurance about our findings.

GLCCI1 variant accelerates pulmonary function decline in patients with asthma receiving inhaled corticosteroids.

BACKGROUND: In steroid-naive patients with asthma, several gene variants are associated with a short-term response to inhaled corticosteroid (ICS) treatment; this has mostly been observed in Caucasians. However, not many studies have been conducted for other ethnicities. Here, we aimed to determine the relationship between the annual decline in forced expiratory flow volume in one second (FEV1 ) and the variant of the glucocorticoid-induced transcript 1 gene (GLCCI1) in Japanese patients with asthma receiving long-term ICS treatment, taking into account the effect of high serum periostin levels, a known association factor of pulmonary function decline and a marker of refractory eosinophilic/Th2 inflammation. METHODS: In this study, 224 patients with asthma receiving ICS treatment for at least 4 years were enrolled. The effects of single-nucleotide polymorphisms (SNPs) in GLCCI1, stress-induced phosphoprotein 1 (STIP1), and T gene on the decline in FEV1 of 30 ml/year or greater were determined. RESULTS: Besides the known contributing factors, that is, the most intensive treatment step, ex-smoking, and high serum periostin levels (≥95 ng/ml), the GG genotype of GLCCI1 rs37973, and not other SNPs, was independently associated with a decline in FEV1 of 30 ml/year or greater. When patients were stratified according to their serum periostin levels, the GG genotype of rs37973 was significantly associated with blood eosinophilia (≥250/µl) in the high serum periostin group. CONCLUSIONS: A GLCCI1 variant is a risk factor of pulmonary function decline in Japanese patients with asthma receiving long-term ICS treatment. Thus, GLCCI1 may be associated with response to ICS across ethnicities.

Interferon-inducible gene family 1-8U expression in colitis-associated colon cancer and severely inflamed mucosa in ulcerative colitis.

Persistent severe inflammation in colonic mucosa is thought to cause the development of colon cancer in patients with ulcerative colitis (UC). However, predisposing genetic abnormalities have not been identified in this sequence. Using differential display PCR, we isolated cDNA fragments corresponding to mRNAs that were differentially expressed in colitis-associated cancer tissues and mucosa with mild inflammation in the colon of five UC patients. This molecular screening approach identified 60 cDNA fragments, and we sequenced 34 fragments. One cDNA fragment, which is identical to IFN-inducible gene family 1-8U, was strongly expressed in all five UC-associated cancers. 1-8U was also expressed in sporadic colon cancer tissues and colon cancer cell lines, but not in normal mucosa. This gene was strongly expressed in severely inflamed colonic mucosa of UC without colitis-associated colon cancer, although 1-8U expression was not related to the extent and duration of the disease. However, 1-8U was expressed in the colonic mucosa of all patients with chronic, continuously severe inflammation. These results indicated that IFN-inducible gene family 1-8U expression in inflamed colonic mucosa might be used as a preferential marker of colitis-associated colon cancer in UC.

Analyses of bronchoalveolar lavage fluid (BALF) in MRL-lpr/lpr mice.

We performed bronchoalveolar lavage (BAL) in MRL-lpr/lpr (MRL/l) and MRL- +/+ (MRL/n) mice and evaluated various cellular and humoral components of the bronchoalveolar lavage fluid (BALF) to clarify the pathogenic mechanism of pulmonary fibrosis in MRL/l mouse. The numbers of macrophages, neutrophils and lymphocytes, N-Acetyl-beta-glucosaminidase (beta-NAG), and fibronectin increased in the BALF from MRL/l mice than that from MRL/n mice, but no significant differences were observed in total protein, beta-glucuronidase, acid phosphatase, or phospholipid level. Increased fibronectin level in the BALF from MRL/l mice may be related with pathogenesis of pulmonary fibrosis.

Reversibility of hepatic fibrosis: from the first report of collagenase in the liver to the possibility of gene therapy for recovery.

Since the authors reported the presence of collagenase in the liver as well as its increased activity in the early stage of hepatic fibrosis and its reduced activity in advanced fibrosis in rats induced by chronic CCl4 intoxication, in baboons fed alcohol chronically and in patients with alcoholic fibrosis, other investigators have demonstrated the same tendency of collagenase activity biologically and histochemically. Very recently, the authors demonstrated definite gene expression of collagenase during the recovery from experimental hepatic fibrosis using Northern blotting and in situ hybridization. The findings of in situ hybridization not only demonstrated the cells expressing collagenase, but also suggested much information on the mechanism of the recovery from fibrosis. Hepatic stellate cells play a key role not only in fibrogenesis but also in fibrolysis. The authors' recent observation revealed that collagenase (matrix metalloproteinase-13 (MMP-13)) gene expression appears very early in the process of recovery from liver fibrosis, and that both stellate cells and hepatocytes express MMP-13. Recovery from liver cirrhosis requires the gene expression of collagenase, increased production of the collagenase enzyme, and activation of the enzyme balanced with the specific inhibitors of collagenase. The understanding of molecular mechanisms of MMP-1 gene expression which is under investigation in our laboratory may provide us a new strategy for the treatment of liver fibrosis including the possibility of gene therapy.

Increased expression of tumor necrosis factor-alpha, interleukin-6, platelet-derived growth factor-B and granulocyte-macrophage colony-stimulating factor mRNA in cells of bronchoalveolar lavage fluids from patients with sarcoidosis.

Cytokines released from activated alveolar macrophages and T-lymphocytes affect the accumulation of monocyte-macrophage-lineage cells and therefore play an important role in the formation of sarcoid granuloma. Although it is likely that certain monokines and lymphokines are involved in the development of sarcoid granulomas, the evidence for this is not unequivocal. In an attempt to clear critical cytokines in the development and maintenance of sarcoid granuloma, we have measured the level of seven cytokine mRNA (TNF-alpha, IL-6, IL-8, TGF-beta, PDGF-B, IFN-gamma, and GM-CSF) in cells obtained by BAL from sarcoidosis patients and normal subjects. To detect cytokine mRNA, we employed a reverse transcription-polymerase chain reaction. We report that the levels of TNF-alpha, IL-6, PDGF-B and GM-CSF mRNA were significantly increased in BAL cells from the patients with pulmonary sarcoidosis compared to controls. No significant differences were observed in the mRNA expression of IL-8, TGF-beta and IFN-gamma. A significant correlation of the expression of the mRNA levels of seven cytokines in the same patients with sarcoidosis was observed between IL-8 and TNF-alpha, PDGF-B, and IL-6, IL-8 and IL-6 and TFN-alpha and PDGF-B and IL-8. This finding indicates that at least these four cytokines are involved in the cytokine network at the local alveolar site of chronic granulomatous inflammation. This study adds a report to the literature that supports a role for cytokine, TNF-alpha, IL-6, PDGF and GM-CSF in particular, in the promotion and maintenance of sarcoid granulomatous inflammation.

Effects of pranlukast, a cysteinyl leukotriene antagonist, on bronchial responsiveness to methacholine in aspirin-intolerant asthmatics treated with corticosteroids.

Cysteinyl leukotrienes (cysLTs) are considered to be the most important mediator involved in the pathogenesis of aspirin-intolerant asthma (AIA). However, the role of cysLTs in the baseline condition of the pathophysiology of AIA when not exposed to non-steroidal antiinflammatory drugs (NSAIDs) as well as that in the pathophysiology of aspirin-tolerant asthma remains to be elucidated. Therefore, we evaluated the effect of pranlukast, a potent, selective cysLT receptor antagonist, on bronchial responsiveness to methacholine, a non-specific stimulus, in 7 well-controlled aspirin-intolerant asthmatics receiving oral or inhaled corticosteroid treatment. Pranlukast was orally administered at a dose of 225 mg twice daily to all patients for 4 weeks, and the methacholine challenge test was performed before and after pranlukast treatment. The methacholine provocative concentration producing a 20% fall in forced expiratory volume in 1 second (PC20-FEV1) was calculated as an index of bronchial hyperresponsiveness (BHR). The geometric mean values of PC20-FEV1 significantly (p = 0.028) increased from 0.34 mg/dl to 0.61 mg/dl after pranlukast treatment. No significant differences were observed in the baseline values of forced vital capacity (FVC) or FEV1 before and after pranlukast treatment. These findings suggest that antagonism of endogenous cysLT by pranlukast may be responsible for the improvement of BHR to methacholine.

Pranlukast, a cysteinyl leukotriene antagonist, reduces serum eosinophil cationic protein levels in patients with asthma.

Cysteinyl leukotrienes (cysLTs) are considered to be important mediators involved in bronchial asthma and the ensuing eosinophilic inflammation. We evaluated the effects of pranlukast, a potent and selective cysLT receptor antagonist, on the clinical course and serum eosinophil cationic protein (ECP) levels of 10 asthmatic patients. A four-week administration of pranlukast increased the morning peak expiratory flow (PEF) (p = 0.007) and decreased as-needed beta 2-agonist use (p = 0.021). Changes in the morning PEF inversely correlated with those in the serum ECP levels (r = -0.80, p = 0.0057). These results suggest that cysLTs are important mediators involved in eosinophilic inflammation, a major pathophysiologic feature of bronchial asthma in humans.

[A statistical investigation of the influence of allergic factors on intractable asthma by multiple factor analysis].

The relationships of the development of intractability in bronchial asthma with 11 factors, namely 1) sex, 2) age of onset, 3) duration of the disease, 4) severity of the disease, 5) disease type, 6) family history within the third degree of consanguinity, 7) history of smoking, 8) history of atopic dermatitis, 9) history of allergic rhinitis, 10) history of chronic sinusitis and 11) history of nasal polyp were studied by multiple factor analysis in 95 patients. The severity of the disease was shown to be the most important factor in whether the disease becomes intractable or not, followed by the age of onset. The history of atopic dermatitis had the least influence, and the influences of the other factors were not markedly different from one another. Evaluation of each factor according to the category score suggested that severe or moderate non-atopic bronchial asthma in males with a positive family history and positive histories of smoking, chronic sinusitis, nasal polyp and atopic dermatitis within a short period after the onset in the second decade or fifth decade or later tend to become intractable.