Serum markers in interstitial pneumonia with and without Pneumocystis jirovecii colonization: a prospective study

<p>Abstract</p> <p>Background</p> <p>In patients with chronic respiratory disease, <it>Pneumocystis jirovecii (P. jirovecii) </it>colonization is observed, and may influence disease progression and systemic inflammation. <it>Pneumocystis </it>pneumonia causes interstitial changes, so making a diagnosis of PCP in patients who have interstitial pneumonia (IP) with <it>P. jirovecii </it>colonization is sometimes difficult based on radiography.</p> <p>Methods</p> <p>This study investigated the prevalence of <it>P. jirovecii </it>colonization in IP patients and assessed pulmonary injury due to <it>P. jirovecii </it>colonization by measurement of serum markers (KL-6, SP-A, SP-D, and (1→3) β-D-glucan (β-D-glucan)) and the peripheral lymphocyte counts, prospectively. A total of 75 patients with idiopathic pulmonary fibrosis (n = 29), collagen vascular-related interstitial pneumonia (n = 19), chronic bronchitis or pneumonia (n = 20), and <it>Pneumocystis </it>pneumonia (n = 7) were enrolled in this prospective study. <it>P. jirovecii </it>DNA was detected in sputum samples, while serum markers and the lymphocyte count were measured in the peripheral blood.</p> <p>Results</p> <p>IP patients (idiopathic pulmonary fibrosis and collagen vascular-related IP) who received oral corticosteroids had a high prevalence of <it>P. jirovecii </it>colonization (23.3%). In IP patients, oral corticosteroid therapy was a significant risk factor for <it>P. jirovecii </it>colonization (<it>P </it>< 0.05). Serum markers did not show differences between IP patients with and without <it>P. jirovecii </it>colonization. The β-D-glucan level and lymphocyte count differed between patients with <it>Pneumocystis </it>pneumonia or <it>P. jirovecii </it>colonization.</p> <p>Conclusion</p> <p>Serum levels of KL-6, SP-A, SP-D, and β-D-glucan were not useful for detecting <it>P. jirovecii </it>colonization in IP patients. However, the serum β-D-glucan level and lymphocyte count were useful for distinguishing <it>P. jirovecii </it>colonization from <it>pneumocystis </it>pneumonia in IP patients.</p

Mechanism of Airway Remodeling Induced by Repeated Inhalation of Methacholine in a Mouse Model of Asthma

Background:Increased severity of asthma is contributed by airway tissue remodeling, which may be associated with chronic allergic inflammation. A recent study revealed the potential capacity of repeated bronchoconstriction, e.g. induced by a muscarine agonist, methacholine(Mch)challenge, to involve in airway remodeling, even though allergic inflammation is not implicated. We have evaluated the influence of repeated bronchoconstriction induced by Mch inhalation on airway remodeling in a murine model of asthma and have examined its machanisms. Methods:Mice were immunized with ovalbumin(OVA), and consequently, challenged by either daily OVA inhalation(the OVA group;a model of asthma with allergic inflammation)or daily Mch inhalation(the Mch group;a model of asthma without allergic inflammation). Lung tissues were obtained and were evaluated histologically after 5, 10, and 15 consecutive inhalation challenges of both OVA and Mch.Results:Eosinophilia in the airway observed only on the OVA group. Subepithelial collagen-band thickness increased also in the OVA group(p<0.01)after 15 challenges, but not in the Mch group. Significant increase in thickness of airway smooth muscle layer and the number of goblet cells were revealed in both the OVA and Mch group after 10(p<0.05 and p<0.01, p<0.01 and p<0.05, respectively, for the comparison of the two challenge groups with the control group)and 15 challenges(p<0.05 and p<0.01, both p< 0.01, respectively, for the comparison with control), further, all these measurements were greater in the OVA group than in the Mch group after both 10 and 15 challenges(both p<0.05 and p<0.01, respectively). An increase in mast cell counts within the airway wall was shown in the OVA group after 10 challenges (p<0.01 compared with control), not in the Mch group at all. Epithelia expression of transforming growthfactor b (TGF-b)increased in both challenge groups after 15 challenges(both p<0.05 compared with control), and was higher than in Mch(p<0.05).Conclusion:Repeated Mch inhalation may induce airway remodeling, while comparatively mild, potentially resulting in progressive severity of asthma. The results implicate that the potential risk associated with Mch challenge should be considered

バイヨウ ヒト キカンシ ジョウヒ サイボウ ニオケル カクシュ サイトカイン シゲキ ガ TGF-βシグナルニ オヨボス エイキョウ

気管支喘息の基本病態は好酸球,T細胞(特にTh2細胞),肥満細胞,などの炎症細胞を中心とする慢性の気道炎症と気道リモデリングによって矛盾なく説明できる.気道リモデリングの分子レベルでの形成機序は未だ不明な部分が多く,最近線維化サイトカインTGF-βの役割が注目されている.特にシグナル伝達分子Smadの制御機構の不均衡により起こって来ることも解明されつつある.今回我々はTh2サイトカインIL-5,GM-CSFおよび調節性サイトカインIL-10が気道上皮細胞における抑制型Smad7発現に与える影響についてReal time RT-PCR法を用いて検討した.IL-10刺激は,コントロールに比較して,Smad7の発現が増強し,一方でIL-5,GM-CSFはその発現は誘導されなかった.また,その発現はIL-10との混合培養にて増強した.更に,IL-10はSmad7発現を減弱させることが知られている遺伝子TIEG発現に関しても抑制することを見出し,IL-10が制御性サイトカインとして気道炎症の抑制に関与していることが示唆されたTransforming growth factor-β (TGF-β) is an important pro-fibrogenic growth factor implicated in airway remodeling and pulmonary fibrosis. TGF-β signals from membrane to nucleus by using Smad proteins. Recently, Smad7 has been identified as an intracellular antagonist for TGF-β signaling and it inhibits TGF-β-induced transcriptional responses. And InterleukinlO (IL-10) is general inhibitor of proliferative and cytokine responses in T cells and is produced by mononuclear phagocytes, natural killer cells and by both Th1 and Th2 type lymphocytes. Therefore, we examined the relationship between expression of smad7 in cultured epithelial cells (Beads 2B) stimulated with IL-10. We thought to determine the relationships between Smad7 expression in human bronchial cell line, BEAS-2B cells stimulated with Th2 type cytokine and regulatory cytokine IL-10. Expression levels of Smad7 was expressed in cultured epithelial cells. Interestingly, Th2 cytokines IL-5, GM-CSF exhibited less Smad7 expression in BEAS-2B cells than IL-10 stimulation. In addition, combination with IL-10 and IL-5 stimulation inhibited decreased Smad7 expression. TGF-β induced TIEG expression in BRAS-2B cells were also decreased in a IL-10 stimulation. These findings suggest that Smad7 in a key molecule that defines the susceptibility of bronchial epithelial cells to TGF-β action and regulation of Smad7 expression in bronchial epithelial cells may be related to the development of airway remodeling

IgE サンセイ ニ アタエル コウサンキュウ ジョウ リガンド ノ ヤクワリ

気管支喘息は気道への好酸球を中心とする慢性アレルギー性炎症性疾患として認識され,その患者は各種IgE抗体を発現し,対応するアレルゲン暴露により気道にIgEを介するアレルギー性炎症が惹起される.一方,CD40LigandはTリンパ球,肥満細胞などに発現し,CD40との伝達を介してBリンパ球のIgE産生細胞への分化,増殖に働いており,IgE産生において重要な働きをしている.しかし好酸球におけるCD40Ligand発現とIgE産生へ役割は明確ではない.我々は気管支喘息患者末梢血好酸球のCD40Ligand発現とそれがBリンパ球IgE産生誘導に与える影響について検討した.(方法)気管支喘息患者末梢血より好酸球を分離精製し,各種サイトカインで刺激しCD40L発現を検討した.また精製Bリンパ球と混合培養し上清中のIgEを測定した,(結果)気管支喘息患者群の末梢血好酸球は健常者群に比較し優位にCD40Ligandを発現し,またBリンパ球は好酸球との混合培養によりIL-4,IL-13存在下にIgEを産生した.(考案)気管支喘息患者好酸球はTリンパ球とは別個に独立してBリンパ球のIgE産生に関与する可能性が示唆された.Bronchial asthma is a chronic inflammatory disease of the airway.The accumulation of eosinophils in the airway is one of characteristic seen in patients with bronchial asthma. Asthmatic patients have a large number of IgE antibodies to environmental allergens. The exposure of these allergens induces IgE mediated allergic inflammation in the airway. Allergic reaction is a most important aspect of airway inflammation of the bronchial asthma. It is well known that CD40/CD40-Ligand interaction is a key factor for IgE production. CD40-Ligand, a surface molecule which can be expressed by T cells, mast cells and basophils has been shown to be involved in the control of B cell proliferation. We have observed following in vitro study. It have been shown that freshly isolated eosinophils from asthmatic subjects can be induced to express CD40-Ligand but not from normal controls. IgE synthesis can be induced by the interaction of B cells with eosinophils in the presence of exogenous IL-13. These result suggest that eosinophils can induce the production of IgE, independently of T cells

バイヨウ キドウ ジョウヒ サイボウ オヨビ ヘイカツキン サイボウ ニオケル キドウ リモデリング カンレン サイトカイン イデンシ ハツゲン ニ オヨボス シンケイ ペプチド ノ エイキョウ

気管支喘息の基本的病態は慢性の気道炎症として認識され,その機序が徐々に解明されてきている.特に重症・難治化には気道リモデリングがその要因として注目されている.今回,我々は神経原性炎症に深く関与している神経ペプチド(サブスタンスP,ニューロキニンA)が気道リモデリング,特に線維化サイトカインTGF-βのシグナル伝達機構に関与するTIEG, smad 7遺伝子発現に与える影響について検討した.これら神経ペプチドは線維化サイトカインTGF-βの発現を誘導し,さらにTGF-βの抑制型シグナル伝達分子smad 7の遺伝子発現を低下させた.これらの結果より神経ペプチドはTGF-βのシグナル伝達分子smad 7発現を抑制することによりリモデリング形成に関与している可能性が示唆された.持続するTh2型気道炎症はTGF-β産生増加へ傾きTIEG発現を誘導し,その結果smad 7の発現を抑制する事が知られている.我々は,気道平滑筋におけるサブスタンスP刺激によりTIEG遺伝子発現が誘導される事を見出した.また, TGF-β前処置後サブスタンスPで刺激することによりその効果は増強される事も確認した.これらの結果より,アレルギー性炎症により惹起された神経原性炎症はTIEG発現を誘導し,結果としてsmad 7発現が抑制され気道の線維化・リモデリング形成を促進している可能性が示唆された.Airway remodeling is a typical issue of asthma. Transforming growth factor (TGF)-β plays an important role for the regulation of airway inflammation and remodeling in asthma. The expression of TGF-β in the asthmatic airways was predominantly detected in eosinophils and fibroblasts and it was significantly correlated with the severity of the disease, basement membrane thickness, and submucosal fibroblast number, thus suggesting that TGF-β is involved in airway remodeling in adult asthma. TGF-β-inducible early gene (TIEG) is a Kruppel-like transcription factor that is rapidly induced upon TGF-β treatment TIEG promotes TGF-β/smad signaling by down-regulating negative feedback through the inhibitory smad 7. Among numerous peptide mediators such as tachykinin, calcitonin gene-related peptide, substance P or neurokinin A is one of the most abundant molecules found in the respiratory tract. Neurogenic inflammation might contribute to selective upregulation of TIEG through unknown mechanisms. We therefore examine whether neuropeptides modulate TGF-β and TIEG expression. In this study, we found that TIEG was significantly increased in the cultured smooth muscle cells stimulating with substance P. Furthermore, we found the synergistic effect on TIEG expression in cultured smooth muscle cells stimulating with substance P and pretreatment of TGF-β. These results suggest that increased TIEG expression in airway epithelial and smooth muscle cells might result in increased substance P, TGF-β activity and contribute to the development of airway inflammation seen in chronic asthma