Shu Hisata

The Multicenter Study of a New Assay for Simultaneous Detection of Multiple Anti-Aminoacyl-tRNA Synthetases in Myositis and Interstitial Pneumonia

Objective Autoantibodies to aminoacyl-tRNA synthetases (ARSs) are useful in the diagnosis of idiopathic inflammatory myopathy (IIM) with interstitial pneumonia (IP). We developed an enzyme-linked immunosorbent assay (ELISA) system using a mixture of recombinant ARS antigens and tested its utility in a multicenter study. Methods: We prepared six recombinant ARSs: GST-Jo-1, His-PL-12, His-EJ and GST-KS expressed in Escherichia coli, and His-PL-7 and His-OJ expressed in Hi-5 cells. After confirming their antigenic activity, with the exception of His-OJ, we developed our ELISA system in which the five recombinant ARSs (without His-OJ) were mixed. Efficiency was confirmed using the sera from 526 Japanese patients with connective tissue disease (CTD) (IIM n = 250, systemic lupus erythematosus n = 91, systemic sclerosis n = 70, rheumatoid arthritis n = 75, Sjögren’s syndrome n = 27 and other diseases n = 13), 168 with idiopathic interstitial pneumonia (IIP) and 30 healthy controls collected from eight institutes. IIPs were classified into two groups; idiopathic pulmonary fibrosis (IPF) (n = 38) and non-IPF (n = 130). Results were compared with those of RNA immunoprecipitation. Results: Sensitivity and specificity of the ELISA were 97.1% and 99.8%, respectively when compared with the RNA immunoprecipitation assay. Anti-ARS antibodies were detected in 30.8% of IIM, 2.5% of non-myositis CTD, and 10.7% of IIP (5.3% of IPF and 12.3% of non-IPF). Anti-ARS-positive non-IPF patients were younger and more frequently treated with glucocorticoids and/or immunosuppressants than anti-ARS-negative patients. Conclusion: A newly established ELISA detected anti-ARS antibodies as efficiently as RNA immunoprecipitation. This system will enable easier and wider use in the detection of anti-ARS antibodies in patients with IIM and IIP.

Gradual Increase of High Mobility Group Protein B1 in the Lungs after the Onset of Acute Exacerbation of Idiopathic Pulmonary Fibrosis

The pathogenesis of acute exacerbation of idiopathic pulmonary fibrosis (IPF) remains to be elucidated. To evaluate the roles of inflammatory mediators in acute exacerbation, the concentrations of high mobility group protein B1 (HMGB1), a chief mediator of acute lung injury, and 18 inflammatory cytokines were measured in the bronchoalveolar lavage fluid, serially sampled from seven IPF patients after the onset of acute exacerbation. HMGB1 gradually increased in the alveolar fluid after the onset of acute exacerbation, in positive correlation with monocytes chemotactic protein-1 (MCP-1), a potent fibrogenic mediator. In the lung tissues of eight IPF patients autopsied after acute exacerbation, intense cytoplasmic staining for HMGB1 was observed in the alveolar epithelial cells in alveolar capillary augmented lesions, where the capillary endothelial cells remarkably reduced the expression of thrombomodulin, an intrinsic antagonist of HMGB1. These results suggest pathogenic roles for HMGB1 and MCP-1 in the late phase of acute exacerbation of IPF.

The disappearance of subpleural and interlobular lymphatics in idiopathic pulmonary fibrosis.

BACKGROUND The lymphatics in the interlobular and subpleural parenchyma contribute to alveolar clearance in the lung, but the information on the remodeling of these lymphatics is quite limited in idiopathic pulmonary fibrosis lungs that contain severe fibrosis in these regions. We compared the alteration of these lymphatics and lymphangiogenesis among idiopathic pulmonary fibrosis and nonfibrotic interstitial pneumonias with a better prognosis. METHODS AND RESULTS The lung tissue specimens of eighteen patients with idiopathic pulmonary fibrosis (ten surgical biopsies and eight autopsies), six with organizing pneumonia, six with cellular nonspecific interstitial pneumonia, and five normal controls were examined by morphometric analysis of the lymphatics identified by immunohistochemistry. In addition, three-dimensional reconstruction of lymphatics, apoptosis of lymphatic endothelial cells and the cells producing growth factors for lymphangiogenesis were also evaluated. Both the subpleural and the interlobular lymphatics in idiopathic pulmonary fibrosis lungs were significantly decreased in the severe fibroconnective lesions, with rare lymphangiogenesis. The three-dimensional images of the subpleural lymphatics in idiopathic pulmonary fibrosis clearly revealed destruction by fibrosis; apoptosis was observed in these lymphatic endothelial cells. In contrast, organizing pneumonia and cellular nonspecific interstitial pneumonia preserved these lymphatics, and active lymphangiogenesis occurred in the alveolar lesions. CONCLUSIONS These results reveal severe damage of the subpleural and interlobular lymphatics in idiopathic pulmonary fibrosis lungs, and suggest impaired alveolar clearance as another pathogenesis of its refractoriness.

The Diagnostic Value of the Interstitial Biomarkers KL-6 and SP-D for the Degree of Fibrosis in Combined Pulmonary Fibrosis and Emphysema

The combined pulmonary fibrosis and emphysema (CPFE) was reported first in 1990, but it has been comparatively underestimated until recently. Although the diagnostic findings of both emphysematous and fibrotic regions are detectable by high-resolution computed tomography (HRCT) of the chest, the degree of progressive fibrosis, which increases with emphysematous lesions, is difficult to evaluate. In this study, we hypothesized that the biomarkers for pulmonary fibrosis, surfactant protein D (SP-D), and KL-6 would serve as good indicators of fibrotic lesions in CPFE. We recruited 46 patients who had been diagnosed in our hospital with both emphysema and fibrosis by their CT scan image from April 2003 to March 2008. The correlation among their pulmonary function tests, composite physiologic index (CPI), and the serum levels of SP-D and KL-6 was evaluated. We found a correlation between KL-6 and %VC, %TLC, or CPI and between SP-D and %VC or CPI. Interestingly, the combined product of KL-6 and SP-D (KL-6xSP-D) was found to highly correlate with %VC and %TLC or CPI. These results show that both KL-6 and SP-D, and especially the product of SP-D and KL-6, are good indicators of the presence of fibrotic lesions in the lungs of CPFE patients.

A Normal Range of KL-6/MUC1 Independent of Elevated SP-D Indicates a Better Prognosis in the Patients with Honeycombing on High-Resolution Computed Tomography

Both SP-D and KL-6/MUC1 are established biomarkers of the interstitial pneumonias, including idiopathic pulmonary fibrosis (IPF), but the causes and clinical outcomes based on their independent effects are not known. Eleven asymptomatic patients, detected with honeycombing on high-resolution computed tomography (HRCT), were compared with 17 other IPF outpatients having slight respiratory symptoms and honeycombing as well. Although SP-D was increased in both groups, KL-6 was significantly higher in the symptomatic IPF group. When the patients (n = 11) having both biomarkers elevated were compared with the other patients (n = 6) with only SP-D elevated, the distribution of fibrotic lesions with honeycombing on HRCT was larger and the survival time was shorter in the patients having both biomarkers elevated. Immunohistochemical analysis also differentiated these biomarkers in the lung. These results suggest both a cause and the prognostic value of dissociation of these biomarkers.

Development of pulmonary alveolar proteinosis following exposure to dust after the Great East Japan Earthquake

We report a unique case of pulmonary alveolar proteinosis that developed 3 weeks after the Great East Japan Earthquake and the subsequent tsunami. The patient had inhaled dust repeatedly while visiting her devastated neighborhood without wearing a protective mask. Five weeks after the earthquake, lung samples taken from the patient showed foreign particle deposition; however, her serum was negative for GM-CSF autoantibody. The patients clinical symptoms resolved following whole lung lavage. We conclude that inhalation of fine dust particles after natural disasters may cause the onset of pulmonary alveolar proteinosis.

Sequential Granulocyte-Macrophage Colony-Stimulating Factor Inhalation after Whole-Lung Lavage for Pulmonary Alveolar Proteinosis. A Report of Five Intractable Cases

&NA; Autoimmune pulmonary alveolar proteinosis (aPAP) is a rare disease characterized by the excessive accumulation of surfactant proteins within the alveolar spaces and by higher titers of autoantibodies to granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) in the serum and bronchoalveolar lavage fluid. The antibodies inhibit the maturation and phagocytosis of alveolar macrophages. Although the standard therapy for aPAP has been whole‐lung lavage (WLL), this procedure is invasive and needs to be repeated for several years. GM‐CSF inhalation therapy is a new procedure for treating aPAP and can induce remission with less invasiveness, although it is generally less effective in severe cases. We evaluated five cases with remarkable improvement by using sequential GM‐CSF inhalation therapy after WLL; however, the treatment failed when this therapy preceded WLL. Therefore, sequential GM‐CSF inhalation after WLL may reinforce the efficiency of WLL in patients with severe aPAP.

Myriad Functions of Stanniocalcin-1 (STC1) Cover Multiple Therapeutic Targets in the Complicated Pathogenesis of Idiopathic Pulmonary Fibrosis (IPF)

Idiopathic pulmonary fibrosis (IPF) is an intractable disease for which the pathological findings are characterized by temporal and spatial heterogeneity. The pathogenesis is composed of myriad factors, including repetitive injuries to epithelial cells, alterations in immunity, the formation of vascular leakage and coagulation, abnormal wound healing, fibrogenesis, and collagen accumulation. Therefore, the molecular target drugs that are used or attempted for treatment or clinical trials may not cover the myriad therapeutic targets of IPF. In addition, the complicated pathogenesis results in a lack of informative biomarkers to diagnose accurately the status of IPF. These facts point out the necessity of using a combination of drugs, that is, each single drug with molecular targets or a single drug with multiple therapeutic targets. In this review, we introduce a humoral factor, stanniocalcin-1 (STC1), which has myriad functions, including the maintenance of calcium homeostasis, the promotion of early wound healing, uncoupling respiration (aerobic glycolysis), reepithelialization in damaged tissues, the inhibition of vascular leakage, and the regulation of macrophage functions to keep epithelial and endothelial homeostasis, which may adequately cover the myriad therapeutic targets of IPF.