Koichiro Nakata

Pulmonary fibrosis in myeloperoxidase antineutrophil cytoplasmic antibody‐associated vasculitides

Objective:  The association of pulmonary fibrosis (PF) with myeloperoxidase antineutrophil cytoplasmic antibody (MPO‐ANCA)‐associated vasculitides has not been well documented. The aim of this study was to assess the clinicopathological characteristics of PF in patients who tested positive for MPO‐ANCA.

Exploratory analysis of a phase III trial of pirfenidone identifies a subpopulation of patients with idiopathic pulmonary fibrosis as benefiting from treatment

BackgroundA phase III trial in Japan showed that pirfenidone is effective for idiopathic pulmonary fibrosis (IPF). To find out which patients specifically benefit from pirfenidone, we analyzed in an exploratory manner the data from the phase III trial.MethodsThe patients in the phase III trial were stratified by baseline percentage predicted vital capacity (%VC), arterial oxygen partial pressure (PaO2), and the lowest oxygen saturation by pulse oximetry (SpO2) during the 6-minute steady-state exercise test (6MET). In the subpopulations, changes in VC and subjective symptoms (cough and dyspnea on the Fletcher, Hugh-Jones [F, H-J] Classification scale) were evaluated in patients treated with high-dose (1800 mg/day) pirfenidone, low-dose (1200 mg/day) pirfenidone, and placebo at week 52.ResultsSignificant efficacy of pirfenidone in reducing the decline in VC could be seen in a subpopulation having %VC ≥ 70% and SpO2 < 90% at baseline. This favorable effect was accompanied by categorical change in VC and progression-free survival time. In the subpopulation, pirfenidone significantly suppressed cough and dyspnea.ConclusionsIPF patients having %VC ≥ 70% and SpO2 < 90% at baseline will most likely benefit from pirfenidone when evaluated using changes in VC (and %VC), and cough and dyspnea symptoms. This subpopulation could expect to benefit most from pirfenidone treatment.Trial RegistrationThis clinical trial was registered with the Japan Pharmaceutical Information Center (JAPIC) on September 13th, 2005 (Registration Number: JAPICCTI-050121).

Efficacy of inhaled N-acetylcysteine monotherapy in patients with early stage idiopathic pulmonary fibrosis

Background and objective:  Idiopathic pulmonary fibrosis (IPF) is a fatal disorder for which there are currently no specific or effective medical treatments. A multicentre, prospective, randomized, controlled clinical trial was conducted to assess the efficacy of inhaled N‐acetylcysteine (NAC) monotherapy in Japanese patients with early stage IPF.

Semi-quantitative analysis of Streptococcus pneumoniae urinary antigen: kinetics of antigen titers and severity of diseases.

Detection of urinary antigen by a rapid immunochromatographic membrane test (Binax NOW) was widely accepted as a powerful tool for diagnosis of Streptococcus pneumoniae pneumonia. This is a qualitative kit, so the value of quantitative analysis of urinary antigen, especially correlation of antigen titers and severity of diseases, remained to be determined. We examined semi-quantitative antigen titer in urines collected from urinary antigen-proven S. pneumoniae pneumonia on admission, and analyzed the kinetics of antigen titer and its relation to severity of diseases. After serial 2-fold dilution of urine, the highest dilution for positive results was determined, and this was designated as maximum dilution factor (MDF). MDFs varied from 1 to 4096 in 29 patients examined (mean MDF, 317.8). Importantly, severe cases of S. pneumoniae pneumonia were higher values of MDFs (mean MDF: 760.5) than those of non-severe cases (mean MDF: 5.4). The patients with high MDFs (≥64) demonstrated higher values of LDH, CRP and lower values of WBC and PaO2 compared to those of low MDFs group (≤32). There was no clear correlation between CRP values and antigen titers, and conversely the majority of severe cases showed relatively weak CRP responses, despite high levels of bacterial antigen. Kinetic analysis of urinary and serum antigen titers in 4 cases of S. pneumoniae pneumonia exhibited consistently higher values of antigen titers in urine than those in serum. The half lives of urinary and serum antigen titers were calculated to be 1.0–3.4 and 1.1–2.3 weeks, respectively. These data suggest that quantitative analysis of urinary antigen may be a useful indicator for severity of disease and course of S. pneumoniae pneumonia. Our results demonstrate an application for S. pneumoniae antigen titer determination in urine and serum, which may be crucial not only for diagnostic measures, but also may provide a better understanding of the pathogenesis of S. pneumoniae infection.

Proteomic Biomarkers for Acute Interstitial Lung Disease in Gefitinib-Treated Japanese Lung Cancer Patients

Interstitial lung disease (ILD) events have been reported in Japanese non-small-cell lung cancer (NSCLC) patients receiving EGFR tyrosine kinase inhibitors. We investigated proteomic biomarkers for mechanistic insights and improved prediction of ILD. Blood plasma was collected from 43 gefitinib-treated NSCLC patients developing acute ILD (confirmed by blinded diagnostic review) and 123 randomly selected controls in a nested case-control study within a pharmacoepidemiological cohort study in Japan. We generated ∼7 million tandem mass spectrometry (MS/MS) measurements with extensive quality control and validation, producing one of the largest proteomic lung cancer datasets to date, incorporating rigorous study design, phenotype definition, and evaluation of sample processing. After alignment, scaling, and measurement batch adjustment, we identified 41 peptide peaks representing 29 proteins best predicting ILD. Multivariate peptide, protein, and pathway modeling achieved ILD prediction comparable to previously identified clinical variables; combining the two provided some improvement. The acute phase response pathway was strongly represented (17 of 29 proteins, p = 1.0×10−25), suggesting a key role with potential utility as a marker for increased risk of acute ILD events. Validation by Western blotting showed correlation for identified proteins, confirming that robust results can be generated from an MS/MS platform implementing strict quality control.

Risk factors for acute exacerbation of idiopathic pulmonary fibrosis – Extended analysis of pirfenidone trial in Japan

BACKGROUND Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is a lifethreatening event and one of the important endpoints in clinical trials involving IPF. Despite this, there has been little evaluation of the potential risk factors for AE-IPF in clinical trials. We evaluated the risk factors for AE-IPF in a phase III clinical trial of pirfenidone in Japanese IPF patients. METHODS The study population comprised 267 patients. The effects of various baseline characteristics as possible risk factors for AE-IPF during the study, as well as those of a ≥10% decline in percent vital capacity (%VC) within 6 months, were evaluated using Cox׳s proportional hazard model. The ≥10% decline in %VC was calculated in two ways: (1) an absolute decline (e.g. from 60% predicted to 50%); and (2) a relative decline (e.g. from 60% predicted to 54%). RESULTS Over 52 weeks, 14 patients experienced AE-IPF. Univariate analysis using Cox׳s proportional hazards model showed that both relative and absolute ≥10% decline in %VC within 6 months were significant risk factors for AE-IPF. Stepwise multivariate analysis demonstrated that absolute or relative decline in both %VC and alveolar to arterial oxygen pressure difference (AaDO2) were significant risk factors for AE. The model using absolute decline [Hazard Ration (HR)=7.405, p=0.0007] and baseline AaDO2 (HR=1.063, p=0.0266) had a better fit than the model using relative decline and baseline AaDO2. CONCLUSIONS Rapid %VC decline (≥10% within 6 months), and high baseline AaDO2, may be risk factors for AE-IPF.

Efficacy of pirfenidone and disease severity of idiopathic pulmonary fibrosis: Extended analysis of phase III trial in Japan

BACKGROUND A phase III clinical trial of pirfenidone in patients with idiopathic pulmonary fibrosis (IPF) in Japan has revealed that pirfenidone attenuated the decline in vital capacity (VC) and improved progression-free survival (PFS). We conducted an extended analysis of the pirfenidone trial to investigate its efficacy with respect to IPF severity in the trial population. METHODS Patients in the phase III trial were stratified by baseline pulmonary functions including %VC predicted, %diffusion capacity for carbon monoxide predicted, and oxygen saturation by pulse oximetry on exertion and were categorized into mild, moderate, and severe groups of functional impairment. The efficacy of pirfenidone for VC and PFS over 52 weeks was compared among the three sub-populations. RESULTS Of 264 patients, 102 (39%), 90 (34%), and 72 patients (27%) were classified as having mild, moderate, and severe grades of functional impairment, respectively. This classification was associated with arterial oxygen partial pressure at rest and degree of dyspnea at baseline. While pirfenidone attenuated VC decline at all grades of severity, covariance analysis revealed pirfenidone to have better efficacy in the sub-population with mild-grade IPF. Mixed model repeated measures analysis confirmed that pirfenidone markedly attenuated VC decline in patients with mild-grade IPF compared to its effects in patients with moderate or severe IPF. Pirfenidone also improved PFS markedly in patients with mild-grade IPF. CONCLUSION This extended analysis suggested that pirfenidone exerted better therapeutic effects in patients with milder IPF. Further analysis with a larger population is needed to confirm these results.

Pulmonary emboli caused by iliac compression syndrome without leg symptoms

Iliac compression syndrome is a clinical condition that occurs as a result of compression of the left common iliac vein by the overlying right common iliac artery. This syndrome most often affects young to middle-aged women, and patients usually have left leg symptoms. We report the unusual case of an 18-year-old male who had pulmonary emboli caused by iliac compression syndrome without leg symptoms. Combined venography and aortography confirmed the diagnosis. The patient was successfully treated with anticoagulants and vena cava filter insertion. Iliac compression syndrome should be considered when pulmonary embolism appears without obvious cause.

The First Recognized Patient with legionella pneumophila Serogroup 9 Pneumonia in Japan

A 77-year-old female was admitted because of high fever, cough and sputum. She had been receiving corticosteroid therapy for 4 years for multiple myeloma and was immunosuppressed. A physical examination on admission showed coarse crackles in the right lower lung field, a chest radiograph showed consolidation in the right middle and lower lung fields, and a blood gas analysis revealed marked hypoxemia. The patient was diagnosed as having refractory pneumonia associated with acute respiratory failure and treated with intravenous cefmetazole followed by imipenem. On hospital day 5, erythromycin therapy was started because of a poor response to the previous antibiotics. The patient became afebrile on the tenth day and was in good health on day 15. A sputum culture on day 4 revealed aLegionella organism on Wadowsky-Yee-Okuda medium, which was subsequently confirmed to beLegionella pneumophila by a DNA hybridization test. This strain was identified at the Centers for Disease Control (Atlanta, GA, USA) by slide agglutination asL. pneumophila serogroup 9. Although our patients symptoms are not apparently different from those caused by other serogroup strains ofL. pneumophila, this is the first recognized patient with culture-provenL. pneumophila serogroup 9 pneumonia in Japan. The clinical course of the disease and the diagnostic difficulties in identifying this type of pneumonia are discussed.