Chih Ying Ou

Genetic variants of pulmonary SP‐D predict disease outcome of COPD in a Chinese population

Although surfactant protein‐D (SP‐D) has been suggested as a biomarker for chronic obstructive pulmonary disease (COPD), the relationship between genetic variants of SP‐D and disease outcome of COPD remains unknown. We hypothesized that genetic polymorphisms of SP‐D are associated with COPD‐related phenotypes and disease prognosis.

Pneumocystis jirovecii pneumonia in systemic lupus erythematosus from southern Taiwan.

BackgroundOpportunistic infection has been documented in systemic lupus erythematosus with special attention paid to Pneumocystis jirovecii because of the significant morbidity and high mortality. ObjectivesThe limited large-scale investigations covering P. jirovecii pneumonia (PCP) in systemic lupus erythematosus following biologics or immunosuppressants therapy prompted us to perform this study in southern Taiwan. MethodsA retrospective study was completed in 858 hospitalized lupus patients from January 2000 to December 2011. The definite diagnosis of PCP was made by the laboratory detection of Pneumocystis organisms together with consistent clinical and radiological manifestations of PCP. Positive polymerase chain reaction results of sputum samples were not regarded as infection in this study, unless P. jirovecii was the sole pathogen found and pulmonary manifestations resolved following antibiotics for PCP treatment alone. ResultsThe laboratory identification of Pneumocystis organisms depended on lung biopsy in 2 cases and bronchoalveolar lavage in 3 patients. Five cases, 2 women and 3 men aged 30 to 50 years (41.8 ± 8.8 years), were identified with a 0.6% incidence. None received chemoprophylactics against P. jirovecii infection. All had lupus nephritis and lymphopenia with low CD4+ T-cell counts. Prior usages of higher daily prednisolone dosages and concomitant biologics or immunosuppressants were observed in all patients. Pneumocystis jirovecii pneumonia contributed to a high mortality rate (60%). ConclusionsWe report the rare occurrence but high mortality of PCP infection in this study. A consensus guideline addressing prophylactic antibiotics against Pneumocystis organisms in highest-risk lupus patients on biologics or immunosuppressants could be helpful in guiding their management.

Using Post-bronchodilator FEV1 is Better Than Pre-bronchodilator FEV1 in Evaluation of COPD Severity

Abstract Background: The current standards for the diagnosis and treatment of patients with COPD clearly rely on the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria based on post-bronchodilator spirometric values. However, clinical evidence for using the post-bronchodilator FEV1 in the severity classification has not been fully investigated. Methods: Patients with COPD were enrolled and followed up prospectively between October 2006 and January 2011. We compared the observed 3-year risk of all causes and respiratory mortality with the risk predicted by the pre- and post-bronchodilator percent predicted FEV1. Other important phenotypes including BMI, MMRC dyspnea scale, ECOG performance status and severe AECOPD (acute exacerbation) were also compared between the two groups. The different severity classifications of COPD, measured according the GOLD guidelines by post- and pre-bronchodilator percent predicted FEV1 were compared for prediction of mortality. Results: There were 35 deaths among the 300 COPD patients (11.7%). Multivariate analysis showed that the post-bronchodilator percent predicted FEV1 was a significant independent predictor of mortality but pre-bronchodilator percent predicted FEV1 was not (p = 0.008 vs 0.126) and it was more strongly correlated with all studied predictors of outcome than the pre-bronchodilator percent predicted FEV1. Kaplan-Meier analysis showed that the discrimination ability to predict mortality from the GOLD criteria using post bronchodilator percent predicted FEV1 (p = 0.009) was better than using pre-bronchodilator percent predicted FEV1 (p = 0.131). Conclusions: The post-bronchodilator percent predicted FEV1 is better than the pre-bronchodilator percent predicted FEV1 in the evaluation of the severity of disease in COPD patients and is more accurate in predicting the risk of death by the GOLD classification.

Comparison of global initiative for chronic obstructive pulmonary disease 2013 classification and body mass index, airflow obstruction, dyspnea, and exacerbations index in predicting mortality and exacerbations in elderly adults with chronic obstructive pulmonary disease.

To examine whether the Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) 2013 revision offers greater predictive ability than the body mass index, airflow obstruction, dyspnea, and exacerbations (BODEx) index in elderly adults with chronic obstructive pulmonary disease (COPD).

Classifying different types of double triggering based on airway pressure and flow deflection in mechanically ventilated patients

BACKGROUND: Double-triggering (DT) is a frequent type of patient-ventilator asynchrony and has potentially severe consequences, such as alveolar overdistention or the generation of intrinsic PEEP. However, the first breath of DT could be patient-triggered (DT-P), auto-triggered (DT-A), or ventilator-triggered (DT-V). OBJECTIVE: To differentiate DT-P, DT-A, and DT-V using airway pressure or flow changes during the trigger-delay phase in ventilated patients. METHODS: Fourteen mechanically ventilated patients with DT were included. All patients were on flow-triggered ventilation modes and received either continuous mandatory ventilation or pressure support ventilation. Breaths in which the first breath was associated with an esophageal pressure drop of > 1 cm H2O were categorized as DT-P. Breaths in which the first breath occurred at the ventilator set cycle were categorized as DT-V. Breaths in which the first breath occurred earlier than the ventilator set cycle without esophageal pressure drop were categorized as DT-A. The pressure drop and flow change at 0.13 s (PD0.13 and F0.13, respectively) in the trigger-delay phase were calculated from the nadir. RESULTS: There were 507 double-triggered breaths: 271 DT-V (53%), 50 DT-A (10%), and 186 DT-P (37%). The PD0.13 for DT-V, DT-A, and DT-P were 0.16 ± 0.12 cm H2O, 0.25 ± 0.17 cm H2O, and 1.34 ± 0.67 cm H2O, respectively. The F0.13 for DT-V, DT-A, and DT-P were 2.11 ± 2.31 L/min, 2.64 ± 2.07 L/min, and 16.51 ± 8.02 L/min, respectively. The best discriminatory criteria for differentiating DT-P from DT-V and DT-A, based on the Youden index (sensitivity + specificity – 1) was PD0.13 ≥ 0.49 cm H2O, which had a Youden index of 95%. CONCLUSION: DT-P can be distinguished from DT-V and DT-A by using airway pressure deflections in the trigger-delay phase.

The Role of Bactericidal/Permeability-Increasing Protein in Men with Chronic Obstructive Pulmonary Disease

Abstract Background and objective: Bactericidal/permeability-increasing protein (BPI) is a member of the pattern recognition receptors of the innate immune system. Recently, an association between genetic polymorphism in the BPI gene and a risk of airflow decline after transplantation was demonstrated, but whether these findings are reproducible in nontransplantation populations, such as those with COPD, is still unknown. The aim of this study is to explore the role of BPI in COPD. Methods: The genotypes of 107 patients with COPD and 110 control subjects were evaluated by polymerase chain reaction and polymorphism analysis of the BPI genes and ELISA analysis of the plasma BPI level. All subjects were men over 40 years old who smoked. Results: BPI mutation PstI (T→C) polymorphism in intron 5 was associated with an increased risk of developing COPD (OR 3.73, 95%CI: 1.62–9.10), and the frequency was significantly increased in the COPD group compared with the control group (26/107 [24.3%] vs 12/110 [10.9%], p = 0.002). In addition, COPD patients exhibited a decreased plasma level of BPI compared with the control group (10.6 ± 2.2 vs 23.4 ± 2.1ng/ml, p < 0.0001). Conclusions: BPI mutation (PstI in intron 5) and a decreased plasma BPI level were significant risk factors in susceptibility to COPD. These results demonstrate that BPI genetic mutation and impaired BPI production or release may result in airflow obstruction in smokers.

Alterations in respiratory mechanics in mechanically ventilated patients following bronchoalveolar lavage.

BACKGROUND/PURPOSE Bronchoalveolar lavage (BAL) can be used for a variety of diagnostic purposes in mechanically ventilated patients. BAL can cause changes in respiratory mechanics. However, the risk factors associated with these changes remain unknown. The current study tried to identify the risk factors that contribute to changes in respiratory mechanics following BAL. METHODS Changes in respiratory mechanics were assessed in 56 mechanically ventilated patients who received BAL using an interrupter method under constant flow. RESULTS Intrinsic positive end-expiratory pressure (PEEPi) was correlated significantly with changes in respiratory system resistance and compliance following BAL in mechanically ventilated patients (p = 0.003). In 14 patients with PEEPi > 1 cmH2O, maximal resistance (Rmax) before BAL was 22.5 +/- 5.9 cmH2O/L/S, increasing to 31.6 +/- 8.5 cmH2O/L/S immediately after BAL, and remaining high (28.4 +/- 7.5 cmH2O/L/S) 30 minutes later (p < 0.001). Increase in minimal resistance (Rmin), delta resistance (DeltaR), and decrease in compliance followed the same time trend. In 42 patients with PEEPi < or = 1 cmH2O, Rmax before BAL was 15.5 +/- 3.5 cmH2O/L/S, increasing to 17.6 +/- 4.6 cmH2O/L/S immediately after BAL, and decreasing to 16.6 +/- 4.3 cmH2O/L/S (p < 0.001) 30 minutes later. Increase in Rmin, DeltaR and decrease in compliance were similar to those seen with Rmax. Increases in Rmax, Rmin and DeltaR, and decrease in compliance following BAL were significantly higher in patients with significant PEEPi than in those without throughout the recording period (p < 0.001). CONCLUSION Patients with significant PEEPi experienced greater changes in respiratory mechanics than those without. Physicians should be cautious when performing BAL in such patients.

Discriminative and predictive properties of multidimensional prognostic indices of chronic obstructive pulmonary disease: A validation study in Taiwanese patients

Chronic obstructive pulmonary disease (COPD) is a pulmonary disease with systemic involvement. Several multidimensional indices have been developed to predict long‐term outcomes. However, these indices have not been compared and validated in Taiwanese patients with COPD.