Measure of lung dielectric proprieties in patients with Idiopathic Pulmonary Fibrosis: correlation with clinical, radiological and pulmonary functional parameters

BACKGROUND

Dielectric properties of biological tissues are biophysical parameters; in lung they change with amount of air, blood and parenchyma. Remote Dielectric Sensing (ReDS™) technology measures dielectric properties of lung tissues quantifying the content of fluids inside the scan volume. We aimed to evaluate the reliability of ReDS™ measure in Idiopathic Pulmonary Fibrosis (IPF) patients and in healthy volunteers, and to investigate the correlation of ReDS™ score with clinical, radiological and functional parameters.

METHODS

We conducted a prospective observational study, including 52 patients with diagnosis of IPF and 17 healthy volunteers; for each patient we recorded: complete functional evaluation, dyspnoea score (mMRC scale), Usual Interstitial Pneumonia (UIP) Computed Tomography (CT) pattern (UIP definite or probable) and ReDS™ measure (expressed in %).

RESULTS

ReDS™ measure was reported as correct both in patients and controls, the firsts with higher scores (33.8% vs 29.1%, p = 0.003). In IPF patients we observed a significant inverse correlation with ReDS™ score and Forced Vital Capacity (FVC), Vital Capacity (VC) and Total Lung Capacity (TLC) measures and, when we considered only patients with UIP definite CT pattern, the correlation was inverse with FVC, VC, TLC, DLCO. In IPF patients the higher was mMRC dyspnoea index, the higher was ReDS™ score. No significant correlations were observed between ReDS™ score and functional parameters in healthy controls.

DISCUSSION

We demonstrated a correlation of ReDS™ scores with some functional (mainly indicative or diagnostic for restriction) and clinical parameters in IPF patients; the score was correlated with density of tissues possibly quantifying tissue fibrosis in IPF patients.

Assessment of Occult Pulmonary Involvement in Ulcerative Colitis

Introduction

Nearly 50% of patients with inflammatory bowel disease (IBD) experience at least one extraintestinal manifestation. Bronchopulmonary involvement is rare in IBD. Pulmonary function test (PFT) abnormality in cases of ulcerative colitis (UC) has been reported to be 17-55%. Occult pulmonary disease may be diagnosed using variables of the PFT. Hence, we aim to evaluate the frequency and type of pulmonary dysfunction in patients with UC in remission.

Methods

Eighty-three patients of UC in remission and 48 controls underwent the PFT including forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), Tiffeneau value (FEV1/FVC), and midexpiratory flow (MEF 25-75%) rate with a spirometer. The patients were divided based on the age of onset of UC into A1 (<16 years), A2 (16-40 years), and A3 (>40 years) and based on the extent of disease into E1 (proctitis), E2 (left-sided colitis), and E3 (extensive colitis).

Results

Patients with UC had significantly abnormal PFT compared with controls (51 [61.5%] vss. 8 [16.67%]; p = 0.000). Patients with UC commonly had a restrictive pattern (33 [64.47%]) of PFT followed by small airway disease (11 [21.56%]) and obstructive pattern (7 [13.72%]). Pulmonary involvement in cases of UC was more in E3 followed by E2 and E1. Pulmonary involvement was more in the late age of onset of disease. BMI was positively and significantly correlated with FEV1 and FVC. Hemoglobin had a positive and significant correlation with FEV1 while a negative correlation with FEV1/FVC and MEF 25-75%. All predictors except for age were found to contribute in higher risk (OR > 1) for PFT abnormality.

Conclusion

Patients with UC have chronic pulmonary inflammation leading to different patterns of lung involvement in the form of restrictive, obstructive airway, and small airway disease. Patients with UC commonly have a restrictive pattern of pulmonary involvement. Impairment of the PFT is related to the disease extent and the age of onset of disease. Assessment of the PFT using a spirometer is a noninvasive, simple, cost-effective, and reliable method for early detection of occult pulmonary involvement in patients of UC.