Clinical Utility of Bronchoalveolar Lavage Neutrophilia and Biomarkers for Evaluating Severity of Chronic Fibrosing Interstitial Lung Diseases

Benhur Joel Shadrach; Naveen Dutt; Poonam Elhence; Mithu Banerjee; Nishant Kumar Chauhan; Ram N Jalandra; Mahendra Kumar Garg; Pawan Garg; Abhishek Tandon; Saumya Shishir; Rishabh Kochar; Bhavesh Chhatwani; Piyush Pareek; Anika Parrikar

doi:10.7759/cureus.42162

Clinical Utility of Bronchoalveolar Lavage Neutrophilia and Biomarkers for Evaluating Severity of Chronic Fibrosing Interstitial Lung Diseases

Cureus. 2023 Jul 19;15(7):e42162. doi: 10.7759/cureus.42162. eCollection 2023 Jul.

Affiliations

¹ Department of Pulmonary Medicine, All India Institute of Medical Sciences, Jodhpur, IND.
² Department of Pathology, All India Institute of Medical Sciences, Jodhpur, IND.
³ Department of Biochemistry, All India Institute of Medical Sciences, Jodhpur, IND.
⁴ Department of Pulmonary Medicine, All India Institute of Medical Sciences, Bathinda, IND.
⁵ Department of Medicine, All India Institute of Medical Sciences, Jodhpur, IND.
⁶ Department of Radiology, All India Institute of Medical Sciences, Jodhpur, IND.

Abstract

Introduction It is hypothesized that bronchoalveolar lavage (BAL) neutrophilia, Krebs von den Lungen-6 (KL-6), and C-reactive protein (CRP) predict the severity of chronic fibrosing interstitial lung diseases (CF-ILDs). Methods This cross-sectional study enrolled 30 CF-ILD patients. Using Pearson's correlation analysis, BAL neutrophils, KL-6, and CRP were correlated with forced vital capacity (FVC), diffusing lung capacity for carbon monoxide (DLCO), six-minute walk distance (6MWD), partial pressure of oxygen (PaO2), computed tomography fibrosis score (CTFS), and pulmonary artery systolic pressure (PASP). Using the receiver operator characteristic (ROC) curve, BAL KL-6 and CRP were evaluated against FVC% and DLCO% in isolation and combination with BAL neutrophilia for predicting the severity of CF-ILDs. Results BAL neutrophilia significantly correlated only with FVC% (r = -0.38, P = 0.04) and DLCO% (r = -0.43, P = 0.03). BAL KL-6 showed a good correlation with FVC% (r = -0.44, P < 0.05) and DLCO% (r = -0.50, P = 0.02), while BAL CRP poorly correlated with all parameters (r = 0.0-0.2). Subset analysis of BAL CRP in patients with CTFS ≤ 15 showed a better association with FVC% (r = -0.28, P = 0.05) and DLCO% (r = -0.36, P = 0.04). BAL KL-6 cut-off ≥ 72.32 U/ml and BAL CRP ≥ 14.55 mg/L predicted severe disease with area under the curve (AUC) values of 0.77 and 0.71, respectively. The combination of BAL neutrophilia, KL-6, and CRP predicted severity with an AUC value of 0.89. Conclusion The combination of BAL neutrophilia, KL-6, and CRP facilitates the severity stratification of CF-ILDs complementing existing severity parameters.

Keywords: bronchoalveolar lavage; c-reactive protein; chronic fibrosing interstitial lung diseases; crp; kl-6; krebs von den lungen-6; neutrophilia; severity.