Bacteriological Profile of Acute Exacerbation of Nonspecific Interstitial Pneumonia (NSIP)

Author(s): Sourabh Pandey, Harshit Jain, Gaurav Verma, Dinesh Singh Mahor

Introduction: Nonspecific interstitial pneumonia (NSIP) is a life-threatening disease of unknown etiology, characterized by distinct radiographic and pathological patterns. Patients with NSIP often experience a progressive decline in respiratory function, or a more acute deterioration referred to as acute exacerbation (AE-NSIP). Among infectious agents, bacterial involvement and its impact on alveolar healing remain underexplored. Recent studies suggest that impaired host defence mechanisms may predispose NSIP patients to infections, thereby influencing disease progression.

Aim: This study investigates bacterial isolates from sputum samples in patients with AE-NSIP and evaluates their clinical significance.

Materials and Methods: Sputum samples from 120 AE-NSIP patients admitted to a tertiary hospital between January 2021 and January 2022 were analysed. Patients unable to produce sputum or those pre-treated with antibiotics were excluded. Gram staining and culture tests were conducted on high-quality sputum samples. Chi-square tests were used to determine the statistical significance of bacterial isolates.

Results: Out of 120 patients, bacterial isolates were identified in 78.3% (n=94), while 21.7% (n=26) showed no isolates. Streptococcus pneumoniae (n=26) and Escherichia coli (n=24) were statistically significant (p<0.05). Other isolates such as Haemophilus influenzae (n=16), Klebsiella pneumoniae (n=8), Enterococcus (n=4), and Moraxella catarrhalis (n=6) were statistically insignificant.

Conclusion: Preservation of lung function in NSIP remains critical. The potential role of bacterial infections in worsening NSIP and the use of prophylactic antibiotics warrant larger, geographically diverse studies.