Ulcerative colitis-related lung diseases have been recognized as one among the extraintestinal manifestations of ulcerative colitis. Airway disease is the most common type of lung disease in these patients; organizing pneumonia, a parenchymal disease comes next, according to a recently study published in the journal Chest.^1,2

In this retrospective study, a team of researchers from Japan attempted to define the features of ulcerative colitis-related lung diseases. For this they reviewed medical records of 563 patients, aged 14-86 years (mean age 42 years), who had been hospitalized to a hospital in Tokyo with ulcerative colitis between January 2011 and July 2016. Forty-four percent of the enrolled subjects were women and 68.2% were never smokers.

During the mean follow-up period of 77 months, 28 patients (5%) developed lung disease with respiratory symptoms and CT evidence of lung involvement without other known causes. Airway disease was the most frequently occurring in 13 patients (2.3%) followed by organizing pneumonia in 10 patients (1.8%). Six patients (0.8%) developed interstitial lung disease (interstitial) pneumonia, while there was one case of pleuritis (0.2%).

Patients with airway disease responded well to steroids, either inhaled or systemic. Antibiotics were used to treat five patients because of frequent exacerbations. Out of the nine patients who underwent colectomy, 5 developed airway disease within one year post-surgery. On multivariate analysis, older patients were more likely to develop airway disease with odds ratio (OR) of 1.06. The risk was increased nearly 4-folds among patients with history of colectomy with OR of 3.58. No patient in this group died after a mean follow-up of 52 months after the diagnosis.

Assessment of organizing pneumonia cases, which occurred within 24 months, revealed drugs as the likely cause in nine of the 10 cases. Patients showed a favorable clinical course when the alleged drug (salazosulfapyridine, 5-aminosalicylic acid and infliximab) was discontinued and/or steroids were given. Recurrence occurred in just one patient. No risk factors for organizing pneumonia could be identified.

The course of the disease in patients with interstitial pneumonia was found to be influenced by coexisting fibrosis. Four patients who also had fibrosis gradually worsened. Two patients with fibrosis died during the mean follow-up period of 64 months post-diagnosis. Older age was the risk factor for interstitial pneumonia with OR 1.08.

Withdrawal of the suspected drug (5-aminosalicylic acid) and short course of steroids led to clinical improvement in the patient with pleuritis, who did not respond to antibiotics.

The gut microbiome is now increasingly being implicated in the pathogenesis of several diseases including lung conditions. The history of colectomy as a risk factor suggests a long recognized “lung-gut nexus”, which may be due to their “common embryologic origin” and “similar histologic features” of columnar epithelial lining with goblet cells and submucosal lymphoid tissue.²

This single-center study illustrates the three major types of ulcerative colitis-related lung disease including the likely risk factors and clinical course for each. Although rare, they do occur in a sizable number of patients and affect mortality. Except for interstitial pneumonia with fibrosis, all types had a favorable prognosis and showed good response to steroids suggesting potential ways to manage such cases. Early diagnosis and management may result in a better quality of life for these patients.

References

1. Moda M, et al. Incidence, characteristics, clinical course, and risk factors of ulcerative colitis-related lung diseases. Chest. 2022 Dec;162(6):1310-1323. doi: 10.1016/j.chest.2022.05.037.
2. Pande A. Exploring the lung-gut nexus. Chest. 2022 Dec;162(6):1229-1230. doi: 10.1016/j.chest.2022.06.039.
3. https://www.healio.com/news/pulmonology/20230213/pulmonary-manifestations-of-ulcerative-colitis-rare-but-can-affect-mortality-risk, Feb. 13, 2023. Accessed on Feb. 14, 2023.