Related Experiment Video
Updated: May 2, 2026

Protective Efficacy and Pulmonary Immune Response Following Subcutaneous and Intranasal BCG Administration in Mice
Published on: September 19, 2016
BCG-induced pneumonitis with lymphocytic pleurisy in the absence of elevated KL-6
Makoto Tobiume, Tsutomu Shinohara1, Takahira Kuno
1Department of Clinical Investigation, National Hospital Organization National Kochi Hospital, 1-2-25 Asakuranishimachi, Kochi 780-8077, Japan. shinoharat@kochi2.hosp.go.jp.
Background:
Pneumonitis is a rare complication of bacillus Calmette-Guerin (BCG) immunotherapy seen in patients with urothelial cancer following the repeated administration of BCG. However, no case of BCG-induced pleurisy has been reported.
Case Presentation:
We here report the first case of pneumonitis with lymphocytic pleurisy following bacillus Calmette-Guerin (BCG) immunotherapy. Although marked T helper cell alveolitis was found by bronchoalveolar lavage and transbronchial biopsies, no acid-fast bacillus could be identified in recovered BALF or pleural effusion. The lymphocyte stimulation test of BCG was strongly positive. However, levels of serum and bronchoalveolar lavage fluid KL-6, a useful marker for hypersensitivity pneumonitis (HP), were within normal ranges.
Conclusion:
We speculate that the pathogenesis of our case may be a hypersensitive reaction to the proteic component of BCG entering the lung and pleural space, which is different from the etiology of the common type of HP.
Related Concept Videos
Atypical Pneumonia
Pulmonary Tuberculosis III
The first classification is based on the development of the disease, and it includes the following categories:
Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features
Pulmonary Tuberculosis II
Here is a detailed explanation of its pathophysiology:
Transmission: The process begins when a person inhales droplet nuclei containing M. tuberculosis. These are typically released into the air when an individual with pulmonary or...
Pneumonia II: Pathophysiology
Pleura of the Lungs

