Excessive inflammation is pathogenic in the pneumonitis associated with severe COVID-19. Neutrophils are among the most abundantly present leukocytes in the inflammatory infiltrates and may form neutrophil extracellular traps (NETs) under the local influence of cytokines. NETs constitute a defense mechanism against bacteria, but have also been shown to mediate tissue damage in a number of diseases.

Ulcerative colitis (UC) is a chronic GI inflammatory disorder involving various extraintestinal organs, including the lungs. Although UC-related lung diseases (UC-LDs) have been widely recognized, much remains unclear.

An 87-year-old woman with a medical history of stroke, paroxysmal atrial fibrillation, type 2 diabetes mellitus, diastolic heart failure, and chronic bilateral lymphedema presents with 1 week of shortness of breath. The patient had a 20-pack-year smoking history and at baseline was able to ambulate freely without assistance. Her symptoms of dyspnea were mostly exertional and progressively worsening for 1 week before admission, despite compliance with her home furosemide. On admission, her temperature was 36.3 °C, BP was 101/59 mm Hg, heart rate was 82 beats/min, respirations were 18 breaths/min, and oxygen saturation was 91% on room air. On physical examination, the patient was tachypneic at rest, and auscultation of the lungs revealed minimal breath sounds on the left side. Admission laboratory test results were notable for leukocyte count of 11.67 × 109/L (82.2% neutrophils, 8.3% monocytes, 6.4% lymphocytes, and 2.1% eosinophils). Results of HIV screening tests were negative.

A 34-year-old man presented to our institution with lightheadedness and dyspnea on exertion. His medical history included chronic pancreatitis, juvenile rheumatoid arthritis (JRA), gastroesophageal reflux disease, hypertension, lumbar degenerative disc disease, seizure disorder, anterior uveitis, and multiple vertebral fractures. In addition, he was a cigarette smoker with a 10-pack-year smoking history.