C61-16 Two Teenage Patients With C3 Glomerulonephritis and Bronchiectasis

Abstract Patients A and B are teenage patients with C3 glomerulonephritis who were referred to pulmonary medicine for evaluation of pulmonary status before starting pegcetacoplan for treatment of their underlying disease. There were no specific pulmonary concerns at time of referral, with a primary goal of establishing care and obtaining baseline lung functioning studies due to case reports of pneumonitis attributed to pegcetacoplan.Patient A presented for evaluation, and on history taking had several years of prolonged wet cough episodes that would often need antibiotics to clear. He had been diagnosed with C3 glomerulonephritis in 2018, and had required extensive treatment to get his disease under control. He was started on mycophenolate in 2018 and was started on eculizumab in 2019 which had continued on, and was on and off prednisone from the same timeframe, currently taking at time of pulmonary evaluation. He was unable to complete initial spirometry due to cough, and underwent a sputum culture that grew Haemophilus influenzae and was treated with amoxicillin-clavulanic acid for 10 days, and subsequently underwent a chest CT. This demonstrated bilateral lower lobe bronchiectasis. Patient B presented similarly, with no original complaints but had several years of prolonged wet coughing after illnesses and was diagnosed with pneumonia 1-2 times, though generally didn’t receive antibiotics. He was initially presented with C3 glomerulonephritis in 2015, and was started on mycophenolate in 2019 after failing initial treatment with an ace inhibitor. He continued on mycophenolate through to pulmonary evaluation. He was asymptomatic and completed basic spirometry, which was normal without a bronchodilator response, lung volumes, and DLCO, which were also normal. He underwent a chest CT that demonstrated central bronchiectasis, mostly in the bilateral upper lobes. Both patients had had previous genetic testing for their glomerulonephritis that was non-diagnostic. C3 glomerulonephritis is not generally associated with lung disease outside of diffuse alveolar hemorrhage. Mycophenolate has been implicated as causing bronchiectasis in patients on it for immunosuppression related to kidney transplants, but has not been described as causing it in patients on it for other indications. This abstract is funded by: None