D103-18 Diffuse Alveolar Hemorrhage and Celiac Disease: A Lane-Hamilton Mimic

Abstract Introduction Lane Hamilton Syndrome (LHS) is a rare occurrence of both Celiac Disease (CD) and Idiopathic Pulmonary Hemosiderosis (IPH). LHS is a mimic of pulmonary vasculitis, as it can present with recurrent hemoptysis or diffuse alveolar hemorrhage. While CD and IPH can coexist within a patient without a clear pathologic mechanism, some hypothesize an autoimmune link, as ANCA positivity is present in many cases. Lane Hamilton Syndrome is unique as a gluten free diet reduces DAH due to IPH as well as the symptoms of CD. Here, we describe the work-up and diagnosis of small vessel ANCA-positive vasculitis misdiagnosed as presumed Lane Hamilton syndrome. Case report A 43-year-old male with years of hemoptysis in the setting of biopsy-proven CD experienced his first episode of DAH in 2012 diagnosed via bronchoalveolar lavage (BAL). With avoidance of gluten ingestion, he experienced fewer instances of hemoptysis until his second episode of DAH in 2021 also diagnosed by BAL. He was then scheduled for VATS biopsy to characterize his DAH, though this was cancelled due to symptom improvement. During 2025, he had several ED presentations and admissions for presumed pneumonia given chest infiltrates on imaging. In August, he was admitted for acute hypoxic respiratory failure and was ultimately intubated. Serial bronchoalveolar lavage revealed progressively bloody samples, diagnostic of DAH. He also had increasingly elevated autoimmune serology titers with a P-ANCA and MPO pattern, diagnostic of microscopic polygangiitis. Ultimately, biopsy via VATS wedge resection of LUL apical and LLL superior segments revealed neutrophils in alveolar capillaries as well as fibrosis consistent with vasculitis rather than LHS. Pathology slides shown here: Following the procedure the patient worsened clinically, however, he rapidly improved with pulse dose steroids. He was later placed on rituximab to reduce steroid burden. Discussion While LHS is well described in pulmonary literature as a known mimic to vasculitis, its diagnosis can be challenging. While approximately 1% of the US population has CD, not all cases of DAH in those with CD should be presumed to be from IPH. While trying to spare invasive diagnostic procedures such as bronchoscopy, providers may trial gluten-free diets in these patients as a therapeutic challenge to treat mild hemoptysis, as in this case. However, this case illustrates that even with the presence of positive ANCA serologies and biopsy proven CD, the presence of hemoptysis in such patients highlights LHS as a diagnosis of exclusion. This abstract is funded by: None