C46-10 Severe Alpha-1-Antitrypsin Deficiency and Pulmonary Vein Thrombosis

Abstract Introduction Alpha-1 antitrypsin deficiency (AATD) is an inherited disorder caused by mutations in the SERPINA1 gene, resulting in reduced or abnormal alpha-1 antitrypsin (AAT) protein. AAT protects the lungs from neutrophil elastase, and deficiency leads to tissue damage manifesting as emphysema and bronchiectasis. Abnormal AAT accumulation may also cause liver disease. AATD follows an autosomal codominant inheritance pattern, with the normal M allele and deficient variants S (moderate) and Z (severe). Individuals with the PiZZ genotype are at greatest risk of clinical disease. Severe AATD has been associated with an increased risk of venous thromboembolism (VTE), including pulmonary embolism, possibly due to systemic inflammation, hepatic dysfunction, and altered coagulation factors. However, pulmonary vein thrombosis (PVT) remains a rare entity, and no studies or case series have directly linked AATD to an elevated risk of PVT. Case Presentation A 72-year-old male with a history of bronchiectasis, chronic obstructive pulmonary disease (COPD) secondary to AATD, and prior Mycobacterium avium complex (MAC) infection presented with hemoptysis for five days. He was receiving weekly alpha-1-proteinase inhibitor infusions but reported noncompliance. He described persistent cough with blood-tinged sputum and baseline dyspnea but denied fever, chills, chest pain, or orthopnea. Chest CT angiography revealed findings consistent with pulmonary vein thrombosis and a left lower lobe infiltrate. The patient was started on apixaban (Eliquis) 10 mg twice daily for seven days, followed by 5 mg twice daily, and a seven-day course of oral amoxicillin-clavulanate. His hemoptysis resolved within three days. He was discharged on continued anticoagulation and instructed to adhere strictly to weekly alpha-1-proteinase inhibitor infusions, with a repeat CTA chest scheduled in one month to reassess the PVT. Discussion The patient’s hemoptysis may have resulted from PVT, bronchiectasis, or pneumonia. While AATD is a known risk factor for VTE and pulmonary embolism, its role in PVT remains uncertain. The pathophysiologic mechanisms linking AATD to thrombosis such as systemic inflammation and hepatic coagulopathy could theoretically contribute to PVT, though no direct evidence currently exists. This case highlights a possible but unproven relationship between AATD and PVT, underscoring the need for further investigation to determine whether AATD predisposes individuals to this rare thrombotic complication. This abstract is funded by: None