Abstract Haploinsufficiency of A20 (HA20) is a rare loss-of-function genetic mutation causing immune system dysregulation leading to chronic inflammation and cell death.1, 2 It most commonly manifests with gastrointestinal and cutaneous lesions, while other organ systems are less commonly affected. Pulmonary complications, such are recurrent infections or nodules, are uncommon, with literature reporting an incidence of 9%, and even further challenging.3 We present a case of pulmonary complications of HA20, a rare manifestation of an orphan disease. The aim of this article is to provide data for diagnostic evaluation, including bronchoscopy and radiographic imaging, and offer suggestions for treatment and management.A 34-year-old man diagnosed with HA20 presented to our pulmonology clinic at referral of his immunologist with worsening cough. He has a history of recurrent lung infections, and at time of presentation receives regular HyQvia Human IgG and hyaluronidase infusion therapy via his immunologist. He was seen at multiple outpatient visits over the course of a year, and extensive diagnostic testing was obtained, including CBC analysis, sputum culture, high resolution CT, and bronchoscopy with cytological analysis. Bloodwork on initial evaluation revealed leukopenia and neutropenia WBC count 2.34k/µL, ANC of 1370 as well as severe IgA deficiency IgA 2 mg/dL and significantly elevated quantitative IgG IgG 2122 mg/dL. High-resolution CT demonstrates cystic changes suggestive of cystic bronchiectasis or chronic cavitary disease, bilateral tree-in-bud nodules, and a 1.8cm spiculated obstructive nodule (Figure 1). Bronchoscopy revealed tracheobronchial erythema, and cytologic analysis of lavage returned fibrinopurulent exudate. Pathological analysis of lavage was negative for malignancy. Cultures were negative for high-risk organisms such as pseudomonas and non-tuberculoid mycobacterium and grew commensal flora. Although cultures were negative, the patient started on oral broad spectrum antibiotic due to his immunocompromised state for commensal flora. Azithromycin 250mg three times weekly was also prescribed based on evidence supporting its role in non-CF bronchiectasis with recurrent infections.4 He was also started on brensocatib 10mg orally once daily and a handheld oscillating positive expiratory pressure (PEP) flutter valve for pulmonary toileting. He remains a patient in our pulmonology clinic.Pulmonary complications of HA20 remain a poorly understood process with limited literature due to their rarity. Our case provides an example for diagnostic approach and offers suggestions for otherwise limited treatment guidelines. This abstract is funded by: None
Calvello et al. (Fri,) studied this question.