PO:22:038 | Recurrent Pneumonias and Persistent Inflammation in VEXAS Syndrome: The Role of BAL in Differential Diagnosis

Francesco Ghellere¹, Bernardo D'Onofrio¹, Maria Chiara Ditto¹, Salvatore Panaro¹, Francesca Piccione^1|2, Giacomo Tanti¹, Enrico Fusaro¹, Simone Parisi¹ | ¹SC Reumatologia, Città della Salute e della Scienza Torino, Italy; ²Fondazione Ricerca Molinette Torino, Italy

Purpose. VEXAS syndrome is an adult-onset autoinflammatory disease linked to somatic UBA1 mutations. Pulmonary involvement is reported in 30–50% of cases. Distinguishing between infectious pneumonia and inflammatory lung disease is often challenging, especially in immunosuppressed patients. We present a case in which BAL analysis was essential for clarifying the diagnosis in a patient with recurrent pneumonias prior to the diagnosis of the rheumatological condition.

Methods. A patient with recent diagnosis of VEXAS syndrome under treatment with Tocilizumab (IV) and corticosteroids was hospitalized for pleuritic chest pain, fever, and CT evidence of bilateral peribronchial consolidations and pleural effusion. Laboratory tests showed marked neutrophilic leukocytosis and elevated CRP (242 mg/L) with normal procalcitonin. Given the history of recurrent pneumonias and immunosuppression, an extensive infectious workup was initiated, including BAL with microbiological and immunocytological analysis.

Results. BAL was negative for bacteria, fungi, viruses, and mycobacteria (culture, PCR panel, antigen testing, serologies, and staining). Cytological analysis revealed a CD4+ T-cell predominant lymphocytic response, reduced macrophages, absence of B-cells, and normal NK cell counts. Lack of improvement with antibiotics and rapid clinical response to intravenous corticosteroids led to the diagnosis of inflammatory lung involvement. The patient showed rapid defervescence, CRP reduction (<10 mg/L), and radiological resolution of consolidations.

Conclusions. This case highlights the importance of an integrated clinical and immunological approach in evaluating pulmonary symptoms in VEXAS syndrome. In this patient the history of recurrent pneumonias could indicate pulmonary involvement of VEXAS syndrome even prior to the onset of rheumatological symptoms. BAL cytology, combined with microbiological exclusion and clinical response to therapy, can differentiate inflammatory flares from infectious pneumonia. According to literature, it affects approximately 34% of VEXAS patients (Beck DB et al., NEJM 2020), often presenting with non-specific consolidations or vasculitis. In this complex patient group, BAL-guided management is crucial to avoid unnecessary antibiotics and promptly initiate immunosuppressive therapy.