Improvement of constrictive bronchiolitis (bronchiolitis obliterans) after rituximab therapy in 2 patients with primary sjögren syndrome.

Constrictive bronchiolitis is one of the manifestations of small-airway involvement in primary Sjögren syndrome (SS) and is associated with fixed airflow obstruction despite treatment with bronchodilators, macrolides, corticosteroids, and corticosteroid-sparing agents. Reports have shown a beneficial effect of rituximab on interstitial lung disease associated with SS, but the effect of rituximab on constrictive bronchiolitis is unknown. Herein, we present 2 cases of patients with constrictive bronchiolitis associated with SS who experienced symptomatic improvement and stabilization of pulmonary function testing (PFT) after rituximab therapy. Lung function declined in one of the patients when B cells reconstituted, with improved PFT results on re-administration of rituximab. Our case reports suggest that B cells may be involved in the pathogenesis of SS-associated constrictive bronchiolitis. Therapy targeting B cells may therefore be helpful in treating this debilitating and refractory condition. Further research is warranted.