Introduction
Some patients with an idiopathic interstitial pneumonia (IIP) have autoimmune features but do not fulfill established criteria for a connective tissue disease (CTD) (1). In 2015, the « European Respiratory Society (ERS) and American Thoracic Society (ATS) Task Force on Undifferentiated Forms of Connective tissue disease-associated interstitial lung disease » proposed the term « interstitial pneumonia with autoimmune features » (IPAF) (2). The classification criteria for IPAF is a combination of three domains : clinical features, serologic features and morphologic features. The physiopathology of the disease remains unclear and there is no specific treatment so that corticosteroids and immunosuppressive agents are the mainstay of the treatment (1).
Interstitial lung disease (ILD) is associated with considerable morbidity and mortality. There can be a lack of therapeutic response in very severe lung involvement despite maximal conventional treatment, in such a way that rituximab (Rtx) may be an effective medical rescue therapy for ILD unresponsive to conventional immunosupressive treatment (3).
We present a patient with IPAF treated successfully with rituximab used as salvage therapy.