Effective Treatment of Rheumatoid Arthritis-Associated Interstitial Lung Disease by B-Cell Targeted Therapy with Rituximab

Rheumatoid arthritis- (RA-) associated interstitial lung disease (RA-ILD) is the extra-articular complication with most adverse impact on the quality of life and survival in RA patients. However, treatment options are limited and controlled studies are lacking. Here, we present the case of a 66-year-old patient suffering from severe RA-ILD, which has been successfully treated with Rituximab (RTX). After failure of conventional DMARD therapy, our patient showed sustained improvement of clinical pulmonary parameters as well as joint inflammation following B-cell depletion with RTX. The six-minute-walk test improved from 380 meters to 536 meters and the forced vital capacity from 2.49 liters to 3.49. The disease activity score could be reduced from 7.7 to 2.8. Therefore, RTX might be considered as an alternative treatment for RA-ILD in patients not responding to conventional DMARD therapy. Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is RA’s extra-articular complication with most adverse impact on quality of life and survival. However, treatment options are limited and controlled studies are lacking. We report a 66-year-old man suffering from severe RA-ILD. Treatment with methotrexate as well as cyclophosophamide failed to improve the respiratory function. Surprisingly, we noticed a fast and sustained improvement with rituximab. Thus we consider rituximab as an alternative treatment strategy for DMARD-resistant RA-ILD. A now 66-year-old Caucasian was diagnosed with idiopathic pulmonary fibrosis (IPF) due to persistent dry coughing and dyspnea concomitant with impaired functional capacity of the lung and typical radiographic findings two years ago. A few months later, the initial respiratory symptoms were followed by polysynovitis associated with high systemic inflammatory activity. With regard to the clinical symptoms and presence of high titers of rheumatoid factor (Rf) as well as anticyclic citrullinated peptide (CCP) antibodies, the diagnosis of RA was established. Consequently, treatment with NSAIDs, prednisolone and a course of leflunomide for half a year has been initiated in a community hospital without substantial improvement. Therefore, the patient presented to our outpatient clinic with persistent polysynovitis and severe systemic inflammatory response (DAS28: 7.47; CRP: 77？mg/L). In light of the previous findings in combination with HRCT (Figure 1) we diagnosed RA-ILD. To obtain histological confirmation, transbronchial lung biopsy was performed, which revealed unspecific fibrotic changes. Since the patient rejected open