PO:06:084 | Interstitial lung involvement in rheumatoid arthritis patients treated with abatacept: a prospective observational study

Francesca Cozzini^1|2, Andreina Manfredi^2|3, Antonio Carletto⁴, Elisa Bellis⁵, Laura Cometi⁶, Vincenzo Venerito⁷, Caterina Vacchi⁸, Fabiola Atzeni⁹, Antonio Carriero¹⁰, Rosaria Foti¹¹, Mariagrazia Catanoso³, Ennio Favalli¹², Chiara Bazzani¹³, Arianna Belvedere³, Cecilia Burattini¹, Andrea Morciano⁴, Annamaria Iagnocco⁵, Gemma Lepri⁶, Florenzo Iannone⁷, Antonio Pezzano⁹, Salvatore D'Angelo¹⁰, Valentina Cateni⁴, Serena Guiducci⁶, Marco Sebastiani^1|14. | ¹Ospedale Guglielmo da Saliceto, Piacenza, Italy; ²Università degli studi di Modena e Reggio Emilia, Modena, Italy; ³IRCCS Arcispedale Santa Maria Nuova, Reggio Emilia, Italy; ⁴AOUI, Università degli studi di Verona, Verona, Italy; ⁵A.O. Mauriziano di Torino, Università degli studi di Torino, Torino, Italy; ⁶AOU di Careggi, Università degli studi di Firenze, Firenze, Italy; ⁷AOU Policlinico di Bari, università degli studi di Bari Aldo Moro, Bari, Italy; ⁸AOU Policlinico di Modena, Modena, Italy; ⁹AOU Gaetano Martino, Università degli studi di Messina, Messina, Italy; ¹⁰Azienda Ospedaliera Regionale San Carlo, Potenza, Italy; ¹¹AO Vittorio Emanuele, Catania, Italy; ¹²ASST Gaetano Pini, Milano, Italy; ¹³ASST Spedali Civili, Brescia, Italy; ¹⁴Università degli studi di Parma, Parma, Italy.

Background. Abatacept has been suggested to be a safe and effective drug for the treatment of rheumatoid arthritis (RA) complicated by interstitial lung disease (ILD), one of the most severe extra-articular manifestations of RA. Objectives. In this prospective multicentre observational study, we aimed to evaluate the effectiveness and safety of abatacept on RA-ILD. Concurrently, the study aimed to evaluate the incidence of new diagnosis of ILD in RA patients treated with abatacept.

Methods. We enrolled all consecutive RA patients already under treatment with abatacept for at least three months referred to 12 rheumatological centres in Italy. ILD patients were followed according to the current clinical practice: forced vital capacity (FVC%) was repeated every six months, while chest high resolution computed tomography (HRCT) was performed annually or when respiratory symptoms worsened. In patients without ILD at baseline, a careful assessment for respiratory symptoms and velcro crackles was performed at enrolment and every six months. HRCT was requested in case of new-onset dyspnoea, persistent dry cough, or detection of velcro crackles.

Results. We enrolled 325 RA patients treated with abatacept. Among them, ILD was already present in 20.6% of cases. A usual interstitial pneumonia (UIP) pattern was detected 25.4% of cases. The two-year retention rate of abatacept was 79.6% ±3.8 and 76.8%±10.6 in patients without and with ILD, respectively, without difference between the two groups. Two cases of infectious pneumonia were reported in ILD group, requiring a transient discontinuation of abatacept. No patients discontinued abatacept for a worsening of lung function, and no episodes of acute exacerbation of ILD were observed during the study. At the end of follow-up, the radiological picture remained stable in 71.6% of subjects, improved in 13.4%, and worsened in 14.9%. A worsening at HRCT was recorded in 29.4% of cases of UIP, and only in 10% of patients with other ILD patterns (p not significant). Regarding lung function tests, FVC improved in 13.4% of cases, remained unchanged in 74.6%, and worsened in 11.9%. During the 24-month period of follow-up, 2 patients developed ILD, with an incidence of 0.39 new ILD cases/100 patients/year.

Conclusions. Our study confirmed the safety and the effectiveness of abatacept in this population of difficult to treat RA patients. Of interest, ILD didn’t affect the retention rate of the drug. Moreover, lung function and HRCT features improved or remained stable in about 85% of patients, suggesting a role for abatacept in the treatment of RA-ILD. Concurrently, we observed a low rate of new cases of ILD, with an incidence rate of 0.39 new ILD cases/100 patients/year. Controlled studies, specifically developed in RA-ILD population, will be necessary to define the efficacy and safety of abatacept compared to other biologic DMARDs.