Targeting CD20 in the treatment of interstitial lung diseases related to connective tissue diseases: A systematic review

Introduction: The effectiveness of CD20 targeting in connective tissue diseases (CTD) with lung involvement is controversial. This paper aims to review the current evidence about rituximab (RTX) use in CTD-related interstitial lung disease (ILD). Methods: We performed a systematic review of papers published between January 2009 and May 2019. We included clinical trials, case/control studies and cohort studies. We excluded letters, case reports, case series, reviews, and full articles when not in English. The selected studies listed as primary or secondary outcome a variation in pulmonary function tests or in the scores used to radiologically stage lung involvement, in CTD-related ILD patients after RTX. Results: Out of 1206 potentially eligible articles, 24 papers were selected: 3 retrospectively described cohorts of patients with different CTD, 14 dealt with systemic sclerosis (SSc)-related ILD, 5 with idiopathic inflammatory myopathies (IIMs)-related ILD, and 2 with Sjögren's Syndrome-related ILD. A direct comparison of the selected studies was hampered by their heterogeneity for outcomes, follow-up duration, the severity of lung involvement, and clinical features of study populations. However, an overall agreement existed concerning the effectiveness of RTX in the stabilization of lung disease, with some studies reporting an improvement of functional parameters from baseline. IIM-related ILD appeared more responsive than other CTD-related ILD to CD20 targeting. Conclusion: RTX is a promising therapeutic tool in CTD-related ILD. This systematic review remarks the unmet need of multicenter prospective studies aiming to evaluate the effectiveness of RTX with adequate sample size and study design.