Interstitial Lung Disease With Systemic Sclerosis

Systemic sclerosis (SSc) is a heterogeneous multisystem disease characterized by vascular dysfunction, immune abnormalities, and progressive fibrosis of the skin and internal organs. Pulmonary involvement, particularly interstitial lung disease (ILD), is one of the most common and clinically important manifestations of SSc and may lead to impaired pulmonary function, respiratory muscle weakness, reduced diaphragmatic function, and decreased exercise capacity. In addition to pulmonary involvement, systemic inflammation, physical inactivity, nutritional disturbances, and musculoskeletal manifestations may contribute to generalized skeletal muscle dysfunction in individuals with SSc. Pelvic floor dysfunction, including urinary and fecal incontinence, pelvic organ prolapse, pelvic pain, and sexual dysfunction, has also been reported in individuals with SSc. Previous studies have suggested that vascular dysfunction, tissue fibrosis, and structural and functional abnormalities of the pelvic floor may contribute to these symptoms. Furthermore, impaired pelvic floor and sexual function in women with SSc have been associated with several disease-related characteristics, including dyspnea, interstitial lung disease, reduced physical activity, functional disability, and impaired quality of life. The pelvic floor muscles form the inferior component of the core muscle system and function synergistically with the diaphragm and abdominal muscles to regulate intra-abdominal pressure. Coordinated activity between the diaphragm and pelvic floor muscles during respiration has been demonstrated. Therefore, pulmonary and respiratory muscle involvement in SSc may potentially be associated with impaired pelvic floor function. However, the relationships between pelvic floor dysfunction and pulmonary function, respiratory muscle strength, exercise capacity, and core endurance in patients with SSc with pulmonary involvement remain insufficiently understood. Investigating these relationships may contribute to a more comprehensive understanding of pelvic floor dysfunction and its associated factors in this population.

The goal of this clinical trial is to evaluate the efficacy on lung function after 24 weeks of rituximab + MMF combination comparatively to placebo + MMF combination in patients with SSc-ILD severe at the initial assessment or at high risk of progression.