Case-Based Immunology: B Cells and Systemic Sclerosis Interstitial Lung Disease.

Interstitial lung disease (ILD) is an important complication of systemic sclerosis (SSc), with high mortality and morbidity. Recent clinical studies in SSc-ILD have led to US Food and Drug Administration-approved therapies in SSc-ILD. Importantly, evidence from these studies has been extrapolated to guide management of ILDs of other systemic autoimmune rheumatic diseases. Pathogenesis of SSc-ILD involves interplay between fibroblasts and the innate and adaptive immune system. A central role for the B cell compartment is supported by clinical and translational studies. We use a case from our center as a basis to discuss the pathogenesis of SSc-ILD, autoantibodies in SSc-ILD, and the role of B cells in the disease. We go on to consider treatment options for the case, the decision-making algorithm for treatment, and risks associated with treatment.