Among immune-related comorbidities, we identified several associations consistent with previously reported epidemiological data (Fig. 1): RA with SLE and psoriasis (Lin et al. 1998; Alarcon-Segovia et al. 2005; Naldi and Mercuri 2010), MS and asthma with psoriasis (Fang et al. 2015; Egeberg et al. 2016), and RF with scarlet fever and throat/ear infections (Soderholm et al. 2018). We also found an association between IBD and RF, consistent with preliminary evidence for shared genetic risk (Abdallah et al. 2016) and data linking IBD with other immune-mediated diseases (Halling et al. 2017).
