Cell-based immunofluorescence assay cutoffs of HD mean + 5 SD for the different Ags and the different cohorts were as follows: (RA: 24.0 [MOG], 20.2 [AQP4], 1.0 [AChR], 25.5 [MuSK]; T1D: 23.5 [MOG], 1.1 [AQP4], 1.4 [AChR], 32.4 [MuSK]; SLE: 6.7 [MOG], 3.9 [AQP4], 10.5 [AChR], 12.6 [MuSK]; SLE-neuro: 8.5 [MOG], 4.7 [AQP4], 3.4 [AChR], 15.8 [MuSK]; neurologic [MS, NMOSD, OND]: 51.2 [MOG], 1.5 [AQP4], 1.0 [AChR], 28.0 [MuSK]). Here, AQP4 is linked to systemic lupus erythematosus.