LIPS detection of anti-TPO, gastric H/K ATPase and anti-AQP4 antibodies. Each circle or square symbol represents an individual normal volunteer (NV) or SjS patient sample, respectively. For determining sensitivity and specificity, the dashed line represents the cut-off level derived from mean plus 3 SD of the antibody titer of the 25 normal volunteers, while the solid line is the cut-off for the mean plus 5 SD. (A) Anti-TPO autoantibodies, (B), Anti-H + /K + gastric ATPase autoantibodies (C). Anti-AQP-4 autoantibodies.