Figure 2.

Recombinant human glutamic acid decarboxylase (GAD)₆₅ in-vitro enzyme activity in the presence of sera from stiff-person syndrome (SPS) (circles, n = 12), type 1 diabetes mellitus (T1D) (squares, n = 7), GAD-alum (rhombuses, n = 9) and high-risk (triangles, n = 6) groups. Open circles in the SPS group (n = 8) represent individuals with co-existent T1D, whereas open triangles in the high-risk group (n = 3) represent individuals who developed T1D after sampling. Results are expressed as a percentage of maximum GAD₆₅ enzyme activity. Significant differences are indicated as P-values and horizontal lines represent the median.