Figure 3.

Principal-component analysis of the presence of 10 antibodies and 19 clinical signs for 57 patients diagnosed with SSc, SLE, or UCTD. The plot is based on principal components 1 and 3, which explain 18.96% and 8.74% of the total variance of the data, respectively. The individual disease populations are circumscribed by an ellipse representing an 87% confidence level.