Skip to main content
Figure 2 | Arthritis Research & Therapy

Figure 2

From: Identification of urinary metabolites that distinguish membranous lupus nephritis from proliferative lupus nephritis and focal segmental glomerulosclerosis

Figure 2

Principal component analysis of urine samples from patients with class III/IV LN and class V LN. (a) Two-dimensional principal component analysis scores plot of urine samples from patients with class III/IV LN (green) and class V LN (black) for peaks in the region from δ 3.40 to 4.50 ppm calculated using the first two principal components. Each point in the scores plot represents the NMR spectrum of an individual patient projected onto the two-dimensional space defined by the first two principal components. The dashed lines encircling the points define the 95% confidence intervals for each group. The color-matched stars indicate the centroid of each group and the line connecting the stars represents the Mahalanobis distance between the group centroids. (b) The loadings plot corresponding to the scores plot shown in Figure 1a. The labeled bucket (point) corresponds to the triplet belonging to taurine in the 1H NMR spectra. The coordinates of each point indicate the PC loadings for that bucket, and represent how strongly that bucket is weighted in the eigenvector defining either the first or second principal component. The loadings plot points are heat map color-coded according to bucket P value: Black (> 1.25 × 10-2), Blue (1.25 × 10-2-10-5). The Bonferroni corrected α-value was 0.0125.

Back to article page