Fig. 1: Aptamer-based screening of lupus nephritis urine samples for 1129 proteins.

a Heatmap representation of aptamer-based screening results of the 1129 proteins analyzed in 23 human urine samples (7 active LN, 8 inactive SLE, 8 healthy controls). 284 urinary proteins were found to be elevated (p < 0.05, fold-change ≥2, Mann–Whitney U-test) when comparing active LN to inactive SLE (top), while 326 urinary proteins were elevated (p < 0.05, fold-change ≥2; Mann–Whitney U-test) when comparing all SLE subjects to healthy controls (bottom). Each map shows the relative concentrations of these proteins after normalizing against urinary creatinine. Each column represents a patient sample, while rows correspond to a creatinine-normalized protein level measured using the screening assay. Proteins that are above the mean value (for each biomarker) are yellow, while those below are blue, with proteins comparable to the mean value are black. b, c The proteins that were significantly elevated in the urine of patients with active LN clustered into 20 pathways with at least 10 upregulated proteins each, as determined by Ingenuity Pathway Analysis, of which 2 are displayed. Additional pathways are included in Supplementary Data. Molecules elevated in LN urine are shaded pink. Documented and putative interactions between the displayed molecules are indicated by solid and interrupted arrows, respectively, based on literature review. d The 50 urine proteins (ranked in order of fold-change) that were significantly elevated in active LN compared to inactive SLE are displayed. Further details regarding these proteins are in included in Supplementary Data (red dots represent active LN; blue dots represent inactive SLE; black dots represent healthy controls). e Random forest classification analysis identification of the 20 most discriminatory urine proteins with the largest impact on distinguishing the study groups, ordered by their GINI coefficient. Source data are provided as a Source Data file.