Antibody-Array-Based Proteomic Screening of Serum Markers in Systemic Lupus Erythematosus: A Discovery Study

Abstract

A discovery study was carried out where serum samples from 22 systemic lupus erythematosus (SLE) patients and matched healthy controls were hybridized to antibody-coated glass slide arrays that interrogated the level of 274 human proteins. On the basis of these screens, 48 proteins were selected for ELISA-based validation in an independent cohort of 28 SLE patients. Whereas AXL, ferritin, and sTNFRII were significantly elevated in patients with active lupus nephritis (LN) relative to SLE patients who were quiescent, other molecules such as OPN, sTNFRI, sTNFRII, IGFBP2, SIGLEC5, FAS, and MMP10 exhibited the capacity to distinguish SLE from healthy controls with ROC AUC exceeding 90%, all with p < 0.001 significance. These serum markers were next tested in a cohort of 45 LN patients, where serum was obtained at the time of renal biopsy. In these patients, sTNFRII exhibited the strongest correlation with eGFR (r = −0.50, p = 0.0014) and serum creatinine (r = 0.57, p = 0.0001), although AXL, FAS, and IGFBP2 also correlated with these clinical measures of renal function. When concurrent renal biopsies from these patients were examined, serum FAS, IGFBP2, and TNFRII showed significant positive correlations with renal pathology activity index, while sTNFRII displayed the highest correlation with concurrently scored renal pathology chronicity index (r = 0.57, p = 0.001). Finally, in a longitudinal cohort of seven SLE patients examined at ∼3 month intervals, AXL, ICAM-1, IGFBP2, SIGLEC5, sTNFRII, and VCAM-1 demonstrated the ability to track with concurrent disease flare, with significant subject to subject variation. In summary, serum proteins have the capacity to identify patients with active nephritis, flares, and renal pathology activity or chronicity changes, although larger longitudinal cohort studies are warranted.

Identification of Novel Autoantibodies Associated With Psoriatic Arthritis

“…A t ‐test was used if the data passed the D'Agostino‐Pearson normality test; otherwise, the nonparametric Mann‐Whitney U test was used to analyze the data. Likewise, the Pearson's method or nonparametric Spearman's method was used for correlation analyses, as described previously . Tests for multiple comparisons were performed using GraphPad Prism software version 6.…”

Insulin-Like Growth Factor Binding Proteins in Autoimmune Diseases

“…In SLE, IGFBP2, IGFBP4 and IGFBP6 were discovered by array-based proteomic screening as diagnostic biomarkers for lupus (89). Later validation studies using a larger study population confirmed the role of IGFBP2 as a diagnostic biomarker for SLE as well as lupus nephritis (88, 90).…”

Urine biomarkers in renal allograft

“…The value of the assays has been validated as a means of reducing the need for kidney transplant biopsy and applying biopsy in a more targeted manner. [40] Together, the previous findings have provided solid foundation for future work aimed at improving kidney transplant outcomes through biomarker-guided decisionmaking. [41] The development of novel biomarkers and detection technologies may lead to the creation of multiplex assays, which allows for the measurement of multiple specific biomarkers simultaneously in the same analyte.…”