Table 1.
Demographics and Clinical characteristics of LN patients used for validations studies.
Table 2.
Characteristics of Controls used for validation studies.
Fig 1.
Serum IGFBP-4 levels were elevated in patients with lupus nephritis.
Serum 86 patients with LN, 23 healthy controls, 20 patients with CKD and 15 patients with RA were assayed for serum IGFBP-4 levels by ELISA. Plotted in (A) are serum levels of IGFBP-4 in the 3 groups, indicating significantly higher levels in LN as compared to the CKD, RA and healthy controls (P < 0.01 and P < 0.0001, respectively). Receiver operating characteristic curves were generated using serum IGFBP-4 levels measured by ELISA (B). Also indicated are the corresponding AUC values. Plotted in (C) are serum IGFBP-4 levels in two groups of patients with LN, those with active LN (rSLEDAI > 0) and those with non-active LN (rSLEDAI = 0), P > 0.3. D: serum IGFBP-4 levels in patients with LN of different ISN/RPS classes, whose blood samples were obtained within 5 months of renal biopsy. No statistical significance were found among the patients with LN of classes II (n = 4), III (n = 9), IV (n = 19), and V (n = 8), P > 0.05.
Fig 2.
Correlation between serum IGFBP-4 levels and clinical parameters.
Serum IGFBP-4 levels were plotted against severity of proteinuria, as measured by spot urinary protein:creatinine ratio (A), serum creatinine (B), eGFR (as calculated using the MDRD study equation (C), and systemic lupus erythematosus disease activity index (SLEDAI, D), respectively. Also plotted are the corresponding R and P values. eGFR, estimated glomerular filtration rate.
Fig 3.
Correlation between serum IGFBP-4 levels with renal pathology.
Serum IGFBP-4 levels in 18 patients with proliferative (ISN/RPS class III and class IV) LN whose blood samples were obtained at the time of renal biopsy were correlated with the activity index (A) and chronicity index (B) of renal pathology, as detailed in methods. Also depicted are correlations of eGFR with chronicity index (C). eGFR, estimated glomerular filtration rate.
Fig 4.
Plotted in (A) are urine protein creatinine ratios (UPCR) versus serum IGFBP4 levels in the CKD control subjects. Plotted in (B) are the serum beta-2-microglobulin levels, as assessed by ELISA, in lupus nephritis patients, healthy controls and CKD controls. Other details are as listed in Fig 1 legend.