Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement
The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.
Urine Cyto/Chemokines Correlate with Renal Histopathology in Systemic Lupus Erythematosus
Landolt-Marticorena1, C., Reich2, H., Morrison3, S., Aghdassi3, E., Pineau4, C. A., Scholey5, J., Gladman3, D.
U of Toronto, Toronto Western Hospital, Toronto, ON
University Heath Network, Toronto, ON
Toronto Western Hospital, Toronto, ON
MUHC, Montreal, QC
University Health Network, Toronto, ON
U. Toronto, Toronto, ON
Renal biopsies are the gold standard for the assessment of renal activity and chronicity in SLE patients. Urinary biomarkers may serve as a less invasive alternative in the management of lupus nephritis (LN). In an initial screen of 20 cyto/chemokines urine concentrations of IP-10, MCP-1, adiponectin, IL-15 and sVCAM were found to be elevated in patients with active LN. We therefore examined the relationship between renal histopathology and the urine concentration of these 5 analytes at the time of biopsy.
Patients (n = 22) satisfying 4 or more ACR criteria undergoing renal biopsy were recruited from a longitudinal clinical cohort. Plasma and urine were obtained coincident with biopsy. 19 healthy controls were also recruited. The plasma and urine concentrations of 5 analytes was determined by a Luminex assay with urine concentrations corrected for creatinine excretion. Patients were segregated into active (ISN/ASN; III to V; n = 19) and inactive (chronic, n = 3) based on renal histopathology. Elevated urine analyte concentration was defined as values >= 2 standard deviations above the mean in controls. Mann Whitney non-parametric test was used for comparisons between groups. The statistical significance of correlations was determined by linear regression analysis.
The urine concentration of IP-10 (p < 0.0001), MCP-1 (p < 0.0001), adiponectin (p = 0.0004), IL-15 (p = 0.0006) and sVCAM (p = 0.007) were significantly elevated in SLE patients versus controls. There was a moderate positive correlation between the urine and plasma concentration of IP-10 (r = 0.54, p = 0.009) but none of the other analytes. Elevated urine concentrations of MCP-1, IP-10, adiponectin and IL-15 were seen in 82.3%, 68.1%, 54.5% and 40.9% respectively. As only 22.7 % of patients had elevated urine sVCAM this analyte was excluded from further analysis. To assess if increased urinary analyte concentrations discriminate between active and inactive LN, the absolute number of elevated values for all 4 analytes were summed to create a global score (maximum = 4). Patients with active renal lesions had a statistically significant increase (p = 0.03) in the global score versus patients with established fibrosis. All 3 patients with fibrosis had scores <= 1 whereas the majority (73.8 %) of patients with active renal lesions had scores >= 2. In patients with proliferative lesions (ISN III or IV) 85.7% patients (n = 14) had scores of 2 or greater whilst 75 % (n = 4) patients with membranous LN (ISN V) had scores of 1 with a single patient having a score of 4.
Urinary elevation in selected cyto/chemokines effectively discriminate between active and chronic renal lesions. The elevation of 2 or more analytes was sufficient to identify proliferative renal lesions. These results suggest that urinary cyto/chemokines reflect underlying renal pathology and may serve as alternatives to renal biopsy.
To cite this abstract, please use the following information:
Landolt-Marticorena, C., Reich, H., Morrison, S., Aghdassi, E., Pineau, C. A., Scholey, J., et al; Urine Cyto/Chemokines Correlate with Renal Histopathology in Systemic Lupus Erythematosus [abstract]. Arthritis Rheum 2009;60 Suppl 10 :564