Visfatin and adiponectin as novel markers for evaluation of metabolic disturbance in recently diagnosed rheumatoid arthritis patients.

The aim is to assess metabolic disturbance in early rheumatoid arthritis patients and its relation to the clinical characteristics of patients. Forty recently diagnosed untreated rheumatoid arthritis (RA) patients with disease duration less than 1 year (group I) along with age- and sex-matched forty healthy volunteers who served as controls (group II) were studied. Disease activity score was used to assess disease activity. Blood pressure, BMI, glucose, insulin and complete lipid profile, visfatin, and adiponectin were measured. Insulin resistance (IR) was estimated by the homeostasis model assessment for insulin resistance (HOMA-IR). Beta-cell function was estimated by the homeostasis model assessment (HOMA-B). Also, rheumatoid factor, anticyclic citrullinated peptide antibodies were measured. Group I had significantly higher fasting insulin, HOMA-(IR, B), visfatin, lipid profile (except HDL), and lower adiponectin versus group II (p = 0.000). There were significant positive correlations between visfatin and the following biochemical parameters: insulin, HOMA-IR, HOMA-B, cholesterol, triglycerides, LDL-C (p = 0.05, 0.029, 0.005, 0.001, 0.002, 0.045, respectively). Also, the disease activity score was positively correlated with visfatin (p = 0.003). Meanwhile, there were significant negative correlations between adiponectin and the following biochemical parameters: insulin, HOMA-IR, HOMA-B, cholesterol, triglycerides, LDL-C, visfatin (p = 0.031, 0.023, 0.001, 0.000, 0.000, 0.016, 0.000, respectively). Also, the disease activity score was negatively correlated with adiponectin (p = 0.001). The findings of the present study showed that recently diagnosed untreated RA patients are characterized by a severe metabolic disturbance state that is driven primarily by disease activity.

Urinary angiostatin, CXCL4 and VCAM-1 as biomarkers of lupus nephritis.

BACKGROUND: The aim was to study urinary angiostatin, CXC chemokine ligand 4 (CXCL4) and vascular cell adhesion molecule-1 (VCAM-1) as biomarkers of renal disease in systemic lupus erythematosus (SLE). METHOD: Patients who fulfilled ≥ 4 American College of Rheumatology (ACR) criteria for SLE with active renal, active non-renal or inactive disease, and a group of healthy controls were studied. Urine samples were assayed for angiostatin, CXCL4 and VCAM-1 by ELISA, and normalized by creatinine. Receiver operating characteristic analysis was performed to obtain the best cutoff values to calculate the performance of these markers in differentiating the different groups of patients as compared to anti-double-stranded DNA (anti-dsDNA) and complement C3. Correlation between these urinary biomarkers and various renal parameters was also tested. RESULTS: Patients with SLE (n = 227; 80 with inactive SLE, 67 with active non-renal disease and 80 with active renal disease; 94% women; age 39.2 ± 13.8 years) and 53 controls (96% women) were studied. All were ethnic Chinese. Urinary angiostatin, CXCL4 and VCAM-1 (normalized for creatinine) were significantly higher in patients with active renal disease than in patients with active non-renal disease, patients with inactive SLE and controls. These markers correlated significantly with total SLE disease activity index (SLEDAI) and renal SLEDAI scores, and with the urinary protein-to-creatinine ratio. Urine angiostatin exhibited higher specificity and sensitivity in differentiating active renal from active non-renal SLE (area under the curve (AUC) 0.87) than serum anti-dsDNA/C3. Urine CXCL4 (AUC 0.64) and VCAM-1 (AUC 0.73), on the other hand, performed similarly to anti-dsDNA/C3. All three markers performed comparably to anti-dsDNA/C3 in distinguishing active from inactive SLE. In a subgroup of 68 patients with paired renal biopsy, the urinary levels of these proteins did not differ significantly between the proliferative and non-proliferative types of lupus nephritis. Urinary CXCL4 and VCAM-1 correlated significantly with the histologic activity score, and urinary angiostatin correlated significantly with proteinuria in this subgroup. CONCLUSIONS: Urinary angiostatin, CXCL4 and VCAM-1 are potential biomarkers for SLE, in particular lupus nephritis. Further longitudinal studies are necessary to delineate the performance of these markers in predicting renal flares and prognosis in SLE patients.