Evaluation of clinical outcomes and renal vascular pathology among patients with lupus

Background and objectives The objective of this study was to determine the clinical significance of renal vascular lesions in lupus nephritis. Design, setting, participants, & measurements Renal vascular lesions defined as thrombotic microangiopathy, lupus vasculopathy, uncomplicated vascular immune deposits, and arterial sclerosis were evaluated in relation to renal and vascular morbidity and overall mortality. Results Biopsies from 161 patients revealed thrombotic microangiopathy (13), lupus vasculopathy (5), and arterial sclerosis (93). No renal vascular lesions were found in 24.8% of patients. At the time of biopsy, arterial sclerosis or lupus vasculopathy patients were older (arterial sclerosis=37.9±13.0 and lupus vasculopathy=44.4±8.9 versus controls=33.1±8.9 years, P,0.05), and the mean arterial pressurewas higher in all groups compared with controls. Nephritis subtype, activity indices, and proteinuria were similar between groups, estimated GFR was lower in arterial sclerosis (70.5±33.3 versus 84.5±26.6 ml/min per 1.73 m ², P=0.03), and chronicity index (thrombotic microangiopathy=3.5, lupus vasculopathy=4.5, and arterial sclerosis=2.5) was higher in all renal vascular lesions subgroups versus controls (1.0, P,0.05). In 133 patientswith similar follow-up, the association between renal vascular lesions and vascular eventswas significant (Fisher exact test, P=0.002) and remained so after multivariate analysis (exact conditional scores test, P=0.04), where the difference between arterial sclerosis and uncomplicated vascular immune deposits was most noticeable (odds ratio [95% confidence interval]=8.35[0.98, 83.12], P=0.05). The associations between renal vascular lesions, renal outcomes, and death were not significant, likely because of insufficient power. Conclusions Renal vascular lesions are common in SLE patients with nephritis and may be associated with arterial vascular events.