Clinical significance of antiphospholipid syndrome nephropathy (APSN) in patients with systemic lupus erythematosus (SLE)

Abstract

Antiphospholipid syndrome nephropathy (APSN) is now a well recognized vaso-occlusive renal lesion associated with acute thrombosis and chronic arterial and arteriolar lesions, leading to zones of cortical ischemic atrophy. Our objective was to evaluate the prevalence and clinical significance of APSN in patients with Systemic Lupus Erythematosus (SLE). Methods Kidney biopsy specimens obtained from 162 patients with lupus glomerulonephritis were retrospectively examined for the presence of APSN. Clinical and laboratory data obtained at the time of kidney biopsy and during a mean follow-up of 7 years were recorded. In cases for which serial kidney biopsy specimens were available, the evolution of APSN was examined. Results We found APSN in 17 (10.4%) patients with lupus glomerulonephritis (GN), 12 with focal or proliferative lesions. Both activity and chronicity indexes were higher in patients with APSN when compared with lupus nephritis without APSN. Patients with APSN had a higher frequency of hypertension and elevated serum creatinine levels at the time or kidney biopsy, as well as a higher frequency of rapidly progressive GN, nephrotic syndrome and death at the end of the follow-up. Anticardiolipin antibodies were found in 52% of those with APSN and in 27% of those without APSN. Serial kidney biopsy specimens were available from 18 patients. An increase of glomerular sclerosis was found in the second biopsy particularly in those patients with APSN in the first biopsy. Conclusions APSN is a risk factor that contributes to an elevated prevalence of hypertension, elevated serum creatinine, nephrotic syndrome and increased glomerular sclerosis. APSN should be included in the classification criteria of APS, and the use of appropriate anticoagulant therapy should be tested.