Antiphospholipid antibodies and kidney involvement in patients with lupus nephritis

A large spectrum of renal manifestations has been described in association with antiphospholipid antibodies (aPL Ab) such as renal artery stenosis, renal infarction, renal vein thrombosis, and the more recently described "antiphospholipid antibodies nephropathy" (APSN): vaso occlusive lesions of intrarenal vessels associating acute thrombosis with chronic arteriolar lesions leading to zone of cortical ischemic atrophy. Acute and chronic APSN have been demonstrated to be significantly associated with presence of aPL Ab in patients with lupus nephritis (LN). From a clinical point of view, the renal manifestations of LN and those of APSN may be similar. Renal insufficiency and arterial hypertension are more frequently observed in APSN while proteinuria and hematuria are more frequent in LN. The impact of aPL Ab on the natural history of lupus nephritis is still far from being clarified. Theoretically the histologic renal lesions caused by aPL Ab as well as the development of persistent arterial hypertension in a consistent number of aPL Ab positive patients with LN should be considered as predictors of a bad renal outcome. In our experience, after a mean follow-up of 14 years, 45% of aPL Ab positive patients vs. 19.5% of negative patients (p = 0.01) developed chronic renal insufficiency.