Catastrophic antiphospholipid syndromes in systemic lupus erythematosus

The objective of this study was to look for the occurrence of catastrophic antiphospholipid syndromes (APS) and to try to detect discriminating factor s for predicting a worse prognosis, related to Lupus anticoagulant (LA) and antiphospholipid antibodies (aPL), in systemic lupus erythematosus (SLE) w ith main renal involvement. Regression, recursive partition and logistic re gression analyses were applied to our 80 SLE patients prospectively followe d up since 1980. Immunologic and other laboratory parameters including beta (2)-glycoprotein 1 dependence, resistance to activated protein C caused by a substitution on the coagulation factor V gene, induction of monocyte proc oagulant activity. Regression studies demonstrated an overall worse prognosis in term of both thrombosis and death for the group of LA/aPL positive patients (33/80). How ever, recursive partition analysis was able to isolate a small high risk-su bgroup (8/33) characterized by persistent LA/aPL antibodies positive result , widespread signs of noninflammatory vasculopathy (skin, brain, kidney) an d renal pathology mimicking that of thrombotic microangiopathy or arteriolo sclerosis, also in the absence of classic SLE-nephritis. Only in this subse t, three catastropic APS were recorded, while, in traditional SLE nephritis , even persistent LA/aPL positive results (sometimes after one previous thr ombosis) did not seem to imply a particularly severe prognosis. All serolog ic criteria employed are unable to identify high-risk patients. We conclude that catastrophic APS is a rare event in renal SLE. Before more predictive serologic markers become available, a simple algorithm, dealing with clinical data and renal histologic patterns, may help physicians to i dentify putatively high risk-LA/aPL antibodies in SLE patients with main re nal involvement. This ominous subset does not belong to the group of classi c SLE-nephritis.