Anticardiolipin antibodies and lupus anticoagulant in patients treated with different methods of renal replacement therapy in comparison to patients with systemic lupus erythematosus

Abstract

Antiphospholipid antibodies were found to be associated with certain clinical manifestations such as recurrent venous thrombosis or arterial occlusions in a wide spectrum of immune disorders [6]. We analyzed the plasma concentration of two isotypes (IgG, IgM) of anticardiolipin antibodies (ACA) and lupus anticoagulant (LAC) activity in 84 patients with end-stage renal disease. They were receiving different types of renal replacement therapy and had a high frequency of thrombotic vascular complications. The prevalence of positive tests and the mean ACA concentration obtained in the plasma of renal patients were compared with those in patients with systemic lupus erythematosus (SLE) and in healthy controls. When analyzed as a whole group, renal patients maintained on dialysis (n = 45: hemodialysis, n = 20; peritoneal dialysis) or with a functioning kidney transplant (n = 19) did not differ in mean ACA concentration and LAC activity (n = 84, ACA: IgG 10 +/- 7 U/ml, IgM 2 +/- 1 U/ml, LAC ratio: 1.0 +/- 0.2) from healthy subjects (n = 50, ACA: IgG 10 +/- 3, IgM 2 +/- 1 U/ml, LAC ratio: 1.0 +/- 0.1) but they had a higher incidence of raised IgG-ACA titers (renal replacement 14% vs. normal controls 4%, p less than 0.05). No significant correlation was found between thrombotic events and raised ACA or LAC activity in dialysis patients. In contrast, the proportion of SLE patients (n = 51) with a raised concentration of ACA was significantly higher (IgG: 69%, IgM: 29%) than that among patients with renal replacement therapy (IgG: 14%, IgM: 4%) or normal controls (IgG: 4%, IgM: 2%, p less than 0.002). Moreover, recurrent manifestations of thrombosis in SLE were associated with very high IgG-ACA (n = 11, IgG 117 +/- 91 U/ml) and LAC activity (LAC ratio: 2.4 +/- 0.7) in comparison to SLE patients without thrombotic events (n = 40, ACA: IgG 23 +/- 13). The results of our investigations demonstrate that the pathogenetic role of these phospholipid antibodies in end-stage renal disease is far from established.