Eight courses of LDL-apheresis (LDL-A) with the liposorber LA-15 system (Kaneka, Osaka, Japan) were analyzed in 6 patients with steroid-resistant nephrotic syndrome. Of the 8 courses of LDL-A, 5 were administered to treat focal glomerular sclerosis and 3 for minimal-change type nephrotic syndrome in 4 male and 4 female patients. The patients averaged 46.1 +/- 12.4 years in age at the time of LDL-A. LDL-A treatment consisted of about 4,000 ml of blood plasma over 2-3 hours, and was performed 1-3 times per week and 9-12 times (average: 11.6) per course. Before and after a course of LDL-A, 24-hour urine protein, creatinine clearance (CCr), biochemistry tests, and coagulation tests (thrombin-anti thrombin III complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC), and beta-thromboglobulin (beta-TG)) were performed. Of the 8 courses, 4 achieved a complete remission, and one achieved a type I incomplete remission (response group). Two patients receiving the other three courses eventually required hemodialysis (non-response group). In the response group, LDL-A was administered for an average of 3.8 +/- 2.0 months after the disease onset. This interval was significantly shorter than that of 23.3 +/- 10.3 months in the non-response group (p = 0.005). Before LDL-A, TAT was 38.0 +/- 19.1 and 7.6 +/- 2.1 ng/ml in the response and non-response groups, respectively, showing a significant difference (p = 0.037). In the response group, CCr was 37.0 +/- 5.0 ml/min before LDL-A, and increased significantly to 55.7 +/- 12.0 ml/min after LDL-A (p = 0.038). The disease did not recur in the response group after an average of 37 months of follow-up. These results indicate that LDL-A should be performed as early as possible after the onset of nephrotic syndrome, and that before LDL-A, TAT was high in the response group.