[The criteria for indication of plasma exchange on lupus nephritis].

Although many reports have been made on the effectiveness of plasma exchange (PE) in active systemic lupus erythematosus (SLE), but there are no clear-cut criteria of indication for lupus nephritis (LN). In order to determine the criteria for indication of LN, 35 patients with LN treated by PE were studied with respect to renal function (F), proteinuria (P), immunological activity (A) and renal histology. The patients were divided into 4 groups according to the severity of renal function: F1 (stable chronic renal failure (CRF) or stable renal function n = 13), F2 (relapse type n = 9), F3 (rapidly progressive LN; creatinine clearance (Ccr) less than 40 ml/min n = 7) and F4 (acute renal failure; Ccr less than 10 ml/min n = 6). Proteinuria was also studied in 4 groups: P1 & P2 (without nephrotic syndrome (NS], P3 (acute type NS n = 15), and P4 (chronic type NS n = 7). These patients were divided into 3 groups to study immunological activity: A1 (chronic stage n = 6), A2 (relapse stage n = 12) and A3 (active stage n = 17). Comparison was made in each parameter. Renal histological classification according to WHO criteria of LN, activity score (AS) and chronicity score (CS) were evaluated and compared. As a result, the following indication was obtained. 1) ABSOLUTE INDICATION: 1. Rapidly progressive LN with high immunological activity; elevated serum creatinine (SCr) greater than 1.0 mg/dl/month or decreased Ccr from normal renal function to less than 40 ml/min within 1-2 months after onset. 2. Acute type NS within 1 year after onset. 3. histological AS greater than 20. 2) RELATIVE INDICATION: 1. Relapse LN with moderate immunological activity, decreased Ccr from normal function to 40-50 ml/min within 3-6 months, the rise in SCr of greater than 1.0 mg/dl/month. 2. Proteinuria is 1.0-3.5 g/day within 1 year after onset. 3. Such complication as CNS, serositis, thrombocytopenia and leukopenia, steroid resistance and/or severe side effects of steroid. 3) NO INDICATION: 1. CRF or stable renal function (Ccr greater than 50 ml/min). 2. Chronic type NS over 1 years with past history of NS and/or edema. 3. Low immunological activity and mild renal histology.