Fig. 4.
Serum reactivity with premixed P0P1P2 and C-22 peptide by ELISA. SLE sera (n = 48), normal human sera (n = 47) and non-SLE inflammatory sera (n = 48) were random tested by ELISA with premixed P0P1P2 proteins using optimized protocol determined in Fig. 2 or with C-22 peptide (INOVA®, USA). OD450nm values are displayed as scatter plots and horizontal bars represent mean values. Horizontal broken line at 0·2 represents the cut-off value, for premixed P0, P1 and P2 ELISA and the line at 20 units is the recommended cut-off for the C-22 ELISA (INOVA®, USA).