Ten-day polyclonal activation results in maximum IgG accumulation and higher MFI values compared to 6 days of activation. A, Percentages of ASCs (CD19+CD27+CD38high) before (d0) and at d6, d10, and d14 of polyclonal activation (n = 9 [re-tx n = 3, multiparous n = 1 and alloantigen nonexposed n = 5]). B, IgG concentrations at d6, d10, and d14 of polyclonal activation (n = 9). C and D, Background corrected MFI values of all beads for HLA class I and class II measured in d6 and d10 concentrated culture supernatants (n = 13 [re-tx n = 11 and multiparous n = 2]). Each dot represents BCM value of one bead. ASC, antibody-secreting cells; BCM, background corrected MFI values; MFI, mean fluorescence intensity; re-tx, repeat transplantation; d0, day 0; d6, day 6; d10, day 10; d14, day 14.