All samples ( ) Positive FXM ( ) Negative FXM ( ) valueRecipient age, m (SD) 35.0 ± 12.7 33.8 ± 11.2 36.2 ± 14.1 0.510 Recipient male gender, (%) 23 (46.0) 9 (36.0) 14 (56.0) 0.156 Donor age, m (SD) 42.2 ± 11.9 43.7 ± 10.6 40.7 ± 13.1 0.385 Donor male gender, (%) 21 (42.0) 12 (48.0) 9 (36.0) 0.390 Previous transplant, (%) 18 (38.3) 12 (50.0) 6 (26.1) 0.092 HLA MM, med (IQR) 4 (4–6) 4 (3–6) 4 (4–6) 0.889 HLA MM DR/DQ, med (IQR) 2 (1-2) 2 (2-2) 2 (1-2) 0.495 % PRA class I, med (min–max) 15 (0–90) 14.0 (2–90) 16 (0–60) 0.259 % PRA class II, med (min–max) 10 (4–24) 13 (1–89) 9 (0–100) 0.466 Class I DSA, (%) 29 (58.0) 14 (56.0) 15 (60.0) 0.774 Class II DSA, (%) 35 (70.0) 18 (72.0) 17 (68.0) 0.758 HLA antibodies analyzed by LABScreen SAB of DSA, m (min–max)1.72 (1–6) 1.84 (1–6) 1.6 (1–4) 0.769 MFI DSA, med (IQR) 2,138 (1,160–7,147) 5,166 (1,457–12,829) 1,457 (1,113–2,293) 0.001 of all HLA-Ab, med (IQR)12 (6–28) 12 (10–26) 8 (4–28) 0.164 MFI all HLA-Ab, med (IQR) 10,128 (3,813–15,407) 13,312 (5,681–18,666) 3,937 (2,192–13,312) 0.006 HLA-A DSA, (%) 16 (32.0) 7 (28.0) 9 (36.0) 0.544 MFI DSA HLA-A, med (IQR) 1,294.5 (763–4,155.5) 4,467 (3,141–11,526) 828 (664–1,113) 0.003 HLA-B DSA, (%) 9 (18.0) 5 (20.0) 4 (16.0) 1.00 MFI DSA HLA-B, med (IQR) 1,427 (759–2,669) 2,669 (1,427–5,670) 838 (706.5–1,190) 0.141 HLA-C DSA, (%) 12 (24.0) 5 (20.0) 7 (28.0) 0.508 MFI DSA HLA-C, med (IQR) 1,866 (843.5–2,739.5) 2,362 (2,303–2,505) 1,247 (612–2,974) 0.329 HLA-DR DSA, (%) 20 (40.0) 9 (36.0) 11 (44.0) 0.564 MFI DSA HLA-DR, med (IQR) 1,752.5 (1,177.5–3,986) 5,145 (1,457–8,651) 1,515 (1,127–2,216) 0.048 HLA-DQ DSA, (%) 21 (42.0) 13 (52.0) 7 (32.0) 0.152 MFI DSA HLA-DQ, med (IQR) 7,147 (1,247–14,710) 12,829 (1,578–17,976) 1,615 (908.5–5,710) 0.042 HLA antibodies by C1q assay All C1q+ Ab, (%) 26 (53.06) 19 (76.0) 7 (28.0) 0.001 DSA C1q+ Ab, (%) 10 (20.41) 9 (36.0) 1 (4.0) 0.005 Non-DSA C1q+ Ab, (%) 16 (32.65) 10 (40) 6 (24.0) 0.023 HLA-A C1q+ Ab, (%) 6 (12.0) 4 (16.0) 2 (8.0) 0.667 HLA-B C1q+ Ab, (%) 8 (16.0) 6 (24.0) 2 (8.0) 0.247 HLA-C C1q+ Ab, (%) 3 (6.0) 1 (4.0) 2 (8.0) 1.0 HLA-DP C1q+ Ab, (%) 6 (6.0) 3 (12.0) 0 0.235 HLA-DQ C1q+ Ab, (%) 19 (38.0) 16 (64.0) 3 (12.0) <0.001 HLA-DR C1q+ Ab, (%) 8 (16.0) 7 (28.0) 1 (4.0) 0.049