Impact of preformed donor-specific antibodies against HLA class I on kidney graft outcomes: Comparative analysis of exclusively anti-Cw vs anti-A and/or -B antibodies

Table 1 Baseline characteristics of donor-specific antibodies-Cw and donor-specific antibodies-A-B groups

	DSA-A-Bn = 23	DSA-Cwn = 12	P
Recipient
Age (yr), median (IQR)	48 (39-55)	39 (33-49)	0.061
Female gender, n (%)	13 (57)	6 (50)	0.713
Retransplant, n (%)	11 (48)	5 (42)	0.728
Previous blood transfusions, n (%)	9 (39)	9 (75)	0.044
Previous pregnancies, n (%)	8 (35)	8 (33)	1
Kidney-pancreas transplantation, n (%)	1 (4)	1 (8)	1
Donor
Age (yr), median (IQR)	45 (36-56)	45 (32-54)	0.542
Female gender, n (%)	8 (35)	8 (33)	1
Living donor, n (%)	1 (4)	2 (17)	0.266
Pretransplant immunological data
Peak PRA, median (IQR)	4 (0-80)	8 (0-52)	0.472
DSA number, median (range)	1 (1-3)	1 (1-2)	0.056
DSAsum MFI, median (IQR)	7583 (2320-12395)	2939 (2529-3650)	0.11
Transplant
ABDR HLA mismatches, mean ± SD	3.22 ± 1.28	4.08 ± 1.16	0.056
FCXM-T + (n = 29), n (%)	1 (6)	3 (27)	0.139
FCXM-B + (n = 29), n (%)	2 (11)	0	0.512
ATG induction, n (%)	14 (61)	9 (75)	0.476
Tacrolimus (vs CsA), n (%)	20 (87)	12 (100)	0.536
Desensitized, n (%)	5 (22)	3 (25)	1
IvIg only, n	2	3
IvIg + PP, n	1	0
IvIg + Rtx + PP, n	2	0

DSA: Donor-specific antibodies; MFI: Mean fluorescence intensity; IQR: Interquartile range; SD: Standard deviation; CKD: Chronic kidney disease; PRA: Panel reactive antibodies; HCV: Hepatitis C virus; CMV: Cytomegalovirus; HLA: Human leukocyte antigen; ATG: Anti-thymocyte globulin; CsA: Cyclosporin; IvIg: Intravenous immunoglobulin; PP: Plasmapheresis; Rtx: Rituximab.

Table 2 Clinical outcomes and follow-up

	DSA-A-Bn = 23	DSA-Cwn = 12	P
Delayed graft function, n (%)	7 (30)	1 (8)	0.216
Acute rejection at 1-yr, n (%)	6 (26)	3 (25)	1
AMR at 1-yr, n (%)	6 (26)	2 (17)	0.685
ACR-only at 1-yr, n (%)	0	1 (8)	0.343
1 yr-eGFR (mL/min), median (IQR)	51 (46-60)	59 (47-64)	0.192
1 yr-ProtU, median (IQR)	0 (0-0.1)	0.1 (0-0.2)	0.163
Censored graft failure, n (%)	2 (9)	0	0.536
Follow-up time (mo), median (IQR) [range]	60 (45-60)	18 (11-50)	0.001
	[28-60]	[3-60]

DSA: Donor-specific antibodies; AMR: Acute antibody-mediated rejection; ACR: Acute cellular rejection; eGFR: Estimated glomerular filtration rate; IQR: Interquartile range; ProtU: Proteinuria.

Table 3 Analysis of possible predictors of acute antibody-mediated rejection occurrence by univariable Cox regression

	HR for AMR	95%CI	P
Recipient
Age (yr), per year	0.96	0.89-1.03	0.269
Female (vs male) gender	0.26	0.05-1.26	0.094
Retransplant	2.18	0.52-9.13	0.287
Previous blood transfusions	0.5	0.12-2.10	0.345
Previous pregnancies	0.24	0.03-1.99	0.187
Donor
Age (yr), per year	1.01	0.96-1.06	0.684
Living donor	1.79	0.22-14.76	0.588
Pretransplant immunological data
Peak PRA, per unit	1.01	1.00-1.03	0.149
DSA Cw (vs AB)	0.6	0.12-2.99	0.537
DSAsum MFI, per 10001	1.07	1.01-1.15	0.034
Transplant
ABDR HLA mismatches, per unit	0.84	0.50-1.41	0.512
ATG (vs basiliximab) induction	1.68	0.34-8.34	0.527
FCXM + (n = 29)	0.75	0.09-6.21	0.787
Desensitized	1.2	0.24-5.97	0.825
Delayed graft function	2.55	0.61-10.68	0.201

¹Only independent predictor identified by multivariable Cox regression model (all variables included) using backward elimination (P-value < 0.050 needed for retention in the model). DSA: Donor-specific antibodies; AMR: Acute antibody-mediated rejection; MFI: Mean fluorescence intensity; ATG: Anti-thymocyte globulin; FCXM: Flow cytometry crossmatch.