Complement activation and long-term graft function in ABO-incompatible kidney transplantation

Table 1 Patient and donor characteristics

		ABO-incompatible (n = 27)	ABO-compatible (n = 108)	P value
Patient and donor characteristics
Recipient age (yr)		51.6 ± 12.3	51.7 ± 11.6	0.95
Donor age (yr)		53.6 ± 12.1	52.7 ± 12.4	0.73
Recipient gender (% male)		63	63	1.00
Donor gender (% male)		63	44	0.07
Related/unrelated donors (% related)		26	51	0.02
Donor MDRD (mL/min/1.73m2)		96.6 ± 20.5	93.3 ± 18.4	0.42
HLA mismatches (A/B/DR)		3.5 ± 1.6	3.2 ± 1.7	0.48
Mean follow-up patient (yr)		3.7 ± 1.7	3.7 ± 1.6	0.98
Underlying renal disease				0.57
	Glomerulonephritis, (%)	30	27
	Hypertensive disease, (%)	7	18
	Diabetic nephropathy, (%)	4	7
	Cystic kidney disease, (%)	33	19
	Urological disease, (%)	7	8
	Other, (%)	19	21
Blood type combination
	A→O, (%)	59
	B→O, (%)	15
	AB → O, (%)	0
	B →A, (%)	11
	A→ B, (%)	7
	AB→ A, (%)	4
	AB → B, (%)	4
Median pre-treatment IgG anti-A/B titer		1:64 (1:6-1:128)
Median pre-treatment IgM anti-A/B titer		1:8 (1:2-1:28)
Panel reactive antibodies (% positive)		9	7	0.60
Previous renal replacement therapy
First transplantation (%)		89	94	0.30
Pre-emptive transplantation (%)		44	53	0.44
Non pre-emptive (%)		56	47	0.83
	Haemodialysis (%)	34	26
	Peritoneal dialysis (%)	22	21
Months on dialysis		22 (9-26)	16 (11-27)	0.41
Ischemia times
Cold ischemia time (min)		161 ± 84	155 ± 59	0.49
Second warm ischemia time (min)		41 ± 27	40 ± 22	0.77
Delayed graft function (%)		8	4	0.37

All values as percentages, mean ± standard deviation or median and interquartile range. P values calculated with t-test, Mann-Whitney U test or chi-square test where applicable. Panel reactive antibodies > 8% were considered positive. HLA: Human leukocyte antigen; IgG: Immunoglobulin G; IgM: Immunoglobulin M; MDRD: Modification of diet in renal disease.

Table 2 Biopsy results

		ABO-incompatible (n = 27)	ABO-compatible (n = 108)	P value
Treated rejections, (%)		33	15	0.03
Acute antibody mediated rejection, (%)		4	1	0.36
Acute T-cell mediated rejection, (%)		30	14	0.05
	Grade IA, (%)	7	7
	Grade IB, (%)	4	3
	Grade IIA, (%)	15	3
	Grade IIB, (%)	4	1
	Grade III, (%)	0	0
Borderline acute T-cell mediated rejection		4	7	0.50
Donor specific antibodies (% positive)		0	6	0.17

P values calculated with chi-square test. Donor specific antibodies were measured according to local practice, i.e., at the discretion of the treating physician, and routinely at 8 wk after transplantation for Groningen patients and yearly for Amsterdam patients.

Table 3 Infectious complications

		ABO-incompatible (n = 27)	ABO-compatible (n = 108)	P value
Total no. of infectious complications per patient		1.7 (1-2.3)	1.0 (0-2)	0.004
	CMV infections, (%)	12	11
	EBV infections, (%)	0	3
	BK infections, (%)	15	6
	Other viral infections, (%)	31	9
	First urinary tract infection, (%)	38	30
	Recurrent urinary tract infections, (%)	8	11
	Other bacterial infections, (%)	23	7
	Other infections, not otherwise specified, (%)	31	20

All values as percentages or median and interquartile range. P values calculated Mann Whitney U test or chi-square test where applicable. CMV: Cytomegalovirus; EBV: Epstein Barr virus.

Table 4 Malignancies

		ABO-incompatible (n = 27)	ABO-compatible (n = 108)	P value
% of patients with a (pre)malignancy		22.2	7.4	0.01
	Solid organ, (%)	11	2.8
	Lymphoma, (%)	0	1.9
	Skin malignancy, (%)	3.7	1.9
	Melanoma, (%)	3.7	0
	Premalignant lesion, (%)	3.7	0.9
% of patients dying from their malignancy		0	38	0.09

P values calculated with chi-square test.