Retrospective Analysis of the Risk Factors of Perioperative Bacterial Infection and Correlation with Clinical Prognosis in Kidney Transplant Recipients

Figures & data

Table 1 Demographic Characteristics of Kidney Transplant Recipients and Donors

	N%		p
	Non-Infected Group (n = 210)	Infected Group (n = 85)
Recipients
Gender (male)	146(69.5)	54(63.5)	0.318
Age	42.0 ±11.04	43.0±11.80	0.697
BMI	20.76(18.88–23.06)	21.67(18.37–23.83)	0.46
Length of stay	19.0(17.0–24.0)	22.0(20.0–29.0)	<0.001
ICU treatment	10.0(4.8)	18.0(21.2)	<0.001
Comorbidity
Hypertension	186(88.6)	80(94.1)	0.147
Anemia	74(35.2)	45(52.9)	0.003
Diabetes	5(2.4)	9(10.6)	0.003
Hepatitis B	10(4.8)	5(5.9)	0.692
Coronary heart disease	5(2.4)	2(2.4)	0.517
Arthrolithiasis	6(2.9)	2(2.4)	0.809
Others	9(4.3)	5(5.9)	0.712
Preoperative dialysis
Hemodialysis, n (%)	150(71.4)	57(67.0)	0.758
Peritoneal dialysis, n (%)	58(27.7)	27(31.8)
No dialysis, n (%)	2(0.9)	1(1.2)
Hemodialysis duration (months)	40(11–82)	42(8–76)	0.281
Peritoneal dialysis duration (months)	45(26–87)	42(12–85)	0.316
Duration of catheterization (d), median (IQR)	14(14–14)	16(14–19)	<0.001
Postoperative D-J stent placement time (d), median (IQR)	30(29–32)	30(30–31)	0.956
Cold ischemia time (min)	770(640–930)	740(610–960)	0.658
Warm ischemia time (min)	6.8±3.6	7.2±4.2	0.582
Early acute rejection reaction, n (%)	3(1.4)	6(7.0)	0.011
DGF, n (%)	23(11.0)	18(21.2)	0.022
Donors
Gender (male)	133(63.3)	52(61.2)	0.354
Age	49.0(40.0–59.25)	48.0(26.0–62.0)	0.469
BMI	23.26±5.96	23.89±6.01	0.226
PRA I >10%, n (%)	6(2.9)	5(5.9)	0.214
PRA II >10%, n (%)	8(3.8)	6(7.1)	0.235
HLA A+B+DR mismatches
0	8(3.8)	2(2.4)	0.855
1	17(8.1)	8(9.4)
2	96(45.7)	43(50.6)
3	83(39.5)	30(35.3)
4	4(1.9)	2(2.3)
5	2(1.0)	0(0)

Abbreviations: BMI, body mass index; SD, standard deviation; IQR, inter-quartile range; DGF, delayed graft function; PRA, panel reactive antibodies; HLA, human leukocyte antigen.

Table 2 Incidence of Infection at Different Sites During the Perioperative Period of Renal Transplantation

Infection Types	N(%)
Pulmonary infection	39(45.9)
Intra-abdominal infection	18(21.2)
Urinary tract infection	15(17.6)
Surgical site infection	9(10.6)
Bacteremia	4(4.7)

Table 3 Causative Agents of Infection and Treatment Choices

Pathogenic Microorganisms	N (%)
Gram-positive bacteria	12(32.4)
Staphylococcus aureus	6(50.0)
Staphylococcus epidermidis	3(25.0)
Enterococcus faecium	3(25.0)
Gram-negative bacteria	25(67.6)
Escherichia coli	10(40.0)
Klebsiella pneumoniae	7(28.0)
Pseudomonas aeruginosa	4(16.0)
Enterobacter cloacae	3(12.0)
Acinetobacter baumannii	1(4.0)
Treatments
Piperacillin-Tazobactam	26(30.6)
Cefoperazone-Sulbactam	32(37.6)
Carbapenems	24(28.2)
Linezolid	9(10.6)
Vancomycin	6(7.1)
Polymyxin B	3(3.5)

Table 4 Effects of Immunosuppressive Drugs on Infection After Kidney Transplant

	N%		p
	Non-Infected Group (n = 210)	Infected Group (n = 85)
Immunosuppression regimens
Induction agent, n (%)
Basiliximab	26(12.4)	9(10.6)	0.666
Antithymocyte globulin	184(87.6)	76(89.4)
Antiproliferative agent, n (%)
Mycophenolate	201(95.7)	82(96.5)	0.766
Azathioprine	9(4.3)	3(3.5)
Tacrolimus blood level, ng/mL, mean±SD
5th day	7.2±6.14	7.4±3.55	0.775
7th day	9.3±4.50	7.1±4.08	<0.001
14th day	10.8±5.49	8.66±3.13	<0.001
Predischarge	10.2±3.25	9.6±3.24	0.184

Table 5 Effects of Laboratory Parameters on Infection After Kidney Transplant

	N%		p
	Non-Infected Group (n=210)	Infected Group (n=85)
Laboratory findings^a (baseline), mean±SD
White blood cell count, ×10^9/L	5.95±1.84	6.12±1.82	0.175
Red blood cell count, ×10^9/L	3.41±0.83	3.59±0.75	0.120
Hemoglobin, g/L	102.65±23.52	108.20±22.36	0.074
Platelet count, ×10^9/L	171.23±58.59	194.77±90.70	0.068
Neutrophil count, ×10^9/L	4.31±1.66	4.54±1.69	0.187
ALT, U/L	30.82±17.72	28.17±13.55	0.324
AST, U/L	20.91±13.04	19.53±8.12	0.926
ALB, g/L	42.38±7.37	43.47±6.05	0.265
BUN, mmol/L	19.69±7.09	18.95±7.43	0.172
Cre, μmol/L	928.02±520.55	880.55±278.09	0.506
CRP	4.84±6.25	7.33±11.46	0.386
PCT	0.34±0.54	0.67±1.31	0.151
Laboratory findings^b, mean±SD
White blood cell count, ×10^9/L	10.34±3.69	15.09±4.94	0.004
Red blood cell count, ×10^9/L	3.09±0.70	3.11±0.73	0.606
Hemoglobin, g/L	93.28±20.23	93.96±19.88	0.708
Platelet count, ×10^9/L	145.48±55.40	157.10±68.89	0.425
Neutrophil count, ×10^9/L	8.38±17.09	13.51±9.59	0.001
ALT, U/L	31.88±22.31	33.78±22.12	0.884
AST, U/L	27.98±25.44	29.93±.44	0.721
ALB, g/L	36.22±7.48	30.18±5.96	0.006
BUN, mmol/L	18.81±6.19	19.74±6.76	0.416
Cre, μmol/L	688.34±502.76	696.32±300.33	0.400
CRP	14.76±7.56	32.42±10.88	0.002
PCT	1.69±5.88	10.13±9.71	<0.001

Notes: ^aIndexes present the baseline value before kidney transplantation, ^bindexes present the first day after kidney transplantation.

Abbreviations: SD, standard deviation; ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALB, albumin; BUN, blood urea nitrogen; Cre, creatinine; CRP, C-reactive protein; PCT, procalcitonin.

Figure 1 Comparison of blood routine indexes between non-infected and infected groups.

Notes: Applied letter-marking method. The same letter indicates no significant difference; no common letter indicates significant difference (intra group comparison). **P < 0.01 and *P < 0.05, significant differences between non-infected and infected groups.

Figure 2 Comparison of liver function between non-infected and infected groups.

Notes: Applied letter-marking method. The same letter indicates no significant difference; no common letter indicates significant difference (intra group comparison). **P < 0.01 and *P < 0.05, significant differences between non-infected and infected groups.

Figure 3 Comparison of renal function between non-infected and infected groups.

Notes: Applied letter-marking method. The same letter indicates no significant difference; no common letter indicates significant difference (intra group comparison). **P < 0.01 and *P < 0.05, significant differences between non-infected and infected groups.

Figure 4 Comparison of CRP and PCT between non-infected and infected groups.

Note: Applied letter-marking method. The same letter indicates no significant difference; no common letter indicates significant difference (intra group comparison). **P < 0.01 and *P < 0.05, significant differences between non-infected and infected groups.

Table 6 Pharmacogenetics Analysis of Non-Infected and Infected Groups

Gene	Genotype	N(%)		P.Value
		Non-Infected Group (n = 210)	Infected Group (n = 85)
CYP3A5*3 (rs776746)	CC	91(43.3)	46(54.1)	0.536
	TC	100(47.6)	36(42.4)
	TT	19(9.1)	3(3.5)
ABCB1 (rs1128503)	TT	91(43.3)	33(38.8)	0.556
	TC	93(44.3)	38(44.7)
	CC	26(12.4)	14(16.5)
ABCB1 (rs2032582)	CC	41(19.5)	27(31.8)	0.032
	TC	114(54.3)	31(36.4)
	TT	55(26.2)	27(31.8)
ABCB1 (rs1045642)	TT	29(13.8)	12(14.1)	0.940
	TC	103(49.0)	37(43.5)
	CC	78(37.2)	36(42.4)
ABCC2 (rs717620)	TT	13(6.2)	5(2.4)	0.873
	TC	72(34.3)	25(11.9)
	CC	125(59.5)	55(64.7)
ABCC2 (rs2273697)	GG	170(81.0)	71(83.5)	0.406
	GA	39(18.6)	13(15.3)
	AA	1(0.4)	1(1.2)
ABCC2 (rs3740066)	TT	10(4.8)	4(4.7)	0.974
	TC	71(33.8)	41(48.2)
	CC	129(61.4)	40(47.1)
POR28 (rs2868177)	TT	79(37.6)	32(37.6)	0.355
	TC	108(51.4)	34(40.0)
	CC	23(11.0)	19(22.4)
PXR (rs6785049)	GG	70(33.3)	27(31.8)	0.850
	GA	118(56.2)	42(49.4)
	AA	22(10.5)	16(18.8)

Table 7 Logistic Regression Analysis of Risk Factors Associated with Infection in Kidney Transplant Recipients

	OR	95% CI	P.value
Pre-anemia^a	1.044	0.103–1.392	0.144
Pre-diabetes^b	1.430	1.211–2.476	0.013
Length of stay	1.041	0.976–1.136	0.891
ICU treatment^c	1.014	0.874–1.136	0.190
Duration of catheterization	1.687	1.044–2.724	0.033
Tacrolimus concentration on day 7	0.869	0.753–0.974	0.013
Tacrolimus concentration on day 14	0.963	0.872–0.981	<0.001
White blood cell count^d	1.154	0.968–1.377	0.110
Neutrophil count^d	1.000	0.899–1.113	0.994
Albumin^d	0.886	0.797–0.986	0.027
CRP^d	1.489	1.307–1.890	<0.001
PCT^d	1.041	1.000–1.083	0.067
ABCB1(rs2032582)^e	3.123	0.929–10.496	0.066
Early acute rejection^f	3.004	2.865–4.352	0.023
DGF	3.763	2.168–8.365	0.002

Notes: ^aPre-anemia was is defined as hemoglobin<120 g/L in men and 110 g/L in women before transplantation, ^bpre-diabetes is defined as recipients with diabetes before transplantation, ^cICU treatment refers to patients transferred to the ICU for treatment in severe cases after transplantation, ^dthese indexes present the first day after kidney transplantation, ^eABCB1 (rs2032582)-TT/CC, ^fearly acute rejection is defined as acute rejection occurring before infection.

Abbreviations: CRP, C-reactive protein; PCT, procalcitonin; DGF, delayed graft function.

Table 8 Comparison of Adverse Reactions Between Non-Infected and Infected Groups

	N(%)
	Non-Infected Group (n = 210)	Infected Group (n = 85)	P.value
AR^a	8(3.8)	9(10.6)	0.024
CKAD	17(8.1)	11(12.9)	0.254
PTDM	4(1.9)	10(11.8)	<0.001
Secondary infection	20(9.5)	27(31.8)	<0.001
Liver dysfunction	5(2.4)	3(4.0)	0.582
Diarrhea	7(3.3)	5(5.9)	0.316

Note: ^aAR is defined as occurred infection before acute rejection.

Abbreviations: OR, odds ratio; CI, confidence interval; AR, acute rejection; CKAD, chronic kidney allograft dysfunction; PTDM, post-transplant diabetes mellitus.