Determination of Rituximab Dose According to Immunologic Risk in ABO-Incompatible Kidney Transplantation

Figures & data

Table 1.  Baseline characteristics of the patient populations.

	Low RTX (n = 17)	Typical RTX (n = 15)	p
Age (year)	41.4 ± 10.1	46.5 ± 7.2	0.12
Male, n (%)	11 (64.7)	7 (46.7)	0.25
F/U period (month)	12.1 ± 9.4	11.5 ± 9.5	0.64
HLA mismatch	3.5 ± 1.2	3.6 ± 1.1	0.73
Donor
(LRD/LURD)	10/7	9/6	0.88
Second  transplantation	0 (0)	6 (40)	<0.01
PRA >50 %	0 (0)	9 (60)	<0.01
Positive CM  (FXCM/CDC)	0/0	2/0 (13.3/0)	0.21
Primary renal disease
Chronic GN	7 (41.2)	5 (33.3)	0.53
DM	2 (11.8)	5 (33.3)
HTN	3 (17.6)	2 (13.3)
ADPKD	0	0
Unknown	5 (29.4)	3 (20.0)
ABO type
A → O	3	1
B → A	5	3
B → O	2	2
AB → B	2	3	0.25
A → B	3	2
AB → O	0	4
AB → A	2	0

Note: RTX, rituximab; F/U, follow up; LRD, living-related donor; LURD, living-unrelated donor; PRA, panel reactive antibody; CM, cross-match; FXCM, flow cytometry cross-match; CDC, complement-dependent cytotoxicity; GN, glomerulonephritis; DM, diabetes mellitus; HTN, hypertension; ADPKD, autosomal dominant polycystic kidney disease.

Table 2.  Comparison of acute rejection and infectious complication.

	Low RTX (n = 17)	Typical RTX (n = 14)	p
Acute rejection	2 (11.8)	2^a (14.3)	0.62
ATCMR	2 (11.8)	2 (15.4)	0.59
AMR	0 (0.0)	1 (7.7)	0.43
Infectious complication	4 (23.5)	4^b (28.6)	0.53
CMV viremia	1 (5.9)	2 (14.3)	0.45
BKV viremia	1 (5.9)	1 (7.1)	0.70
Bacterial infection	1 (5.9)	1 (7.1)	0.70
Fungal infection	1 (5.9)	0 (0.0)	0.53
Others	0 (0.0)	2 (14.3)	0.21
Postoperative bleeding	2 (11.8)	2 (14.3)	0.56

Notes: ^aIn one patient, both ATCMR and AMR were developed. ^bIn two patients, two types of infection developed. In one patient, CMV viremia and bacterial infection developed, and in another patient, CMV viremia and BKV viremia developed.

Figure 1.  (A) Change of CD19, (B) CD20 positive cell counts, and (C) antibody titer before and after RTX infusion. In low RTX group (left) and typical RTX group (right), CD19+/CD20+ cell counts were successfully depleted to <1%. Antibody titer showed decreasing pattern after the infusion of RTX. RTX, rituximab.

Figure 2.  (A) The minimally required number of PP/IVIG according to baseline anti-ABO antibody titer. Note that the PP/IVIG number significantly increased with the increase of baseline titer (r² = 0.78, p < 0.01). (B) The minimally required number of PP/IVIG did not differ between low RTX and typical RTX groups. (C) TRR according to baseline antibody titer. It showed significantly decreasing pattern with the increase of baseline antibody titer (r² = 0.23, p < 0.01). (D) TRR did not differ between low RTX and typical RTX groups. PP/IVIG, plasmapheresis/intravenous immunoglobulin; RTX, rituximab; TRR, titer reduction rate.

Figure 3.  (A) The titer at transplantation according to baseline anti-ABO antibody titer. In patients with baseline titer equal or less than 1:1256, most patients took KT at titer of less than 1:16. (B) The distribution of target titer did not differ significantly between low RTX and typical RTX group. (C) In comparison of the change of anti-ABO antibody (IgG) titer, it was suppressed well in both low RTX and typical RTX groups up to 1 year after KT. KT, kidney transplantation; RTX, rituximab.

Figure 4.  Comparison of the change of Scr and antibody titer between the low RTX and typical RTX groups. (A) No significant difference was found between the two groups up to 1 year after KT in Scr level. Scr, serum creatinine; KT, kidney transplantation, RTX, rituximab.