Investigation of Serum Angiotensin II Type 1 Receptor Antibodies at the Time of Renal Allograft Rejection.
BACKGROUND
Angiotensin II type 1 receptor (AT1R) is responsible for cardiovascular effects mediated by angiotensin II. This study aimed to investigate the impact of antibodies directed against AT1R (anti-AT1R) in renal allograft rejection.


METHODS
We evaluated 53 patients who had biopsy-proven rejection including antibody-mediated rejection (AMR) (N=22), T-cell-mediated rejection (TCMR) (N=29), and mixed AMR and TCMR (N=2). Donor specific HLA antibodies (DSA) and anti-AT1Rs were simultaneously determined.


RESULTS
Anti-AT1Rs were detected in 9.4% (5/53) of rejection patients (one with acute AMR, two with chronic active AMR, one with acute TCMR, and one with mixed acute AMR & TCMR). HLA antibodies and DSA were detected in 75.5% (40/53) and 49.1% (26/53) of patients, respectively. There was no significant difference in transplant characteristics between anti-AT1R(+) and anti-AT1R(-) patients except for the association of HLA class-I DSA(+) and anti-AT1R(+). Four of five anti-AT1R(+) patients had DSA and were also found to have AMR. A single anti-AT1R(+)/DSA(-) patient developed acute TCMR. Detection rates of DSA, HLA antibodies, or anti-AT1R were not different between AMR and TCMR. However, DSA(+)/anti-AT1R(+) was more frequently found in AMR than in TCMR (P=0.036). Patients with anti-AT1R showed a greater tendency to develop high-grade rejection as Banff IIA/IIB or AMR.


CONCLUSIONS
The presence of anti-AT1R was significantly associated with HLA class-I DSA in renal allograft rejection patients. Both anti-AT1R and DSA positivity was associated with AMR in patients with renal allograft rejection.
Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Hyeyoung
H
Lee
Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Ji-Il
JI
Kim
Department of Surgery, College of Medicine, The Catholic University of Korea, Seoul, Korea.
In-Sung
IS
Moon
Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Byung Ha
BH
Chung
Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Chul-Woo
CW
Yang
Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Yonggoo
Y
Kim
Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Kyungja
K
Han
Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Eun-Jee
EJ
Oh
D000328:Adult; D000906:Antibodies / Q000097:blood; D005260:Female; D006084:Graft Rejection / Q000209:etiology*; D006680:HLA Antigens / Q000276:immunology; D006801:Humans; D007668:Kidney / Q000473:pathology; D016030:Kidney Transplantation / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D044140:Receptor, Angiotensin, Type 1 / Q000276:immunology*; D014019:Tissue Donors; D014184:Transplantation, Homologous
D000906:Antibodies; D006680:HLA Antigens; D044140:Receptor, Angiotensin, Type 1
Angiotensin II receptor antibodies; Biopsy; Rejection; Renal transplantation