Increased expression of renin in chronic allograft nephropathy.
BACKGROUND
Chronic allograft nephropathy (CAN) is the main cause of renal transplant failure in the first decade posttransplant. The precise pathogenetic mechanism for CAN is not completely understood. A possible role of renin-angiotensin system for CAN has been suggested through clinical observations that angiotensin-converting enzyme inhibition and angiotensin II receptor blockers prevent CAN.


METHODS
Distribution of renin-positive cells in allograft biopsy specimens was examined immunohistochemically in 23 renal transplant recipients diagnosed with CAN Biopsy specimens obtained from seven recipients with stable renal function were examined as controls. Histologic evaluation was performed based on the Banff 97 classification.


RESULTS
Renin-positive cells were found in the juxtaglomerular apparatus (JGA) adjoining the afferent arterioles in both groups. When the number of renin-positive cells in JGA was defined as a renin index, it was significantly higher in the CAN than the control group (P = .007). There was no significant difference in age, interval between transplantation and biopsy, and blood pressure between groups. Only a significantly higher serum creatinine was found in the CAN group.


CONCLUSIONS
The increased renin-positive cells in JGA suggest a significant role of the intrarenal renin-angiotensin system activation in the development of CAN.
Oka
K
K
Department of Pathology, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Moriyama
T
T
Takahara
S
S
Naruse
M
M
Namba
Y
Y
Ichimaru
N
N
Kyo
M
M
Kokado
Y
Y
Okuyama
A
A
Ito
T
T
Imai
E
E
Aozasa
K
K
D000328:Adult; D015415:Biomarkers / Q000032:analysis; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D007166:Immunosuppressive Agents / Q000145:classification / Q000627:therapeutic use; D016030:Kidney Transplantation / Q000473:pathology* / Q000502:physiology; D008297:Male; D011507:Proteinuria; D012083:Renin / Q000378:metabolism*; D012189:Retrospective Studies; D013997:Time Factors; D014184:Transplantation, Homologous
D015415:Biomarkers; D007166:Immunosuppressive Agents; D012083:Renin