Glomerular Expression of Plasmalemmal Vesicle‐Associated Protein‐1 in Patients with Transplant Glomerulopathy

Abstract

Transplant glomerulopathy (TG) is a prominent feature of chronic rejection that is characterized by double contours of the glomerular capillaries (GC). In this report, we demonstrate that one of the histopathological features of TG is a phenotypic change of glomerular endothelial cells which is illustrated by increased caveolae formation. To verify the endothelial changes in this disease, we examined the expression of plasmalemmal vesicle‐associated protein‐1 (PV‐1), a glycoprotein associated with plasmalemmal vesicles (caveolae), in the glomeruli of TG patients using pathologische anatomie Leiden‐endothelium (PAL‐E) antibody. Twenty‐six cases of chronic allograft nephropathy (CAN) with TG were examined, compared with 16 cases of CAN without TG, type I MPGN (4 cases), and transplant glomerulitis (8 cases). Overall, 24 of 26 (92.3%), 4 of 16 (25%), 0 of 4, 0 of 8 cases were PAL‐E‐positive for GC, respectively. Further, the extent of glomerular PAL‐E expression was positively correlated with both the grade of TG (rs= 0.72, p = 0.0003) and proteinuria (g/day) (rs= 0.51, p = 0.02). A correlation was not observed between glomerular PAL‐E positivity and peritubular capillary C4d deposits (Yetes chi = 0.23, p = 0.89). In summary, the present study demonstrates expression of PV‐1 in the GC of TG which is correlated with the grade of TG and proteinuria. Transplant glomerulopathy (TG) is a prominent feature of chronic rejection that is characterized by double contours of the glomerular capillaries (GC). In this report, we demonstrate that one of the histopathological features of TG is a phenotypic change of glomerular endothelial cells which is illustrated by increased caveolae formation. To verify the endothelial changes in this disease, we examined the expression of plasmalemmal vesicle‐associated protein‐1 (PV‐1), a glycoprotein associated with plasmalemmal vesicles (caveolae), in the glomeruli of TG patients using pathologische anatomie Leiden‐endothelium (PAL‐E) antibody. Twenty‐six cases of chronic allograft nephropathy (CAN) with TG were examined, compared with 16 cases of CAN without TG, type I MPGN (4 cases), and transplant glomerulitis (8 cases). Overall, 24 of 26 (92.3%), 4 of 16 (25%), 0 of 4, 0 of 8 cases were PAL‐E‐positive for GC, respectively. Further, the extent of glomerular PAL‐E expression was positively correlated with both the grade of TG (rs= 0.72, p = 0.0003) and proteinuria (g/day) (rs= 0.51, p = 0.02). A correlation was not observed between glomerular PAL‐E positivity and peritubular capillary C4d deposits (Yetes chi = 0.23, p = 0.89). In summary, the present study demonstrates expression of PV‐1 in the GC of TG which is correlated with the grade of TG and proteinuria.