High endothelial venule-like vessels in the interstitial lesions of human glomerulonephritis

To clarify the characteristics of high endothelial venule (HEV) -like vessels in the interstitium of human glomerulonephritis, we investigated the expression of HEVs related molecules such as P-selectin and L-selectin ligands; MECA-79 epitope and variant sulfated forms of sialyl Lewis X (variant sLe(x), clones 2H5, 2173, GS-13 and GS-36) in kidney specimens by means of immunohistochemical studies, and P-selectin and hevin mRNA signals by using in situ hybridization analyses. In lymphoid organs, HEVs strongly expressed P-selectin, MECA-79, variant sLex and hevin mRNA signals. In normal kidneys (n = 4), only P-selectin was faintly positive in the vessels of interstitium, but other molecules could not be detected. Interstitial P-selectin expression was upregulated in patients with tubulointerstitial diseases (n = 4) and proliferative glomerulonephritis (n = 51) such as IgA-related nephropathy (n = 39), membranoproliferative glomerulonephritis (n = 4) and crescentic glomerulonephritis (n = 2), but not in nonproliferative glomerular diseases (n = 39) such as minimal change nephrotic syndrome (n = 18) (1.00 +/- 0.41, 0.64 +/- 0.11, 0.21 +/- 0.05, respectively). Interstitial P-selectin expression also correlated with interstitial local cellular infiltration (r = 0.60, p < 0.0001). In addition, P-selectin mRNA signals were detected on the peritubular capillaries and HEV-like vascular endothelial cells. MECA-79 and variant sLex (2H5 and 2173) were weakly expressed on the HEV-like vessels located at the corticomedullary regions in three cases (7%) and in nine cases (27%) with interstitial cellular infiltration, respectively. However, we could not detect GS-13, GS-36 or hevin mRNA signals in the diseased kidney specimens. In conclusion, HEV-like vessels in renal interstitium expressed molecules somewhat different from HEVs in lymphoid organs and were associated with interstitial leukocyte accumulation in human proliferative glomerulonephritis possibly through the de novo expression of P-selectin and partly L-selectin ligands (MECA-79 epitope and variant sLe(x)) in the interstitial lesions.