Adhesion Molecules in Kidney Diseases - Adhesion Molecules - page 243

observed. h e sample patients showed signii cantly elevated E-selectin expression
in the peritubular capillaries, suggesting an activated capillary endothelium.
Expression of most adhesion molecules signii cantly increased in the interstitial
areas. h ere was a signii cant correlation between the number of interstitial cells
expressing LFA-1 and E-selectin expression in peritubular capillaries as well as
interstitial ICAM-1 expression. h is is in agreement with the concept that the
activated capillary endothelium promotes leukocyte adhesion and extravasation
into the interstitial tissue (Honkanen et al. 1998). White et al. showed α5-integrin
staining in the tubular epithelium in areas of tubulo-interstitial disease, which
occurred primarily on the basolateral cell surface in renal biopsies from patients
with MG. No tubular epithelial cell staining was seen in biopsies where the tubules
and interstitium were normal, suggesting that α5-integrin is expressed in the
epithelium only during tubular injury. h ese data show that α5-integrin is induced
in the tubular epithelium of patients with kidney disease and tubulo-interstitial
injury and provide new insight into the role of integrins in renal injury and i brosis
(White et al. 2007) (Table 2) .
IgA Nephropathy
IgAN is the most common GN in patients undergoing renal biopsy worldwide.
Diagnosis is based on the occurrence of mesangial deposits of IgA in the glomeruli
in the presence of recurrent episodes of intra-infectious macroscopic hematuria
or persistent microscopic hematuria and/or proteinuria, frequently followed by
hypertension and progressive reduction of the glomerular i ltration rate. ICAM-1
expression in glomeruli from patients with IgAN has been reported signii cantly
higher in patients with advanced stage than in patients with the mild stage. Its
expression was closely linked to glomerular cell proliferation and to lymphocyte
and monocyte ini ltration (Tomino et al. 1994). Indirect immunol uorescence
coni rmed ICAM-1 expression in glomeruli from patients with IgAN. A marked
expression of ICAM-1 was observed in the glomerular capillary walls and mesangial
areas in advanced stage, but not in mild IgAN patients. ICAM-1 expression in the
glomeruli may be useful in assessing the degree of renal lesions in these patients.
In contrast, as there were no signii cant changes in ICAM-1 serum levels in the
mild and advanced stages of disease, serum ICAM-1 assay cannot be considered
useful in evaluating the degree of kidney injury (Nguyen et al. 1999).
Staining for the α1β1 subunit and α5β1 integrin in moderate or severe IgAN
was increased along the capillary walls and in the mesangial region. Wagrowska-
Danilewicz and Danilewicz (2004) . reported an upregulation of α5β1 integrins
on endothelial cells within glomeruli from IgAN patients with severe proteinuria,
rel ecting the role of this integrin in the mechanism of glomerular endothelial cell
injury. h e positive association between the interstitial expression of α5β1 and the
degree of interstitial i brosis, independent of the degree of proteinuria, suggests
that this molecule may play a role in the pathogenesis of chronic progressive renal
disease in IgAN (Wagrowska-Danilewicz and Danilewicz 2004) (Table 2) .