DISTRIBUTION OF RENAL INTEGRIN RECEPTORS AND THEIR LIGANDS IN CONGENITAL NEPHROTIC SYNDROME OF THE FINNISH TYPE

The aim of this study was to examine the distribution of beta 1 and al pha v integrins (Ints) and some of their ligands in the kidneys of pat ients with congenital nephrotic syndrome of the Finnish type (CNF) and in controls using indirect immunofluorescence with monoclonal antibod ies. The mesangial reactivity of Int alpha 1 and Int beta 1 subunits w as more variable and an increased glomerular reactivity with Int alpha 3 and Int-alpha 6 antibodies was found in CNF kidneys than in control s, Int alpha 2 subunit was either completely missing from or found in significantly lesser amounts in CNF kidney glomeruli. The immunoreacti vity for Int alpha v was more variable, fainter and also more granular in CNF samples than in control kidneys. The glomerular reactivity for Int beta 5 was more diffuse and weaker, and in sclerotic Bowman's cap sules more intense in CNF kidneys than in controls. Immunoreactivity f or Int beta 6 was restricted and was comparable in extent in CNF and c ontrol kidneys. Of the extracellular matrix components studied, the ex pression of EDAFn, EDBFn, OncFn, Ln alpha 2 chain, Ln beta 1 chain and tenascin was increased, This is also seen in several glomerular disea ses with inflammation and sclerosis. Immunoreactivity for vitronectin was decreased. Several differences were found in the intensity or loca tion of the immunostaining for the beta 1 and alpha v Ints and their l igands in CNF kidneys compared with controls, which have not been foun d in any other proteinuric disease. Disturbed Int expression pattern i n CNF may specifically reflect the disturbance of glomerular function caused by the primary defect in this disease.