DETECTION OF ACTIVATED PLATELETS IN URINE BY DOUBLE - IMMUNOFLUORESCENCE IN CHILDREN WITH IGA NEPHROPATHY

The relationship between the activation of platelets (PLT) in urine an d renal histological findings in children with IgA nephropathy (IgAN), thin basement membrane disease (TBMD), and minimal-change nephrotic s yndrome (MCNS) was examined. The ratio of activated PLT to total PLT ( activated and nonactivated PLT) was examined by double immunofluoresce nce using rhodamine-conjugated P selectin antibody (activated PLT) and fluorescein isothiocyanate conjugated PLT membrane glycoprotein antib ody (GPIIb/IIIa, total PLT); the effect of urine on activation on PLT was also investigated. The number of activated PLT and the ratio of ac tivated PLT to total PLT in urinary sediments were significantly highe r in children with IgAN with diffuse mesangial proliferation than in t hose with TBMD or MCNS. PLT were activated by addition of urine in 13 out of 27 children with IgAN, and the activity was higher in the urine of those with active glomerular or interstitial lesions, while the ur ine of children with TBMD or MCNS had no effect. The presence of activ ated PLT and the effect of urine on PLT activation may be associated w ith the active glomerular or interstitial lesions in IgAN.