EXPRESSION OF PLATELET-DERIVED GROWTH-FACTOR RECEPTORS IN NORMAL AND DISEASED HUMAN KIDNEY

We studied the expression of PDGF-alpha and -beta receptors in 10 norm al and 40 pathologic human kidneys (five minimal change disease, five membranous nephropathy, 25 IgA nephropathy, five lupus nephritis), by both immunohistochemistry and in situ hybridization techniques. In nor mal-appearing kidneys, both PDGF-alpha and -beta receptors were expres sed at the glomerular and interstitial level, the latter receptor more intensely than the former. The distribution and degree of expression of both receptors in nonproliferative glomerulonephritides were compar able with those found in normal-appearing kidneys. PDGF-beta receptor gene and protein expression were upregulated in proliferative nephriti des both at the glomerular and the interstitial level and strictly cor related with the grade of histologic lesions. Finally, PDGF beta recep tor expression was observed at a low level in normal-appearing renal v essels, and strikingly increased in injured arteries. Diseased kidneys displayed only a slight increase of PDGF-alpha receptor expression, c hiefly at the interstitial level. Noteworthy, a few cases of lupus nep hritis showed a moderate increase of PDGF-alpha receptor also at the g lomerular level.