Renal immunoexpression of ghrelin is attenuated in human proliferative glomerulopathies.

BACKGROUND Ghrelin is a novel 28 amino acid growth hormone-releasing peptide hormone that has been shown to inhibit cell proliferation and to decrease the production of proinflammatory cytokines by monocytes/macrophages. Moreover it decreases the release of endothelin-1 (ET-1), as well as mononuclear cell binding. MATERIAL AND METHODS Seventeen patients with proliferative glomerulopathies (PG) and 15 patients with non-proliferative glomerulopathies (NPG) were examined by percutaneous renal biopsy. As a control 11 biopsy specimens of the kidneys removed because of trauma were used. The immunoexpression of ghrelin and ET-1 was assessed semiquantitatively whereas the interstitial monocytes/macrophages and interstitial area were evaluated quantitatively. RESULTS The mean value of the immunoexpression of ghrelin was significantly diminished in PG patients as compared to both NPG group and controls while the mean values of ET-1, interstitial CD68+ cells, as well as interstitial area were in PG group increased in comparison with controls and NPG patients, most of them significantly. In all groups there were significant negative correlations between immunostaining of ghrelin and ET-1, whereas negative correlation between immunostaining of ghrelin and CD68+ cells was significant only in PG group. CONCLUSIONS We can confirm the presence of ghrelin in tubular epithelial cells in normal and diseased human kidneys. Lack or low level of this protein in proliferative glomerulopathies may be, in part, responsible for interstitial accumulation of monocytes/macrophages in these cases.