Roles of neutrophil gelatinase-associated lipocalin in continuous ambulatory peritoneal dialysis-related peritonitis

We measured the neutrophil gelatinase-associated lipocalin (NGAL) concentration in peritoneal dialysate effluent (PDE) collected following an acute episode of continuous ambulatory peritoneal dialysis (CAPD)-related peritonitis.

NGAL concentration in PDE increased in the first 3 days after developing peritonitis and correlated well with the neutrophil count. In patients with culture-negative peritonitis, the NGAL in PDE was lower than that in patients with gram-positive or gram-negative peritonitis. Apart from providing additional diagnostic support to bacterial-induced peritonitis, measurement of NGAL in PDE may be useful to differentiate the neutrophil-dependent culture-negative peritonitis from that associated with non-bacterial or non-cellular etiologies.

Human peritoneal mesothelial cell (HPMC) is another source of NGAL during peritonitis. NGAL was specifically induced in HPMC by IL-1beta. Incubation of HPMC with recombinant NGAL reversed the transforming growth factor-beta-induced up-regulation of Snail and vimentin but rescued the down-regulation of E-cadherin. Our data suggest that NGAL may exert a protective effect in modulating the epithelial-to-mesenchymal transition activated following peritonitis.