Neoangiogenesis was observed in a rat model of experimental EPS. VEGF and angiopoietin/Tie system play an important role in the neoangiogenesis in this model. An analysis using this experimental rat model may elucidate the development of EPS in peritoneal dialysis patients.

It appears that the administration of the MMP inhibitor ONO-4817 might be a new approach to the amelioration of PS.

Marked thickening of the peritoneum and vasculopathy in the submesothelial compact zone have been reported in long-term peritoneal dialysis patients. Bone marrow (BM)-derived cell lines are considered to be useful tools for therapy of various diseases. To clarify the role of BM-derived cells in the peritoneal fibrosis (PF) model, we analyzed several lineages of cells in the peritoneum. BM cells from green fluorescent protein (GFP) transgenic mice were transplanted into naïve C57Bl/6 mice. Chlorhexidine gluconate (CG) was injected intraperitoneally to induce PF. Immunohistochemical analysis was performed with parietal peritoneum using anti-Sca-1 or -c-Kit and -GFP antibodies. Isolated BM cells were also transplanted into the CG-stimulated peritoneum. BM-derived cells from GFP transgenic mice appeared in the submesothelium from days 14 to 42. Both GFP- and stem cell marker-positive cells were observed in the submesothelium and on the surface. Isolated c-Kit-positive cells, transplanted into the peritoneal cavity, differentiated into mesothelial cells. In this study, we investigated whether or not BM-derived cells play a role in the repair of PF and immature cells have the potential of inducing repair of the peritoneum. The findings of this study suggest a new concept for therapy of PF.

The objective of the present study was to evaluate the sensitivity and efficiency of the matrix metalloproteinase-9 (MMP-9) test kit for the diagnosis of bacterial peritonitis in patients undergoing peritoneal dialysis (PD). Peritoneal effluents were collected from seven continuous ambulatory PD (CAPD) patients with peritonitis, four patients with suspected peritonitis, 30 maintenance PD patients without infection, and seven patients at initiation of PD. The MMP-9 test kit was used to analyze 112 peritoneal effluent samples. These peritoneal effluents were also used to count leukocytes and examine microorganisms. MMP expression was measured by gelatin zymography, and activities were measured by an enzyme-linked immunosorbent assay (ELISA). The relationship between the reactivity of the test kit and the number of leukocytes in the samples was examined. There was a significant difference in the number of leukocytes in peritoneal effluents between the negative and positive groups detected by the MMP-9 test kit (P < 0.0001). The results obtained with the MMP-9 test kit were negative for peritoneal effluent samples that did not show increased cell counts. The reactivity of the MMP-9 test kit showed no significant differences among various microorganisms, and remained stable. The MMP-9 test kit appears to be a simple and reliable method for early diagnosis of CAPD peritonitis, and reflects the leukocyte count in peritoneal effluents.