Expression of vascular endothelial growth factor, fibroblast growth factor, and lactate dehydrogenase by human peritoneal mesothelial cells in solutions with lactate or bicarbonate or both.

In patients on long-term continuous ambulatory peritoneal dialysis, the efficiency of dialysis declines because of peritoneal neovascularization and loss of peritoneal mesothelial cells. In this study, we investigated the influence of lactate and bicarbonate in peritoneal dialysis fluid on such changes of the peritoneum. We studied the production of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), which induce peritoneal neovascularization, by human peritoneal mesothelial cells (HPMCs) cultured with lactate or bicarbonate or both. Lactate dehydrogenase (LDH) was also measured to assess cell necrosis. Levels of VEGF, bFGF, and LDH in the culture supernatant showed a significant decrease after incubation of HPMCs with 15 mEq/L lactate plus 25 mEq/L bicarbonate, or with 40 mEq/L bicarbonate, as compared with incubation with 40 mEq/L lactate. Levels of VEGF and bFGF showed a concentration-dependent decrease when the cells were incubated with lactate or bicarbonate; a concentration-dependent increase of LDH was simultaneously observed. These results suggest that dialysis fluid containing 40 mEq/L bicarbonate is superior to fluid containing 40 mEq/L lactate with regard to its influence on the production of VEGF and bFGF although lactate and bicarbonate are both toxic for HPMCs.

Hepatitis C virus infection in 2,744 hemodialysis patients followed regularly at nine centers in Hiroshima during November 1999 through February 2003.

Patients on maintenance hemodialysis (HD) are at increased risk of infection with hepatitis C virus (HCV). A prospective follow-up study on HCV infection from November 1999 to February 2003 was conducted in nine hemodialysis (HD) units in Hiroshima. A total of 2,744 HD patients were surveyed regularly for HCV RNA in serum. The prevalence of HCV RNA decreased from 15.7% (262/1,664) on the first survey to 12.9% (242/1,882) in the last one (P<0.05). This decrease may be attributed to the inclusion of patients with a lower prevalence of HCV RNA compared to patients leaving dialysis centers (111/1,080 [10.3%] vs. 132/862 [15.3%], P<0.01). During the 40 months of this study, 16 de novo HCV infections were documented in the nine HD units corresponding to an incidence of 0.33% per year. These cases included eight new HCV infections, three re-infections, and five infections that presumably occured in the window period when tested during the first survey. Our study shows that the annual incidence of de novo HCV infection during HD was 0.33%, and emphasizes the need for frequent serum HCV RNA testing and for stringent disinfection procedures in order to prevent the transmission of HCV in these settings.