Peritoneal mesothelial cells are harmed by peritoneal dialysis fluids (PDF) used in renal replacement therapy with peritoneal dialysis. The mechanisms of the cellular damage are not yet described in detail. Primary human peritoneal mesothelial cells derived from omentum of five donors were independently exposed to peritoneal dialysis fluids. The extent of cell damage was assessed using lactate dehydrogenase (LDH) release in the cell culture supernatant and cells were lysed in order to extract mRNA and proteins. Transcriptional changes induced by PDF were analyzed using gene expression microarrays and changes of the proteome were analyzed using 2D-electrophoresis.