Peritonitis history, anuria or PD duration affected the concentration of several PDE metabolites, including kynurenine, tryptophan, phenylalanine, serine, valine, symmetric dimethylarginine (SDMA) and total-DMA (SDMA + Asymmetric dimethylarginine (ADMA)). The gene discussed is ALDH7A1; the disease is peritonitis.