Leukocytes in Peritoneal Dialysis Effluents

The concentration of leukocytes and the fraction of neutrophil granulocytes are two important criteria in the diagnosis of peritonitis in continuous ambulatory peritoneal dialysis (CAPD). We have found that leukocytes are unstable in dialysis effluents, resulting in false low leukocyte concentrations if not counted immediately. At 25°C the leukocyte count decreases 25%–30% in 4–6 hours. Sampling in tubes containing EDTA and storage at 4°C make the leukocyte concentration stable for 6 hours, while the combination of EDT A and storage at 4°C ensures stability for 24 hours. When samples are handled accordingly, concentrations as high as 2 × 108/L are observed without any clinical signs of peritonitis, especially within the first months of CAPD-treatment. Thus, we suggest a leukocyte-concentration of 2 × 1 08/L as the diagnostic limit for peritonitis. Concerning fraction of neutrophils a diagnostic limit of 0.50 still seems relevant.