[Evaluation of a simple area measurement method of mesothelial cells in continuous ambulatory peritoneal dialysis...

The surface area of mesothelial cells isolated from continuous ambulatory peritoneal dialysis (CAPD) effluent is useful for detecting peritoneal cell damage caused by dialysis. We developed and evaluated a simple and rapid method for measuring mesothelial cell area.

CAPD effluents were centrifuged and Sternheimer stain was added to the sediments for mesothelial cell staining. Mesothelial cell area was measured by an optical microscope with an ocular micrometer. Mean mesothelial cell area was calculated from the diameters of 50 mesothelial cells using pir2. Peritoneal function was evaluated by the ratio of creatinine in the effluent to the blood (D/P Cre) in frequent and short time peritoneal equilibration test (fast PET).

Measurement of the cell area was begun 5 minutes post staining when the mesothelial cells were stained red-purple. Mesothelial cell areas had a strong positive correlation with CAPD periods (r = 0.806, p < 0.0001) and a weak positive correlation with fast PET (D/P Cr) (r = 0.420, p < 0.05). Mesothelial cell area significantly increased with the use of acidic dialysate compared with neutral dialysate (279.8 + 10.5 im2 vs. 241.8 +/- 9.5 microm2, p = 0.0277).

The mesothelial cell areas calculated by our method were similar to those calculated by the conventional method in dialysis periods and peritoneal function. Therefore this measurement method simply and rapidly detects changes in mesothelial cell area caused by CAPD.