SERUM CA-125 LEVEL IN END-STAGE RENAL-DISEASE PATIENTS MAINTAINED ON CHRONIC PERITONEAL-DIALYSIS OR HEMODIALYSIS - THE EFFECT OF CONTINUOUSPRESENCE OF PERITONEAL-FLUID, PERITONITIS, AND PERITONEAL CATHETER IMPLANTATION

Serum CA-125, an ovarian tumor marker, is used to screen and follow up patients with ovarian cancer. Normal values (< 35 U/ml) have been rep orted in patients with end-stage renal disease and patients maintained on chronic hemodialysis (HD). Non-malignant ascites has been associat ed with high serum levels of CA-125, suggesting that the presence of f luid in the peritoneal cavity may stimulate its release. We studied 38 HD and 43 chronic ambulatory peritoneal dialysis (CAPD) patients with regard to serum CA-125 levels. In the HD patients, the mean +/- SE se rum CA-125 level was 10.1 +/- 1.7 U/ml (range <5-39) with 8% of the pa tients having serum levels of > 35 U/ml. In the CAPD patients, the mea n serum CA-125 level in all samples collected (n = 68) was 17.7 +/- 2. 7 U/ml (range < 5-101, p < 0.01 vs. HD) with 16% of the sera showing l evels of > 35 U/ml. The high serum CA-125 levels in the CAPD patients were from sera obtained within 2 months of diagnosis of peritonitis, p eritoneal dialysis (PD) catheter implantation, or intra-abdominal surg ery. When serum samples from this 2-month period were excluded, the me an serum CA-125 level was 8.9 +/- 1.5 U/ml (p = NS vs. HD) and only 1 patient had an abnormal level. Peritoneal dialysate CA-125 levels duri ng an episode of peritonitis were significantly higher than at the bas eline (69.1 +/- 14.2 vs. 2 1 +/- 2.5, p = 0.004) and both were signifi cantly higher than the serum levels (p < 0.0001). Serum CA-125 levels were also the same in both sexes and races. In conclusion, it was foun d that while the serum CA-125 level is within normal limits in the maj ority of HD and stable CAPD patients, it is not uncommon that it is el evated in CAPD patients within 2 months of peritonitis, PD catheter pl acement, or intra-abdominal surgery, particularly when peritoneal exch anges are temporarily on hold in the latter two. The serum CA-125 leve l should be interpreted with caution in the CAPD patients as it may be a non-specific marker of peritoneal irritation. It was also found tha t there was a significant removal of CA-125 by the peritoneal fluid wh ich markedly increased during episodes of peritonitis.