Interleukin-6 and interleukin-8 in dialysate and serum from patients on continuous ambulatory peritoneal dialysis

We investigated interleukin-6 (IL-6) and interleukin-8 (IL-8) in peritoneal dialysate and serum from 17 patients on continuous ambulatory peritoneal dialysis (CAPD) with a total of 24 episodes of peritonitis and from 14 non-infected CAPD controls. Bacterial growth was found in 20 (83%) of the dialysate samples. Staphylococcus epidermidis caused 40% of the culture-verified peritonitis. Samples from dialysate were obtained during the first month of dialysis and during peritonitis from the first three dialysate bags on day 1 (the day of admittance) and from night bags on days 3 and 10. Serum samples were drawn on days 1 and 10. Interleukin-6 was increased in all dialysate samples on day 1. The peak median concentration was 23,500 pg/mL (range 1,710 to 340,000 pg/mL) in the first dialysate. Interleukin-8 was also elevated from all patients in the first dialysate, with a peak median value of 2,000 pg/mL (range, 110 to 185,000 pg/mL). Interleukin-6 and IL-8 concentrations from peritoneal fluid on days 1, 3, and 10 were significantly higher than concentrations from CAPD controls (IL-6 median value, 90 pg/mL, P < 0.001; IL-8 median value, nondetectable, P < 0.001). In serum, IL-6 and IL-8 were detected in 83% and 65% of the episodes, respectively. A correlation (P = 0.007) was seen between IL-6 and IL-8 in the first dialysate sample, but not in the subsequent dialysate samples. The highest acute phase reactant (CRP) level obtained during the peritonitis episode correlated to IL-6 in serum (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)