Effluent plasminogen activator inhibitor 1 predicts ultrafiltration in incident peritoneal dialysis patients

Abstract Background The peritoneal equilibration test (PET) measures ultrafiltration and small solute clearance in peritoneal dialysis (PD). We aimed to assess if PET and biomarkers predict ultrafiltration in the first two days of PD. Biomarkers included in the study were matrix metalloproteinase-2 (MMP2), plasminogen activator inhibitor 1 (PAI1), aquaporin1 (AQP1), toll-like receptor 4 (TLR4), and CA125. Methods We enrolled 36 incident PD patients, and a fast PET was performed after the PD catheter insertion. Effluent MMP2, PAI1, AQP1, TLR4, and CA125 were collected with the fast PET and were measured using commercially available ELISA kits. The association of ultrafiltration and variables was analyzed using linear regression. Results The mean age of 36 patients was 69 ± 13 years, and 22 (61.1%) patients were male. The average daily ultrafiltration was 652 ± 775 ml in the first two days of PD. The D/P creatinine 1-hour was 0.59 ± 0.21, MMP2 13.9 ± 13.1 ng/ml, and PAI1 1.59 ± 1.88 ng/ml. MMP2 (p = 0.007) and PAI1 (p < 0.001) were significantly associated with ultrafiltration in univariable linear regression, but D/P creatinine (p = 0.064) was not. PAI1, independent of MMP2 and D/P creatinine, was associated with ultrafiltration with a coefficient of 404.18 (95% confident intervals 143.85 to 664.50, p = 0.003) in multivariable linear regression. Conclusion Measurements of effluent PAI1 at the PD catheter insertion predict ultrafiltration in the first two days of PD. The association of PAI1 and ultrafiltration is independent of MMP2 and D/P creatinine using fast PET.