Peritoneal Protein Leakage, Systemic Inflammation, and Peritonitis Risk in Patients on Peritoneal Dialysis

Abstract

♦ Background: Whether peritoneal protein leakage predicts risk for peritonitis in patients on peritoneal dialysis (PD) is unknown. In this observational cohort study, we aimed to determine that association and, further, to explore if it might be explained by systemic inflammation. ♦ Methods: We prospectively followed 305 incident PD patients to first-episode peritonitis, censoring, or the end of the study. Demographics, comorbidity score, biochemistry, and peritoneal protein clearance (PrC) were collected at baseline. The predictors of first-episode peritonitis were analyzed prospectively. ♦ Results: During follow-up, 14 868 patient months and 251 episodes of peritonitis were observed. The baseline PrC was 73.2 mL/day (range: 53.2 -102 mL/day). Patients with a high PrC were prone to be older and malnourished. They also had a higher comorbidity score and higher Creactive protein values. In 132 first episodes of peritonitis, baseline PrC was shown to be a significant independent predictor after adjustment for age, sex, body mass index, diabetes, residual renal function, hemoglobin, and peritoneal transport rate. Systemic inflammatory markers such as serum albumin, C-reactive protein, and interleukin-6 could not explain the association of PrC and high risk for peritonitis. ♦ Conclusions: Baseline peritoneal protein leakage was able to independently predict risk for peritonitis, which is not explained by systemic inflammation. The underlying mechanisms should be explored in future.

Peritoneal Protein Losses Depend on More Than Just Peritoneal Dialysis Modality and Peritoneal Membrane Transporter Status

“…Reports suggested increased PPCl in older patients , although several other observational studies reported no effect of age . We noted a univariate association with patient age, but in our cohort more older patents were treated by CAPD, whereas younger and more active patients were treated by APD and CCPD.…”

“…However, on multivariable testing, patient age was no longer a significant factor. PPCl could also be affected by the intra‐abdominal capillary surface area available for transport, and several studies have reported greater PPCl in male patients , although others found no effect with gender . We did not note an effect of gender, but noted that patient size, as expressed by ICW, ECW, skeletal muscle mass and height, were all associated with PPCl on univariate analysis, but not weight, body mass index or body surface area.…”

Membrane transport status does not predict peritonitis risk in patients on peritoneal dialysis

“…Our study did not find a significant association between higher membrane transport status and poorer outcomes, including survival time on PD until peritonitis, technique failure or death. This is consistent with more recent literature now suggesting that higher peritoneal MTS does not portend a poorer prognosis on PD …”

“…This is consistent with more recent literature now suggesting that higher peritoneal MTS does not portend a poorer prognosis on PD. [23][24][25] The association of age and diabetes mellitus with patient survival on PD is consistent with other studies, 19,20,[26][27][28] suggesting that these factors have clinical significance in predicting prognosis of PD patients. An association between smoking status and peritonitis has been noted in previous literature, 5,9,29,30 which may be because cigarette smoke affects both cell-mediated and humoral-mediated immune responses, thereby increasing risk of infection.…”

Can the Three Pore Model Correctly Describe Peritoneal Transport of Protein?

“…Initially, the studies were focused at the quantification of peritoneal transport of different proteins and other macromolecules, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] and recent investigations addressed also the relationship of the peritoneal protein leak and plasma protein level with clinical indices and complications of the treatment, as mortality, morbidity, nutrition, systemic inflammation, peritonitis, and fluid overload. [15][16][17][18][19][20][21] However, the mechanisms of peritoneal transport of protein and anatomical structures involved in the transport are still debated and not fully identified.…”