Serviço de Nefrologia, Centro Hospitalar Universitário do Algarve, Faro, Portugal.
Unidade Multidisciplinar de Investigação Biomédica (UMIB), Instituto de Ciências Biomédicas Abel Salazar, e ITR - Laboratory for Integrative and Translational Research in Population Health, Universidade do Porto, Porto, Portugal.
Semin Dial. 2024 May-Jun;37(3):242-248. doi: 10.1111/sdi.13194. Epub 2024 Feb 29.
Longitudinal evolution of peritoneal protein loss (PPL), a reflection of hydrostatic pressure-driven leak of plasma proteins through the large-pore pathway, is not clear. Time on PD causes loss of mesothelial cells, vasculopathy, and increased thickness of the submesothelial fibrous layer. Are these structural changes associated with progressive increase of PPL, in a parallel with the rise in the D/P creatinine? The aim of the present study was to identify longitudinal changes of PPL over time. This single-center, longitudinal study included 52 peritoneal dialysis (PD) patients with a median follow-up of 26.5 months, evaluated at two different time points with a minimum interval of 6 months. Repeated measures analysis was performed using paired sample t-test or the nonparametric Wilcoxon signed-rank test, depending on the distribution. After a median interval of 15.5 months, lower levels of residual renal function and urine volume, lower Kt/V, and creatinine clearance were found. D/P creatinine and PPL were stable, but a decrease in ultrafiltration was present. Systemic inflammation, nutrition, and volume overload showed no significant change with time on PD. Analysis of a subpopulation with over 48 months between initial and subsequential assessment (n = 11) showed again no difference in inflammation, nutritional and hydration parameters from baseline, but importantly PPL decreased after more than 4 years on PD (mean difference 1.2 g/24, p = 0.033). D/P creatinine and dip of sodium remained unchanged. The absence of deleterious effects of time on PD is reassuring, pointing to the benefit of updated PD prescription, including the standard use of more biocompatible solutions towards membrane preservation and adjusted prescription avoiding overhydration and inflammation while maintaining nutritional status. After controlling for confounders, PPL may act as a biomarker of acquired venous vasculopathy, even if small pore fluid transport rates and free water transport are preserved.
腹膜蛋白丢失（PPL）的纵向演变尚不清楚，它反映了大孔途径中血浆蛋白因静水压力驱动而渗漏。PD 时间会导致间皮细胞丢失、血管病变和亚膜下纤维层厚度增加。这些结构变化是否与 PPL 的逐渐增加有关，与 D/P 肌酐的升高呈平行关系？本研究旨在确定随时间推移 PPL 的纵向变化。这项单中心、纵向研究纳入了 52 名腹膜透析（PD）患者，中位随访时间为 26.5 个月，在两个不同时间点进行评估，两次评估之间的间隔至少为 6 个月。使用配对样本 t 检验或非参数 Wilcoxon 符号秩检验（取决于分布）进行重复测量分析。中位随访间隔 15.5 个月后，残余肾功能和尿量降低，Kt/V 和肌酐清除率降低。D/P 肌酐和 PPL 稳定，但超滤减少。系统性炎症、营养和容量超负荷随 PD 时间无显著变化。对初始和后续评估之间超过 48 个月的亚组人群（n=11）进行分析，再次显示基线炎症、营养和水合参数无差异，但重要的是，PD 4 年以上后 PPL 下降（平均差异 1.2g/24h，p=0.033）。D/P 肌酐和钠下降无变化。PD 时间无不良影响令人放心，表明更新 PD 处方的益处，包括标准使用更具生物相容性的溶液以保护膜，以及调整处方避免过度水化和炎症，同时维持营养状况。在控制混杂因素后，PPL 可能作为获得性静脉血管病变的生物标志物，即使小孔隙液体转运率和游离水转运率保持不变。
