Biocompatibility and buffers: effect of bicarbonate-buffered peritoneal dialysis fluids on peritoneal cell function

Area of Science:

• Nephrology
• Cell Biology
• Biocompatibility Studies

Background:

• Conventional peritoneal dialysis fluids (PDF) can impair leukocyte and human peritoneal mesothelial cell (HPMC) function.
• Low pH, high lactate, hyperosmolality, and high glucose in PDF contribute to bioincompatibility.
• Bicarbonate-buffered PDF show better in vitro biocompatibility than lactate-buffered PDF, but their effect on human peritoneal fibroblasts (HPFB) is less understood.

Purpose of the Study:

• To compare the effects of bicarbonate-buffered and lactate-buffered PDF on HPMC and HPFB.
• To assess the impact of PDF on Interleukin-1 beta-stimulated IL-6 release as a measure of cell function.

Main Methods:

• Cultured human omental HPMC and HPFB were used as a model system.
• Cells were pre-exposed to different PDF solutions (lactate-buffered vs. bicarbonate-buffered) for varying durations.
• Interleukin-1 beta-stimulated IL-6 release was measured to evaluate cell function.

Main Results:

• Short exposure to lactate-buffered PDF significantly reduced HPMC IL-6 release; bicarbonate-buffered PDF required longer exposure for a similar effect.
• HPFB showed no significant IL-6 inhibition after short PDF exposure (up to 90 minutes).
• Significant suppression of HPFB IL-6 release was only observed during prolonged coincubation (24 hours) with both PDF types.

Conclusions:

• Bicarbonate-buffered PDF demonstrate reduced inhibition of peritoneal cell function compared to conventional lactate-buffered PDF.
• Human peritoneal fibroblasts (HPFB) appear more resistant to the bioincompatible effects of PDF than human peritoneal mesothelial cells (HPMC).