Beáta Szebeni (1,2), István Márton Takács (2), Domonkos Pap (1,2), Apor Veres-Székely (2), György Reusz (2), Attila J. Szabó (1,2), Ádám Vannay (1,2)
1 MTA-SE, Pediatrics and Nephrology Research Group, Budapest, Hungary
2 Ist Department of Pediatrics, Semmelweis University, Budapest, Hungary
Introduction: Peritoneal fibrosis can be observed almost all patients undergoing peritoneal dialysis (PD), however some patients survive for long periods on PD, others suffer from fibrosis-related membrane failure in short time.
Aims: The present study has been dedicated to search for an explanation of this phenomenon.
Methods: We have enrolled PD effluents from patients (n=7, 5 boys and 2 girls, median age 17.1 [2-31,3] years) receiving continuous ambulatory peritoneal dialysis (CAPD) treatment in the 1st Department of Pediatrics, Semmelweis University. All patients were dialysed with 1.5% glucose containing PD solution at the time of sample collection. Primary peritoneal fibroblasts (pPF) were isolated from PD effluents of these patients. To test the ability of these pPFs to proliferate or produce exracellular matrix (ECM) components MTT/LDH test or Sirius-red staining have been performed, respectively. The ability of cell free PD effluents collected from these PD patients to stimulate proliferation and ECM production of NRK-49F cells were measured by using the same methods.
Results: pPFs were successfully isolated from PD effluents and were identified as fibroblasts based on their morphology, α-smooth muscle actin (SMA) immunopositivity and cytokeratine negative staining. Proliferation rate of these primary peritoneal fibroblasts was increased after PDGF-BB treatment compared to vehicle treated controls. Moreover, these cells also responded to TGF-β treatment with increased collagen production. We observed increased proliferation rate of NRK-49F cells after cell free PD effluent treatment compared to PD solution treated controls. This elevation was highest in case of the patient who underwent PD for 10 months and lowest in case of the patient who underwent PD for 4 years. In paralell, LDH level was highest in case of the patient who underwent PD for 4 years.
Conclusion: Our proposed work may support the early identification of patients receiving PD with high risk of developing peritoneal fibrosis.