Within few years the peritoneal membrane of adult peritoneal dialysis (PD) patients
undergoes substantial morphological transformation, including progressive fibrosis,
vasculopathy and neoangiogenesis. Ultrafiltration capacity steadily declines and
ultimately results in PD failure. In children, peritoneal biopsies demonstrating PD
associated alterations have not yet been obtained. They, however, should be particularly
informative, since secondary tissue and vascular pathology related to ageing or diabetes
is absent.
An international, prospective peritoneal membrane biopsy study in children on PD will
therefore be performed. Biopsies will be obtained at time of PD catheter insertion, on
occasion of intercurrent abdominal surgery (e.g. hernia repair, catheter exchange) and at
time of renal transplantation. Quantitative histomorphometry and tissue protein
expression analyses will be correlated with time integrated PD treatment modalities and
functional characteristics as well as inflammatory and cardiovascular comorbidity
surrogate parameter. Blood will be obtained during clinical routine sampling. Biopsies
will be obtained during clinically indicated operations, without substantially increasing
operation time and associated surgical risks. The detailed histomorphometry of the PD
membrane will give additional information, potentially impacting on the individual PD
regime.
3/2018: The analyses of the pediatric PD biopsy demonstrated early and major
transformation of the peritoneal membrane with neutral pH low GDP fluids, and significant
vasculopathy already in children with CKD stage 5, further progressing with PD. The
underlying mechanisms are partly understood, only. In view of these major findings and
the numerous open questions, collection of biosamples will be continued in children and
also in adult PD patients. The following questions will be addressed: Molecular
counterparts of peritoneal semi-permeability, solute and water transport (beyond AQP1),
pathomechanisms and molecular and functional impact of peritoneal transformation with low
and high GDP fluids, and the respective pathomechanisms and molecular and functional
impact of vascular disease in CKD and with different PD fluids. The impact of renal
transplantation following PD will be assessed in a subgroup of patients with tenckhoff
catheter removal several weeks after transplantation and a functioning graft.
