Mesothelial-to-mesenchymal transition (MMT) is an autoregulated physiological process of tissue repair that in uncontrolled conditions,
such as peritoneal dialysis (PD), can lead to peritoneal fibrosis. The maximumexpression of sclerotic peritoneal syndromes
(SPS) is the encapsulating peritoneal sclerosis (EPS) for which no specific treatment exists. The SPS includes a wide range of
peritoneal fibrosis that appears progressively and is considered as a reversible process, while EPS does not. EPS is a serious
complication of PD characterized by a progressive intra-abdominal inflammatory process that results in bridles and severe fibrous
tissue formation which cover and constrict the viscera. Recent studies show that transdifferentiated mesothelial cells isolated from
the PD effluent correlate very well with the clinical events such as the number of hemoperitoneum and peritonitis, as well as with
PD function (lower ultrafiltration and high Cr-MTC). In addition, in peritoneal biopsies from PD patients, the MMT correlates
very well with anatomical changes (fibrosis and angiogenesis). However, the pathway to reach EPS from SPS has not been fully and
completely established. Herein, we present important evidence pointing to the MMT that is present in the initial peritoneal fibrosis
stages and it is perpetual over time, with at least theoretical possibility that MMT initiated the fibrosing process to reach EPSThis work was supported by Grant SAF2010-21249 from the
Ministerio de Economía y Competitividad to M. López-
Cabrera and by Grant S2010/BMD-2321 from Comunidad
Autónoma de Madrid to M. López-Cabrera and R. Selgas
This work was also partially supported by Grants PI 09/0776
from Fondo de Investigaciones Sanitarias to A. A. Peralta
and RETICS 06/0016 (REDinREN, Fondos FEDER, EU) to
R. Selga