This is a discussion of Systemic Sclerosis: An update.
My name is Chris Derk.
I'm an Associate Professor of Clinical Medicine and the Fellowship Program Director for
the Division of Rheumatology at the University of Pennsylvania in Philadelphia,
Pennsylvania in the United States.
I will talk to you today about systemic sclerosis
and I will start with the definition of this disease.
It is a rare but well-described autoimmune connective tissue disorder,
which is of unknown etiology and is characterized by a triad of fibrosis,
vascular dysfunction, as well as immune dysregulation.
What we're seeing is the current pathophysiology of this disease.
There is some sort of etiologic agent,
which we do not know what it is,
which stimulates or activates the molecular and cellular target cells in a patient,
who has the specific genetic background for this disease.
This leads to activation of fibroblasts,
which produce increase collagen,
which in itself deposits in skin,
as well as visceral organs.
It has an effect on endothelial cells.
There is a vascular dysfunction or the vessels themselves could be obliterated.
There could be thickening of the vessels and they're more sensitive to vasospasm,
which leads to tissue hypoxia and injury.
B cells are activated, autoantibodies are produced,
and while there's many autoantibodies have been described
and some of them have related to specific types of the disease,
they have not shown to be pathogenic at this stage.
Early on, there's a cellular infiltrate in the tissues involved inclusive the skin,
as well as the other organs,
and this early infiltrate is predominantly with
CD4 T-cells in the skin and CD8+ T-cells in the lungs.
While this is very early on in the disease,
it often disappears quite fast.
Our ability to detect this early and
potentially capture the patients at this early part of the disease,
they all should be of some help in modifying this disease.