Imaging in Stem Cell Transplant and Cell-based Therapy

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environmental and dietary factors. Antigens derived from dietary and environmental
cause stimulate excessive inflammatory response within the bowel, which results in
trans-mural inflammation and complications such as fistula formation and bowel
wall fibrosis in the long term.
Several forms of stem cell therapy such as hematopoietic and mesenchymal stem
cell therapy have been tried in treating Crohn’s disease, primarily due to the immune
modulatory effects of these cells. Therapies such as autologous and allogenic stem
cell therapy are aimed at altering the immune response generated by the body to
various antigens rather than targeting the antigens themselves. Proposed mecha-
nisms of action for autologous and allogenic stem cell therapy include resetting the
patient’s immune system by suppression of T lymphocytes and providing a new
immune system respectively.
MSC are used in management of Crohn’s disease due to their ability to inhibit
fibrosis and inflammation as well as promote tissue healing. Both systemic therapy
through intravenous and intra arterial routes and localized therapy in fistulizing
Crohn’s disease have been described (Fig. 4.6) [ 33 ]. While the data on systemic
mesenchymal stem cells is limited, several ongoing phase 3 clinical trials have
reported no adverse side effects [ 34 ].
The data for local therapy is more promising with healing of fistulae as well as
complete long-term fistula closure reported in patients with perianal disease who
were injected with adipocyte derived mesenchymal stem cells [ 35 ]. The most
recent of these data is from a series of 33 patients who were studied at 1  year
following local peri anal injection and showed long-term fistula closure in 88%
cases [ 36 ].

Inflammatory bowel

disease and peri-anal

fistulous disease

Injection of stem

cells

Fistula closure

Altered immunity

Fig. 4.6 Role of stem cells in inflammatory bowel disease and in treatment of peri-anal fistula
(arrows)

4 Clinical Applications of Stem Cell Transplant in Treating Non-Hematologic...