International Journal of Stroke Managing Editor spoke to Drs. Sean Savitz and Farhaan Vahidy on the eve of the online publication of this very novel study. You can download this interview here.
The spleen in stroke patients undergoes dynamic changes of
contractions and re-expansion in the days following the onset of stroke
symptoms, releasing inflammatory cells and contributing to further brain injury,
according to researchers at The University of Texas Health Science Center at
Houston (UTHealth) Medical School.
“We’ve known from animal studies that the spleen contracts
after stroke, followed by the release of inflammatory white blood cells leading
to secondary brain injury, so we wanted to observe what happens to the spleen in
patients after a stroke,” said Sean I. Savitz, principal investigator and professor
of neurology at the UTHealth Medical School.
 |
| Photo credit: NIH |
“This is a completely understudied
area. The spleen is not normally an organ that neurologists or neuroscientists pay
attention to. This was our initial attempt to look at the size of the spleen in
stroke patients.”
The spleen is part of the lymphatic system, which fights infection by releasing white blood cells. It also helps control the amount of blood in the body and destroys old and damaged cells.
The study included 29 stroke patients and 20 healthy
volunteers. The research team performed daily abdominal ultrasounds to measure
the size of the spleens. In the stroke patients, spleens initially reduced in
size and then re-expanded. The spleens of the healthy volunteers showed minimal
variation in daily spleen size compared with the stroke patients.
Savitz said the study demonstrated a good correlation
between the contraction of the spleen and the amount of white blood cells in
the body. The results also suggested that some patients whose spleens
contracted for a longer period of time, releasing more inflammatory white blood
cells, had poorer clinical outcomes. Further studies will be needed to confirm
and explain these early findings, Savitz said.
Savitz and fellow researchers became interested in studying the
spleen after animal studies at UT-Health and elsewhere showed that stem cells
administered intravenously after a stroke travelled to the spleen, as well as to
the brain.
“The big question was why,” said Savitz, who is director of
the Stroke Program at UTHealth and an attending physician at Memorial
Hermann-Texas Medical Center. “Emerging work by our group and other researchers
suggest that some types of stem cells have a dampening effect on the inflammatory
response emanating from the spleen. The spleen is a possible target in the
future for treating stroke.”
Savitz’s research team at UTHealth included first authors
Preeti Sahota, M.D., and Farhaan Vahidy, M.D.
