Increase of peripheral Th17 lymphocytes during acute cellular rejection in liver transplant recipients

Hua Fan, Li-Xin Li, Dong-Dong Han, Jian-Tao Kou, Ping Li and Qiang He
Beijing, China

BACKGROUND: Although many human inflammatory and
autoimmune diseases were previously considered to be mediated
by T helper type 1 (Th1) cells, the recently described Th17 cells
play dominant roles in several of these diseases. We and others
speculated that allograft rejection after organ transplantation
may also involve Th17 cells. Episodes of acute rejection occur
in 30% of liver transplants. This study aimed to determine the
frequency of circulating Th17 cells in patients who had received
liver transplants for benign end-stage liver disease and to
identify any association between acute rejection episodes and
levels of Th17 cells in the peripheral blood.
METHODS: A prospective study compared Th17 cells from 76
consecutive benign end-stage liver disease patients who had
undergone orthotopic liver transplantation from 2007 to 2011
with those from 20 age-matched healthy individuals. Peripheral
blood samples were collected at different time points within
one year after transplant. Blood samples and liver biopsies were
also collected at the diagnosis of acute rejection. Percentages of
circulating CD4+IL-17+ cells were measured by flow cytometry.
The transplant patients were classified into two groups: a
rejection group consisting of 17 patients who had an episode
of acute rejection, and a non-rejection group comprising
the remaining 59 patients with no acute rejection episodes.
Percentages of circulating Th17 cells were compared between the
two groups and controls.
RESULTS: The levels of circulating CD4+IL-17+ T cells in the
rejection group were higher during acute rejection than those
in the non-rejection group (2.56±0.43% versus 1.79±0.44%,
P<0.001). The frequency of CD4+IL-17+ cells in peripheral
blood was positively correlated with the rejection activity index
(r=0.79, P=0.0002).CONCLUSION: Circulating Th17 cells may be useful as a
surrogate marker for predicting acute rejection in liver transplant
recipients.
(Hepatobiliary Pancreat Dis Int 2012;11:606-611)