Objective To determine if cellular and soluble HLA-DR molecules may be rele
vant in severely injured patients for the development of gram-positive or g
ram-negative sepsis.
Summary Background Data HLA-DR molecules play central role in the specific
immune response to infection. The reduced HLA-DR expression on monocytes is
considered to correlate with infectious complications and the development
of sepsis. Data on the role of HLA-DR expression on T cells and soluble HLA
-DR molecules are rare.
Methods HLA-DR expression on monocytes and T cells was measured by flow cyt
ometry. Plasma levels of soluble HLA-DR were studied by enzyme-linked immun
osorbent assay.
Results HLA-DR expression on circulating T cells, calculated as mean fluore
scence intensity in channels, was reduced at day 1 after admission in 20 pa
tients with subsequent severe sepsis compared with 46 patients without seps
is. The septic patients immediately after trauma had significantly lower so
luble HLA-DR plasma levels than the nonseptic patients. At day 2 after admi
ssion, HLA-DR expression on monocytes was significantly lower in the severe
sepsis group than in the patients without sepsis, and lasted until day 14
after injury.
Conclusions In severely injured patients, decreased levels of cellular and
soluble HLA-DR appear as early indicators of an immune deviation associated
with the development of severe sepsis. Moreover, immune alterations of dif
ferent cell types may promote distinct kinds of septicemia.