Early changes of CD4-positive lymphocytes and NK cells in patients with severe Gram-negative sepsis.
BACKGROUND
Our aim was to define early changes of lymphocytes and of NK cells in severe sepsis and to correlate them with serum levels of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1).


METHODS
Blood was sampled from 49 patients with proven highly suspected infection by Gram-negative pathogens, within 12 hours of the advent of severe sepsis, and was also sampled from six healthy volunteers. White blood cells were targeted with monoclonal antibodies and were analyzed by flow cytometry. The concentrations of sTREM-1 were estimated by ELISA.


RESULTS
The presence of CD3/CD4 cells was significantly lower (P < 0.0001) and that of NK cells significantly higher among patients with sepsis compared with controls (P = 0.011). The proportions (median +/- standard error) of ANNEXIN-V/CD4/CD3-positive cells, of ANNEXIN-V/CD8/CD3-positive cells and of ANNEXIN-V/CD14-positive cells of the patient population were 7.41 +/- 2.26%, 7.69 +/- 3.42% and 1.96 +/- 4.22%, respectively. Patients with NK cells >20% survived longer compared with those patients with NK cells < or =20% (P = 0.041), and patients with sTREM-1 concentrations >180 pg/ml survived longer compared with those patients with sTREM-1 concentrations < or =180 pg/ml (P = 0.042). A negative correlation was found between the percentages of ANNEXIN-V/CD4/CD3-positive cells and of CD3/CD4 cells (rs = -0.305, P = 0.049), and a positive correlation was found between the serum sTREM-1 concentration and the percentage of NK cells (rs = +0.395, P = 0.014). NK cells isolated from two healthy volunteers released sTREM-1 upon triggering with endotoxins.


CONCLUSIONS
Early severe sepsis is characterized by CD4-lymphopenia and increased NK cells, providing a survival benefit for the septic patient at percentages >20%. The survival benefit resulting from elevated NK cells might be connected to elevated serum levels of sTREM-1.
Giamarellos-Bourboulis
Evangelos J
EJ
4th Department of Internal Medicine, University of Athens, Medical School, 1 Rimini Str, Athens, Greece. giamarel@ath.forthnet.gr
Tsaganos
Thomas
T
Spyridaki
Ekaterini
E
Mouktaroudi
Maria
M
Plachouras
Diamantis
D
Vaki
Ilia
I
Karagianni
Vassiliki
V
Antonopoulou
Anastasia
A
Veloni
Vassiliki
V
Giamarellou
Helen
H
D000368:Aged; D000369:Aged, 80 and over; D015496:CD4-Positive T-Lymphocytes; D015331:Cohort Studies; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000097:blood / Q000276:immunology*; D006801:Humans; D007694:Killer Cells, Natural; D018655:Lymphocyte Count; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood; D011379:Prognosis; D011971:Receptors, Immunologic / Q000097:blood; D018805:Sepsis / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D016019:Survival Analysis; D000073871:Triggering Receptor Expressed on Myeloid Cells-1
D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; D000073871:Triggering Receptor Expressed on Myeloid Cells-1