T helper cell subset ratios in patients with severe sepsis.
BACKGROUND
T helper 1 (Thl) lymphocytes produce interferon gamma (IFNgamma), favouring cell mediated immunity; Th2 cells secrete interleukin-4 (IL-4), favouring humoral immunity. Cytokines produced in sepsis may effect Th subset predominance and subsequent immune responses.


METHODS
We measured Th subsets in ten patients with severe sepsis, seven APACHE II score-matched non-septic critically ill control patients, and ten healthy subjects. Mononuclear leukocytes were isolated and Th subsets identified by flow cytometry.


RESULTS
The median (range) Th1/Th2 ratio was 0.46 (0.2-2.5) in patients with sepsis, which was significantly lower than both non-septic controls (median 2.5 (0.2-5.9), p = 0.050) and healthy subjects (median 3.9 (1.2-10.8), p = 0.01).


CONCLUSIONS
In patients with sepsis, Th2 antibody mediated (humoral) immune responses predominate. This type of response may lead to fibroblast activation and ultimately immunosuppression. Modulation of Th cell subset predominance may present a novel therapeutic option in the treatment of severe sepsis.
Academic Unit of Anaesthesia & Intensive Care, Institute of Medical Sciences, Foresterhill, Aberdeen, UK.
N R
NR
Ferguson
H F
HF
Galley
N R
NR
Webster
D018806:APACHE; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D016638:Critical Illness; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D018805:Sepsis / Q000276:immunology*; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology*; D018418:Th2 Cells / Q000166:cytology / Q000276:immunology*