Glutamine as a modulator of the immune system of critical care patients: effect on Toll-like receptor expression. A preliminary study.
OBJECTIVE
We evaluated the expression of Toll-like receptors 2 and 4 (TLR-2 and TLR-4) in circulating monocytes from peripheral blood of critical care patients treated with and without glutamine. Because no research has been published to date on the effect of glutamine on TLR receptors in critical patients, it was determined in an initial sample of 30 patients.


METHODS
This was a prospective, randomized, single-blind study with 15 patients assigned to receive parenteral nutrition with a daily glutamine supplement of 0.35 g/kg. The control group received isocaloric-isonitrogenous parenteral nutrition. Blood samples were extracted before beginning the treatment and at 5 and 14 d. Expressions of CD14, TLR-2, and TLR-4 were determined by flow cytometry. Levels of TLRs were expressed as mean fluorescence intensity (mfi).


RESULTS
Basal characteristics were similar in both groups. The expressions of TLR-2 in the treatment group with glutamine were 4.67 +/- 3.82 mfi before treatment, 3.91 +/- 2.04 mfi at 5 d, and 4.28 +/- 2.47 mfi at 14 d. The expressions of TLR-2 in the control group were 5.49 +/- 3.20 mfi before treatment, 4.48 +/- 2.15 mfi at 5 d, and 4.36 +/- 2.36 mfi at 14 d. The expressions of TLR-4 in the treatment group were 1.65 +/- 1.89 mfi before treatment, 1.23 +/- 1.10 mfi at 5 d, and 1.77 +/- 1.97 at 14 d. The expressions of TLR-4 in the control group were 1.51 +/- 1.76 mfi before treatment, 1.36 +/- 0.99 mfi at 5 d, and 1.26 +/- 0.59 mfi at 14 d. Infections were detected in 11 patients who received glutamine and 13 control patients (P = 0.51).


CONCLUSIONS
In critical care patients, parenteral nutrition supplemented with glutamine does not increase the expression of TLR-2 or TLR-4 in peripheral blood monocytes.
Pérez-Bárcena
Jon
J
Intensive Care Unit, University Hospital Son Dureta, Palma de Mallorca, Spain. jperez@hsd.es
Regueiro
Verónica
V
Marsé
Pedro
P
Raurich
Joan María
JM
Rodríguez
Alberto
A
Ibáñez
Jordi
J
de Lorenzo Mateos
Abelardo García
AG
Bengoechea
José Antonio
JA
D000293:Adolescent; D000328:Adult; D000368:Aged; D016470:Bacteremia / Q000453:epidemiology / Q000517:prevention & control; D003422:Critical Care; D016638:Critical Illness / Q000628:therapy*; D005260:Female; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D005973:Glutamine / Q000494:pharmacology*; D006801:Humans; D018950:Lipopolysaccharide Receptors / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology*; D010288:Parenteral Nutrition; D011014:Pneumonia / Q000453:epidemiology / Q000517:prevention & control; D011446:Prospective Studies; D018805:Sepsis / Q000453:epidemiology / Q000517:prevention & control; D016037:Single-Blind Method; D051195:Toll-Like Receptor 2 / Q000187:drug effects* / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000187:drug effects* / Q000378:metabolism
D018950:Lipopolysaccharide Receptors; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D005973:Glutamine