Kl. Meert et al., ELEVATED TRANSFORMING GROWTH-FACTOR-BETA CONCENTRATION CORRELATES WITH POSTTRAUMA IMMUNOSUPPRESSION, The journal of trauma, injury, infection, and critical care, 40(6), 1996, pp. 901-906
Objective: To determine whether trauma induces an increase in the conc
entration of circulating transforming growth factor-beta (TGF-beta), a
nd whether there is a temporal correlation between plasma TGF-beta P c
oncentration and the development of posttrauma cellular immunosuppress
ion. Materials and:Methods: Male Sprague-Dawley rats were anesthetized
, subjected to bilateral femur fractures or sham injury, and killed 1,
3, or 5 days later. Plasma TGF-beta levels, splenocyte phenotypes, mi
togen-induced proliferation, interleukin-2 (IL-2) production, and IL-2
receptor (IL-2R) expression were determined at each time point. Measu
rements and Main Results: Splenocyte proliferation increased on day 1
postinjury without corresponding change in IL-2 or plasma TGF-beta lev
els, Splenocyte proliferation and IL-2 production were suppressed on d
ay 3 postinjury, while plasma TGF-beta levels peaked, No differences w
ere observed between trauma and control groups on day 5. Splenocyte ph
enotypes and IL-2R expression were similar in injured and control rats
at all times. Conclusions: Suppression of lymphocyte proliferation an
d IL-2 production after trauma occurs concomitantly with a rise in pla
sma TGF-beta, The immune response is restored with normalization of TG
F-beta concentration, These observations suggest that TGF-beta may con
tribute to posttrauma immunosuppression.