Relationship between body temperature and systemic inflammation markers induced by lipopolysaccharide in dependence of an oral deoxynivalenol exposure

Body core temperature is a stable parameter under physiological conditions as well as an important cardinal symptom for clinical monitoring in systemic inflammation. Besides fever further indicators of an inflammatory reaction are changes in white blood cell counts, TNF-α and kynureninetryptophan ratio, but their interrelationship is not yet fully clarified. Thus we investigated these relationships in healthy as well as in pigs exposed to LPS and/or DON.

A total of 44 barrows were exposed for 4 weeks either to a DON-contaminated (4.59mg DON/kg feed) or a control (CON) diet. They were surgically equipped with an intraabdominal temperature logger and a multi-catheter system (V.portae hepatis, V. lienalis, Vv.jugulares int. et ext.) to facilitate simultaneous infusion of either 0.9%NaCl (CON) or LPS (7.5µg/kg BW) for 60min and venous blood sampling. Body temperature was measured every 5min and blood samples for leukocyte counts, TNF-α and kynurenine-tryptophan analysis (Kyn-Trp ratio) were taken every 15min, from 30min before until 180min after start of infusion. The combination of diet and infusion created six groups: CON_CON_jug.-CON_por., CON_CON_jug.-LPS_por., CON_LPS_jug.- CON_por., DON_CON_jug.-CON_por., DON_CON_jug.-LPS_por., DON_LPS_jug.-CON_por.. Data were evaluated by PROC MIXED with group and time and their interaction and PROC CORR (SAS Enterprise Guide 6.1).

Leukocytes: LPS-induced leukopenia from 15min p.i., with lowest levels at 75min p.i. and temperature increased at the same time and reached a plateau at 60min p.i.. Sole DON-feeding resulted in higher leukocyte counts (p=0.04). Combined treatment yielded an earlier leukopenia (p< 0.05) and lower temperature rise (~0.5°C, p=0.08) in DON_LPS_jug.-CON_por. compared to CON_LPS_jug.-CON_por.. A significantly positive correlation between both parameters was found in DON_ CON_jug.-CON_por., while all LPS groups were negatively correlated (p< 0.001) with the strongest relationship in CON_LPS_jug.-CON_por. (R=- 0.7).

TNF-α: LPS induced a sudden increase in TNF-α from 30min p.i., peaking at 60min p.i.. Significantly positive correlations with temperature were found in all LPS groups (p< 0.05) with the strongest relationship in CON_LPS_jug.-CON_por. (R=0.4).

Kyn-Trp ratio: LPS induced an increase in ratio at 180min p.i. (p< 0.001). Significantly positive correlations were found in both DON-LPS groups and, with the strongest relationship, in CON_LPS_jug.-CON_por. (R=0.6).

We were able to confirm a significant relationship between body core temperature and leukocyte counts, Kyn-Trp ratio and TNF-α in descending order under pathophysiological conditions and with the strongest dependency in control-fed, systemic LPS-infused pigs.

Disclosure of Interest: None Declared.