Transforming growth factor-ß1 attenuates inflammation and lung injury with regulating immune function in ventilator-induced lung injury mice.

Ventilator-induced lung injury (VILI) is a lung injury induced or aggravated by mechanical ventilation. Transforming growth factor (TGF)-ß1 is a cytokine that mediates immune function, enabling inflammatory attenuation and tissue repair. Here, we hypothesized that it plays an important role in the attenuation of VILI and inflammation. Ventilation with high tidal volume was performed on C57BL/6 mice to establish a VILI model. After 4 h of ventilation, mice were sacrificed (end of ventilation [EOV]) or extubated for resuscitation at 4 h (post-ventilation 4 h [PV4h]), 8 h (PV8h) and 24 h post-ventilation (PV1d). Recombinant mouse TGF-ß1 (rTGF-ß1) and the neutralization antibody of TGF-ß1 (nTAb) were used in vivo to examine the effect of TGF-ß1 on immune function and inflammatory attenuation in VILI mice. Lung injury was exacerbated at the same trend as the interleukin (IL)-1ß level, peaking at PV1d, whereas IL-6 and tumor necrosis factor (TNF)-α levels gradually reduced. Most active phagosomes, swollen round mitochondria, and cavitating lamellar bodies were observed at PV4h. The CD4+ T cells were significantly increased from PV4h to PV1d, and the CD8a + T cells were higher in the PV4h and PV1d groups; furthermore, the mice in the PV8h group showed highest proportion of CD4+CD8a+ T cells and CD4+/CD8a+ ratio. CD19 + and CD5 + CD19 + B cells in VILI mice began to increase at PV1d. The pulmonary expression of latent and monomer TGF-ß1 increased at PV4h and PV8h. Treatment of rTGF-ß1 only induced high expression of latent and monomer TGF-ß1 at EOV to decrease pulmonary levels of IL-1ß, IL-6, and TNF-α; however, lung injury attenuated from EOV to PV1d. TGF-ß1 induced the delayed elevation of CD4+/CD8a+ T cells ratio and activation of pulmonary CD4+CD8a+ double-positive T cells under certain conditions. Elastic fibers and celluloses, although relatively less proteoglycan, were observed with the overexpression of TGF-ß1 at PV4h and PV8h. In conclusion, TGF-ß1 attenuates the inflammatory response and lung injury of VILI via immune function regulation.

[Value of creatinine clearance rate estimated based on serum cystatin C in patients with acute kidney injury].

OBJECTIVE: To investigate diagnostic value of creatinine clearance rate (CCr) based on serum cystatin C (SCys C) in acute kidney injury (AKI), and whether it could predict the need for renal replacement therapy (RRT). METHODS: The patients enrolled with the length of intensive care unit (ICU) stay over 3 days were collected from August 2010 to May 2011. According to the diagnosis of AKI during the ICU stay, patients were divided into the AKI group (n=21) and non-AKI group (n=30). After patients were admitted, the level of SCys C and creatinine (SCr) were measured so as to count CCr based on SCys C (SCys C-CCr) or on SCr (SCr-CCr) respectively, meanwhile urine volume and acute physiology and chronic health evaluation II (APACHE II) score were monitored. The value of CCr counted by SCys C and SCr on predict AKI and the correlations between RRT were compared. RESULTS: SCr-CCr and SCys C-CCr in AKI group both were significantly lower than non-AKI group all the way through on admission, and 2 days and 1 day before AKI diagnosed and the day AKI diagnosed. The level of SCys C-CCr on 2 days prior to AKI diagnosed was significantly lower than the day admitted (70.6±8.4 ml×min(-1)×1.73 m(-2) vs. 114.8±15.8 ml×min(-1)×1.73 m(-2), P<0.01), whereas the level of SCr-CCr were not significantly changed (76.4±19.3 ml×min(-1)×1.73 m(-2) vs. 78.7±22.1 ml×min(-1)×1.73 m(-2), P>0.05). Receptor operative curve (ROC) analysis indicated that SCys C-CCr could predict AKI earlier than SCr-CCr, as the area under curve (AUC) of SCys C-CCr and SCr-CCr on 2 days prior to AKI diagnosed were 0.859 and 0.664, respectively, and the sensitivity were 90.5% and 47.6%, the specificity were 76.2% and 81.0%. In AKI group 6 patients were treated with RRT, the AKI patients receiving RRT had significantly higher APACHE II score on admission (29.6±4.5 vs. 17.0±5.6, P<0.05) and less urine volume within 24 hours (740±465 ml vs. 1780±1230 ml, P<0.05) than patients not received RRT, however, SCys C-CCr has no significant difference between the sub-group (50.4±11.2 ml×min(-1)×1.73 m(-2) vs. 53.0±8.4 ml×min(-1)×1.73 m(-2), P>0.05). SCys C-CCr did not predict the need of RRT on the day to diagnose AKI (AUC=0.65). CONCLUSIONS: The sensitivity of SCys C-CCr were high, but its specificity not. The SCys C-CCr may be helpful for excluding diagnose of AKI in high risk patients. However, it could not predict the need for renal replacement therapy on the day AKI diagnosed.