Acute phase response after liver transplantation for fulminant hepatic failure and cirrhosis

Plasma Acute Phase Proteins as Predictors of Chronic Lung Allograft Dysfunction in Lung Transplant Recipients

Cumulating reports suggest that acute phase proteins (APPs) have diagnostic and prognostic value in different clinical conditions. Among others, APPs are proposed to serve as markers that help to control the outcome of transplant recipients. Here, we questioned whether plasma concentrations of APPs mirror the development of chronic lung allograft dysfunction (CLAD). We performed blinded analysis of serial plasma samples retrospectively collected from 35 lung transplanted patients, of whom 25 developed CLAD and 10 remained stable during the follow-up period of 3 to 4.5 years. Albumin (ALB), alpha1-antitrypsin (AAT), high sensitivity C-reactive protein (CRPH), antithrombin-3 (AT3), ceruloplasmin (CER), and alpha2-macroglobulin (A2MG) were measured by the nephelometric method. We found that within the first six months post-transplantation, levels of A2MG, CER and AAT were higher in stable patients relative to those who later developed CLAD. Moreover, in stable patient’s plasma CRPH levels decreased during the follow-up period whereas opposite, in those developing CLAD, the CRPH gradually increased. The ALB levels became significantly lower at the end of the follow-up period in CLAD relative to a stable group. A logistic regression model based on A2MG, CER and AT3 at cut-offs levels of ≥175.5 mg/dL, ≥37.8 mg/dL and ≥27.35 mg/dL enabled to discriminate between stable and CLAD patients with a sensitivity of 87.5%, 100% and 62.5%, and specificity of 65.9%, 72.7% and 79.5%, respectively. We identified A2MG (below 175.5 mg/dL) as an independent predictor of CLAD (hazard ratio 11.5, 95% CI (1.5–91.3), p<0.021). Our findings suggest that profiles of certain APPs may help to predict the development of lung dysfunction at the very early stages after transplantation.

C-reactive protein at ICU admission as a marker of early graft dysfunction after liver transplant. A prospective, single-center cohort study

OBJECTIVE

To explore the behavior of C-reactive protein (CRP) after orthotopic liver transplantation (OLT) during the first postoperative days, and its usefulness as a marker of severe early allograft dysfunction (EAD).

DESIGN

A prospective, single-center cohort study was carried out.

SETTING

The Intensive Care Unit (ICU) of a regional hospital with a liver transplant program since 1997.

PATIENTS

The study comprised a total of 183 patients admitted to our ICU immediately after liver transplantation between 2009 and 2015.

VARIABLES OF INTEREST

C-reactive protein levels upon ICU admission and after 24 and 48h, severe EAD and hospital mortality.

RESULTS

The CRP levels after OLT were: upon ICU admission 57.5 (51.6-63.3)mg/L, after 24h 80.1 (72.9-87.3)mg/L and after 48h 69.9 (62.5-77.4)mg/L. Severe EAD patients (14.2%) had higher mortality (23.1 vs 2.5; OR 11.48: 2.98-44.19) and lower CRP upon ICU admission (39.3 [29.8-48.7]mg/L) than the patients without EAD (0.5 [53.9-67.0]; p<0.05] - the best cut-off point being 68mg/L (sensitivity 92.3%; specificity 40.1%; Youden index 0.33). Lower CRP upon ICU admission was correlated to higher mortality (24.5 [9.2-39.7] vs 59.4 [53.4-65.4]; p<0.01, AUC 0.79 [0.65-0.92]).

CONCLUSION

Liver transplant is a strong inflammatory stimulus accompanied by high levels of C-reactive protein. A blunted rise in CRP on the first postoperative day after OLT may be a marker of poor allograft function and is related to hospital mortality.

Neuroinflammation in hepatic encephalopathy: mechanistic aspects

Hepatic encephalopathy (HE) is a major neurological complication of severe liver disease that presents in acute and chronic forms. While elevated brain ammonia level is known to be a major etiological factor in this disorder, recent studies have shown a significant role of neuroinflammation in the pathogenesis of both acute and chronic HE. This review summarizes the involvement of ammonia in the activation of microglia, as well as the means by which ammonia triggers inflammatory responses in these cells. Additionally, the role of ammonia in stimulating inflammatory events in brain endothelial cells (ECs), likely through the activation of the toll-like receptor-4 and the associated production of cytokines, as well as the stimulation of various inflammatory factors in ECs and in astrocytes, are discussed. This review also summarizes the inflammatory mechanisms by which activation of ECs and microglia impact on astrocytes leading to their dysfunction, ultimately contributing to astrocyte swelling/brain edema in acute HE. The role of microglial activation and its contribution to the progression of neurobehavioral abnormalities in chronic HE are also briefly presented. We posit that a better understanding of the inflammatory events associated with acute and chronic HE will uncover novel therapeutic targets useful in the treatment of patients afflicted with HE.

Melatonin prolongs graft survival of pancreas allotransplants in pigs

Oxidative stress is involved in ischemia-reperfusion injury and allograft rejection after transplantation. We studied two well-known antioxidants, melatonin and ascorbic acid (AA), in relation to the survival of a pancreas transplantation model without immunosuppression. Forty-eight Landrace pigs were divided into three groups (n = 16 each; eight donors and eight recipients) that received melatonin, AA, or no antioxidant therapy (controls). Melatonin and AA were administered (10 mg/kg body weight) intravenously to donors and recipients during surgery and on postoperative days 1-7. The molecules were also added (5 mm) to a University of Wisconsin preservation solution during organ cold storage. Melatonin significantly delayed acute rejection and prolonged allograft survival (25.1 ± 7.7 days) compared with the controls (8.1 ± 0.8 days, P = 0.013) and the AA group (9.4 ± 1.6 days, P = 0.049). Melatonin reduced indicators of oxidative stress, malondialdehyde, and 4-hydroxyalkenals, in pancreatic samples collected during procurement, cold ischemia, and reperfusion. Melatonin also reduced serum pig-major acute-phase protein/inter-α-trypsin inhibitor heavy chain 4 (pMAP/ITIH(4)) in the early post-transplantation period. AA only partially reduced oxidative damage 30 min postreperfusion and failed to prevent pMAP/ITIH(4) elevations. These findings suggested that melatonin may be a useful therapeutic tool for organ transplantation.