Effects of ghrelin administration on the early postoperative inflammatory response after esophagectomy

Effect of ghrelin administration on postoperative inflammatory response and bodyweight loss in patients with oesophageal cancer undergoing oesophagectomy: a systematic review and meta-analysis

OBJECTIVES

To investigate the effect of postoperative ghrelin therapy on postoperative inflammatory response and bodyweight loss in patients undergoing an oesophagectomy for oesophageal cancer.

METHODS

We conducted a systematic search using electronic information databases in accordance to PRISMA standards to identify studies comparing outcomes after oesophagectomy in patients who were and were not administered ghrelin in the postoperative period. Meta-analysis of the outcomes using random effects modelling was conducted. The Cochrane collaboration's tool and ROBINS-I tool were used for risk of bias assessment of the included studies.

RESULTS

Five studies including 192 patients were selected for analysis. Ghrelin therapy was associated with a significantly shorter duration of systemic inflammatory response syndrome (SIRS) (MD: - 2.72, P = 0.0001), lower CRP level on postoperative day 3 (MD: - 3.64, P < 0.0001), and less total bodyweight loss (MD: - 1.87, P = 0.14). There was no differences between the two groups in IL-6 level on postoperative day 3 (MD: - 19.65, P = 0.32), total lean body weight loss (MD: - 1.87, P = 0.14), total body fat loss (MD: 0.15, P = 0.84), pulmonary complications (OR: 0.47, P = 0.12), anastomotic leak (OR: 1.17, P = 0.78), wound complications (OR: 1.64, P = 0.63), postoperative bleeding (OR: 0.32, P = 0.33), arrhythmia (OR: 1.22, P = 0.77).

CONCLUSIONS

Administration of ghrelin following oesophagoectomy may reduce duration of postoperative SIRS and bodyweight loss. Whether shorter duration of SIRS and less bodyweight loss resulted from postoperative ghrelin therapy can translate into improved morbidity or mortality outcomes remains unknown. There is a need for randomised controlled trials with robust statistical power to investigate the role of postoperative ghrelin therapy on morbidity and mortality outcomes in patients undergoing oesophagectomy.

Attribution of Ghrelin to Cancer; Attempts to Unravel an Apparent Controversy

Ghrelin is an endogenous peptide hormone mainly produced in the stomach. It has been known to regulate energy homeostasis, stimulate secretion of growth hormone, and mediate many other physiologic effects. Various effects attributed to ghrelin contribute to many aspects of cancer development and progression. Accordingly, a large body of evidence has emerged about the association of ghrelin with several types of cancer in scales of cell-line, animal, and human studies. However, existing data are controversial. This controversy occurs in two main domains: one is the controversial results in local effects of ghrelin on different types of human cancer cell-lines; the second is the apparent disagreement in the results of in-vitro and clinical studies that investigated ghrelin association to one type of cancer. These inconsistencies have hampered the indications to consider ghrelin as a potential tumor biomarker or therapeutic agent in cancer patients. Previous studies have reviewed different parts of current literature about the ghrelin-cancer relationship. Although they have highlighted these controversial results in various ways, no specific recommendations have been given to address it. In this study, we comprehensively reviewed in-vitro, in-vivo, and clinical studies and attempted to use the following approaches to unravel the inconsistencies detected: (a) to distinguish local and systemic effects of ghrelin in interpreting its summary clinical role in each cancer; (b) scrutinizing factors that regulate local effects of ghrelin and could justify different effects of ghrelin on different cancer cell-lines. These approaches could have notable implications for future in-vitro and clinical studies.

Usefulness of intraoperative nerve monitoring in esophageal cancer surgery in predicting recurrent laryngeal nerve palsy and its severity

BACKGROUND

Recurrent laryngeal nerve (RLN) palsy is a critical postoperative complication in esophageal cancer surgery. However, intraoperative prediction of its occurrence and severity is difficult. In this prospective study, we evaluated the usefulness of intraoperative nerve monitoring (IONM) in predicting RLN palsy and its severity.

METHODS

Twenty patients who underwent subtotal esophagectomy with 3-field lymph node dissection were enrolled. Intraoperative electromyography (EMG) amplitudes of the vocal cords were measured by IONM at RLN and vagus nerve (VN) stimulation. Comparison was made between the vocal cords with RLN palsy and those without palsy and additionally between the vocal cords with transient RLN palsy and those with persistent palsy.

RESULTS

Among 40 vocal cords in 20 patients, 26 were intact and 14 were paralyzed. Seven had transient, six had permanent palsy. The mean EMG amplitude of intact vocal cords was significantly larger than that of paralyzed ones at VN (506 ± 498 µV vs. 258 ± 226 µV, p = 0.022) and RLN stimulation (642 ± 530 µV vs. 400 ± 308 µV, p = 0.038). The cut-off value for postoperative palsy were 419 µV [positive predictive value (PPV): 48.0%, negative predictive value (NPV): 84.6%] at VN and 673 µV (PPV: 44.8%, NPV: 90.9%) at RLN stimulation. The mean EMG amplitude of persistently paralyzed vocal cords tended to be small, compared with that of recovered ones at both VN (168 ± 173 µV vs. 336 ± 266 µV, p = 0.11) and RLN (244 ± 223 µV vs. 536 ± 344 µV, p = 0.051) stimulation.

CONCLUSION

The absolute EMG amplitude of IONM might be helpful to predict the occurrence and severity of RLN palsy after esophageal surgery although the predictive value is low.

Immunoregulatory influence of abundant MFG-E8 expression by esophageal cancer treated with chemotherapy

Milk fat globule‐epidermal growth factor factor 8 (MFG‐E8) is secreted from macrophages and is known to induce immunological tolerance mediated by regulatory T cells. However, the roles of the MFG‐E8 that is expressed by cancer cells have not yet been fully examined. Expression of MFG‐E8 was examined using immunohistochemistry in surgical samples from 134 patients with esophageal squamous cell carcinoma. The relationships between MFG‐E8 expression levels and clinicopathological factors, including tumor‐infiltrating lymphocytes, were evaluated. High MFG‐E8 expression was observed in 23.9% of the patients. The patients with tumors highly expressing MFG‐E8 had a significantly higher percentage of neoadjuvant chemotherapy (NAC) history (P < .0001) and shorter relapse‐free survival (P = 0.012) and overall survival (OS; P = .0047). On subgroup analysis, according to NAC history, patients with high MFG‐E8 expression had significantly shorter relapse‐free survival (P = .027) and OS (P = .0039) only when they had been treated with NAC. Furthermore, tumors with high MFG‐E8 expression had a significantly lower ratio of CD8⁺ T cells/regulatory T cells in tumor‐infiltrating lymphocytes (P = .042) only in the patients treated with NAC, and those with a lower ratio had a shorter OS (P = .026). High MFG‐E8 expression was also found to be an independent prognostic factor in multivariate analysis. The abundant MFG‐E8 expression in esophageal squamous cell carcinoma might have a negative influence on the long‐term survival of patients after chemotherapy by affecting T‐cell regulation in the tumor microenvironment.

The ghrelin paradox in the control of equine chondrocyte function: The good and the bad

Increasing evidence suggests a role for ghrelin in the control of articular inflammatory diseases like osteoarthritis (OA). In the present study we examined the ability of ghrelin to counteract LPS-induced necrosis and apoptosis of chondrocytes and the involvement of GH secretagogue receptor (GHS-R)1a in the protective action of ghrelin. The effects of ghrelin (10^-7-10^-11 mol/L) on equine primary cultured chondrocytes viability and necrosis in basal conditions and under LPS treatment (100 ng/ml) were detected by using both acridine orange/propidium iodide staining and annexin-5/propidium iodide staining. The presence of GHS-R1a on chondrocytes was detected by Western Blot. The involvement of the GHS-R1a in the ghrelin effect against LPS-induced cytotoxicity was examined by pretreating chondrocytes with D-Lys3-GHRP-6, a specific GHS-R1a antagonist, and by using des-acyl ghrelin (DAG, 10^-7 and 10^-9 mol/L) which did not recognize the GHS-R 1a. Low ghrelin concentrations reduced chondrocyte viability whereas 10^-7 mol/L ghrelin protects against LPS-induced cellular damage. The protective effect of ghrelin depends on the interaction with the GHS-R1a since it is significantly reduced by D-Lys3-GHRP-6. The negative action of ghrelin involves caspase activation and could be due to an interaction with a GHS-R type different from the GHS-R1a recognized by both low ghrelin concentrations and DAG. DAG, in fact, induces a dose-dependent decrease in chondrocyte viability and exacerbates LPS-induced damage. These data indicate that ghrelin protects chondrocytes against LPS-induced damage via interaction with GHS-R1a and suggest the potential utility of local GHS-R1a agonist administration to treat articular inflammatory diseases such as OA.

Improvement of cisplatin-related renal dysfunction by synthetic ghrelin: a prospective randomised phase II trial

Background:

Ghrelin, a 28-amino acid peptide predominantly produced by the stomach, exerts powerful renal protective effects by increasing levels of insulin-like growth factor-1 (IGF-1). The aim of this study was to evaluate the effects of ghrelin on the incidence of renal dysfunction in patients receiving cisplatin-based chemotherapy.

Methods:

Forty patients with oesophageal cancer receiving cisplatin-based chemotherapy were assigned to either the ghrelin group (n=20), which received ghrelin (0.5 μg kg⁻¹ h⁻¹) for 5 days, or a placebo group (n=20). The primary endpoint was serum creatinine. Secondary endpoints were serum cystatin C, chemotherapy-related adverse events, changes in serum ghrelin-related hormone levels, correlation between markers of renal injury and hormone concentrations, and effects on the second cycle of chemotherapy.

Results:

Blood acyl ghrelin, total ghrelin, and IGF-1 concentrations on day 4 were significantly higher in the ghrelin group. The renal dysfunction, serum creatinine and cystatin C levels, dose reduction, and delay in the initiation of the second cycle of chemotherapy were lower in the ghrelin group than in the control group. Serum creatinine levels were significantly correlated with serum IGF-1 levels.

Conclusion:

Continuous synthetic ghrelin administration during cisplatin-based chemotherapy attenuated renal dysfunction and harmful effects on subsequent chemotherapy, possibly by increasing IGF-1 levels.

Prognostic Impact of Peritumoral IL-17-Positive Cells and IL-17 Axis in Patients with Intrahepatic Cholangiocarcinoma

BACKGROUND

Development of cancer has been linked to inflammatory cytokines such as interleukin (IL)-6 and IL-17. In this study, we assessed the expression of these cytokines in intrahepatic cholangiocarcinoma (ICC) and determined their correlation to the survival probability.

METHODS

A total of 72 consecutive patients who underwent curative resection of ICC at Osaka University Hospital from March 1998 to November 2014 were enrolled. Immunohistochemical analysis was performed for IL-17 and its receptor A (IL-17RA), as well as IL-6. Enzyme-linked immunosorbent assay (ELISA) was performed for preoperative plasma levels of IL-6 and IL-17 in 32 patients with ICC.

RESULTS

Immunohistochemical analysis showed that the IL-6(high) (n = 34) and IL-17RA(high) (n = 29) groups had significantly worse disease-free survival (DFS) than IL-6(low) (n = 38) and IL-17RA(low) (n = 43) groups, respectively. Although IL-17(+) cells were abundant in the intratumoral area, patients with high peritumoral, but not intratumoral, IL-17(+) cells (n = 28) corresponded with a significantly lower overall survival (OS) and DFS (OS, p = 0.023; DFS, p = 0.026) than those with low group. Moreover, multivariate Cox proportional hazards analysis revealed that IL-6, peritumoral IL-17(+), and IL-17RA are independent prognostic factors for DFS (p = 0.023, p = 0.0088, p = 0.039, respectively). In addition, high preoperative plasma levels of IL-6 in patients with ICC corresponded with significantly lower DFS (p = 0.002).

CONCLUSIONS

Our data suggested that IL-6, peritumoral IL-17(+) cells, and IL-17RA expression are postoperative useful markers for predicting recurrence in patients with ICC.

Perturbation of acyl ghrelin profile after liver transplantation

BACKGROUND

A significant problem to be solved for patients after liver transplantation (LT) is malnutrition with anorexia in the early posttransplant period. We hypothesized that this problem was due to the change in ghrelin metabolism during LT. The aim of this study was to examine the balance of acyl ghrelin (AG) and desacyl ghrelin and the dependence of the regulation mechanism on hepatic-related enzymes in patients during LT.

MATERIALS AND METHODS

AG, desacyl ghrelin, and acyl/total ghrelin (A/T) concentrations in blood samples were measured in 15 patients with liver failure (LF), 15 patients after LT, and 10 controls. The correlations between the participants' ghrelin profiles and hepatic function-related data, including liver enzymes, were evaluated. In vitro assays using synthetic AG for assessment of deacylation activity in serum were performed.

RESULTS

AG and A/T ratio were significantly higher in the LF patients than the patients after LT and controls (AG: 25.9 ± 12.6 versus 16.4 ± 12.6 and 9.8 ± 7.6 fmol/mL, P < 0.05; A/T ratio: 17.4 ± 4.1 versus 12.2 ± 5.5 and 11.8% ± 5.9%, P < 0.05). The serum cholinesterase level was inversely correlated with AG and A/T ratio (P < 0.01). In vitro assays showed that deacylation activity was significantly lower in patients with LF than controls (10.5% versus 42.4%, 90 min; P < 0.01). Degradation of AG was partially suppressed by a cholinesterase inhibitor.

CONCLUSIONS

Deacylation activity was lower in LF patients, which could cause elevation of AG levels. Serum cholinesterase may be responsible for deacylation in humans.

Impact of synthetic ghrelin administration for patients with severe body weight reduction more than 1 year after gastrectomy: a phase II clinical trial

PURPOSE

Ghrelin is mainly secreted from the stomach and plays a role in appetite, weight gain, and the promotion of a positive energy balance. The levels of ghrelin decrease immediately after gastrectomy. We herein investigated the effect of the administration of synthetic ghrelin to treat postoperative severe weight loss in a prospective, one-arm clinical trial to develop new strategies for weight gain.

METHODS

Ten patients (four distal gastrectomy and six total gastrectomy) received ghrelin treatment. Eligibility criteria included patients who underwent gastrectomy more than 1 year previously and 15 % body weight loss from the preoperative weight or a body mass index under 19. Synthetic human ghrelin (3 μg/kg) was administered to the patients twice a day for 1 week. Oral intake of calories, appetite [evaluated using the visual analog scale (VAS)], and body weight before and during administration of ghrelin were compared.

RESULTS

There was a significant difference in the oral food intake before and during treatment (before treatment: 1236 ± 409 kcal vs. during treatment: 1398 ± 365 kcal, p = 0.039), and the VAS for appetite significantly improved with each day of ghrelin administration (p < 0.05). Significant amounts of body weight were gained (39.5 ± 6.8 vs. 40.1 ± 6.9, p = 0.037).

CONCLUSIONS

The administration of synthetic ghrelin improved the food intake and was effective for treating appetite loss and body weight loss. Synthetic ghrelin may be a promising new therapy for severe body weight loss following gastrectomy.