Soluble B7-H2 as a novel marker in early evaluation of the severity of acute pancreatitis

Decrease of Membrane B7-H5 on CD14+ Cells in Severe Acute Pancreatitis Is Related to RANSON Scores and APACHE II Scores

BACKGROUND

B7-H5 is an important ligand which is deeply involved in the immune response in various diseases. However, its clinical usefulness as an early indicator in acute pancreatitis (AP) remains unclear.

AIMS

To determine the role of B7-H5 in severe acute pancreatitis (SAP).

METHODS

Whole blood samples from patients with SAP (n = 20) and healthy donors (n = 20) were collected. Expression of soluble B7-H5 (sB7-H5) in plasma was determined by ELISA and membrane B7-H5 (mB7-H5) on the peripheral CD14+ cells was determined by flow cytometry. Peripheral blood mononuclear cells (PBMCs) were isolated from healthy donors and stimulated with serum from SAP patients, lipopolysaccharide (LPS), TNF-α, or IFN-γ, then, sB7-H5 and mB7-H5 were measured. The relationship between expression levels of mB7-H5 and clinical features of SAP patients were analyzed.

RESULTS

The expression levels of sB7-H5 in plasma were increased and the expression levels of mB7-H5 on the peripheral CD14+ cells were decreased in SAP patients. These changes of B7-H5 expression pattern in cultured PBMCs could be induced by stimulation with serum from SAP patients, LPS, TNF-α, or IFN-γ. Expression levels of mB7-H5 were negatively related to levels of hematocrit, urea nitrogen, creatinine, lactic acid, RANSON scores, and APACHE II scores.

CONCLUSION

Changes of B7-H5 expression pattern were involved in immune response of SAP. Innate immunity activation-induced decrease of mB7-H5 might be related to poor prognosis of SAP patients.

Dysregulated B7H4/JAK2/STAT3 Pathway Involves in Hypertriglyceridemia Acute Pancreatitis and Is Attenuated by Baicalin

BACKGROUND

Patients with hypertriglyceridemia (HTG) are prone to develop more severe acute pancreatitis (AP). However, the specific molecular mechanism still has not been elaborated clearly, and effective drugs for treating HTG-AP are not yet readily available. Baicalin is an ingredient isolated from a natural product that with potential to attenuate inflammation and pain in AP.

AIMS

The aim of the present study was to explore the effect of baicalin on HTG-AP and the possible mechanism involved.

METHODS

A mouse model of HTG-AP was successfully established by administering Poloxamer 407 and L-arginine intraperitoneally. We analyzed pathological changes, and performed TUNEL staining, DHE staining, and western blot to detect apoptosis, inflammation, oxidative stress, and B7H4/JAK2/STAT3 signaling in the pancreas.

RESULTS

Treatment with baicalin decreased serum triglyceride, cholesterol, lipase, amylase levels, and attenuated pancreatic edema. After intervention with baicalin, apoptosis and inflammation in HTG-AP mice were alleviated, as indicated by the decrease of Bax, cleaved-caspase-3, IL-6, TNF-α, and IL-1β. Baicalin also alleviated oxidative stress by decreasing NOX2, increasing SOD2 protein expression, and regulating Nrf2/Keap1 signaling in HTG-AP mice. Furthermore, baicalin decreased the upregulated B7H4/JAK2/STAT3 pathway in HTG-AP.

CONCLUSIONS

In conclusion, our data suggested that baicalin could attenuate HTG-AP, possibly through regulating B7H4/JAK2/STAT3 signaling.

Fire in the belly: A scoping review of the immunopathological mechanisms of acute pancreatitis

Introduction

Acute pancreatitis (AP) is characterised by an inflammatory response that in its most severe form can cause a systemic dysregulated immune response and progression to acute multi-organ dysfunction. The pathobiology of the disease is unclear and as a result no targeted, disease-modifying therapies exist. We performed a scoping review of data pertaining to the human immunology of AP to summarise the current field and to identify future research opportunities.

Methods

A scoping review of all clinical studies of AP immunology was performed across multiple databases. Studies were included if they were human studies of AP with an immunological outcome or intervention.

Results

205 studies met the inclusion criteria for the review. Severe AP is characterised by significant immune dysregulation compared to the milder form of the disease. Broadly, this immune dysfunction was categorised into: innate immune responses (including profound release of damage-associated molecular patterns and heightened activity of pattern recognition receptors), cytokine profile dysregulation (particularly IL-1, 6, 10 and TNF-α), lymphocyte abnormalities, paradoxical immunosuppression (including HLA-DR suppression and increased co-inhibitory molecule expression), and failure of the intestinal barrier function. Studies including interventions were also included. Several limitations in the existing literature have been identified; consolidation and consistency across studies is required if progress is to be made in our understanding of this disease.

Conclusions

AP, particularly the more severe spectrum of the disease, is characterised by a multifaceted immune response that drives tissue injury and contributes to the associated morbidity and mortality. Significant work is required to develop our understanding of the immunopathology of this disease if disease-modifying therapies are to be established.

Soluble B7-H5 Is a Novel Diagnostic, Severity, and Prognosis Marker in Acute Pancreatitis

As an important ligand in T lymphocyte costimulatory pathways, B7-H5 is involved deeply in the immune response in various diseases. However, its clinical usefulness as an early indicator in acute pancreatitis (AP) remains unclear. In this study, the levels of sB7-H5 and cytokines in plasma samples of 75 AP patients, 20 abdominal pain patients without AP, and 20 healthy volunteers were determined. Then, the correlation of sB7-H5 and clinical features, cytokines, the Ranson score, APACHE II score, Marshall score, and BISAP score was analysed, and the value of sB7-H5 for diagnostic, severity, and prognosis of AP was evaluated. We found that the levels of sB7-H5 were specifically upregulated in AP patients. Receiver operating characteristic (ROC) analysis revealed that sB7-H5 can identify AP patients from healthy or abdominal pain patients with 78.9% or 86.4% sensitivity and 93.3% or 90.0% specificity. Further analysis showed that the levels of sB7-H5 were significantly correlated with WBC (p = 0.004), GLU (p = 0.008), LDH (p < 0.001), Ca²⁺ (p = 0.006), AST (p = 0.009), PLT (p = 0.041), IL-6 (p < 0.001), IL-10 (p < 0.001), and TNF-α (p < 0.001). And levels of sB7-H5 were gradually increased among patients with mildly acute pancreatitis (MAP), moderately severe acute pancreatitis (MSAP), and severe acute pancreatitis (SAP). It can distinguish the severity of AP with good sensitivity and specificity. Moreover, when dividing the patients into two groups according to the median level of sB7-H5, the local complication and length of stay of low levels of the sB7-H5 group were significantly less than those in high levels of the sB7-H5 group. And the levels of sB7-H5 in AP patients were significantly correlated with the Ranson score (p < 0.001), APACHE II score (p < 0.001), Marshall score (p < 0.001), and BISAP score (p < 0.001). The AUCs of assessing local complications of sB7-H5 at day 1 and day 3 were 0.704 (p = 0.0024) and 0.727 (p = 0.0373). These results showed the potential value of sB7-H5 as a diagnostic, severity, and prognosis marker of AP.

Dysregulated NF-κB-Dependent ICOSL Expression in Human Dendritic Cell Vaccines Impairs T-cell Responses in Patients with Melanoma

Therapeutic cancer vaccines targeting melanoma-associated antigens are commonly immunogenic but are rarely effective in promoting objective clinical responses. To identify critical molecules for activation of effective antitumor immunity, we have profiled autologous dendritic cell (DC) vaccines used to treat 35 patients with melanoma. We showed that checkpoint molecules induced by ex vivo maturation correlated with in vivo DC vaccine activity. Melanoma patient DCs had reduced expression of cell surface inducible T-cell costimulator ligand (ICOSL) and had defective intrinsic NF-κB signaling. Chromatin immunoprecipitation assays revealed NF-κB-dependent transcriptional regulation of ICOSL expression by DCs. Blockade of ICOSL on DCs reduced priming of antigen-specific CD8⁺ and CD4⁺ T cells from naïve donors in vitro Concentration of extracellular/soluble ICOSL released from vaccine DCs positively correlated with patient clinical outcomes, which we showed to be partially regulated by ADAM10/17 sheddase activity. These data point to the critical role of canonical NF-κB signaling, the regulation of matrix metalloproteinases, and DC-derived ICOSL in the specific priming of cognate T-cell responses in the cancer setting. This study supports the implementation of targeted strategies to augment these pathways for improved immunotherapeutic outcomes in patients with cancer.

Clinical significance of B7-H2 expression in peripheral blood CD14+CD16+ monocytes in patients with acute pancreatitis

BACKGROUND

Acute pancreatitis (AP) is a common acute abdominal disease, and different types of AP have a different prognosis. The immune response and imbalanced immunity in AP patients are related to its severity. Inflammatory factors and related immune cells are of great importance in the pathogenesis of AP. Therefore, finding inflammatory cells and new inflammatory immune factors is of great significance for accurate treatment of AP.

AIM

To explore the clinical significance of CD14⁺CD16⁺ monocytes expressing B7-H2 in peripheral blood of patients with AP.

METHODS

A total of 63 patients with AP were enrolled in the study group, including 25 mild AP (MAP) cases, 20 moderately severe AP (MSAP) cases, and 18 severe AP (SAP) cases. Twenty healthy subjects were included as a control group. Flow cytometry was used for detection of B7-H2 expression on CD14⁺CD16⁺ cell subsets to evaluate its relevance to the severity of pancreatitis and clinical significance.

RESULTS

At 24 h after disease onset in patients with AP, CD14⁺CD16⁺cells expressing B7-H2 experienced abnormally high expression, which was significantly higher than that of the control group (t = 11.10, P < 0.001). B7-H2 expression on CD14⁺CD16⁺ cell membrane in each group of AP patients was significantly higher than that on CD14⁺CD16^- cell membrane(P < 0.01); B7-H2 expression on CD14⁺CD16⁺ and CD14⁺CD16^- cells (373.30 ± 89.72 and 78.62 ± 13.05) in the SAP group was the highest, followed by that in the MSAP group (279.55 ± 76.95 and 44.92 ± 12.44) and the MAP group (181.15 ± 35.75 and 23.32 ± 4.28), and the difference between any two of the three groups was significant (P < 0.01). At 24 h, 48 h, and 72 h after disease onset in the MAP group and MSAP group, there was no significant difference in B7-H2 expression on CD14⁺CD16⁺ and CD14⁺CD16^- monocyte membrane (P > 0.05). However, B7-H2 expression on CD7⁺CD16⁺ or CD14⁺CD16^- cell membrane in the SAP group at 24 h, 48 h, and 72 h showed a clear upward trend, and the difference was significant (P < 0.05).

CONCLUSION

B7-H2 is highly expressed on CD14⁺CD16⁺ and CD14⁺CD16^- monocyte membrane in patients with AP, which is closely related to the severity of AP. B7-H2 expression on CD14⁺CD16⁺ monocyte membrane in patients with AP is significantly increased compared with that on CD14⁺CD16^- monocytes, providing new clues for further recognition of immune response and imbalance in AP and for accurate targeted therapy of AP.

Serum C-reactive protein, procalcitonin, and lactate dehydrogenase for the diagnosis of pancreatic necrosis

BACKGROUND

The treatment of people with pancreatic necrosis differs from that of people with oedematous pancreatitis. It is important to know the diagnostic accuracy of serum C-reactive protein (CRP), serum procalcitonin, and serum lactate dehydrogenase (LDH) as a triage test for the detection of pancreatic necrosis in people with acute pancreatitis, so that an informed decision can be made as to whether the person with pancreatic necrosis needs further investigations such as computed tomography (CT) scan or magnetic resonance imaging (MRI) scan and treatment for pancreatic necrosis started. There is currently no standard clinical practice, although CRP, particularly an increasing trend of CRP, is often used as a triage test to determine whether the person requires further imaging. There is also currently no systematic review of the diagnostic test accuracy of CRP, procalcitonin, and LDH for the diagnosis of pancreatic necrosis in people with acute pancreatitis.

OBJECTIVES

To compare the diagnostic accuracy of CRP, procalcitonin, or LDH (index test), either alone or in combination, in the diagnosis of necrotising pancreatitis in people with acute pancreatitis and without organ failure.

SEARCH METHODS

We searched MEDLINE, Embase, Science Citation Index Expanded, National Institute for Health Research (NIHR HTA and DARE), and other databases until March 2017. We searched the references of the included studies to identify additional studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively. We also performed a 'related search' and 'citing reference' search in MEDLINE and Embase.

SELECTION CRITERIA

We included all studies that evaluated the diagnostic test accuracy of CRP, procalcitonin, and LDH for the diagnosis of pancreatic necrosis in people with acute pancreatitis using the following reference standards, either alone or in combination: radiological features of pancreatic necrosis (contrast-enhanced CT or MRI), surgeon's judgement of pancreatic necrosis during surgery, or histological confirmation of pancreatic necrosis. Had we found case-control studies, we planned to exclude them because they are prone to bias; however, we did not locate any. Two review authors independently identified the relevant studies from the retrieved references.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data, including methodological quality assessment, from the included studies. As the included studies reported CRP, procalcitonin, and LDH on different days of admission and measured at different cut-off levels, it was not possible to perform a meta-analysis using the bivariate model as planned. We have reported the sensitivity, specificity, post-test probability of a positive and negative index test along with 95% confidence interval (CI) on each of the different days of admission and measured at different cut-off levels.

MAIN RESULTS

A total of three studies including 242 participants met the inclusion criteria for this review. One study reported the diagnostic performance of CRP for two threshold levels (> 200 mg/L and > 279 mg/L) without stating the day on which the CRP was measured. One study reported the diagnostic performance of procalcitonin on day 1 (1 day after admission) using a threshold level of 0.5 ng/mL. One study reported the diagnostic performance of CRP on day 3 (3 days after admission) using a threshold level of 140 mg/L and LDH on day 5 (5 days after admission) using a threshold level of 290 U/L. The sensitivities and specificities varied: the point estimate of the sensitivities ranged from 0.72 to 0.88, while the point estimate of the specificities ranged from 0.75 to 1.00 for the different index tests on different days of hospital admission. However, the confidence intervals were wide: confidence intervals of sensitivities ranged from 0.51 to 0.97, while those of specificities ranged from 0.18 to 1.00 for the different tests on different days of hospital admission. Overall, none of the tests assessed in this review were sufficiently accurate to suggest that they could be useful in clinical practice.

AUTHORS' CONCLUSIONS

The paucity of data and methodological deficiencies in the studies meant that it was not possible to arrive at any conclusions regarding the diagnostic test accuracy of the index test because of the uncertainty of the results. Further well-designed diagnostic test accuracy studies with prespecified index test thresholds of CRP, procalcitonin, LDH; appropriate follow-up (for at least two weeks to ensure that the person does not have pancreatic necrosis, as early scans may not indicate pancreatic necrosis); and clearly defined reference standards (of surgical or radiological confirmation of pancreatic necrosis) are important to reliably determine the diagnostic accuracy of CRP, procalcitonin, and LDH.

A reduced lymphocyte ratio as an early marker for predicting acute pancreatitis

The early diagnosis and severity grading for acute pancreatitis (AP) are difficult to determine because of the complexity and differences in disease process. To date, few studies have investigated the role of lymphocyte ratio (LR) in AP. Therefore, the objective of the present study was to investigate the prognostic value of LR as an indicator in AP, as well as determine an optimal cut-off value for the severity prediction. There were two hundred four patients involved in this study, ninety-two of whom had severe acute pancreatitis (SAP). The LR was analyzed on admission and correlated with severity, which was determined using the Atlanta classification. The optimal cut-off value for LR was generated using receiving operator characteristic (ROC) curves. The results showed that the LR in the SAP group decreased significantly compared to the mild acute pancreatitis (MAP) group (8.82 vs. 13.43). The optimal cut-off value obtained from ROC curves was 0.081, with a sensitivity of 80.4%, a specificity of 53.3%, a positive likelihood ratio of 1.722, and a negative likelihood ratio of 0.368. In conclusion, the LR is obviously related to the condition of AP patients and is valuable for the differential diagnosis of SAP in early stages of AP.