Cardiovascular Involvement in Sepsis

Immunohistochemistry in the Postmortem Diagnosis of Sepsis: A Systematic Review

It is not uncommon for the forensic pathologist to question whether a deceased person had experienced sepsis that could have either been the cause of or contributed to the person's death. Often, the missing typical pathologic factors or lack of clinical and circumstantial information on the death render the autopsy of a sepsis-related death a difficult task for the forensic pathologist. Several authors emphasize on how an immunohistochemical analysis could help in diagnosing death related to sepsis. The research we carried out analyzes the main scientific studies in the literature, primarily the tracing of 21 immunohistochemical antigens evaluated to help diagnose death related to sepsis. The purpose of this review was to analyze and summarize the markers studied until now and to consider the limitations of immunohistochemistry that currently exist with regard to this particular field of forensic pathology. Immunohistochemistry provided interesting and promising results, but further studies are needed in order for them to be confirmed, so that they may be applied in standard forensic practice.

Sepsis and Cerebral Dysfunction: BBB Damage, Neuroinflammation, Oxidative Stress, Apoptosis and Autophagy as Key Mediators and the Potential Therapeutic Approaches

Sepsis-associated cerebral dysfunction is complex pathophysiology, generated from primary infections that are developed elsewhere in the body. The neonates, elderly population and chronically ill and long-term hospitalized patients are predominantly vulnerable to sepsis and related cerebral damage. Generally, electrophysiological recordings, severity and sedation scales, computerized imaging and spectroscopy techniques are used for its detection and diagnosis. About the underlying mechanisms, enhanced blood-brain barrier permeability and metalloprotease activity, tight junction protein loss and endothelial cell degeneration promote the influx of inflammatory and toxic mediators into the brain, triggering cerebrovascular damage. An altered neutrophil count and phenotype further dysregulate the normal neuroimmune responses and neuroendocrine stability via modulated activation of protein kinase C-delta, nuclear factor kappa-B and sphingolipid signaling. Glial activation, together with pro-inflammatory cytokines and chemokines and the Toll-like receptor, destabilize the immune system. Moreover, superoxides and hydroperoxides generate oxidative stress and perturb mitochondrial dynamics and ATP synthesis, propagating neuronal injury cycle. Activated mitochondrial apoptotic pathway, characterized by increased caspase-3 and caspase-9 cleavage and Bax/Bcl2 ratio in the hippocampal and cortical neurons, stimulate neurocognitive impairments. Additionally, altered LC3-II/I and P62/SQSTM1, p-mTOR, p-AMPK1 and p-ULK1 levels and dysregulated autophagosome-lysosome fusion decrease neuronal and glial energy homeostasis. The therapies and procedures for attenuating sepsis-induced brain damage include early resuscitation, cerebral blood flow autoregulation, implantable electric vagus nerve stimulation, antioxidants, statins, glucocorticoids, neuroimmune axis modulators and PKCδ inhibitors. The current review enumerates the pathophysiology of sepsis-induced brain damage, its diagnosis, the role of critical inducers and mediators and, ultimately, therapeutic measures attenuating cerebrovascular degeneration.

IL-22/IL-22R1 axis is involved in myocardial injury of a mouse cecal ligation and puncture model

Myocardial depression is a hallmark of severe sepsis, which may result from a complex interplay among several factors. However, the mechanisms are still unclear yet. In this study, we aimed to explore if IL-22/IL-22R1 axis plays a role in the myocardial injury during sepsis. A cecal ligation and puncture (CLP) mouse model was established to explore the histopathological changes and to analyze the role of IL-22/IL-22R1 axis in myocardial injury during the process of sepsis. Histopathologically, myocardial injury was apparently observed with the progress of sepsis but it was improved at 72 h after surgery. On the contrary, the heart tissue in the sham group revealed injury at a limited degree at the first 8 h after surgery and then restored to normal. Results from immunohistochemical study and real-time qPCR showed that IL-22, IL-22R1 and IL-22BP had different changing trends in the progress of sepsis at both protein and mRNA levels. The expression of IL-22R1 and IL-22BP was markedly induced after CLP modeling (P < 0.01), while that of IL-22 was sharply reduced in both groups (P < 0.01). The differences in the expression of IL-22, IL-22R1 and IL-22BP between the sham and CLP groups were significant only at 72 h after surgery (P < 0.05) but not at the other time points (P > 0.05). In conclusion, IL-22/IL-22R1 axis is involved and may have a potential immunoprotective role in the cardiac tissue repair, but the immunoprotection on the cardiac tissue of CLP mice was remarkably damaged in the progress of sepsis and even in the recovery phase.

Bactibilia in women affected with diseases of the biliary tract and pancreas. A STROBE guidelines-adherent cross-sectional study in Southern Italy

PURPOSE

Bile is a hepatobiliary lipid-rich sterile solution, and its colonization by microorganisms defines the condition of bactibilia. In this study, we aimed to assess the bile microbiological flora and its potential link with comorbidity in women.

METHODOLOGY

We performed a microbiologic investigation on 53 female patients with biliopancreatic diseases who granted consent, and we analysed the data using a MATLAB platform.

RESULTS

We found that the most frequent disease associated with bactibilia was pancreas head carcinoma (PHC) (P=0.0015), while the least frequent disease was gall bladder carcinoma (GBC) (P=0.0002). The most common microorganisms were Pseudomonas spp. (P<0.0001) and Escherichia coli (P<0.0001). In particular Pseudomonas spp. and E. coli were negatively correlated to PHC presence and positively correlated to CCA by both univariate and multivariate analysis.

CONCLUSIONS

Gram-negative bacteria have been linked to a tumour-associated inflammatory status. In the last 30 years, the analysis of mortality rate in Italy for PHC and GBC shows an increasing and a decreasing trend, respectively. Although this study targeted only 53 patients and does not reflect the frequency of diagnosis in a Southern Italian population, the decrease in GBC may raise the suggestion ofnon-adherence to a Mediterranean diet that may have become more prevalent in Southern Italy since the 1990s.

Septic cardiomyopathy: The value of lactoferrin and CD15 as specific markers to corroborate a definitive diagnosis

Current scientific consensus about the physiopathology in the progression from severe sepsis to septic shock and death focuses on myocardial contractile dysfunction. Nevertheless, objective parameters to establish a pathological correlate of a fatal outcome are lacking; then a cause of death due to sepsis can remain an unsolved problem. We first reviewed all death cases recorded at our institutions during the period from 2007 until 2015. Then, we conducted a retrospective study of a selected autopsy series of people who had received “sepsis” as cause of death. Two pathologists re-examined the heart sections while the most suitable myocardial sample for each case was stained for immunohistochemistry with antibodies targeted for specific inflammatory-related molecules. We used specific antibodies for the following markers: alpha-smooth muscle actin (alpha-SMA); fibronectin; matrix metallopeptidase 9 (MMP-9); intercellular adhesion molecule 1 (ICAM-1); caspase-3; lactoferrin (LF); cluster differentiation 15 (CD15). The statistical significance of differences was assessed using student’s t-test for unpaired data or non-parametric Mann–Whitney or Wilcoxon tests for skewed variables or one-way analysis of variance and post hoc Scheffe’s test for continuous variables and Pearson’s χ²-test for discrete variables. Linear regression analysis was used to determine the presence of a correlation between continuous variables. At our institutions, 2220 deaths have been recorded during the period study. Sepsis accounted as a cause of death for the 20% of total. We finally enrolled 56 cases; of these, only 20 were positive for microbiological analysis. At histological examination, clear inflammation was detectable in the 32% of cases; otherwise, immunohistochemical reaction showed a positive reaction for LF and CD15 in more than a half cases (56%). We still ignore all the underlying mechanisms of sepsis and all its pathophysiological connections with cardiac metabolism; in this sense, we aim to corroborate the diagnostic value of anti-LF and anti-CD15 staining for the post-mortem detection of myocardial inflammation.