Long-lasting impairment of the immune system is believed to be the underlying reason for delayed deaths after surviving sepsis. We tested the hypothesis of persisting changes to the immune system in survivors of sepsis for the first time. In our prospective, cross-sectional pilot study, eight former patients who survived catecholamine-dependent sepsis and eight control individuals matched for age, sex, diabetes and renal insufficiency were enrolled. Each participant completed a questionnaire concerning morbidities, medications and infection history. Peripheral blood was collected for determination of i) immune cell subsets (CD4+, CD8+ T cells; CD25+ CD127- regulatory T cells; CD14+ monocytes), ii) cell surface receptor expression (PD-1, BTLA, TLR2, TLR4, TLR5, Dectin-1, PD-1 L), iii) HLA-DR expression, and iv) cytokine secretion (IL-6, IL10, TNF-α, IFN-γ) of whole blood stimulated with either α-CD3/28, LPS or zymosan. After surviving sepsis, former patients presented with increased numbers of clinical apparent infections, including those typically associated with an impaired immune system. Standard inflammatory markers indicated a low-level inflammatory situation in former sepsis patients. CD8+ cell surface receptor as well as monocytic HLA-DR density measurements showed no major differences between the groups, while CD4+ T cells tended towards two opposed mechanisms of negative immune cell regulation via PD-1 and BTLA. Moreover, the post-sepsis group showed alterations in monocyte surface expression of distinct pattern recognition receptors; most pronouncedly seen in a decrease of TLR5 expression. Cytokine secretion in response to important activators of both the innate (LPS, zymosan) and the adaptive immune system (α-CD3/28) seemed to be weakened in former septic patients. Cytokine secretion as a reaction to different activators of the immune system seemed to be comprehensively impaired in survivors of sepsis. Among others, this could be based on trends in the downregulation of distinct cell surface receptors. Based on our results, the conduct of larger validation studies seems feasible, aiming to characterize alterations and to find potential therapeutic targets to engage.

Sepsis remains one of the leading causes of death in intensive care units. Although sepsis is caused by a viral, fungal or bacterial infection, it is the dysregulated generalized host response that ultimately leads to severe dysfunction of multiple organs and death. The concomitant profound metabolic changes are characterized by hyperglycemia, insulin resistance, and profound transformations of the intracellular energy supply in both peripheral and immune cells. A further hallmark of the early phases of sepsis is a massive formation of reactive oxygen (ROS; e.g., superoxide) as well as nitrogen (RNS; e.g., nitric oxide) species. Reactive carbonyl species (RCS) form a third crucial group of highly reactive metabolites, which until today have been not the focus of interest in sepsis. However, we previously showed in a prospective observational clinical trial that patients suffering from septic shock are characterized by significant methylglyoxal (MG)-derived carbonyl stress, with the glyoxalase system being downregulated in peripheral blood mononuclear cells. In this review, we give a detailed insight into the current state of research regarding the metabolic changes that entail an increased MG-production in septicemia. Thus, we point out the special role of the glyoxalase system in the context of sepsis.

Background: Postoperative abdominal infections belong to the most common triggers of sepsis and septic shock in intensive care units worldwide. While monocytes play a central role in mediating the initial host response to infections, sepsis-induced immune dysregulation is characterized by a defective antigen presentation to T-cells via loss of Major Histocompatibility Complex Class II DR (HLA-DR) surface expression. Here, we hypothesized a sepsis-induced differential occupancy of the CCCTC-Binding Factor (CTCF), an architectural protein and superordinate regulator of transcription, inside the Major Histocompatibility Complex Class II (MHC-II) region in patients with postoperative sepsis, contributing to an altered monocytic transcriptional response during critical illness. Results: Compared to a matched surgical control cohort, postoperative sepsis was associated with selective and enduring increase in CTCF binding within the MHC-II. In detail, increased CTCF binding was detected at four sites adjacent to classical HLA class II genes coding for proteins expressed on monocyte surface. Gene expression analysis revealed a sepsis-associated decreased transcription of (i) the classical HLA genes HLA-DRA, HLA-DRB1, HLA-DPA1 and HLA-DPB1 and (ii) the gene of the MHC-II master regulator, CIITA (Class II Major Histocompatibility Complex Transactivator). Increased CTCF binding persisted in all sepsis patients, while transcriptional recovery CIITA was exclusively found in long-term survivors. Conclusion: Our experiments demonstrate differential and persisting alterations of CTCF occupancy within the MHC-II, accompanied by selective changes in the expression of spatially related HLA class II genes, indicating an important role of CTCF in modulating the transcriptional response of immunocompromised human monocytes during critical illness.

Purpose of review: Clinical management of postdural puncture headache (PDPH) remains an interdisciplinary challenge with significant impact on both morbidity and quality of life. This review aims to give an overview of the most recent literature on prophylactic and therapeutic measures and to discuss novel findings with regard to currently published consensus practice guideline recommendations. Recent findings: Although current evidence does not support a recommendation of any specific prophylactic measure, new data is available on the use of intrathecal catheters to prevent PDPH and/or to avoid invasive procedures. In case of disabling or refractory symptoms despite conservative treatments, the epidural blood patch (EBP) remains the therapeutic gold standard and its use should not be delayed in the absence of contraindications. However, recent clinical studies and meta-analyses provide additional findings on the therapeutic use of local anesthetics as potential noninvasive alternatives for early symptom control. Summary: There is continuing research focusing on both prophylactic and therapeutic measures offering promising data on potential alternatives to invasive procedures, although there is currently no treatment option that comes close to the effectiveness of an EBP. A better understanding of PDPH pathophysiology is not only necessary to identify new therapeutic targets, but also to recognize patients who benefit most from current treatments, as this might enhance their therapeutic efficacy.

Background: Postoperative immunosuppression has been recognized as an important driver of surgery-related morbidity and mortality. It is characterized by lymphocyte depression and impaired monocyte capability to present foreign antigens to T-cells via Major Histocompatibility Complex, Class II (MHC-II) molecules. In patients with postoperative abdominal sepsis, we previously detected a persisting differential binding of the CCCTC-Binding Factor (CTCF), a superordinate regulator of transcription, inside the MHC-II region with specific impact on human leucocyte antigen (HLA) gene expression. In this prospective exploratory study, we investigated to which extent major surgery affects the MHC-II region of circulating CD14⁺-monocytes. Results: In non-immunocompromised patients undergoing elective major abdominal surgery, a postoperative loss of monocyte HLA-DR surface receptor density was accompanied by a decline in the transcription levels of the classical MHC-II genes HLA-DRA, HLA-DRB1, HLA-DPA1 and HLA-DPB1. The surgical event decreased the expression of the transcriptional MHC-II regulators CIITA and CTCF and led to a lower CTCF enrichment at an intergenic sequence within the HLA-DR subregion. During the observation period, we found a slow and only incomplete restoration of monocyte HLA-DR surface receptor density as well as a partial recovery of CIITA, HLA-DRA and HLA-DRB1 expression. In contrast, transcription of HLA-DPA1, HLA-DPB1, CTCF and binding of CTCF within the MHC-II remained altered. Conclusion: In circulating monocytes, major surgery does not globally affect MHC-II transcription but rather induces specific changes in the expression of selected HLA genes, followed by differential recovery patterns and accompanied by a prolonged reduction of CTCF expression and binding within the MHC-II region. Our results hint toward a long-lasting impact of a major surgical intervention on monocyte functionality, possibly mediated by epigenetic changes that endure the life span of the individual cell.

Study Design Retrospective analysis. Objectives Sepsis, one of the most frequent and life-threatening complications on intensive care units (ICUs), is associated with a need for mechanical ventilation (MV) as well as adverse respiratory outcomes in hospitalized individuals. However, it has poorly been investigated in patients with spinal cord injury (SCI); a population at high risk for pulmonary and infectious complications. Setting Spinal Cord Injury Center, Heidelberg University Hospital. Methods Over a 5-year period, 182 individuals with SCI requiring MV during their ICU stay were analyzed. Data assessment included demographics, medical characteristics, focus and causative pathogen of sepsis, length of stay, weaning outcomes, and mortality. Results Sepsis was recorded in 28 patients (15%), containing a subgroup of individuals suffering from infectious SCI and co-occurring primary sepsis with Staphylococcus aureus as the predominant microorganism. In most individuals, sepsis was found as secondary complication, which was associated with pulmonary foci, Gram-negative bacteria, and high mortality. More than 80% of individuals with secondary sepsis required induction of MV due to respiratory failure. Furthermore, respiratory failure was found to be independent of sepsis focus, spectrum of causative pathogens, SCI etiology, or severity of injury. Subsequent weaning from the respirator was prolonged in more than 90% with a high proportion of weaning failure. Conclusions Sepsis predominantly occurs as a secondary complication after SCI and is associated with detrimental outcomes. Although the lung is frequently affected as a failing organ, not all sepsis foci are pulmonary. Awareness of both actual sepsis focus and causative pathogen is central to initiate an adequate sepsis treatment.