Immunoglobulins IgG1, IgM and IgA: a synergistic team influencing survival in sepsis

Outcomes of intravenous immunoglobulin treatment of immunocompromised patients with viral respiratory infections

BACKGROUND

Limited guidelines exist for treating immunocompromised patients hospitalized for acute viral respiratory infection. Little is known about clinical and economic benefits of intravenous immunoglobulin (IVIG) administration in patients with acute viral respiratory infections.

OBJECTIVE

To compare clinical and economic outcomes among immunocompromised patients hospitalized with viral respiratory infections who received IVIG with those who did not.

METHODS

We performed a retrospective cohort study on all patients hospitalized for a respiratory viral infection between 2011 and 2016 at 2 large academic centers including data on age, sex, virus species, immunosuppression type, and receipt of IVIG. Outcomes included death, hospital readmission, length of stay (LOS) in the hospital, and LOS in the intensive care unit (ICU).

RESULTS

A total of 270 patient admissions were reviewed, and 35.6% received IVIG. The average age was 40.6 years, 50% were female, and 74% were transplant patients. The most common virus was rhinovirus (50.7%). Use of IVIG was significantly associated with a shorter ICU LOS (β = -0.534, P = .012) and a longer hospital LOS (β = 0.887, P < .01). IVIG administered within 48 hours of hospitalization (n = 229) was associated with a shorter ICU LOS (β = -2.08, P = .001) and a shorter hospital LOS for patients hospitalized at least 2 days (β = -0.461, P = .007). There were no significant differences in readmission rates or death.

CONCLUSION

This double-center, retrospective cohort analysis is one of the first studies to evaluate the effect of IVIG on immunocompromised patients hospitalized with respiratory viral infections. IVIG was associated with a shorter hospital and ICU LOS, especially when administered within 48 hours of admission.

Longitudinal assessment of immunoglobulin response and disease progression in critically ill patients with community acquired pneumonia

BACKGROUND

Low endogenous immunoglobulin(Ig)-levels are common in critically ill patients with sepsis, but it is unknown whether low Ig-levels are associated with poor outcome, and in which patients Ig-replacement therapy (IgRT) improves outcome. Given the crucial role of immunoglobulins in eliminating certain encapsulated pathogens, we examined the relationship between serial Ig-levels and disease course in critically ill patients with community acquired pneumonia (sCAP) caused by encapsulated or other pathogens.

METHODS

We included a cohort of consecutive critically ill patients with CAP, and PaO2/FiO2-ratio < 200 with or without septic shock, from an existing biorepository where microbiological causes of infection had been adjudicated in a protocolized manner. We used generalized linear mixed models to assess the association between IgG and IgM (measured on admission days 1, 3 and 7) and disease course (Sequential Organ Failure Assessment (SOFA)-score on day 2, 4, and 8) for all-cause sCAP and for episodes caused by Streptococcus (S.) pneumoniae or Haemophilus (H.) influenzae.

RESULTS

We included 255 eligible patients admitted with CAP, of which 82 (32%) episodes were caused by S. pneumoniae or H. influenzae. 151 (59%) patients had low IgG (< 7.0 g/L), 77 (30%) had low IgM (< 0.4 g/L), and 56 (22%) had both. A lower IgG-level was related to a slightly higher SOFA-score at admission (β =  - 0.07 per 1 g/L IgG, p = 0.029), but an IgG-level decline over time was not associated with a SOFA-score increase (β =  - 0.04, p = 0.564). IgM-levels were not associated with changes in SOFA-score over time. Neither association was affected by the presence or absence of S. pneumoniae and H. influenzae.

CONCLUSION

In critically ill patients with CAP, IgG and IgM dynamics in the first week of ICU stay are not associated with clinically relevant changes in disease course, regardless of the causative pathogen.

Current perspectives in the management of sepsis and septic shock

Within patients with sepsis, there exists significant heterogeneity, and while all patients should receive conventional therapy, there are subgroups of patients who may benefit from specific therapies, often referred to as rescue therapies. Therefore, the identification of these specific patient subgroups is crucial and lays the groundwork for the application of precision medicine based on the development of targeted interventions. Over the years, efforts have been made to categorize sepsis into different subtypes based on clinical characteristics, biomarkers, or underlying mechanisms. For example, sepsis can be stratified into different phenotypes based on the predominant dysregulated host response. These phenotypes can range from hyperinflammatory states to immunosuppressive states and even mixed phenotypes. Each phenotype may require different therapeutic approaches to improve patient outcomes. Rescue strategies for septic shock may encompass various interventions, such as immunomodulatory therapies, extracorporeal support (e.g., ECMO), or therapies targeted at specific molecular or cellular pathways involved in the pathophysiology of sepsis. In recent years, there has been growing interest in precision medicine approaches to sepsis and phenotype identification. Precision medicine aims to tailor treatments to each individual patient based on their unique characteristics and disease mechanisms.

Serum immunoglobulin levels in group E of chronic obstructive pulmonary disease: insights for clinical management and immunoglobulin therapy strategies

OBJECTIVE

The study aimed to characterize serum immunoglobulin (Ig) concentrations and their relationship with clinical and paraclinical features in patients with COPD group E in the stable stage. Additionally, the study focused on evaluating the relationship between serum Ig levels and the risk of exacerbations over the next 12 months, thereby clarifying the role of serum Ig deficiency in affecting the future risk for these patients.

METHODS

A prospective observational study assessed IgG, IgA, IgM, and IgE levels in 67 COPD patients and 30 healthy controls at Military Hospital 103 from October 2017 to August 2020. Primary outcomes included Ig isotype levels in COPD patients, with secondary outcomes exploring differences compared to controls and associations with clinical variables.

RESULTS

COPD patients showed significantly lower IgG concentrations and higher IgA levels than controls. IgM and IgE levels did not differ significantly. Subgroup analysis revealed notable decreases in IgG1 and IgG3 concentrations, with 10.4% of patients exhibiting reduced IgG levels and 0.3% diagnosed with common variable immunodeficiency. No significant associations were found between Ig levels and exacerbation risk or clinical variables.

CONCLUSIONS

Serum IgG and IgM concentrations were significantly reduced in COPD patients compared to normal individuals, with IgG1 and IgG3 concentrations notably low. Serum IgA levels were significantly higher in COPD patients compared with normal controls. However, no significant association was found between Ig concentrations, particularly serum IgG deficiency and its subclasses, with the frequency and risk of exacerbations during 12 months of longitudinal follow-up. Caution is warranted in the use of immunoglobulin therapy in the treatment of COPD patients.

TRIAL REGISTRATION

An independent ethics committee approved the study (Ethics Committee of Military Hospital 103 (No. 57/2014/VMMU-IRB), which was performed in accordance with the Declaration of Helsinki, Guidelines for Good Clinical Practice.

HERPES SIMPLEX VIRUS-1 SUSCEPTIBILITY AS A RISK FACTOR FOR SEPSIS, WITH CYTOMEGALOVIRUS SUSCEPTIBILITY ELEVATING SEVERITY: INSIGHTS FROM A BIDIRECTIONAL MENDELIAN RANDOMIZATION STUDY

ABSTRACT

Objective: We conducted a two-sample bidirectional Mendelian randomization (MR) study to investigate the causal relationships between herpes viruses and sepsis. Methods: Publicly available genome-wide association study data were used. Four viruses, HSV-1, HSV-2, EBV, and CMV, were selected, with serum positivity and levels of antibody in serum as the herpes virus data. Results: In forward MR, susceptibility to HSV-1 was a risk factor for sepsis. The susceptibility to CMV showed a severity-dependent effect on sepsis and was a risk factor for the 28-day mortality from sepsis, and was also a risk factor for 28-day sepsis mortality in critical care admission. The EBV EA-D antibody level after EBV infection was a protective factor for 28-day sepsis mortality in critical care admission, and CMV pp28 antibody level was a risk factor for 28-day sepsis mortality in critical care admission. No statistically significant causal relationships between HSV-2 and sepsis were found. No exposures having statistically significant association with sepsis critical care admission as an outcome were found. In reverse MR, the sepsis critical care admission group manifested a decrease in CMV pp52 antibody levels. No causal relationships with statistical significance between sepsis exposure and other herpes virus outcomes were found. Conclusion: Our study identifies HSV-1 susceptibility as a sepsis risk, with CMV susceptibility elevating severity. Varied effects of EBV and CMV antibodies on sepsis severity are noted. Severe sepsis results in a decline in CMV antibody levels. Our results help prognostic and predictive enrichment and offer valuable information for precision sepsis treatment.

Adjunctive immunotherapeutic agents in patients with sepsis and septic shock: a multidisciplinary consensus of 23

BACKGROUND

In the last decades, several adjunctive treatments have been proposed to reduce mortality in septic shock patients. Unfortunately, mortality due to sepsis and septic shock remains elevated and NO trials evaluating adjunctive therapies were able to demonstrate any clear benefit. In light of the lack of evidence and conflicting results from previous studies, in this multidisciplinary consensus, the authors considered the rational, recent investigations and potential clinical benefits of targeted adjunctive therapies.

METHODS

A panel of multidisciplinary experts defined clinical phenotypes, treatments and outcomes of greater interest in the field of adjunctive therapies for sepsis and septic shock. After an extensive systematic literature review, the appropriateness of each treatment for each clinical phenotype was determined using the modified RAND/UCLA appropriateness method.

RESULTS

The consensus identified two distinct clinical phenotypes: patients with overwhelming shock and patients with immune paralysis. Six different adjunctive treatments were considered the most frequently used and promising: (i) corticosteroids, (ii) blood purification, (iii) immunoglobulins, (iv) granulocyte/monocyte colony-stimulating factor and (v) specific immune therapy (i.e. interferon-gamma, IL7 and AntiPD1). Agreement was achieved in 70% of the 25 clinical questions.

CONCLUSIONS

Although clinical evidence is lacking, adjunctive therapies are often employed in the treatment of sepsis. To address this gap in knowledge, a panel of national experts has provided a structured consensus on the appropriate use of these treatments in clinical practice.

Catastrophic Streptococcus pyogenes Disease: A Personalized Approach Based on Phenotypes and Treatable Traits

Streptococcal toxic shock syndrome (STTS) is a critical medical emergency marked by high morbidity and mortality, necessitating swift awareness, targeted treatment, and early source control due to its rapid symptom manifestation. This report focuses on a cohort of 13 patients admitted to Vall d'Hebron University Hospital Intensive Care Unit, Barcelona, from November 2022 to March 2023, exhibiting invasive Streptococcus pyogenes infections and meeting institutional sepsis code activation criteria. The primary infections were community-acquired pneumonia (61.5%) and skin/soft tissue infection (30.8%). All patients received prompt antibiotic treatment, with clinical source control through thoracic drainage (30.8%) or surgical means (23.1%). Organ support involved invasive mechanical ventilation, vasopressors, and continuous renal replacement therapy as per guidelines. Of note, 76.9% of patients experienced septic cardiomyopathy, and 53.8% required extracorporeal membrane oxygenation (ECMO). The study identified three distinct phenotypic profiles-hyperinflammatory, low perfusion, and hypogammaglobulinemic-which could guide personalized therapeutic approaches. STTS, with a mean SOFA score of 17 (5.7) and a 53.8% requiring ECMO, underscores the need for precision medicine-based rescue therapies and sepsis phenotype identification. Integrating these strategies with prompt antibiotics and efficient source control offers a potential avenue to mitigate organ failure, enhancing patient survival and recovery in the face of this severe clinical condition.

Destabilisation of T cell-dependent humoral immunity in sepsis

Sepsis is a heterogeneous condition defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. For some, sepsis presents as a predominantly suppressive disorder, whilst others experience a pro-inflammatory condition which can culminate in a 'cytokine storm'. Frequently, patients experience signs of concurrent hyper-inflammation and immunosuppression, underpinning the difficulty in directing effective treatment. Although intensive care unit mortality rates have improved in recent years, one-third of discharged patients die within the following year. Half of post-sepsis deaths are due to exacerbation of pre-existing conditions, whilst half are due to complications arising from a deteriorated immune system. It has been suggested that the intense and dysregulated response to infection may induce irreversible metabolic reprogramming in immune cells. As a critical arm of immune protection in vertebrates, alterations to the adaptive immune system can have devastating repercussions. Indeed, a marked depletion of lymphocytes is observed in sepsis, correlating with increased rates of mortality. Such sepsis-induced lymphopenia has profound consequences on how T cells respond to infection but equally on the humoral immune response that is both elicited by B cells and supported by distinct CD4+ T follicular helper (TFH) cell subsets. The immunosuppressive state is further exacerbated by functional impairments to the remaining lymphocyte population, including the presence of cells expressing dysfunctional or exhausted phenotypes. This review will specifically focus on how sepsis destabilises the adaptive immune system, with a closer examination on how B cells and CD4+ TFH cells are affected by sepsis and the corresponding impact on humoral immunity.

Targeting the host response in sepsis: current approaches and future evidence

Sepsis, a dysregulated host response to infection characterized by organ failure, is one of the leading causes of death worldwide. Disbalances of the immune response play an important role in its pathophysiology. Patients may develop simultaneously or concomitantly states of systemic or local hyperinflammation and immunosuppression. Although a variety of effective immunomodulatory treatments are generally available, attempts to inhibit or stimulate the immune system in sepsis have failed so far to improve patients' outcome. The underlying reason is likely multifaceted including failure to identify responders to a specific immune intervention and the complex pathophysiology of organ dysfunction that is not exclusively caused by immunopathology but also includes dysfunction of the coagulation system, parenchymal organs, and the endothelium. Increasing evidence suggests that stratification of the heterogeneous population of septic patients with consideration of their host response might led to treatments that are more effective. The purpose of this review is to provide an overview of current studies aimed at optimizing the many facets of host response and to discuss future perspectives for precision medicine approaches in sepsis.

Protective and immunomodulatory effects of mesenchymal stem cells on multiorgan injury in male rats with heatstroke

Heatstroke (HS) causes multiple organ dysfunction syndrome (MODS) with a mortality rate of 60% after hospitalization. Currently, there is no effective and targeted approach for the treatment of HS. Despite growing evidence that mesenchymal stem cells (MSCs) may reduce multiorgan damage and improve survival through immunomodulatory effects in several diseases, no one has tested whether MSCs have immunomodulatory effects in heatstroke. The present study focused on pathological changes and levels of the cytokines and immunoglobulins to investigate the mechanisms underlying the protective effect and the anti-inflammatory effects of MSCs. We found that MSCs treatment significantly reduced the 28-day mortality rate (P < 0.05), the levels of hepatic and renal function markers on day 1 (P < 0.01) and the pathological lesion scores of multiple organs in HS rats. The levels of IgG1, IgM, and IgA of the HS + MSC group was significantly higher than that in HS group on days 3 and 28(P < 0.05). In conclusion, MSCs contribute to protecting against multiorgan injury, reducing pro-inflammatory cytokines, stabilizing immunoglobulins, and reducing the mortality rate of HS rats.

Multifaceted Tissue-Protective Functions of Polyvalent Immunoglobulin Preparations in Severe Infections-Interactions with Neutrophils, Complement, and Coagulation Pathways

Severe infections induce immune defense mechanisms and initial tissue damage, which produce an inflammatory neutrophil response. Upon dysregulation of these responses, inflammation, further tissue damage, and systemic spread of the pathogen may occur. Subsequent vascular inflammation and activation of coagulation processes may cause microvascular obstruction at sites distal to the primary site of infection. Low immunoglobulin (Ig) M and IgG levels have been detected in patients with severe infections like sCAP and sepsis, associated with increased severity and mortality. Based on Ig's modes of action, supplementation with polyvalent intravenous Ig preparations (standard IVIg or IgM/IgA-enriched Ig preparations) has long been discussed as a treatment option for severe infections. A prerequisite seems to be the timely administration of Ig preparations before excessive tissue damage has occurred and coagulopathy has developed. This review focuses on nonclinical and clinical studies that evaluated tissue-protective activities resulting from interactions of Igs with neutrophils, complement, and the coagulation system. The data indicate that coagulopathy, organ failure, and even death of patients can possibly be prevented by the timely combined interactions of (natural) IgM, IgA, and IgG with neutrophils and complement.

The immunomodulating activity of trimodulin (polyvalent IgM, IgA, IgG solution): a post hoc analysis of the phase II CIGMA trial

BACKGROUND

The phase II CIGMA trial performed in 160 patients with severe community-acquired pneumonia (sCAP) found treatment with trimodulin (human polyvalent immunoglobulin [Ig]: ~ 23% IgM, ~ 21% IgA, ~ 56% IgG) was associated with a lower mortality in those patients with elevated baseline serum levels of C-reactive protein (CRP) and/or subnormal IgM.

METHODS

In this post hoc analysis, the pharmacodynamic effects of trimodulin treatment (182.6 mg/kg/day for 5 days) were investigated on Ig replenishment, cellular markers of inflammation (absolute neutrophil [ANC] and lymphocyte [ALC] count, neutrophil-to-lymphocyte ratio [NLR]), and soluble markers of inflammation (procalcitonin [PCT] and CRP). The impact of these pharmacodynamic effects on mortality was also evaluated.

RESULTS

Compared with healthy subjects, baseline serum levels of IgM, IgG, and ALC were significantly lower, and ANC, NLR, PCT and CRP significantly higher in sCAP patients (p < 0.0001). Low Ig concentrations increased with trimodulin. Normalization of ANC (analysis of variance [ANOVA] p = 0.016) and PCT (ANOVA p = 0.027) was more rapid with trimodulin compared with placebo. These and other effects were more evident in patients with low baseline IgM levels. Normalization of PCT and CRP levels was both steadier and faster with trimodulin treatment. In patients with low baseline ALC, trimodulin was associated with a lower 28-day all-cause mortality rate (14.5% vs 32.1% in placebo, p = 0.043) and more ventilator-free days ([VFD]; median VFD: 3.5 vs 11 in placebo, p = 0.043). These numerical differences were greater if baseline IgM was also low (low ALC, low IgM: 8.1% mortality vs 34.1% placebo, p = 0.006; 3 VFD vs 15 VFD, p = 0.009, respectively). Results were consistent in patients with high baseline CRP (low ALC, high CRP: 10.9% mortality vs 34.1% placebo, p = 0.011).

CONCLUSIONS

This post hoc pharmacodynamic analysis of a blinded phase II trial suggests that trimodulin compensates for, and more rapidly modifies, the dysregulated inflammatory response seen in sCAP patients. Trimodulin was associated with significantly lower mortality and more VFD in subgroups with high CRP and low ALC. This effect was particularly marked in patients who also had low baseline IgM values. These findings require confirmation in prospective trials.

Advances in the Study of Immunosuppressive Mechanisms in Sepsis

Sepsis is a life-threatening disease caused by a systemic infection that triggers a dysregulated immune response. Sepsis is an important cause of death in intensive care units (ICUs), poses a major threat to human health, and is a common cause of death in ICUs worldwide. The pathogenesis of sepsis is intricate and involves a complex interplay of pro- and anti-inflammatory mechanisms that can lead to excessive inflammation, immunosuppression, and potentially long-term immune disorders. Recent evidence highlights the importance of immunosuppression in sepsis. Immunosuppression is recognized as a predisposing factor for increased susceptibility to secondary infections and mortality in patients. Immunosuppression due to sepsis increases a patient's chance of re-infection and increases organ load. In addition, antibiotics, fluid resuscitation, and organ support therapy have limited impact on the prognosis of septic patients. Therapeutic approaches by suppressing excessive inflammation have not achieved the desired results in clinical trials. Research into immunosuppression has brought new hope for the treatment of sepsis, and a number of therapeutic approaches have demonstrated the potential of immunostimulatory therapies. In this article, we will focus on the mechanisms of immunosuppression and markers of immune monitoring in sepsis and describe various targets for immunostimulatory therapy in sepsis.

Clinical efficacy of IgM-enriched immunoglobulin as adjunctive therapy in neonatal and pediatric sepsis: a systematic review and meta-analysis

Background

Sepsis is a major cause of mortality and morbidity globally, with around one-quarter of all sepsis-related deaths occurring in children under the age of 5. We conducted a meta-analysis and systematic review of the literature to evaluate the clinical effectiveness of an IgM-enriched immunoglobulin preparation in pediatrics patients and neonates with sepsis.

Methods

Systematic searches of PubMed, the Cochrane Library and Embase databases were performed in November 2022, with no date limitations, to identify studies in which IgM-enriched immunoglobulin was used as adjunctive therapy in neonatal and pediatric patients with sepsis.

Results

In total, 15 studies fulfilled the eligibility criteria, 13 neonatal studies and 2 pediatric studies. Pooled estimates from all studies indicated that mortality rates were significantly lower in patients who received treatment with the IgM-enriched immunoglobulin compared with controls (OR 0.41; 95% CI 0.32-0.55). Further analyses in neonatal studies, alone, showed a significant benefit with longer treatment durations (>3 days) vs. the recommended treatment duration (3 days) (OR 0.32; 95% CI 0.22-0.47) vs. (OR 0.61; 95% CI 0.41-0.92). Treatment with IgM-enriched immunoglobulin was associated with a lower mortality risk compared with controls in prospective studies vs. retrospective analyses (OR 0.37; 95% CI 0.27-0.51) vs. (OR 0.73; 95% CI 0.41-1.30).

Conclusions

This systematic review suggests that adjunctive treatment with IgM-enriched immunoglobulin may reduce the risk of mortality in neonatal and pediatric populations. However, large randomized controlled trials are required to further substantiate and evaluate these findings.

The Role of the Intravenous IgA and IgM-Enriched Immunoglobulin Preparation in the Treatment of Sepsis and Septic Shock

Polyclonal Intravenous Immunoglobulins (IvIg) are often administered to critically ill patients more as an act of faith than on the basis of relevant clinical studies. This particularly applies to the treatment of sepsis and septic shock because the current guidelines recommend against their use despite many investigations that have demonstrated their beneficial effects in different subsets of patients. The biology, mechanisms of action, and clinical experience related to the administration of IvIg are reviewed, which aim to give a more in-depth understanding of their properties in order to clarify their possible indications in sepsis and septic shock patients.

A new hope? Possibilities of therapeutic IgA antibodies in the treatment of inflammatory lung diseases

Inflammatory lung diseases represent a persistent burden for patients and the global healthcare system. The combination of high morbidity, (partially) high mortality and limited innovations in the last decades, have resulted in a great demand for new therapeutics. Are therapeutic IgA antibodies possibly a new hope in the treatment of inflammatory lung diseases? Current research increasingly unravels the elementary functions of IgA as protector against infections and as modulator of overwhelming inflammation. With a focus on IgA, this review describes the pathological alterations in mucosal immunity and how they contribute to chronic inflammation in the most common inflammatory lung diseases. The current knowledge of IgA functions in the circulation, and particularly in the respiratory mucosa, are summarized. The interplay between neutrophils and IgA seems to be key in control of inflammation. In addition, the hurdles and benefits of therapeutic IgA antibodies, as well as the currently known clinically used IgA preparations are described. The data highlighted here, together with upcoming research strategies aiming at circumventing the current pitfalls in IgA research may pave the way for this promising antibody class in the application of inflammatory lung diseases.

Adjuvant intravenous immunoglobulin administration on postoperative critically ill patients with secondary peritonitis: a retrospective study

BACKGROUND

The use of intravenous immunoglobulin (IVIG) in sepsis patients from bowel perforation is still debatable. However, few studies have evaluated the effect of IVIG as an adjuvant therapy after source control. This study aimed to analyze the effect of IVIG in critically ill patients who underwent surgery due to secondary peritonitis.

METHODS

In total, 646 medical records of surgical patients who were treated for secondary peritonitis were retrospectively analyzed. IVIG use, initial clinical data, and changes in Sequential Organ Failure Assessment (SOFA) score over the 7-day admission in the intensive care unit for sepsis check, base excess, and delta neutrophil index (DNI) were analyzed. Mortalities and periodic profiles were assessed. Propensity scoring matching as comparative analysis was performed in the IVIG group and non-IVIG group.

RESULTS

General characteristics were not different between the two groups. The survival curve did not show a significantly reduced mortality in the IVIG. Moreover, the IVIG group did not have a lower risk ratio for mortality than the non-IVIG group. However, when the DNI were compared during the first 7 days, the reduction rate in the IVIG group was statistically faster than in the non-IVIG group (P<0.01).

CONCLUSIONS

The use of IVIG was significantly associated with faster decrease in DNI which means faster reduction of inflammation. Since the immune system is rapidly activated, the additional use of IVIG after source control surgery in abdominal sepsis patients, especially those with immunocompromised patients can be considered. However, furthermore clinical studies are needed.

Facial Swelling After Dental Work Done: A Case of Ludwig's Angina

Ludwig's angina is a fast-spreading cellulitis located on the floor of the oropharynx and neck (Tami, Othman, Sudhakar, & McKinnon, 2020). Patients may present with a wide range of symptoms depending on the severity of the condition (Reynolds & Chow, 2007). Emergency nurse practitioners need to promptly identify, diagnose, and treat patients with this problem, with close attention to the patient's airway. A compromised airway is the leading cause of mortality from this condition (McDonnough et al., 2019). The diagnosis is generally made with a comprehensive history and physical examination, laboratory values, and imaging studies such as computer tomography (Bridwell, Gottlieb, Koyfman, & Long, 2021). Management includes admission to the hospital, broad-spectrum antibiotics, and specialist surgical consultation (Bridwell et al., 2021).

Insights into the Roles of B Cells in Patients with Sepsis

Sepsis is a life-threatening yet common disease, still posing high mortality worldwide. Sepsis-related deaths primarily occur during immunosuppression; the disease can hamper the numbers and function of B cells, which mediate innate and adaptive immune responses to maintain immune homeostasis. Dysfunction of B cells, along with aggravated immunosuppression, are closely related to poor prognosis. However, B cells in patients with sepsis have garnered little attention. This article focuses on the significance of B-cell subsets, including regulatory B cells, in sepsis and how the counts and function of circulating B cells are affected in patients with sepsis. Finally, potential B-cell-related immunotherapies for sepsis are explored.

Expert consensus on the monitoring and treatment of sepsis-induced immunosuppression

Emerged evidence has indicated that immunosuppression is involved in the occurrence and development of sepsis. To provide clinical practice recommendations on the immune function in sepsis, an expert consensus focusing on the monitoring and treatment of sepsis-induced immunosuppression was developed. Literature related to the immune monitoring and treatment of sepsis were retrieved from PubMed, Web of Science, and Chinese National Knowledge Infrastructure to design items and expert opinions were collected through an online questionnaire. Then, the Delphi method was used to form consensus opinions, and RAND appropriateness method was developed to provide consistency evaluation and recommendation levels for consensus opinions. This consensus achieved satisfactory results through two rounds of questionnaire survey, with 2 statements rated as perfect consistency, 13 as very good consistency, and 9 as good consistency. After summarizing the results, a total of 14 strong recommended opinions, 8 weak recommended opinions and 2 non-recommended opinions were produced. Finally, a face-to-face discussion of the consensus opinions was performed through an online meeting, and all judges unanimously agreed on the content of this consensus. In summary, this expert consensus provides a preliminary guidance for the monitoring and treatment of immunosuppression in patients with sepsis.

Outcomes of ICU patients treated with intravenous immunoglobulin for sepsis or autoimmune diseases

OBJECTIVES

To evaluate the outcomes of hospitalized patients in two intensive care units (ICU) treated with intravenous immunoglobulin (IVIg) added to standard-of-care therapy. The indications for IVIg therapy were sepsis or autoimmune disease.

METHODS

We conducted a retrospective study involving adult patients with sepsis and autoimmune diseases, who received IVIg in the ICU at Wolfson and Sheba Medical Centers. A predefined chart was compiled on Excel to include a complete demographic collection, patient comorbidities, chronic medication use, disease severity scores (Charlson Comorbidity Index; SOFA and APACHE II index scores), indication and dosage of IVIg administration, duration of hospitalization and mortality rates.

RESULTS

Patients (n - 111) were divided into 2 groups: patients with sepsis only (n-67) and patients with autoimmune disease only (n-44). Septic patients had a shorter ICU stay, received IVIg early, and had reduced mortality if treated with high dose IVIg. Patients with autoimmune diseases did not have a favorable outcome despite IVIg treatment. In this group, IVIg was administered later than in the sepsis group.

CONCLUSIONS

IVIg therapy improved the outcomes for ICU patients with sepsis.

Septic Shock: Management and Outcomes

The incidence rates of sepsis and septic shock as a complication have become more common over the past several decades. With this increase, sepsis remains the most common cause of intensive care unit (ICU) admissions and one of the most mortality factors, with a huge burden on healthcare facilities. Septic shock has devastating consequences on patients' lives, including organ failures and other long-term complications. Due to its dynamic clinical presentations, guidelines and tools have been established to improve the diagnosis and management effectively. However, there is still a need for evidence-based standardized procedures for the diagnosis, treatment, and follow-up of sepsis and septic shock patients due to the inconsistency of current guidelines and studies contrasting with each other. The standardization would help physicians better manage sepsis, minimize complications and reduce mortality. Septic shock is usually challenging to manage due to its variety of clinical characteristics and physiologic dynamics, affecting the outcomes. Therefore, this review presented the available data in the literature on septic shock diagnosis, management, and prognosis to have an overview of the updated best practice approach to septic shock.

The emerging roles and therapeutic potential of B cells in sepsis

Sepsis is a life-threatening syndrome caused by anomalous host response to infection. The pathogenesis of sepsis is complex, and immune dysfunction is the central link in its occurrence and development. The sepsis immune response is not a local and transient process but a complex and continuous process involving all major cell types of innate and adaptive immunity. B cells are traditionally studied for their ability to produce antibodies in the context of mediating humoral immunity. However, over the past few years, B cells have been increasingly recognized as key modulators of adaptive and innate immunity, and they can participate in immune responses by presenting antigens, producing cytokines, and modulating other immune cells. Recently, increasing evidence links B-cell dysfunction to mechanisms of immune derangement in sepsis, which has drawn attention to the powerful properties of this unique immune cell type in sepsis. Here, we reviewed the dynamic alterations of B cells and their novel roles in animal models and patients with sepsis, and provided new perspectives for therapeutic strategies targeting B cells in sepsis.

Sepsis-induced immunosuppression: mechanisms, diagnosis and current treatment options

Sepsis is a common complication of combat injuries and trauma, and is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. It is also one of the significant causes of death and increased health care costs in modern intensive care units. The use of antibiotics, fluid resuscitation, and organ support therapy have limited prognostic impact in patients with sepsis. Although its pathophysiology remains elusive, immunosuppression is now recognized as one of the major causes of septic death. Sepsis-induced immunosuppression is resulted from disruption of immune homeostasis. It is characterized by the release of anti-inflammatory cytokines, abnormal death of immune effector cells, hyperproliferation of immune suppressor cells, and expression of immune checkpoints. By targeting immunosuppression, especially with immune checkpoint inhibitors, preclinical studies have demonstrated the reversal of immunocyte dysfunctions and established host resistance. Here, we comprehensively discuss recent findings on the mechanisms, regulation and biomarkers of sepsis-induced immunosuppression and highlight their implications for developing effective strategies to treat patients with septic shock.

Impaired Circulating Antibody-Secreting Cells Generation Predicts the Dismal Outcome in the Elderly Septic Shock Patients

Purpose

Sepsis is a condition that derives from a dysregulated host response to infection. Although B lymphocytes play a pivotal role in immune response, little is known about status of their terminally differentiated cells, antibody-secreting cells (ASCs) during immunosuppressive phase of sepsis, especially in elderly patients. Our aim was to extensively characterize the immune functions of ASCs in elderly septic patients.

Patients and Methods

Clinical and laboratory data were collected on days 1, 3, and 7 of hospitalization. Circulating ASCs were evaluated by flow cytometry from fresh whole blood in elderly septic patients at the onset of disease. RNA sequencing analyzed ASCs gene expression profile. Receiver operating characteristic (ROC) curve analysis and logistic regression predicted the survival rate of 28-day mortality.

Results

A total of 103 septic patients were enrolled. The number and proportion of ASCs among total lymphocytes dramatically increased in septic patients, and RNA sequencing analysis showed that ASCs from septic patients exhibited a different gene expression profile. Furthermore, we found these ASCs could promote the function of T cells. Logistic regression analysis showed ASCs population was an independent outcome predictor in septic shock patients.

Conclusion

Our study revealed the complex nature of immune disorders in sepsis and identified circulating ASCs population as a useful biomarker for predicting mortality in elderly septic patients, which provided a novel clue to combat this severe disease.

Low SARS-CoV-2 antibody titers may be associated with poor clinical outcomes for patients with severe COVID-19

Recently, immune response to coronavirus disease (COVID-19) has attracted attention where an association between higher antibody titer and worsening disease severity has been reported. However, our experiences with severe COVID-19 patients with low antibody titers led to hypothesizing that suppressed humoral immune response may be associated with poorer prognosis in severe COVID19. In this study, antibody titers in severe COVID19 patients were measured at 7, 10, 12, and 14 days after onset. Patients were divided into survivors and non-survivors. SARS-CoV-2 IgM in survivors and non-survivors were 0.06 AU and 0.02 AU (P = 0.048) at 10 days, 0.1 AU and 0.03 AU (P = 0.02) at 12 days, and 0.17 AU and 0.06 AU (P = 0.02) at 14 days. IgG in survivors and non-survivors were 0.01 AU and 0.01 AU (P = 0.04) at 7 days, 0.42 AU and 0.01 AU (P = 0.04) at 12 days, and 0.42 AU and 0.01 AU (P = 0.02) at 14 days. Multivariate analysis showed better survival among patients with IgM positivity at 12 days (P = 0.04), IgG positivity at 12 days (P = 0.04), IgM positivity at 14 days (P = 0.008), and IgG positivity at 14 days (P = 0.005). In severe COVID-19, low antibody titers on days 12 and 14 after onset were associated with poorer prognosis.

Advances in Immune Monitoring Approaches for Sepsis-Induced Immunosuppression

Sepsis represents a life-threatening organ dysfunction due to an aberrant host response. Of note is that majority of patients have experienced a severe immune depression during and after sepsis, which is significantly correlated with the occurrence of nosocomial infection and higher risk of in-hospital death. Nevertheless, the clinical sign of sepsis-induced immune paralysis remains highly indetectable and ambiguous. Given that, specific yet robust biomarkers for monitoring the immune functional status of septic patients are of prominent significance in clinical practice. In turn, the stratification of a subgroup of septic patients with an immunosuppressive state will greatly contribute to the implementation of personalized adjuvant immunotherapy. In this review, we comprehensively summarize the mechanism of sepsis-associated immunosuppression at the cellular level and highlight the recent advances in immune monitoring approaches targeting the functional status of both innate and adaptive immune responses.

Precision medicine in sepsis and septic shock: From omics to clinical tools

Sepsis is a heterogeneous disease with variable clinical course and several clinical phenotypes. As it is associated with an increased risk of death, patients with this condition are candidates for receipt of a very well-structured and protocolized treatment. All patients should receive the fundamental pillars of sepsis management, which are infection control, initial resuscitation, and multiorgan support. However, specific subgroups of patients may benefit from a personalized approach with interventions targeted towards specific pathophysiological mechanisms. Herein, we will review the framework for identifying subpopulations of patients with sepsis, septic shock, and multiorgan dysfunction who may benefit from specific therapies. Some of these approaches are still in the early stages of research, while others are already in routine use in clinical practice, but together will help in the effective generation and safe implementation of precision medicine in sepsis.

Efficacy of Intravenous Immunoglobulin Therapy for Patients With Sepsis and Low Immunoglobulin G Levels: A Single-Center Retrospective Study

PURPOSE

The efficacy of intravenous immunoglobulin (IVIG) administration in patients with sepsis or septic shock remains unclear. A single-center retrospective study was conducted to evaluate the association between IVIG supplementation and favorable outcomes in patients with sepsis and low serum immunoglobulin G (IgG) levels.

METHODS

A total of 239 patients with sepsis were identified whose serum IgG levels were determined upon admission to the intensive care unit between January 2014 and March 2021. Patients with low IgG levels (<670 mg/dL) were divided into the IVIG and non-IVIG groups. Patient data were collected from electronic medical records to evaluate the patients' characteristics, sepsis severity, and prognosis. The primary outcome was 28-day mortality. The propensity score was calculated by using the following variables: age, Sequential Organ Failure Assessment score, immunocompromised status, and serum IgG levels. Logistic regression analysis using propensity score as the adjusted variable was performed to evaluate the outcome.

FINDINGS

Of 239 patients, 87 had low IgG levels. Of these patients, 47 received IVIG therapy. The 28-day (odds ratio [OR], 0.15; 95% CI, 0.04-0.54; P = 0.004) and 90-day (OR, 0.31; 95% CI, 0.11-0.83; P = 0.020) mortality rates were significantly lower in the IVIG group than in the non-IVIG group. Moreover, the number of days free from renal replacement therapy was significantly higher in the IVIG group than in the non-IVIG group (OR, 1.06; 95% CI, 1.01-1.11; P = 0.025). Serum IgG levels in the IVIG group showed no significant difference compared with those in the non-IVIG group. No significant differences in the patients' characteristics were observed between the groups.

IMPLICATIONS

This study found that IVIG administration in patients with sepsis and low serum IgG levels was associated with improved prognosis. Further studies are warranted to evaluate the validity of IVIG therapy for patients with sepsis and low serum IgG levels.

Higher levels of IgA and IgG at sepsis onset are associated with higher mortality: results from the Albumin Italian Outcome Sepsis (ALBIOS) trial

Background

The role of intravenous immunoglobulins (IVIG) during sepsis is controversial, as different trials on IVIG have observed inconsistent survival benefits. We aimed to elucidate the possible association and clinical significance between circulating levels of immunoglobulins.

Methods

In a subset of 956 patients with severe sepsis and septic shock of the multicentre, open-label RCT ALBIOS, venous blood samples were serially collected 1, 2, and 7 days after enrolment (or at ICU discharge, whichever came first). IgA, IgG and IgM concentrations were assayed in all patients on day 1 and in a subgroup of 150 patients on days 2 and 7. Ig concentrations were measured employing a turbidimetric assay, OSR61171 system.

Results

IgA on day 1 had a significant predictive value for both 28-day and 90-day mortality (28-day mortality, HR: 1.50 (95% CI 1.18–1.92); 90-day mortality, HR: 1.54 (95% CI 1.25–1.91)). IgG, but not IgM, on day 1 showed similar results for 28-day (HR 1.83 (95% CI 1.33–2.51) and 90-day mortality HR: 1.66 (95% CI 1.23–2.25)). In addition, lower levels of IgG but not of IgA and IgM, at day 1 were associated with significantly higher risk of secondary infections (533 [406–772] vs 600 [452–842] mg/dL, median [Q1–Q3], p = 0.007).

Conclusions

In the largest cohort study of patients with severe sepsis or septic shock, we found that high levels of IgA and IgG on the first day of diagnosis were associated with a decreased 90-day survival. No association was found between IgM levels and survival. As such, the assessment of endogenous immunoglobulins could be a useful tool to identify septic patients at high risk of mortality.

Trial registration #NCT00707122, Clinicaltrial.gov, registered 30 June 2008

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00952-z.

Plasma IgM Levels Differentiate between Survivors and Non-Survivors of Culture-Positive and Culture-Negative Sepsis and SIRS: A Pilot Study

Immunoglobulin IgM is important for controlling viral and bacterial infections, and low immunoglobulin levels have been found in sepsis. There is a clear need to stratify sepsis patients according to the presence of an invading organism, compared to no organism identified, and SIRS patients, where organ dysfunction is a result of a non-infective process. The aim of this pilot study in a small cohort of patients with sepsis was to evaluate the association between IgM plasma levels and survival in 47 patients with sepsis and 11 patients diagnosed with organ failure without the identification of a pathogen (SIRS). Patients were admitted to the intensive care unit (ICU) at The Royal Glamorgan Hospital, Llantrisant, UK between 2010 and 2014. We found that low IgM levels were associated with sepsis, but not SIRS. IgM levels did not differ significantly for culture-positive (CP) compared with culture-negative (CN, no organism found) sepsis samples. Kaplan–Meier analysis was used to compare survival curves according to IgM levels, with no significant difference. We observed significantly higher survival in the CP samples when comparing with CN. Cut-off value for IgM (266 μg/mL) for diagnosis of sepsis patients was determined using receiver operator characteristic (ROC) curves with 70% sensitivity, 69% specificity and 92% negative predictive values (NPV), respectively. The corresponding area under the curve (AUC) for the discrimination of sepsis patients was AUC = 0.73, and in a subgroup analysis of CP was AUC = 0.77 and for CN was AUC = 0.79. We confirm IgM as a good diagnostic marker of sepsis. These findings indicate a difference in the pathology between culture-positive versus negative sepsis, SIRS and survival. This indicates that IgM is likely relevant to pathology, because of its role in the early immune response against pathogens, the potentially protective role of natural IgM antibodies, and supports its application in immunoglobulin therapy.

The Dual Role of a Polyvalent IgM/IgA-Enriched Immunoglobulin Preparation in Activating and Inhibiting the Complement System

Activation of the complement system is important for efficient clearance of a wide variety of pathogens via opsonophagocytosis, or by direct lysis via complement-dependent cytotoxicity (CDC). However, in severe infections dysregulation of the complement system contributes to hyperinflammation. The influence of the novel IgM/IgA-enriched immunoglobulin preparation trimodulin on the complement pathway was investigated in in vitro opsonophagocytosis, binding and CDC assays. Immunoglobulin levels before and after trimodulin treatment were placed in relation to complement assessments in humans. In vitro, trimodulin activates complement and induces opsonophagocytosis, but also interacts with opsonins C3b, C4b and anaphylatoxin C5a in a concentration-dependent manner. This was not observed for standard intravenous IgG preparation (IVIg). Accordingly, trimodulin, but not IVIg, inhibited the downstream CDC pathway and target cell lysis. If applied at a similar concentration range in healthy subjects, trimodulin treatment resulted in C3 and C4 consumption in a concentration-dependent manner, which was extended in patients with severe community-acquired pneumonia. Complement consumption is found to be dependent on underlying immunoglobulin levels, particularly IgM, pinpointing their regulative function in humans. IgM/IgA provide a balancing effect on the complement system. Trimodulin may enhance phagocytosis and opsonophagocytosis in patients with severe infections and prevent excessive pathogen lysis and release of harmful anaphylatoxins.

Sepsis-Pathophysiology and Therapeutic Concepts

Sepsis is a life-threatening condition and a global disease burden. Today, the heterogeneous syndrome is defined as severe organ dysfunction caused by a dysregulated host response to infection, with renewed emphasis on immune pathophysiology. Despite all efforts of experimental and clinical research during the last three decades, the ability to positively influence course and outcome of the syndrome remains limited. Evidence-based therapy still consists of basic causal and supportive measures, while adjuvant interventions such as blood purification or targeted immunotherapy largely remain without proof of effectiveness so far. With this review, we aim to provide an overview of sepsis immune pathophysiology, to update the choice of therapeutic approaches targeting different immunological mechanisms in the course of sepsis and septic shock, and to call for a paradigm shift from the pathogen to the host response as a potentially more promising angle.

Impaired B-Cell Maturation Contributes to Reduced B Cell Numbers and Poor Prognosis in Sepsis

BACKGROUND

Reduced B cell numbers play a critical role in sepsis immunosuppression. The role of B-cell maturation regulated by T follicular helper (Tfh) cells in reduced B cell numbers during sepsis remains unclear. We tested the hypothesis that impaired B-cell maturation contributes to reduced B cell numbers.

DESIGN

Retrospective study and observational prospective cohort study.

SETTINGS

Critical care units.

METHODS

To identify the exact lymphocyte counts that affect the prognosis of sepsis, we first conducted a retrospective study. Then in the prospective cohort study, differences in B-cell maturation, B cell death, and numbers of circulating Tfh (cTfh) cell were compared between 28-day survivors and 28-day non-survivors, mainly by flow cytometry and enzyme-linked immunosorbent assay.

MAIN RESULTS

In retrospective study (n = 123), we found patients with lymphocyte counts less than 0.4 × 10 cells/L had higher mortality than patients with lymphocyte counts above 0.4 × 10 cells/L. In observational prospective cohort study (n = 40), compared with survivors, non-survivors had fewer numbers of mature B cell and circulating Tfh (cTfh) cell (sepsis onset: memory B cells: 3.44% vs. 4.48%, antibody-secreting cells: 4.53% vs. 6.30%, cTfh cells: 3.57% vs. 4.49%; 24 h after sepsis onset: memory B cells: 4.05% vs. 7.20%, antibody-secreting cells: 5.25% vs. 8.78%, cTfh cells: 3.98% vs. 6.15%), while there were no differences in cell death of mature B cells between them. We further noticed the numbers of cTfh cell positively correlated with the numbers of mature B cell and immunoglobulin concentrations.

CONCLUSIONS

Impaired B-cell maturation contributes to reduced B cell numbers, while the numbers of cTfh cell, acting as a warning indicator for sepsis prognosis, may be a new therapeutic target for treating sepsis.

Treatment with IgM-enriched immunoglobulin in sepsis: a matched case-control analysis

The therapeutic potential of IgM-enriched immunoglobulin preparations (IgGAM) in sepsis remains a field of debate. The use of polyclonal immunoglobulins as adjuvant therapy (Esen & Tugrul, 2009; Kaukonen et al., 2014; Molnár et al., 2013; Taccone et al., 2009) has been shown to improve clinical outcomes in terms of mortality. This study analyze the impact of IgM-enriched IgG (IgGM) as additional immunomodulation. Patients and methods: This is a retrospective registry of 1196 patients with severe sepsis and septic shock from nine Intensive Care Units in Colombia, from routine clinical practice; 220 patients treated with IgGAM were registered. Fully matched comparators for severity and type of infection selected among patients non-treated with IgGAM. Mortality after 28 days was 30.5% among IgGAM-treated patients and 40.5% among matched comparators. Results: Multivariate Cox regression analysis showed IgGAM treatment to be the only variable protective from death after 28 days (hazard ratio 0.62; 0.45-0.86; p: 0.004). Results reinforce the importance of IgGAM treatment for favorable outcome after septic shock and are in line with recent published meta-analyses. This study showed that treatment with IgGM in patients with sepsis was an independent modulator of the 28-day associated with a lower mortality.

Adjunctive IgM-enriched immunoglobulin therapy with a personalised dose based on serum IgM-titres versus standard dose in the treatment of septic shock: a randomised controlled trial (IgM-fat trial)

INTRODUCTION

In patients with septic shock, low levels of circulating immunoglobulins are common and their kinetics appear to be related to clinical outcome. The pivotal role of immunoglobulins in the host immune response to infection suggests that additional therapy with polyclonal intravenous immunoglobulins may be a promising option in patients with septic shock. Immunoglobulin preparations enriched with the IgM component have largely been used in sepsis, mostly at standard dosages (250 mg/kg per day), regardless of clinical severity and without any dose adjustment based on immunoglobulin serum titres or other biomarkers. We hypothesised that a personalised dose of IgM enriched preparation based on patient IgM titres and aimed to achieve a specific threshold of IgM titre is more effective in decreasing mortality than a standard dose.

METHODS AND ANALYSIS

The study is designed as a multicentre, interventional, randomised, single-blinded, prospective, investigator sponsored, two-armed study. Patients with septic shock and IgM titres <60 mg/dL will be randomly assigned to an IgM titre-based treatment or a standard treatment group in a ratio of 1:1. The study will involve 12 Italian intensive care units and 356 patients will be enrolled. Patients assigned to the IgM titre-based treatment will receive a personalised daily dose based on an IgM serum titre aimed at achieving serum titres above 100 mg/dL up to discontinuation of vasoactive drugs or day 7 after enrolment. Patients assigned to the IgM standard treatment group will receive IgM enriched preparation daily for three consecutive days at the standard dose of 250 mg/kg. The primary endpoint will be all-cause mortality at 28 days.

ETHICS AND DISSEMINATION

The study protocol was approved by the ethics committees of the coordinating centre (Comitato Etico dell'Area Vasta Emilia Nord) and collaborating centres. The results of the trial will be published within 12 months from the end of the study and the steering committee has the right to present them at public symposia and conferences.

TRIAL REGISTRATION DETAILS

The trial protocol and information documents have received a favourable opinion from the Area Vasta Emilia Nord Ethical Committee on 12 September 2019. The trial protocol has been registered on EudraCT (2018-001613-33) on 18 April 2018 and on ClinicalTrials.gov (NCT04182737) on 2 December 2019.

Population-Specific Metabolic Alterations in Professional Antigen-Presenting Cells Contribute to Sepsis-Associated Immunosuppression

Sepsis is a complex host response triggered by an infection, with the patient's immune system between hyper- and hypo-responsiveness being the main reason for the syndromes' development and propagation. Studies conducted in peripheral blood mononuclear cells uncovered an association between an impaired immunometabolism and the severity and outcome of the disease. With this prospective observational study, we aimed to evaluate the immunometabolic phenotype of monocytes and B cells and its association with the cell function.Monocytes and B cells were isolated from patients with sepsis (n = 10; onset, days 4 and 8) and healthy volunteers (n = 10) and subsequently analyzed for metabolic changes and human leukocyte antigen-DR (HLA-DR) expression. Contemporaneously, immune checkpoints on monocytes and the ex vivo cytokine responses (interleukins 6 and 8) upon lipopolysaccharide or zymosan stimulation were analyzed. The distribution of B cell subsets was assessed, and plasma levels of immunoglobulins and tricarboxylic acid cycle intermediates were quantified.Both monocytes and B cells exhibited decreased HLA-DR expression in patients with sepsis. Monocytes displayed a stable upregulated glycolysis while B cells augmented glycolysis and respiration over time. The monocytes' ability to respond to stimulation was stimuli-dependently reduced but recovered over time. The B cell compartment shifted toward antibody-producing subsets and elevated immunoglobulins within the first days.Our results provide evidence for the induction of a state of trained immunity in monocytes and an early but transient immunosuppressive phenotype accounting for peripheral sepsis-induced vulnerability to infections. B cells exhibit an unsustainable activation contributing to adaptive immunosuppression.

Correlation of Immunoglobulins and Lymphocytes Levels With the Clinical and Microbiological Response of Septic Patients With Gram-Negative Bacteremia

Background

Immunoglobulins (Igs) and cells of the innate and adaptive immune systems play a critical role in a host's response to sepsis. The aim of this study was to investigate the possible differences in the levels of Igs, white blood cells (WBCs), and T and B lymphocytes cells in relation to the microbiological and clinical responses of patients with sepsis or septic shock from carbapenem non-susceptible Gram-negative bacteria (CnS-GNB).

Methods

This pilot cohort study involved 24 hospitalized patients with sepsis or septic shock due to bacteremia from CnS-GNB. The microbiological and clinical responses of the patients were evaluated in relation to their blood levels of IgA, IgE, IgM and IgG, as well as WBCs and subpopulations of T and B cells upon sepsis diagnosis. A microbiological response was determined as clearance of bacteremia at 14 days of active antibiotic treatment for the isolated bacterial pathogen. Clinical response was defined as the resolution of all clinical and laboratory signs of infection and sepsis at 14 days of active antibiotic treatment for the isolated pathogen.

Results

From the 24 patients included in the study 18 (75%) and six patients (25%) presented and did not present microbiological response respectively, while 16 patients presented clinical response (64%) and eight patients (36%) did not have clinical response. The levels of the Igs did not show statistically significant differences between patients with sepsis from CnS-GNB bacteremia who exhibited microbiological or clinical response. There were also no statistically significant differences in the levels of WBCs and the subpopulations of T and B cells levels for these patients (P > 0.05). According to this pilot study, peripheral blood Igs and lymphocyte subpopulations levels do not affect the clinical and microbiological response of septic patients with bacteremia from CnS-GNB.

Conclusions

In patients with sepsis or septic shock from CnSGNB, there were no differences in the levels of Igs, circulating WBCs and T and B cells subpopulations between those with microbiological or clinical response and non-responders.

Effect of Therapeutic Plasma Exchange on Immunoglobulin Deficiency in Early and Severe Septic Shock

BACKGROUND

Deficiency of immunoglobulins of the classes IgG, IgG1, IgA and IgM is associated with severity of disease and mortality in sepsis and septic shock. Therapeutic plasma exchange (TPE) with fresh frozen plasma (FFP) has recently gained attention as an adjunctive therapeutic option in early septic shock. We hypothesized that TPE might modulate immunoglobulin deficiencies besides sole elimination of circulating injurious molecules.

METHODS

We conducted a prospective single center study with TPE in 33 patients with early septic shock (onset < 12 h) requiring high doses of norepinephrine (NE > 0.4μg/kg/min). Clinical and biochemical data, including measurement of immunoglobulin subgroups IgG, IgG1, IgM and IgA were obtained before and after TPE. The following immunoglobulin cut-off values were used to analyze subgroups with low immunoglobulin concentrations at baseline (IgG ≤ 6.5, IgG1 ≤ 3, IgM ≤ 1.5 and IgA ≤ 0.35 g/L).

RESULTS

At inclusion, median (IQR) SOFA score was 18 (15-20) and NE dose was 0.8 (0.6-1.2) μg/kg/min. The majority of patients demonstrated profound reductions in immunoglobulins levels of all classes. Globally, immunoglobulin levels were not significantly changed after a single TPE session. However, in patients with low baseline immunoglobulin levels a significant increase in all classes was observed (IgG 1.92 (0.96-3) g/L (+41%), IgG1 2.1 (1.46-2.32) g/L (+96%), IgA 0.44 (0.12-0.62) g/L (59%) and IgM 0.18 (0.14-0.34) g/L (+55%), p < 0.001 for comparison to patients above cut-off).

CONCLUSIONS

The majority of early and severe septic shock patients had reduced immunoglobulin levels and a single TPE could attenuate immunoglobulin deficiencies of all classes. The clinical relevance of this observation has to be investigated in a proper designed trial.

Best-practice IgM- and IgA-enriched immunoglobulin use in patients with sepsis

Background

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. Despite treatment being in line with current guidelines, mortality remains high in those with septic shock. Intravenous immunoglobulins represent a promising therapy to modulate both the pro- and anti-inflammatory processes and can contribute to the elimination of pathogens. In this context, there is evidence of the benefits of immunoglobulin M (IgM)- and immunoglobulin A (IgA)-enriched immunoglobulin therapy for sepsis. This manuscript aims to summarize current relevant data to provide expert opinions on best practice for the use of an IgM- and IgA-enriched immunoglobulin (Pentaglobin) in adult patients with sepsis.

Main text

Sepsis patients with hyperinflammation and patients with immunosuppression may benefit most from treatment with IgM- and IgA-enriched immunoglobulin (Pentaglobin). Patients with hyperinflammation present with phenotypes that manifest throughout the body, whilst the clinical characteristics of immunosuppression are less clear. Potential biomarkers for hyperinflammation include elevated procalcitonin, interleukin-6, endotoxin activity and C-reactive protein, although thresholds for these are not well-defined. Convenient biomarkers for identifying patients in a stage of immune-paralysis are still matter of debate, though human leukocyte antigen–antigen D related expression on monocytes, lymphocyte count and viral reactivation have been proposed. The timing of treatment is potentially more critical for treatment efficacy in patients with hyperinflammation compared with patients who are in an immunosuppressed stage. Due to the lack of evidence, definitive dosage recommendations for either population cannot be made, though we suggest that patients with hyperinflammation should receive an initial bolus at a rate of up to 0.6 mL (30 mg)/kg/h for 6 h followed by a continuous maintenance rate of 0.2 mL (10 mg)/kg/hour for ≥ 72 h (total dose ≥ 0.9 g/kg). For immunosuppressed patients, dosage is more conservative (0.2 mL [10 mg]/kg/h) for ≥ 72 h, without an initial bolus (total dose ≥ 0.72 g/kg).

Conclusions

Two distinct populations that may benefit most from Pentaglobin therapy are described in this review. However, further clinical evidence is required to strengthen support for the recommendations given here regarding timing, duration and dosage of treatment.

Low immunoglobulin G level is associated with poor outcomes in patients with sepsis and septic shock

BACKGROUND

Despite studies on low immunoglobulin G (IgG) levels in critically ill patients, their association with clinical outcomes in sepsis patients remains disputed. Herein, we determined the association between low IgG levels and clinical outcomes and investigated the 28-day mortality in patients with low IgG levels.

METHODS

We retrospectively identified 238 patients whose serum IgG levels were measured upon intensive care unit admission using medical record data collected between January 2013 and August 2018. We extracted data on patient characteristics, severity scores (APACHE II, SOFA score), neutrophil-lymphocyte ratio (NLR), procalcitonin levels, and serum IgG levels and calculated the cut-off value for the IgG level according to the evaluated clinical outcomes. The primary outcome was 28-day mortality.

RESULTS

There were no significant differences in NLR and procalcitonin levels between survivors and non-survivors; serum IgG levels were significantly higher in survivors than in non-survivors (P = 0.004). A serum IgG cut-off value of 670 mg/dL was calculated from receiver operating characteristic curve analysis, and serum IgG levels significantly predicted survival with an area under the curve of 0.63 (95% CI, 0.54-0.72) (P = 0.004). Patients with low IgG levels (<670 mg/dL) had significantly higher mortality rates than those with normal IgG levels (≥670 mg/dL) (P < 0.001).

CONCLUSION

Our results reveal that low IgG levels (<670 mg/dL) in critically ill patients are associated with poor clinical outcomes related to 28-day mortality. In patients with sepsis, low IgG levels could be a predictor of poor outcome.

Use of Intravenous Immunoglobulins in Sepsis Therapy-A Clinical View

Sepsis is a life-threatening organ dysfunction, defined by a dysregulated host immune response to infection. During sepsis, the finely tuned system of immunity, inflammation and anti-inflammation is disturbed in a variety of ways. Both pro-inflammatory and anti-inflammatory pathways are upregulated, activation of the coagulation cascade and complement and sepsis-induced lymphopenia occur. Due to the manifold interactions in this network, the use of IgM-enriched intravenous immunoglobulins seems to be a promising therapeutic approach. Unfortunately, there is still a lack of evidence-based data to answer the important questions of appropriate patient populations, optimal timing and dosage of intravenous immunoglobulins. With this review, we aim to provide an overview of the role of immunoglobulins, with emphasis on IgM-enriched formulations, in the therapy of adult patients with sepsis and septic shock.

Regulation of dendritic cell function improves survival in experimental sepsis through immune chaperone

Dendritic cells (DCs) are professional Ag-presenting cells that play a critical role in both innate and adaptive immune responses. DCs recognize and respond to bacteria through multiple PRRs, including TLRs. Heat shock protein gp96/grp94 is a master essential chaperone for TLRs in the endoplasmic reticulum. We generated DC-specific gp96-knockout (KO) mice and showed that gp96 KO DCs were unable to respond to multiple TLR ligands. TLR-mediated hyperinflammatory response can lead to sepsis. However, the roles of neither DCs nor the DC-intrinsic gp96 in the process are completely understood. In a LPS-induced sepsis model, we hereby found that deletion of gp96 in DCs significantly reduced serum TNF-α levels and improved survival. Furthermore, using the well-defined polymicrobial sepsis model of cecal ligation and puncture, we found that DC-specific ablation of gp96 improved survival with significantly attenuated liver and renal injuries, decreased circulating inflammatory cytokines, altered DC maturation and activation, and increased serum Ig. Collectively, we demonstrate that deletion of gp96 in DCs is beneficial in protecting mice against sepsis induced by both endotoxemia and polymicrobial infections. We conclude that targeting gp96 in DCs may provide a potential novel approach for reducing the morbidity and mortality of sepsis.

Clinical, laboratory features and prognosis of children receiving IgM-enriched immunoglobulin (3 days vs. 5 days) as adjuvant treatment for serious infectious disease in pediatric intensive care unit: a retrospective single-center experience (PIGMENT study)

Introduction

Although there are studies about sepsis treatment in different age groups, data on immunoglobulin-M (IgM)-enriched intravenous immunoglobulin use in pediatric intensive care units (PICUs) are limited. The aim of this study was to evaluate the clinical features and prognoses of children receiving IgM-enriched intravenous immunoglobulin to treat sepsis, septic shock, and multi-organ failure.

Method

We extracted data from the medical records of 254 children who received IgM-enriched intravenous immunoglobulin infusion (104 children for 3 days, 150 children for 5 days) in addition to standard treatment between 2010 and 2017.

Results

When the 5-day vs. 3-day IgM-enriched immunoglobulin treatments were compared, the mortality rate was shown to be lower in patients who received the longer duration of treatment (p < .001). Better outcomes were observed among children with septic shock (p < .01).

Conclusion

Our clinical work with 5-days IgM-enriched intravenous immunoglobulin may reveal a survival benefit of this treatment for children with septic shock.

Personalized medicine with IgGAM compared with standard of care for treatment of peritonitis after infectious source control (the PEPPER trial): study protocol for a randomized controlled trial

Background

Peritonitis is responsible for thousands of deaths annually in Germany alone. Even source control (SC) and antibiotic treatment often fail to prevent severe sepsis or septic shock, and this situation has hardly improved in the past two decades. Most experimental immunomodulatory therapeutics for sepsis have been aimed at blocking or dampening a specific pro-inflammatory immunological mediator. However, the patient collective is large and heterogeneous. There are therefore grounds for investigating the possibility of developing personalized therapies by classifying patients into groups according to biomarkers. This study aims to combine an assessment of the efficacy of treatment with a preparation of human immunoglobulins G, A, and M (IgGAM) with individual status of various biomarkers (immunoglobulin level, procalcitonin, interleukin 6, antigen D-related human leucocyte antigen (HLA-DR), transcription factor NF-κB1, adrenomedullin, and pathogen spectrum).

Methods/design

A total of 200 patients with sepsis or septic shock will receive standard-of-care treatment (SoC). Of these, 133 patients (selected by 1:2 randomization) will in addition receive infusions of IgGAM for 5 days. All patients will be followed for approximately 90 days and assessed by the multiple-organ failure (MOF) score, by the EQ QLQ 5D quality-of-life scale, and by measurement of vital signs, biomarkers (as above), and survival.

Discussion

This study is intended to provide further information on the efficacy and safety of treatment with IgGAM and to offer the possibility of correlating these with the biomarkers to be studied. Specifically, it will test (at a descriptive level) the hypothesis that patients receiving IgGAM who have higher inflammation status (IL-6) and poorer immune status (low HLA-DR, low immunoglobulin levels) have a better outcome than patients who do not receive IgGAM. It is expected to provide information that will help to close the knowledge gap concerning the association between the effect of IgGAM and the presence of various biomarkers, thus possibly opening the way to a personalized medicine.

Trial registration

EudraCT, 2016–001788-34; ClinicalTrials.gov, NCT03334006. Registered on 17 Nov 2017.

Trial sponsor: RWTH Aachen University, represented by the Center for Translational & Clinical Research Aachen (contact Dr. S. Isfort).

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3244-4) contains supplementary material, which is available to authorized users.

The clinical efficacy of intravenous IgM-enriched immunoglobulin (pentaglobin) in sepsis or septic shock: a meta-analysis with trial sequential analysis

Background

Sepsis is characterized by a complex immune response. This meta-analysis evaluated the clinical effectiveness of intravenous IgM-enriched immunoglobulin (IVIgGM) in patients with sepsis and septic shock.

Methods

Four databases, PubMed, the Cochrane Library, the ISI Web of Knowledge, and Embase, were systematically searched from inception to June 2018 to update the 2013 edition of the Cochrane review by two investigators, who independently selected studies, extracted relevant data, and evaluated study quality. Data were subjected to a meta-analysis and trial sequential analysis (TSA) for the primary and secondary outcomes. Level of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) scale.

Results

Nineteen studies comprising 1530 patients were included in this meta-analysis. Pooled analyses showed that the use of IVIgGM reduced the mortality risk of septic patients (relative risk 0.60; 95% confidence interval [CI] 0.52–0.69, I² = 0%). TSA showed that IVIgGM had a significant effect on mortality. Additionally, the meta-analysis suggested that use of IVIgGM shortened length of mechanical ventilation (mean difference − 3.16 days; 95% CI − 5.71 to − 0.61 days) and did not shorten length of stay in the intensive care unit (mean difference − 0.38 days; 95% CI − 3.55 to 2.80 days). The GRADE scale showed that the certainty of the body of evidence was low for both benefits and IVIgGM.

Conclusion

Administration of IVIgGM to adult septic patients may be associated with reduced mortality. Treatment effects tended to be smaller or less consistent when including only those studies deemed adequate for each indicator. The available evidence is not clearly sufficient to support the widespread use of IVIgGM in the treatment of sepsis.

Trial registration PROSPERO registration number: CRD42018084120. Registered on 11 February 2018.

Electronic supplementary material

The online version of this article (10.1186/s13613-019-0501-3) contains supplementary material, which is available to authorized users.

Effects of the timing of administration of IgM- and IgA-enriched intravenous polyclonal immunoglobulins on the outcome of septic shock patients

BACKGROUND

The administration of endovenous immunoglobulins in patients with septic shock could be beneficial and preparations enriched with IgA and IgM (ivIgGAM) seem to be more effective than those containing only IgG. In a previous study Berlot et al. demonstrated that early administration of ivIgGAM was associated with lower mortality rate. We studied a larger population of similar patients aiming either to confirm or not this finding considering also the subgroup of patients with septic shock by multidrug-resistant (MDR) pathogens.

METHODS

Adult patients with septic shock in intensive care unit (ICU) treated with ivIgGAM from August 1999 to December 2016 were retrospectively examined. Collected data included the demographic characteristics of the patients, the diagnosis at admission, SOFA, SAPS II and Murray Lung Injury Score (LIS), characteristics of the primary infection, the adequacy of antimicrobial therapy, the delay of administration of ivIgGAM from the ICU admission and the outcome at the ICU discharge. Parametric and nonparametric tests and logistic regression were used for statistic analysis.

RESULTS

During the study period 107 (30%) of the 355 patients died in ICU. Survivors received the ivIgGAM earlier than nonsurvivors (median delay 12 vs 14 h), had significantly lower SAPS II, SOFA and LIS at admission and a lower rate of MDR- and fungal-related septic shock. The appropriateness of the administration of antibiotics was similar in survivors and nonsurvivors (84 vs 79%, respectively, p: n.s). The delay in the administration of ivIgGAM from the admission was associated with in-ICU mortality (odds ratio per 1-h increase = 1.0055, 95% CI 1.003-1.009, p < 0.001), independently of SAPS II, LIS, cultures positive for MDR pathogens or fungi and onset of septic shock. Only 46 patients (14%) had septic shock due to MDR pathogens; 21 of them (46%) died in ICU. Survivors had significantly lower SAPS II, SOFA at admission and delay in administration of ivIgGAM than nonsurvivors (median delay 18 vs 66 h). Even in this subgroup the delay in the administration of ivIgGAM from the admission was associated with an increased risk of in-ICU mortality (odds ratio 1.007, 95% CI 1.0006-1.014, p = 0.048), independently of SAPS II.

CONCLUSIONS

Earlier administration of ivIgGAM was associated with decreased risk of in-ICU mortality both in patients with septic shock caused by any pathogens and in patients with MDR-related septic shock.